- Abnormal N-heterocyclic carbene palladium complex: Living catalyst for activation of aryl chlorides in Suzuki-Miyaura cross coupling
-
Palladium complexes bearing abnormal N-heterocyclic carbene were used as catalysts in Suzuki-Miyaura cross coupling of aryl chlorides at 25 °C. The catalyst remained active for 10 successive catalytic runs and can activate 4-chlorotoluene at 25 °C with 0.01 mol% catalyst loading resulting in a TON of 9500 within 6 h.
- Sau, Samaresh Chandra,Santra, Subhankar,Sen, Tamal K.,Mandal, Swadhin K.,Koley, Debasis
-
-
Read Online
- PVP-stabilized palladium nanoparticles electrochemically obtained as effective catalysts in aqueous medium Suzuki-Miyaura reaction
-
In this paper the synthesis of stable palladium nanoparticles (PdNPs) by electrochemical methods at room temperature is reported. Direct electroreduction of H2PdCl4 aqueous solution in the presence of poly-(N-vinyl-2-pirrolydone) (PVP) onto platinum electrodes was performed by the application of a constant current density pulse. By simultaneous stirring of the electrolyte, the NPs formed on the electrode surface were stabilized with PVP in the solution. The resulting PdNPs were characterized by transmission electron microscopy and the total content of palladium was analytically determined by atomic absorption measurements. The average size of the NPs (in the range of 10-22 nm) was tuned by changing the current density applied. The PdNPs prepared by this methodology exhibited highly efficient catalytic activity on Suzuki-Miyaura coupling reaction in aqueous medium. Particularly high turnover numbers (TON up to 104-105) were achieved by these PVP-stabilized PdNPs with aryl iodides and bromides.
- Uberman, Paula M.,Martin, Sandra E.,Perez, Luis A.,Lacconi, Gabriela I.
-
-
Read Online
- CuBr/proline-catalyzed cross-coupling of unactivated benzene with aryl halides
-
Direct C-H arylation of unactivated benzene with aryl halides was achieved using a readily available copper catalyst. The reaction was carried out at 80 °C, using CuBr as catalyst, proline as ligand and t-BuOK as base. This radical cross-coupling reaction between unactivated benzene and aryl iodides proceeds via homolytic aromatic substitution and offers an efficient method for the synthesis of various biaryls in good to excellent yields.
- Liu, Wei,Hou, Fanyi
-
-
Read Online
- Fe3O4@SiO2@ l -arginine@Pd(0): A new magnetically retrievable heterogeneous nanocatalyst with high efficiency for C-C bond formation
-
The surface of Fe3O4@SiO2 nanoparticles was modified using l-arginine as a green and available amino acid to trap palladium nanoparticles through a strong interaction between the metal nanoparticles and functional groups of the amino acid. The proposed green synthetic method takes advantage of nontoxic reagents through a simple procedure. Characterization of Fe3O4@SiO2@l-arginine@Pd(0) was done using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, vibrating sample magnetometry and inductively coupled plasma analysis. The catalytic activity of Fe3O4@SiO2@l-arginine@Pd(0) as a new nanocatalyst was investigated in C-C coupling reactions. Waste-free, use of green medium, efficient synthesis leading to high yield of products, eco-friendly and economic catalyst, excellent reusability of the nanocatalyst and short reaction time are the main advantages of the method presented.
- Ghorbani-Choghamarani, Arash,Azadi, Gouhar
-
-
Read Online
- Bis(imino)pyridine palladium(II) complexes as efficient catalysts for the Suzuki-Miyaura reaction in water
-
Bis(imino)pyridine palladium(II) complexes 3 and 4 of type [PdCl(L)PF 6] are found to be efficient catalysts for Suzuki-Miyaura reactions of aryl halides and arylboronic acids. The reactions proceed smoothly to generate the corresponding biaryl compounds in moderate to excellent yields. The synthesis of various fluorinated biphenyl derivatives was successfully achieved by the complex 4 catalyzed the Suzuki-Miyaura reaction in the presence of surfactants bearing a long alkyl chain. Copyright
- Liu, Ping,Yan, Mei,He, Ren
-
-
Read Online
- LIQUID CRYSTALLINE 4-ALKYLAMINO-4 prime -CYANOBIPHENYLS.
-
A number of mesomorphic 4-alkylamino-4 prime -alkylamino-4 prime -cyanobiphenyls were synthesized. These compounds melt at higher temperatures and form nematic and smectic. A state with higher thermal stability than that of analogaous 4-alkoxy-4 prime -cyanobiphenyls. 4-Octylamino-4 prime -cyanobiphenyl is characterized by a significantly higher dielectric anisotropy in comparison with its 4-octyloxy analog, in the nematic state, but not in the smectic state. Density data and refractometric indices of several 4 substituted 4 prime -cyanobiphenyls are presented; refractometric data confirm higher polarizability of 4-alkylamino-4 prime -cyanobiphenyls as compared with their 4-alkoxy analogs.
- Ruoliene,Adomenas,Tubelyte,Seskauskas,Grozhik
-
-
Read Online
- Fullerene-ionic-liquid conjugates: A new class of hybrid materials with unprecedented properties
-
A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique propert
- Campisciano, Vincenzo,Parola, Valeria La,Liotta, Leonarda F.,Giacalone, Francesco,Gruttadauria, Michelangelo
-
-
Read Online
- Effect of Alkyl Structures on the Anti-stacking and Anchoring of Pd/Diamine-Functionalized Graphene Nanoparticles in Application in Suzuki Reaction
-
Three diamines (1,8-diaminooctane/p-phenylenediamine/biphenylenediamine) with different alkyl groups were used to synthesize the functionalized graphene networks. Pd as the common metal catalyst was used to explore the effects of alkyl types of diamines on anti-stacking, metal anchoring ability of functional graphene and hence the catalytic performance. The results were discussed by characterization of the material and its catalytic properties. All catalysts showed excellent catalytic performance on the Suzuki cross-coupling reaction with a high yield of up to 100%. The p-phenylenediamine and biphenylenediamine functionalized graphene with larger specific surface area was beneficial to improve the stability of the graphene catalyst and maintain good catalytic activity after 5 cycles. The Pd nanoparticles in 1,8-octanediamine materials have smaller size and a smaller loading with the same or even better catalytic performance than p-phenylenediamine, biphenylenediamine materials, due to the stronger electron donating ability of N of octanediamine than that of p-phenylenediamine.
- Tian, Yinbing,Tang, Zijie,Ru, Yu,Wang, Yuanyuan,Dai, Liyi
-
-
Read Online
- A highly sensitive fluorescence method reveals the presence of palladium in a cross-coupling reaction mixture not treated with transition metals
-
We previously reported a Suzuki-Miyaura coupling in dimethyl carbonate without adding additional transition metals. Here, we show an analysis of the reaction mixture that revealed the presence of palladium using a fluorogenic Tsuji-Trost reaction.
- Inamoto, Kiyofumi,Campbell, Laura D.,Doi, Takayuki,Koide, Kazunori
-
-
Read Online
- The recyclable cyclopalladated ferrocenylimine self-assembly catalytic film and investigation of its role in the mechanism of heterogeneous catalysis
-
An efficient, reusable and stable catalyst nano-sheet film (Si-CDI-Pd) was developed, in which cyclopalladated ferrocenylimines were grafted onto silicon, glass and quartz surfaces by covalent bonds. Water contact angle, ultraviolet-visible spectroscopy (UV-Vis), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), low-angle X-ray diffraction (LAXD) and cyclic voltammetry (CV) were used to characterize the structural and compositional information of the modified surfaces. The immobilized catalyst films were tested for the Suzuki-Miyaura reaction and displayed high activity for the preparation of various biaryls at elevated temperatures in neat water without ligands. It also presented good stability and reusability. It can be reused at least 8 times with little Pd leaching into the crude product. The reasonable and feasible reaction mechanism of the heterogeneous Suzuki-Miyaura reaction based on the results of AFM, XPS, and CV tests of different reaction times were explored in detail, in which a cycle of PdII to Pd 0 and Pd0 to PdII on the surface was clearly detected and illustrated. In this approach, Pd0 on the surface of nano-sheet films as an active surface to catalyze the coupling reaction of aromatic halides and borophenylic acid proceeded via a mechanism of surface-catalyzed process.
- Fu, Zhihua,Li, Tiesheng,He, Xiaohang,Liu, Jie,Wu, Yangjie
-
-
Read Online
- Graphene-supported small-sized palladium nanoparticles made by facile photochemical approaches
-
Abstract To achieve small-sized and well-dispersed palladium (Pd) nanoparticles, we make use of effective photochemical approaches to synthesis of clean Pd nanoparticles on the surface of graphene at room temperature. By modulating the photochemical reaction conditions, the size and dispersion of graphene-Pd composites can be well controlled, where PdClt;inf;4;/inf;;sup;2-/sup and graphene oxide (GO) are the reaction precursors, Hantzsch 1,4-dihydropyridine (HEH) is used as an electron donor and an amine-type ligand to stabilize small Pd nanoparticles on the surface of graphene. As a result, the easy and effective photochemical approaches to the graphene-Pd composites with well-dispersed, small-sized Pd nanoparticles and highly conductive reduced GO, are established. Good to excellent yields have also been achieved with the graphene-supported Pd nanoparticles catalysts for the Suzuki coupling reaction.
- Zhang, Hui-Hui,Liu, Bin,Wang, Jing,Feng, Ke,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
-
-
Read Online
- A fluorous ethylenediamine promoted direct C-H arylation of unactivated arenes with aryl halides
-
A novel and recyclable fluorous ethylenediamine was prepared. Together with potassium tert-butoxide, the fluorous ethylenediamine showed a good activity in promoting the coupling of aryl halides with benzene derivatives without the aid of transition-metal catalysts. Furthermore, a chain homolytic aromatic substitution mechanism was proposed in this paper.
- Zhu, Yi-Wei,Shi, Yi-Xin
-
-
Read Online
- Polyacrylamide-g-Reduced Graphene Oxide Supported Pd Nanoparticles as a Highly Efficient Catalyst for Suzuki–Miyaura Reactions in Water
-
Abstract: To improve the dispersibility of graphene oxide (GO) in solvents, the grafting of polyacrylamide (PAM) from the GO surface was performed by redox polymerization system. The hydrophilic nature and high polarity of PAM have made effective dispersion of GO. Then, Pd nanoparticles (Pd NPs) were anchored on the surface of polyacrylamide grafted reduced graphene oxide nanosheets (PAM-g-rGO/Pd). The obtained nanocomposite was used for Suzuki–Miyaura cross-coupling reaction in an environmental friendly solvent under ambient conditions. The results showed that the prepared catalyst system exhibited high catalytic activity and stability which could be reused at least eight times without significant loss of its catalytic activity. This is mainly because of its small particle size, uniform dispersion of Pd NPs on the surface of PAM-g-GO/Pd, and lack of agglomeration of these nanoparticles during the preparation at room temperature. Graphical Abstract: [Figure not available: see fulltext.]
- Mahdavi, Hossein,Rahmani, Ozra
-
-
Read Online
- An efficient palladium and bis(2-pyridylmethyl)amine-based system for Suzuki-Miyaura cross-coupling under aqueous and aerobic condition
-
A novel PdCl2/bis(2-pyridylmethyl)amine-based ligand (1) catalytic system, which is water-soluble and air-stable, has been successfully synthesized and applied for Suzuki-Miyaura cross-coupling reaction. In the presence of catalytic amount of PdCl2/1 system, arylboronic acids can couple with a wide range of aryl halides, including aryl bromides and aryl chlorides. The reactions proceed under mild conditions to give excellent yields, and a wide range of functionalities is tolerated.
- Yu, Jianjun,Wang, Limin,Liu, Mingtao,Qiu, Jun,Shen, Qiang,Fang, Lei,Tang, Jun
-
-
Read Online
- Unexpected multifunctional effects of methylated cyclodextrins in a palladium charcoal-catalyzed Suzuki-Miyaura reaction
-
(Chemical Equation Presented) Native and modified cyclodextrins (CDs) have shown polyvalent properties in a biphasic Pd/C-catalyzed Suzuki-Miyaura reaction. In addition to their mass transfer ability, the CDs favored the dispersion of the catalyst in water. With the randomly methylated CDs (RaMe-β-CD), the gains of initial activities were multiplied by factors between 3.8 and 343 depending on the nature of the substrates. The reusability of the system was also demonstrated.
- Cassez, Andy,Ponchel, Anne,Hapiot, Frederic,Monflier, Eric
-
-
Read Online
- (π-Allyl)Pd complexes containing N-heterocyclic carbene and pseudohalogen ligands - Synthesis, reactivity toward organic isothiocyanates and isocyanides, and their catalytic activity in suzuki-miyaura cross-couplings
-
Dinuclear (π-allyl)palladium chlorides, [(π-allyl)Pd(μ-Cl)] 2, were cleaved by N-heterocyclic carbenes (NHCs) to give mononuclear (π-allyl)palladium-NHC chlorides, [(π-allyl)Pd(Cl)(NHC)] (1-6) [NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPR), 1,3-bis(2,6- diisopropylphenyl)-4,5-dihydroimidazol-2-ylidine (SIPR), 1,3-bis(2,4,6- trimethylphenyl)imidazol-2-ylidene (IMes)]. Complexes 1-6 were subsequently treated with aqueous NaN3, KSCN, KOCN, and CF3COOAg to produce the corresponding mononuclear (π-allyl)palladium-NHC pseudohalogen complexes, [(π-allyl)Pd(X)(NHC)] (X = N3, NCS, SCN, NCO, CF 3COO) (7-30). These products could also be obtained by treating dinuclear pseudohalogen-bridged Pd complexes, [(π-allyl)Pd(μ-X)] 2, which were prepared by replacing the μ-Cl ligand in [(π-allyl)Pd(μ-Cl)]2, with aqueous NaN3, KSCN, KOCN, or CF3COOAg, followed by cleavage with the NHCs. Reactions of [(π-allyl)Pd(N3)(NHC)] with organic isothiocyanates (R-NCS) or CH3O(CO)C≡CO(CO)CH3 resulted in selective 1,3-dipolar cycloaddition into the Pd-azido bond to give heterocyclic compounds. By contrast, analogous reactions of [(η3-allyl)Pd(N 3)(IPr)] with an organic isocyanide (R-NC: R = tert-butyl, benzyl) gave the adduct [(η3-allyl)Pd(N3)(IPr)]·(R-NC) as the only product or a mixture of the adduct and a dipolar cycloaddition product, [(η3-allyl)Pd{CN4(R)}(IPr)], depending on the isocyanides used. Finally, a series of (π-allyl)Pd-NHC pseudohalogen complexes, [(π-allyl)Pd(X)(NHC)], exhibited high catalytic activity in Suzuki-Miyaura cross-coupling reactions of aryl chlorides with arylboronic acids. A series of (π-allyl)palladium complexes containing N-heterocyclic carbene and pseudohalogen ligands are prepared and their reactivity toward organic isothiocyanates and isocyanides is studied. Suzuki-Miyaura cross-coupling reactions of aryl chlorides with aryl boronic acid catalyzed by these (π-allyl)palladium complexes are reported. Copyright
- Kim, Hyun-Kyung,Lee, Jung-Hyun,Kim, Yong-Joo,Nu Zheng, Zhen,Lee, Soon W.
-
-
Read Online
- Biodeposited Pd/Au bimetallic nanoparticles as novel Suzuki catalysts
-
The use of two nanoparticulate palladium based catalysts in the Suzuki reaction is described. One monometallic (Pd) and one bimetallic (Pd/Au) catalyst were prepared by the environmentally benign method of bioreductive precipitation by Shewanella oneidensis. Both catalysts successfully mediated the Suzuki coupling, however, the Au doped catalyst was shown to deliver more reproducible results with a broader reaction scope.
- Heugebaert, Thomas S.A.,De Corte, Simon,Sabbe, Tom,Hennebel, Tom,Verstraete, Willy,Boon, Nico,Stevens, Christian V.
-
-
Read Online
- Functional group compatible palladium-catalyzed cross-coupling reactions between aryllithium and aryl halide mediated by a five-membered cyclic silyl ether
-
A functional group compatible palladium-catalyzed cross-coupling reaction between aryllithiums and aryl halides mediated by a five-membered cyclic silyl ether as a precursor for an activated arylsilane has been developed. The reaction proceeds under mild conditions without the addition of a fluoride salt or a base to activate the silyl reagent.
- Son, Eun-Cheol,Tsuji, Hayato,Saeki, Tomoyuki,Tamao, Kohei
-
-
Read Online
- Nano-Fe3O4@SiO2 supported Pd(0) as a magnetically recoverable nanocatalyst for Suzuki coupling reaction in the presence of waste eggshell as low-cost natural base
-
In this study, a simple and efficient protocol was used for the synthesis of the nano-Fe3O4@SiO2 supported Pd(0) (Fe3O4@SiO2-Pd). SiO2 nanoparticles were prepared by the simple method from rice husk biomass as the source of biosilica. The Fe3O4@SiO2-Pd was characterized by a series of techniques such as SEM, EDS, XRD, TEM, ICP-AES, FT-IR and VSM. The Fe3O4@SiO2-Pd was used as a magnetically recoverable nanocatalyst for Suzuki coupling reaction in the presence of waste eggshell as low-cost solid base. The present method has significant advantages, such as use of natural and waste materials, use of an inexpensive catalyst, simple experimental procedure and low catalyst loading. In addition, the magnetically recoverable nanocatalyst can easily be recovered from the reaction system by using an external magnet and reused several times with insignificant loss of catalytic activity.
- Khazaei, Ardeshir,Khazaei, Marzieh,Nasrollahzadeh, Mahmoud
-
-
Read Online
- Color-coded ligands: Tracking the catalyst using highly pigmented porphyrazine ligands in biphasic reactions
-
We demonstrate the concept that highly colored imidazolium porphyrazine ligands and complexes may be useful for visualizing the location of a catalyst and/or ligand. This was analytically demonstrated by the application of UV-vis spectrophotometry to detect the ligand and ICP-OES spectroscopy for quantification of the Pd in the biphasic systems. In the first instance, a toluene/water system was used, in which the complex and ligand preferred the organic phase. Water-soluble substrates were made to react under these conditions by employing the complexes as catalysts in Heck and Suzuki C-C bond forming reactions. In the second instance, an ionic liquid containing biphasic mixture was used, in which the ligand/catalyst was retained in the ionic liquid. Catalyst recycling experiments were met with limited success.
- Tshivhase, Mmboneni,Williams, D. Bradley G.
-
-
Read Online
- Chemically converting graphene oxide to graphene with organic base for Suzuki reaction
-
Chemically converted graphene has been synthesized via the reduction of graphene oxide by using organic bases, including 1,8-diazoicyclo (5, 4, 0) undecene-7, triethylamine and 1,4-diazobicyclo (2, 2, 2) octane, as the reducing agent. The chemical characteristics of these organic bases, especially the dissociation constants (pKa), have great influence on the structure and properties of the resultant CCG. Remarkably, the reaction between graphene oxide and some organic bases such as 1,8-diazoicyclo (5, 4, 0) undecene-7 can modify the surface properties of chemically converted graphene for anchoring Pd nanoparticles. The resultant recyclable catalyst exhibits high conversion of 97.2% for yielding biphenyl from coupling bromobenzene and phenylboronic acid. Even after the 5th run, the conversion of bromobenzene can still be as high as 94.2%, indicating excellent recyclability of this catalyst.
- Zhang, Xu,Yu, Chang,Wang, Chunlei,Wang, Zhiyu,Qiu, Jieshan
-
-
Read Online
- Sulfur-containing palladacycles: Efficient phosphine-free catalyst precursors for the Suzuki cross-coupling reaction at room temperature
-
Cyclopalladated compounds derived from the ortho-metalation of benzylic tert-butyl thioethers are excellent catalyst precursors for the Suzuki cross-coupling reaction of aryl bromides and chlorides with phenylboronic acid under mild reaction conditions. A broad range of substrates and functional groups are tolerated in this protocol, and highly catalytic activity is attained.
- Zim, Danilo,Gruber, Adriane S.,Ebeling, Gunter,Dupont, Jairton,Monteiro, Adriano L.
-
-
Read Online
- Dinuclear NHC-palladium complexes containing phosphine spacers: Synthesis, X-ray structures and their catalytic activities towards the Hiyama coupling reaction
-
Six dinuclear N-heterocyclic carbene (NHC) palladium complexes, [PdCl 2(IMes)]2(μ-dppe) (1), [PdCl2(IPr)] 2(μ-dppe) (2), [PdCl2(IMes)]2(μ-dppb) (3), [PdCl2(IPr)]2(μ-dppb) (4), [PdCl 2(IMes)]2(μ-dpph) (5), and [PdCl2(IPr)] 2(μ-dpph) (6) [IMes = N,N′-bis-(2,4,6-trimethylphenyl) imidazol-2-ylidene; IPr = N,N′-bis-(2,6-di(iso-propyl)phenyl)imidazol-2- ylidene; dppe = 1,2-bis(diphenylphosphino)ethane, dppb = 1,4- bis(diphenylphosphino)butane; and dpph = 1,6-bis(diphenylphosphino)hexane], have been synthesized through bridge-cleavage reactions of chloro-bridged dimeric compounds, [Pd(μ-Cl)(Cl)(NHC)]2, with the corresponding diphosphine ligands. The obtained compounds were fully characterized by 1H NMR, 13C NMR and 31P NMR spectroscopy, FT-IR, elemental analysis and single-crystal X-ray crystallography. Moreover, further explorations of the catalytic potential of the dinuclear carbene palladium complexes as catalysts for the Pd-catalyzed transformations have been performed under microwave irradiation conditions, and the complexes exhibited moderate to good catalytic activity in the Hiyama coupling reaction of trimethoxyphenylsilane with aryl chlorides.
- Yang, Jin,Li, Pinhua,Zhang, Yicheng,Wang, Lei
-
-
Read Online
- Ligandless C-C bond formation via Suzuki-Miyaura reaction in micelles or water-ethanol solution using PdPtZn and PdZn nanoparticle thin films
-
PdPtZn and PdZn nanoparticle (NP) thin films were synthesized by the reduction of [PdCl2(cod)], [PtCl2(cod)] (cod = cis,cis-1,5-cyclooctadiene) and [Zn(acac)2] (acac = acetylacetonate) complexes at an oil-water interface. The structure and morphology of the as-prepared NPs were characterized with X-ray diffraction, transmission electron microscopy and energy dispersive analysis of X-rays. Catalytic activity of the prepared NPs was investigated in the Suzuki-Miyaura cross-coupling reaction in H2O-EtOH and various micellar media systems such as cetyltrimethylammonium bromide (cationic surfactant), sodium dodecylsulfate (anionic surfactant) and Pluronic P123 (non-ionic surfactant). PdPtZn and PdZn thin films exhibited higher catalytic activity compared to Pd thin film in the Suzuki-Miyaura coupling reaction due to the appropriate interaction between palladium, platinum and zinc metals. PdPtZn and PdZn nanoparticle thin films were synthesized by the reduction of [PdCl2(cod)], [PtCl2(cod)] and [Zn(acac)2] complexes at an oil-water interface. Catalytic activity of the nanoparticles was investigated in Suzuki-Miyaura cross-coupling reactions in various micellar systems or water-ethanol solution.
- Hoseini, S. Jafar,Zarei, Atiyeh,Rafatbakhsh Iran, Hajar
-
-
Read Online
- Green synthesis of palladium nanoparticles using Hippophae rhamnoides Linn leaf extract and their catalytic activity for the Suzuki-Miyaura coupling in water
-
During this study, we report the green synthesis of palladium nanoparticles using Hippophae rhamnoides Linn leaf extract and their application as heterogeneous catalysts for the Suzuki-Miyaura coupling in water. The synthesized nanoparticles are characterized by XRD, SEM, TEM and UV-vis techniques. This method has the advantages of high yields, simple methodology, and elimination of ligand, organic solvent and homogeneous catalysts and easy work-up. Furthermore, the catalyst exhibits high catalytic activity, superior cycling stability and excellent substrate applicability.
- Nasrollahzadeh, Mahmoud,Sajadi, S. Mohammad,Maham, Mehdi
-
-
Read Online
- Graphene oxide supported Au nanoparticles as an efficient catalyst for reduction of nitro compounds and Suzuki-Miyaura coupling in water
-
This paper reports on the synthesis of graphene oxide supported Au nanoparticles and their application as a separable catalyst for ligand-free Suzuki-Miyaura coupling reactions in water and reduction of nitro compounds. The catalyst was characterized using powder XRD, BET, FT-IR, Raman, SEM and EDS. This method has the advantages of high yields, simple methodology, and elimination of ligand, organic solvent and homogeneous catalysts and easy work up. Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture and recycled several times without any significant loss of catalytic activity. This journal is
- Fakhri, Parisa,Nasrollahzadeh, Mahmoud,Jaleh, Babak
-
-
Read Online
- Cu(OAc)2 entrapped on ethylene glycol-modified melamine–formaldehyde polymer as an efficient heterogeneous catalyst for Suzuki–Miyaura coupling reactions
-
This work is described as an environmental friendly approach for Cu(OAc)2 entrapped on ethylene glycol-modified melamine–formaldehyde-based polymeric material (Cu@MCOP) which has been successfully synthesized by simple approaches using commercially available starting materials via solvothermal techniques and without using any toxic reagents and chemicals. The structural, morphological, physicochemical characteristics and catalytic activity of the heterogeneous catalyst (Cu@MCOP) were analyzed by various instrumental methods including powder X-ray diffraction, FT-IR, UV-DRS, X-ray photoelectron spectroscopy, SEM and elemental mapping which have been used to authenticate the polymeric materials Cu@MCOP. The catalytic performance of Cu@MCOP as solid heterogeneous catalyst was evaluated in synthesis of various biphenyl derivatives through Suzuki–Miyaura cross-coupling reactions of various aryl halides with substituted organoboranes under normal reaction conditions. Furthermore, the copper catalyst was easily available, low cost, cheap and best instead of palladium, which shows good catalytic activity and excellent yield (up to 86%); the catalyst can be separated easily and recycled for more than five times. Graphic abstract: [Figure not available: see fulltext.].
- Sadhasivam, Velu,Sankar, Balakrishnan,Elamathi, Ganesan,Mariyappan, Mathappan,Siva, Ayyanar
-
-
Read Online
- QUENCHING OF SINGLET AND TRIPLET EXCITED AROMATIC HYDROCARBONS BY SULPHIDES. THE AMINE AND SULPHIDE ENHANCED PHOTO-INDUCED DEGRADATION OF CHLORO- AND CYANOAROMATIC HYDROCARBONS.
-
Sulphides have been shown to be capable of quenching the excited singlet and triplet states of several aromatic hydrocarbons and their derivatives.The quenching is proposed to involve an electron transfer mechanism.The use of sulphides and amines to generate aromatic hydrocarbon radical cations from the excited states of these compounds has been utilised in order to carry out reductive decyanation reactions of cyanoaromatic hydrocarbons.
- Beecroft, R. A.,Davidson, R. S.,Goodwin, D.,Pratt, J. E.
-
-
Read Online
- A simple catalyst for aqueous phase Suzuki reactions based on palladium nanoparticles immobilized on an ionic polymer
-
Palladium nanoparticles immobilized on a cross-linked imidazolium-containing polymer were evaluated as a catalyst for Suzuki carbon-carbon cross-coupling reactions using water as the solvent. The nanocatalysts show good catalytic activities for aryl iodides and aryl bromides and moderate activity with aryl chloride substrates. Coupling of sterically hindered substrates could also be achieved in reasonable yields. The heterogeneous catalyst is stable, can be stored without precautions to exclude air or moisture, and can be easily recycled and reused.
- Ghazali-Esfahani, Saeideh,Pǎunescu, Emilia,Bagherzadeh, Mojtaba,Fei, Zhaofu,Laurenczy, Gabor,Dyson, Paul J.
-
-
Read Online
- Activation of aryl chlorides in water under phase-transfer agent-free and ligand-free Suzuki coupling by heterogeneous palladium supported on hybrid mesoporous carbon
-
In this study, heterogeneous palladium catalysts supported on ordered mesoporous cobalt oxide-carbon nanocomposites were applied to the water-mediated Suzuki coupling reaction of chlorobenzene and phenylboronic acid and exhibited a high yield of biphenyl (49%) under mild reaction conditions free of phase-transfer agents and ligands. Product yields in the reaction of aryl chlorides containing electron-withdrawing groups attached to their benzene ring can reach approximately 90%. Thiol-functionalized mesoporous silica, which can trap soluble Pd species, was used to confirm the negligible leaching in solution and therefore heterogeneous reaction. This heterogeneous catalyst is stable, showing unobvious activity loss after 10 catalytic runs. Characterization by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption fine structure analysis, and N2 sorption techniques revealed intercalated CoO nanoparticles inside a carbon matrix with uniform mesopore sizes (～3 nm), high surface area (～504 m2/g), and large pore volumes (～0.38 cm3/g). Additionally, very small Pd clusters consisting of approximately three atoms and Pd-O bonds formed on the interface between CoO and Pd nanoparticles. The unsaturated coordinative Pd may be responsible for the activation of chlorobenzene in the absence of any additives or ligands. Uniform mesopores and the hydrophobic nature of the carbon support may also facilitate the mass transfer of the reactant molecules and enrichment inside pores. For comparison, the catalytic activities of Pd catalysts supported on pristine mesoporous carbon and carbon embedded with nickel oxide nanoparticles were also tested.
- Duan, Linlin,Fu, Rao,Xiao, Zhiguang,Zhao, Qingfei,Wang, Jian-Qiang,Chen, Shangjun,Wan, Ying
-
-
Read Online
- Mechanistic origin of antagonist effects of usual anionic bases (OH -, CO32-) as modulated by their countercations (Na+, Cs+, K+) in palladium-catalyzed Suzuki-Miyaura reactions
-
The mechanism of the reaction of trans-ArPdBrL2 (Ar=p-Z-C 6H4, Z=CN, H; L=PPh3) with Ar'B(OH)2 (Ar'=p-Z'-C6H4, Z'=H, CN, MeO), which is a key step in the Suzuki-Miyaura process, has been established in N,N-dimethylformamide (DMF) with two bases, acetate (nBu4NOAc) or carbonate (Cs 2CO3) and compared with that of hydroxide (nBu 4NOH), reported in our previous work. As anionic bases are inevitably introduced with a countercation M+ (e.g., M+OH -), the role of cations in the transmetalation/reductive elimination has been first investigated. Cations M+ (Na+, Cs +, K+) are not innocent since they induce an unexpected decelerating effect in the transmetalation via their complexation to the OH ligand in the reactive ArPd(OH)L2, partly inhibiting its transmetalation with Ar'B(OH)2. A decreasing reactivity order is observed when M+ is associated with OH-: nBu 4N+> K+> Cs+> Na +. Acetates lead to the formation of trans-ArPd(OAc)L2, which does not undergo transmetalation with Ar'B(OH)2. This explains why acetates are not used as bases in Suzuki-Miyaura reactions that involve Ar'B(OH)2. Carbonates (Cs2CO3) give rise to slower reactions than those performed from nBu4NOH at the same concentration, even if the reactions are accelerated in the presence of water due to the generation of OH-. The mechanism of the reaction with carbonates is then similar to that established for nBu4NOH, involving ArPd(OH)L2 in the transmetalation with Ar'B(OH)2. Due to the low concentration of OH- generated from CO3 2- in water, both transmetalation and reductive elimination result slower than those performed from nBu4NOH at equal concentrations as Cs2CO3. Therefore, the overall reactivity is finely tuned by the concentration of the common base OH- and the ratio [OH -]/[Ar'B(OH)2]. Hence, the anionic base (pure OH - or OH- generated from CO32-) associated with its countercation (Na+, Cs+, K +) plays four antagonist kinetic roles: acceleration of the transmetalation by formation of the reactive ArPd(OH)L2, acceleration of the reductive elimination, deceleration of the transmetalation by formation of unreactive Ar'B(OH)3- and by complexation of ArPd(OH)L2 by M+. Copyright
- Amatore, Christian,Jutand, Anny,Le Duc, Gaetan
-
-
Read Online
- Suzuki-Miyaura coupling in the presence of (2,2,2-triferrocenylethyl)diphenylphosphane
-
The electron rich and sterically bulky title phosphane was prepared and efficiently applied in the palladium catalyzed Suzuki-Miyaura cross-coupling reaction. With electron rich aryl chlorides and bromides the yields and reaction times were significantly improved by microwave heating.
- Garabatos-Perera, Jose Ramon,Butensch?n, Holger
-
-
Read Online
- Quaternized POSS modified rGO-supported Pd nanoparticles as a highly efficient catalyst for reduction and Suzuki coupling reactions
-
Functionalized two-dimensional graphene oxide sheets and their inorganic-organic nanohybrids have aroused great interest because of their excellent synergetic effect on metal-based nanocatalyst PdNPs supported on highly hydrophilic quaternized polyhedral oligomeric silsesquioxane (QPOSS) functionalized reduced graphene oxide (rGO) and were successfully constructed as a nanohybrid catalyst for efficient heterogeneous catalytic reactions. Octaammonium POSS (OAPOSS) was first covalently grafted to carboxylated GO nanosheets through an amidation reaction, and then the OAPOSS decorated on rGO nanosheets was quaternized with glycidyltrimethylammonium chloride (GDTMAC) via an epoxide ring-opening reaction to obtain a highly functional hydrophilic QPOSS@rGO hybrid. Finally, the PdNPs were loaded onto QPOSS@rGO nanosheets through an in situ reduction route. The quaternary ammonium groups on QPOSS@rGO can strongly coordinate with PdNPs, making it particularly advantageous for stabilizing PdNPs and preventing the leaching of Pd metals. Compared to the PdNPs@rGO catalyst without modification with hydrophilic QPOSS, the low-dose PdNPs@QPOSS@rGO nanocatalysts exhibited outstanding catalytic efficiency in the reduction of methylene blue and nitrophenols. In addition, the as-designed nanocatalysts also showed high catalytic activity for the Suzuki coupling reaction when utilizing pure water as a green solvent. It was proved that QPOSS and rGO can synergistically catalyze and promote the diffusion of reactants. In particular, the PdNPs@QPOSS@rGO nanohybrid catalyst showed no significant loss of catalytic activity after reusing it five times. Our results demonstrated that highly hydrophilic QPOSS endows the resulting PdNPs@QPOSS@rGO nanohybrid with good dispersibility and stability in water, which remarkably further improves the catalytic activity of the nanocatalyst.
- Xia, Siwen,Yang, Yu,Lü, Changli
-
-
Read Online
- Di- and Tetranuclear Palladium(II) Complexes Containing C,N-Bidentate Furoylhydrazone for Suzuki–Miyaura Reactions
-
Furoylhydrazones of general formula 4-R–C6H4–CH=NNH–CO–2-C4H3O [R = H (HL1) and OCH3 (HL2)] have been conveniently prepared from furan-2-carbohydrazide. The reaction of HL1 with Li2[PdClsu
- Qian, Hengyu,Zhang, Tongyan,Song, Liping,Yu, Shuyan,Yuan, Qi,Sun, Luyan,Zhang, Dengfeng,Yin, Zhigang,Dai, Yongxia
-
-
Read Online
- Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
-
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
- Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
-
p. 208 - 218
(2021/12/29)
-
- Silk?Fibroin-Supported Palladium Catalyst for Suzuki-Miyaura and Ullmann Coupling Reactions of Aryl Chlorides
-
Recently, we have reported the preparation of a silk fibroin-supported Palladium catalyst (Pd/SF) and its use in the Suzuki-Miyaura cross-coupling of aryl iodides. Since its synthetic applicability and structural features are still far from being fully ex
- Albano, Gianluigi,Farinola, Gianluca M.,Giannini, Cinzia,Musio, Roberta,Omenetto, Fiorenzo G.,Rizzo, Giorgio,Sibillano, Teresa
-
-
- Nickel- and Palladium-Catalyzed Cross-Coupling of Stibines with Organic Halides: Site-Selective Sequential Reactions with Polyhalogenated Arenes
-
Herein, we disclose a general and efficient method for the synthesis of Sb-aryl and Sb-alkyl stibines by the nickel-catalyzed cross-coupling of halostibines with organic halides. The synthesized Sb-aryl stibines couple with aryl halides to give biaryls efficiently via palladium catalysis. Sequential reactions of stibines with polyhalogenated arenes bearing active C–I/C–Br sites and inactive C–Cl sites successfully proceeded, resulting in the formation of a variety of complex molecules with good site selectivity. Drugs such as diflunisal and fenbufen, as well as a fenofibrate derivative, were synthesized on gram scales in good yields, together with the high recovery of chlorostibine. Furthermore, catalytic mechanisms are proposed based on the results of control experiments.
- Ghaderi, Arash,Kambe, Nobuaki,Le, Liyuan,Lu, Hao,Qiu, Renhua,Tang, Ting,Tong, Zhou,Wong, Wai-Yeung,Xu, Zhi,Yin, Shuang-Feng,Zeng, Dishu,Zhang, Dejiang,Zhang, Zhao
-
p. 854 - 867
(2022/01/19)
-
- 'Awaken' aryl sulfonyl fluoride: a new partner in the Suzuki-Miyaura coupling reaction
-
An example of the activation of the -SO2F group, which is traditionally considered a stable group even in the presence of a transition metal, is described using a novel partner in the Suzuki-Miyaura coupling reaction catalyzed by Pd(OAc)2 and Ruphos as ligands. The products showed good to outstanding yields and broad functional group compatibility under optimal conditions. The sequential synthesis of non-symmetric terphenyls and the gram grade process highlight the approach's synthetic utility. DFT calculations have shown that Pd0 prefers to insert between C-S bonds rather than S-F bonds. This journal is
- Ding, Chengrong,Guan, Chenfei,Miao, Huihui,Zhang, Guofu,Zhao, Yiyong
-
supporting information
p. 3560 - 3564
(2022/03/07)
-
- Nitrile Synthesis via Desulfonylative-Smiles Rearrangement
-
Herein, we designed a simple nitrile synthesis from N-[(2-nitrophenyl)sulfonyl]benzamides via base-promoted intramolecular nucleophilic aromatic substitution. The process features redox-neutral conditions as well as no requirement of toxic cyanide species and transition metals. Our process shows broad scope and various functional group compatibility, affording a variety of (hetero)aromatic nitriles in good to excellent yields.
- Abe, Masahiro,Nitta, Sayasa,Miura, Erina,Kimachi, Tetsutaro,Inamoto, Kiyofumi
-
p. 4460 - 4467
(2022/03/15)
-
- Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
-
A gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoroborate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.
- Medina-Mercado, Ignacio,Porcel, Susana
-
-
- COMPLEXES OF N-HETEROCYCLIC CARBENES FOR TRANSITION METAL CATALYSIS
-
Described herein is a new class of highly active Pd(II)-NHC complexes bearing anilines as throw-away ligands. These catalysts are well-defined, air- and moisture-stable and can be easily purified by chromatographic techniques. High activity and generality has been exemplified in the Suzuki-Miyaura cross-coupling by C-N, C-O and C-Cl cleavage. Facile syntheses of these catalysts is also described.
- -
-
Paragraph 31
(2021/07/17)
-
- A comparative study of palladium-based coordination compounds with bidentate (N,N, P,P and P,O) ligands; Design, synthesis, X-ray structural, catalytic activity and DFT studies
-
This account describes our recent studies on four new asymmetric cyclometallated Pd(II) complexes with a formula [L1 → Pd ← L2](ClO4) (L1 = benzylamine and L2 = bis (diphenylphosphino) methane oxide (
- Babaee, Heshmatollah,Javad Sabounchei, Seyyed,Naghipour, Ali,Notash, Behrouz,Sayadi, Mohsen,Sedghi, Asieh
-
-
- Highly Active Fe3O4@SBA-15@NHC-Pd Catalyst for Suzuki–Miyaura Cross-Coupling Reaction
-
A novel Pd-NHC functionalized magnetic Fe3O4@SBA-15@NHC-Pd was synthesized and used as an efficient heterogeneous catalyst in the Suzuki–Miyaura C–C bond formation reactions. The Fe3O4@SBA-15@NHC-Pd characterized by X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy?(TEM), Energy Dispersive X-ray analysis (EDX), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA). The Inductively Coupled Plasma-Optical emission spectroscopy (ICP-OES)?analysis was used to determine the exact amount of Pd (0.33?wt%) in Fe3O4@SBA-15@NHC-Pd. The TEM images of the catalyst showed the existence of palladium nanoparticles immobilized in the catalyst's structure, while no reducing agent was used. The NHC moieties in the catalyst structure could be stabilize Pd(0) nanoparticles prevents agglomeration. The magnetic catalyst was effectively used in the Suzuki–Miyaura cross-coupling reaction of substituted phenylboronic acid derivatives with (hetero)aryl bromides in the presence of a K2CO3 at room temperature in aqueous media and magnetic catalyst could be simply extracted from the reaction mixture by an external magnet. Different aryl bromides were converted to coupled-products in excellent yields with spectacular TOFs values (up to 1,960,339?h?1); in the presence of 1?mg of Fe3O4@SBA-15@NHC-Pd catalyst (contains 3.1 × 10–6?mol% Pd) at room temperature in aqueous media. After reusability experiments, it is found that this catalyst was effectively used up to ten times in the reaction with almost consistent catalytic efficiency. A decrease in the activity of the 10th reused catalyst was found as 9%. Graphic Abstract: [Figure not available: see fulltext.]
- ?zdemir, ?smail,Akko?, Mitat,Alt?n, Serdar,Bu?day, Nesrin,Ya?ar, Sedat
-
-
- Facile synthesis of NC(sp3)O pincer palladium complexes and their use as efficient catalysts for Suzuki-Miyaura reaction of aryl bromides in aqueous medium
-
Two NC(sp3)O pincer palladium(II) complexes 3a-3b were readily prepared in high yields in only two steps. Of the first step, catalytic hydrophosphination of 2-alkenoylpyridines and subsequent in situ phosphine oxidation produced the NC(sp3)O pincer preligands 2a-2b. The second step is palladation of the preligands 2a-2b where PdCl2 was used as the Pd source to afford the desired Pd pincers 3a-3b via C(sp3)-H bond activation. Single crystal X-ray diffraction analysis of complex 3a unambiguously confirmed the NCO tridentate coordination mode of the complexes. The two complexes 3a-3b were applied to catalyze the Suzuki-Miyaura reaction. Complex 3b was found to be more efficient and exhibited very high activity in the Suzuki reaction of structurally diverse aryl bromides with arylboronic acids in aqueous ethanol under air. At a reaction temperature of 70 °C, a TON of up to 1.9 × 105 and a TOF of up to 9800 h?1 were achieved. At lower temperatures 3b was still very active, giving a TON of up to 9.5 × 103 and a TOF of up to 3900 h?1 at room temperature.
- Gong, Jun-Fang,Li, Nan,Pan, Ya-Ping,Song, Mao-Ping,Yang, Jing-Jing,Zhu, Zhi-Wu
-
-
- Suzuki coupling reactions catalyzed by Schiff base supported palladium complexes bearing the vitamin B6 cofactor
-
Novel Schiff bases were synthesized by condensing aromatic amines with pyridoxal-5’-phosphate and characterized by using FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The resulting Schiff bases were utilized as bidentate ligands, coordinating via imine nitrogen and phenolate oxygen atoms, to stabilize palladium ions. Aryl substituents on imine nitrogen allowed for fine tuning of the stereoelectronic properties of the Schiff bases. The catalytic activity of the selected palladium complexes was investigated in the Suzuki cross-coupling reaction of a series of aryl halides with boronic acids in H2O/EtOH (1:1). Out of four complexes investigated in the cross-coupling reactions, Pd(L8)2, bearing a methoxy substituent on aryl imine, showed the highest activity at low catalyst loading. The scope of the reaction was also investigated with 26 samples.
- Neshat, Abdollah,Gholinejad, Mohammad,?zcan, Hafize,Khosravi, Faezeh,Mobarakeh, Ali Mousavizadeh,Zaim, ?mer
-
-
- From the grafting of NHC-based Pd(II) complexes onto TiO2 to the in situ generation of Mott-Schottky heterojunctions: The boosting effect in the Suzuki-Miyaura reaction. Do the evolved Pd NPs act as reservoirs?
-
The assumption that the real active species involved in the Suzuki-Miyaura reaction are homogeneous, heterogeneous or both is often proposed. However a lack of characterization of the true catalytic entities and their monitoring makes assumptions somewhat elusive. Here, with the aim of getting new insights into the formation of active species in the Suzuki-Miyaura reaction, a family of palladium(II) complexes bearing bis(NHC) ligands was synthesized for immobilization at the surface of TiO2. The studies reveal that once the complexes are anchored onto TiO2, the mechanism governing the catalytic reaction is different from that observed for the non-anchored complexes. All complexes evolved to Pd NPs at the surface of TiO2 under reaction conditions and released Pd species in the liquid phase. Also, this reactivity was boosted by the in situ generation of Mott-Schottky heterojunctions, opening new routes towards the design of heterogenized catalysts for their further implementation in reverse-flow reactors.
- De Tovar, Jonathan,Rataboul, Franck,Djakovitch, Laurent
-
p. 133 - 147
(2021/05/10)
-
- Efficient nitriding reagent and application thereof
-
The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
- -
-
Paragraph 0197-0199
(2021/03/31)
-
- Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
-
Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
- Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
-
supporting information
p. 10632 - 10636
(2021/04/09)
-
- Fe3O4-SAHPG-Pd0 nanoparticles: A ligand-free and low Pd loading quasiheterogeneous catalyst active for mild Suzuki–Miyaura coupling and C-H activation of pyrimidine cores
-
This paper reports a green magnetic quasiheterogeneous efficient palladium catalyst in which Pd0 nanoparticles have been immobilized in self-assembled hyperbranched polyglycidole (SAHPG)-coated magnetic Fe3O4 nanoparticles (Fe3O4-SAHPG-Pd0). This catalyst has been used for effective ligandless Pd catalyzed Suzuki–Miyaura coupling reactions of different aryl halides with substituted boronic acids at room temperature and in aqueous media. Herein, SAHPG is used as support; it also acts as a reducing agent and stabilizer to promote the transformation of PdII to Pd0 nanoparticles. Also, this environmental friendly quasiheterogeneous catalyst is employed for the first time in the synthesis of new pyrimido[4,5-b]indoles via oxidative addition/C-H activation reactions on the pyrimidine rings, which were obtained with higher yield and faster than when Pd(OAc)2 was used as the catalyst. Interestingly, the above-mentioned catalyst could be recovered in a facile manner from the reaction mixture by applying an external magnet device and recycled several times with no significant decrease in the catalytic activity.
- Azizollahi, Hamid,Eshghi, Hossein,García-López, José-Antonio
-
-
- Pd Nanoparticles Embedded Into MOF-808: Synthesis, Structural Characteristics, and Catalyst Properties for the Suzuki–Miyaura Coupling Reaction
-
Abstract: A heterogeneous single-site catalyst Pd@MOF-808 was successfully synthesized by water-based, green synthesis procedure. The catalytic experiments exhibited the Pd@MOF-808 promoted efficiently the Suzuki–Miyaura coupling reaction without the assistance of organic phosphine ligands at atmospheric pressure conditions. The catalyst also could be applied in the gram-scale synthesis of industrially anti-inflanmatory analgestic Fenbufen. Graphic Abstract: [Figure not available: see fulltext.]
- Li, Tang,Pang, Wan,Wang, Jie,Zhang, Xiaoli,Zhao, Zesheng
-
-
- Cellulose Schiff base-supported Pd(II): An efficient heterogeneous catalyst for Suzuki Miyaura cross-coupling
-
Cellulose-supported Schiff base Pd(II) complex [(Cell-Sc-Pd(II))] has been designed and synthesized by multistep approach. (Cell-Sc-Pd(II)) was characterized by techniques, viz. FT-IR, XRD, XPS, EDS, FE-SEM and TGA. Catalytic activity of (Cell-Sc-Pd(II)) is explored for Suzuki Miyaura cross-coupling of phenyl boronic acid and aryl halides. Special features of present method are high TONs and TOFs, low catalyst loading (0.0016?mol %), reusability of the catalyst at least for?five times and synthesis of novel biphenyl derivatives of xanthenes. Graphic abstract: [Figure not available: see fulltext.]
- Pharande,Rashinkar,Pore
-
p. 4457 - 4476
(2021/07/26)
-
- Photoelectric properties of aromatic triangular tri-palladium complexes and their catalytic applications in the Suzuki-Miyaura coupling reaction
-
The photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes1-4, abbreviated as [Pd3]+, were investigated. The cyclic voltammogram of [Pd3]+in CH3CN-nBu4NPF6showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd3]+exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K. These peculiar triangular tri-palladium complexes showed excellent catalytic activities and exclusive reactivity with aryl iodides over the other halogenated aromatics in the Suzuki-Miyaura coupling reaction. The electronic and steric hindrance effects of substituents on the aryl iodides and aryl boronic acids including heteroaromatics like pyridine, pyrazine and thiophenes were explored and most substrates achieved up to 99% of yields. (2-[1,1′-Biphenyl]-2-ylbenzothiazole) which was analogous to the selective cyclooxygenase-2 (COX-2) inhibitors was also synthesized with our tri-palladium catalyst and gave good isolated yield (94%). The study of the catalytic process revealed that the mechanism of the reaction may involve the replacement of the sulphur ligand on [Pd3]+by iodine from aryl iodides, which was beneficial for the matching of C-I bond energy.
- Li, Jia,Li, Xujun,Liu, Xiang,Maestri, Giovanni,Malacria, Max,Wang, Xiaoshuang,Wang, Yanlan,Wu, Lingang
-
supporting information
p. 11834 - 11842
(2021/09/06)
-
- Efficient and Economical Preparation of Hypercrosslinked Polymers-palladium Based on Schiff Base as Recyclable Catalyst for Suzuki-Miyaura Reactions
-
A novel hypercrosslinked polymer (HCP) was prepared via Friedel-Crafts alkylation reaction of Schiff base with benzene and formaldehyde dimethyl acetal (FDA) promoted by FeCl3. The HCP was then metalated with Pd(II) to form heterogeneous catalyst. The protocol featured low cost, mild conditions, readily available materials, easy separation and high yield. Physicochemical methods, including IR, N2 sorption, ICP, TGA, XPS, SEM, EDX, and TEM, were used to characterize the catalyst structure and composition. The results reveal that the heterogeneous catalyst possesses high specific surface area, large pore volume, good chemical and thermal stability, and highly dispersed palladium. The heterogeneous catalysts were applied in Suzuki-Miyaura coupling reaction to evaluate their catalytic performance. The experiments reflected that the HCPs-Pd(OAc)2 was an efficient catalyst for Suzuki-Miyaura reactions with the yield of biaryl up to 99%, while the TON could reach 2250. The reusability test showed the catalyst was easily recovered and reused for at least six times without obvious decrease in activity.
- Gao, Xiyue,Lin, Hongwei,Liu, Shasha,Luo, Qionglin,Ouyang, Yuejun,Xiang, Bailin,Xiang, Dexuan,Yao, Huan,Zhang, Li
-
supporting information
p. 1879 - 1882
(2021/10/29)
-
- Introduction of a Recyclable Basic Ionic Solvent with Bis-(NHC) Ligand Property and The Possibility of Immobilization on Magnetite for Ligand- and Base-Free Pd-Catalyzed Heck, Suzuki and Sonogashira Cross-Coupling Reactions in Water
-
A new versatile and recyclable NHC ligand precursor has been developed with ligand, base, and solvent functionalities for the efficient Pd-catalyzed Heck, Suzuki and Sonogashira cross-coupling reactions under mild conditions. Furthermore, NHC ligand precursor was immobilized on magnetite and its catalytic activity was also evaluated towards the coupling reactions as a heterogeneous catalyst. The NHC ligand precursor was prepared with imidazolium functionalization of TCT followed by a simple ion exchange by hydroxide ions. However, the results revealed an excellent catalytic activity for the both homogeneous and heterogeneous catalytic systems. 1.52?g.cm?3 and 1194 cP was obtained for the density and viscosity of the NHC ligand precursor respectively. On the other hand, the heterogeneous type could be readily recovered from the reaction mixture and reused for several times while preserving its properties. Heterogeneous nature of the magnetic catalyst was studied by hot filtration, mercury poisoning, and three-phase tests. High to excellent yields were obtained for all entries for the both homogeneous and heterogeneous catalysts, which reflects the high consistency of the catalyst. Graphic Abstract: [Figure not available: see fulltext.]
- Min, Qingwang,Miao, Penghua,Chu, Deyu,Liu, Jinghan,Qi, Meijuan,Kazemnejadi, Milad
-
p. 3030 - 3047
(2021/02/16)
-
- Pd salen complex@CPGO as a convenient, effective heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions
-
A Pd(II) Schiff base complex supported on graphene oxide nanosheets (Pd(II) salen@CPGO) has been synthesized and characterized by FT-IR, ICP-AES, XRD, SEM/EDX and TEM. The synthesized nanocatalyst has been found to be an efficient heterogeneous catalyst for Suzuki–Miyaura and Heck–Mizoroki coupling reactions. Pd(II) salen@CPGO could be separated and recovered easily from the reaction mixture and recycled several times without a discernible decrease in its catalytic activity. The construction of a solid sheet-supported Pd catalyst would be expected to be a promising system to perform heterogeneous catalytic reactions.
- Ghabdian, Mahdieh,Nasseri, Mohammad Ali,Allahresani, Ali,Motavallizadehkakhky, Alireza
-
p. 1713 - 1728
(2018/05/25)
-
- Hydrophilic role of deep eutectic solvents for clean synthesis of biphenyls over a magnetically separable Pd-catalyzed Suzuki-Miyaura coupling reaction
-
The development of an efficient and sustainable catalytic system for the preparation of biphenyls through the Suzuki-Miyaura coupling reaction is still a great challenge to green chemistry. Encouraging the prevailing challenge, in the present work, a heterogeneous Pd catalyst was synthesized through a green method and used for the production of biphenyls in deep eutectic solvents (DESs) as green reaction media. In order to prepare the catalyst, magnetite-graphene oxide nanocomposite was modified with cellulose via the click reaction and applied as support for Pd nanoparticles. Cellulose acted as both reducing and stabilizing agent for Pd nanoparticles and eliminated the requirement of a reducing agent. The prepared catalyst was characterized by different methods such as FT-IR, EDX, EDX-mapping, XPS, SEM, TEM, XRD, VSM, and ICP-OES analyses. Catalytic properties of the obtained catalyst was explored in the coupling reaction of aryl halides with aryl boronic acids in different hydrophilic and hydrophobic DESs. The presence of cellulose with hydrophilic character on the structure of catalyst offered well dispersion of the catalyst in hydrophilic DESs, which led to enhancement of its catalytic activity. Among various hydrophilic DESs, the DES composed of dimethylammonium chloride and glycerol was verified as the most effective solvent for the preparation of biphenyls. The catalyst was compatible with a variety of substrates, with which all the Suzuki coupling products were achieved in high to excellent yields. Thanks to the low solubility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES could be readily recovered by evaporating water and reused up to five successive runs with a stable activity. This simple and new separation strategy provided a clean and highly efficient synthetic methodology for the synthesis of various biphenyls. Moreover, hot filtration test efficiently confirmed that the catalyst is heterogeneous and completely stable under reaction conditions.
- Karimi, Sabah,Masteri-Farahani, Majid,Niakan, Mahsa,Shekaari, Hemayat
-
-
- Sustainable and recyclable magnetic nanocatalyst of 1,10-phenanthroline Pd(0) complex in green synthesis of biaryls and tetrazoles using arylboronic acids as versatile substrates
-
A magnetic nanocatalyst was purveyed as a heterogeneous recoverable palladium-based catalyst anchored on green, sustainable and phosphine free support. Resulted Fe3O4@SiO2-Phen-Pd(0) nanocatalyst bearing powerful phenanthroline ligand was thoroughly characterized by physicochemical approaches like UV–vis, FT-IR, EDX, XRD, TGA, ICP, VSM, DLS, FESEM, and TEM analyses. After finding trustable data, the obtained magnetic catalyst was considered to be applied in the Suzuki-Miyaura type C-C couplings and getting corresponding tetrazoles using arylboronic acid derivatives as alternate precursors of aromatic halides and stupendous data were observed.
- Bagherzadeh, Nastaran,Sardarian, Ali Reza,Eslahi, Hassan
-
-
- Green and sustainable palladium nanomagnetic catalyst stabilized by glucosamine-functionalized Fe3O4@SiO2 nanoparticles for Suzuki and Heck reactions
-
A novel magnetic and heterogeneous palladium-based catalyst stabilized by glucosamine-functionalized magnetic Fe3O4@SiO2 nanoparticle was synthesized. The strategy relies on the covalently bonding of glucosamine to cyanuric chloride-functionalized magnetic nanoparticles followed by complexation with palladium. The structure of magnetic nanocatalyst was fully determined by FT-IR, XRD, DLS, FE-SEM, TEM, ICP, UV-Vis, TGA, VSM, and EDX. The obtained results confirmed that the palladium nanoparticles stabilized by glucosamine immobilized onto the magnetic support exhibited high activity in cross-coupling reactions of Suzuki-Miyaura and Mizoroki-Heck. Various aryl halides were coupled with arylboronic acid (Suzuki cross-coupling reaction) and olefins (Heck reactions) under the green conditions to provide corresponding products in high to excellent yields. Interestingly, the catalyst can be easily isolated from the reaction media by magnetic decantation and can subsequently be applied for consecutive reaction cycles (at least seven times) with no notable reduction in the catalytic activity.
- Eslahi, Hassan,Sardarian, Ali Reza,Esmaeilpour, Mohsen
-
-
- NiFe2O4@SiO2@ZrO2/SO42-/Cu/Co nanoparticles: A novel, efficient, magnetically recyclable and bimetallic catalyst for Pd-free Suzuki, Heck and C-N cross-coupling reactions in aqueous media
-
The novel heterogeneous bimetallic nanoparticles of Cu-Co were synthesized based on magnetic nanoparticles, and the magnetic nanocatalyst was characterized by XRD, FE-SEM, EDX mapping, BET, TEM, HRTEM, FTIR, TGA, and VSM. This catalyst was successfully applied as a recyclable magnetically catalyst in Heck, Suzuki, and C-N cross-coupling reactions with various aryl halides (iodides, bromides, and chlorides as challengeable substrates), with olefins, phenylboronic acid, and amines, respectively. We considered the rise of synergetic effects from the different Lewis acid and Br?nsted acid sites present in the catalyst. The catalyst was synthesized with cheap, available materials and a simple synthesis method. The catalyst can be separated easily using an external magnet. It was recycled for more than ten runs without a sensible loss of its catalytic activity, and no significant leaching of the Cu and Co quantity was observed. The significant benefits of the method are high-level generality, simple operation, and there are no heavy metals and toxic solvents. This is a quick, easy, efficacious and environmentally friendly protocol, and no by-products are formed in the reaction. These features make it an appropriate practical alternative protocol. In comparison with recent works, the other advantage of this catalyst is the synthesis of a wide variety of C-C and C-N bond derivatives (more than 40 derivatives). The other significant advantage is the low temperature of the reaction and the use of the least possible amount of the catalyst (0.003 g). The efficiency was good to excellent and the catalyst selectivity has been high. We aspire that our study inspires more interest to design novel catalysts based on using low-cost metal ions (such as cobalt and copper) in the cross-coupling reactions. This journal is
- Alavi G., Seyyedeh Ameneh,Nasseri, Mohammad Ali,Kazemnejadi, Milad,Allahresani, Ali,Hussainzadeh, Mahdi
-
p. 7741 - 7757
(2021/05/13)
-
- New biomaterials for Ni biosorption turned into catalysts for Suzuki-Miyaura cross coupling of aryl iodides in green conditions
-
In parallel with increasing Ni production and utilisation, Ni pollution in the soil-water continuum has become an alarming and global problem. Solutions for removing Ni from industrial effluents have been widely investigated and biosorption has emerged as an efficient, cost-effective, scalable and sustainable alternative for water treatment. However, the biosorption capacity is limited by the chemical composition of the biomaterial and the Ni-enriched biomaterials are rarely valorised. In this work, the biosorption capacity of three abundant biomaterials with different chemical properties - water hyacinth, coffee grounds and pinecones - was studied before and after functionalization, and reached a maximum biosorption capacity of 51 mg g?1of Ni(ii). A bioinspired functionalization approach was investigated introducing carboxylate moieties and was conducted in green conditions. The Ni-enriched biomaterials were valorised by transformation into catalysts, which were characterised by MP-AES and XRPD. Their characterisation revealed a structure similar to nickel formate, and hence the Eco-Ni(HCOO)2catalysts were tested in Suzuki-Miyaura reactions. Several aryl iodides were successfully cross-coupled to phenylboronic acids using Eco-Ni(HCOO)2without any ligand, a mild and green base in a mixture of green solvents.
- Adler, Pauline,Boulanger, Clotilde,Cases, Lucie,Diliberto, Sébastien,Grison, Claude,Pelissier, Franck
-
p. 28085 - 28091
(2021/09/15)
-
- Highly efficient photocatalytic Suzuki coupling reaction by Pd3P/CdS catalyst under visible-light irradiation
-
Monodispersed palladium phosphide (Pd3P) (5.2 ± 0.5 nm) was firstly applied to photocatalytic Suzuki coupling reaction under visible light irradiation with CdS nanoflake as a photosensitizer. This heterogeneous system exhibited high yields to corresponding products and excellent stability in alcohol solvent at room temperature.
- Yang, Huai-Qing,Chen, Qian-Qian,Liu, Fulai,Shi, Rui,Chen, Yong
-
p. 676 - 680
(2020/07/06)
-
- Recoverable palladium-catalyzed carbon-carbon bond forming reactions under thermomorphic mode: Stille and suzuki-miyaura reactions
-
The reaction of [PdCl2(CH3CN)2] and bis-4,40-(RfCH2OCH2)-2,2'-bpy (1a-d), where Rf = n- C11F23 (a), n-C10F21 (b), n-C9F19 (c) and n-C8F17 (d), respectively, in the presence of dichloromethane (CH2Cl2) resulted in the synthesis of Pd complex, [PdCl2[4,4'-bis-(RfCH2OCH2)-2,2'-bpy] (2a-d). The Pd-catalyzed Stille arylations of vinyl tributyltin with aryl halides were selected to demonstrate the feasibility of recycling usage with 2a as the catalyst using NMP (N-methyl-2-pyrrolidone) as the solvent at 120-150 °C. Additionally, recycling and electronic effect studies of 2a-c were also carried out for Suzuki-Miyaura reaction of phenylboronic acid derivatives, 4-X-C6H4-B(OH)2, (X = H or Ph) with aryl halide, 4-Y-C6H4-Z, (Y = CN, H or OCH3; Z = I or Br) in dimethylformamide (DMF) at 135-150 °C. At the end of each cycle, the product mixtures were cooled to lower temperature (e.g., -10 °C), and then catalysts were recovered by decantation with Pd leaching less than 1%. The products were quantified by gas chromatography/mass spectrometry (GC/MS) analysis or by the isolated yield. The complex 2a-catalyzed Stille reaction of aryl iodides with vinyl tributyltin have good recycling results for a total of 8 times, with a high yield within short period of time (1-3 h). Similarly, 2a-c-catalyzed Suzuki-Miyaura reactions also have good recycling results. The electronic effect studies from substituents in both Stille and Suzuki-Miyaura coupling reactions showed that electron withdrawing groups speed up the reaction rate. To our knowledge, this is the first example of recoverable fluorous long-chained Pd-catalyzed Stille reactions under the thermomorphic mode.
- Chan, Ka Long,Chiu, Chiao-Fan,Elakkat, Vijayanath,Lu, Norman,Shen, Chia-Rui,Su, Han-Chang,Tessema, Eskedar,Tsai, Zong-Lin
-
-
- Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: Development and application in a lab-on-a-chip context
-
Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions. This thin film-format demonstrated good catalytic efficiency (TON up to 3.4 × 103) and stability. Incorporation into a quartz crystal microbalance (QCM) instrument illustrated the potential for using this approach in lab-on-a-chip-based synthesis applications.
- Anaspure, Prasad,Nicholls, Ian A.,Suriyanarayanan, Subramanian
-
p. 35161 - 35164
(2021/11/30)
-
- Polydopamine-Encapsulated Dendritic Organosilica Nanoparticles as Amphiphilic Platforms for Highly Efficient Heterogeneous Catalysis in Water
-
Aqueous heterogeneous catalysis is a green, sustainable catalytic process that attracts increasing attention, but it often suffers from poor mass transfer, substrate adsorption and catalyst dispersion. Herein, we synthesized a type of amphiphilic core-shell catalysts with a hydrophilic polydopamine (PDA) shell and a hydrophobic dendritic organosilica nanoparticle (DON) core for heterogeneous catalysis in water. The hydrophilic shell allowed the catalyst dispersing well in water, and the hydrophobic core facilitated the absorption of organic reactants. The hierarchical core-shell structure facilitated rational arrangement of the location of catalytic species to match the reaction sequence. The obtained metal, enzyme and metal-enzyme amphiphilic catalysts demonstrated improved stability, selectivity and activity in aqueous reactions, including Pd-catalyzed cross-couplings (Suzuki, Liebeskind-Srogl, Heck and Sonogashira), enzymatic enantioselective reduction, chemoenzymatic cascade synthesis of chiral compounds and chemoenzymatic cascade degradation of organophosphates. The amphiphilic catalysts could be easily in situ recovered, and their high catalytic performance was sustained for five cycles.
- Gao, Jing,Guo, Na,Jiang, Yanjun,Liu, Guanhua,Liu, Pengbo,Liu, Yunting,Wang, Zihan,Zhang, Lei
-
supporting information
p. 1975 - 1982
(2021/06/09)
-
- Sterically enhanced 2-iminopyridylpalladium chlorides as recyclable ppm-palladium catalyst for Suzuki–Miyaura coupling in aqueous solution
-
Sterically hindered 2-iminopyridine derivatives and their palladium chlorides complexes are designed and prepared, which efficiently promote the Suzuki–Miyaura coupling (SMC) reaction in aqueous solution. Besides the good to excellent yields and broad substrate scope, these catalysts can be reused for at least four new batches of the substrates. Spontaneous separation of coupling products in the aqueous reaction medium is the additional striking feature of this catalytic process. Furthermore, catalytic performance of palladium complexes bearing the azo-bridged phenyl groups was greatly influenced by the UV irradiation due to the cis/trans photoisomerization of azo unit of the catalysts. In conclusion, titled palladium complexes provide a green, sustainable, cost-effective, and convenient process to synthesize SMC products at multi-gram-scale reaction.
- Liang, Tongling,Lin, Wenhua,Ma, Yanping,Sun, Wen-Hua,Zhang, Liping
-
-
- Water-Dispersible Pd–N-Heterocyclic Carbene Complex Immobilized on Magnetic Nanoparticles as a New Heterogeneous Catalyst for Fluoride-Free Hiyama, Suzuki–Miyaura and Cyanation Reactions in Aqueous Media
-
Abstract: Pd–N-heterocyclic carbine complex immobilized on magnetic nanoparticles is synthesized and characterized by different techniques such as FT-IR, XPS, TEM, EDX, FESEM, VSM, TGA, and ICP. The synthesized catalyst was used as a new water dispersible heterogeneous catalyst in the fluoride-free Hiyama, Suzuki–Miyaura and cyanation reactions in pure water. By this method, different types of biaryls and aryl nitriles were synthesized in good to high yields by the reaction of a variety of aryl iodides, bromides and chlorides with triethoxyphenylsilane, phenylboronic acid and K4[Fe(CN)6]·3H2O, respectively. The presence of sulfonates as hydrophilic groups on the surface of the catalyst confers a highly water dispersible, active and yet magnetically recoverable Pd catalyst. The possibility to perform the reaction in water as a green medium, ease of the catalyst recovery and reuse by magnetic separation, and the absence of any additives or co-solvents make this method as an eco-friendly and economical protocol for the synthesis of biaryl derivatives and aryl nitriles. Graphic Abstract: A new water dispersible heterogeneous Pd–N-heterocyclic carbene for the efficient fluoride-free Hiyama, Suzuki–Miyaura and cyanation reactions in pure water is developed.[Figure not available: see fulltext.].
- Chahkamali, Farhad Omarzehi,Sansano, José Miguel,Sobhani, Sara
-
-
- Fe-MIL-101 modified by isatin-Schiff-base-Co: a heterogeneous catalyst for C-C, C-O, C-N, and C-P cross coupling reactions
-
A metal-organic framework functionalized with a cobalt-complex is preparedviapost-synthetic modification of Fe-MIL-101-NH2. Initially, Fe-MIL-101-NH2reacted with isatin to produce Fe-MIL-101-isatin-Schiff-base, which can anchor the cobalt by the addition of cobalt acetate. The resulting MOF-Co catalyst is characterized by employing multiple techniques. This new modified MOF acts as a heterogeneous and recyclable catalyst for efficient Ullmann, Buchwald-Hartwig, Hirao, Hiyama and Mizoroki-Heck cross-coupling reactions of several aryl halides/phenylboronic acid/phenyltosylate with phenols, anilines/heterocyclic amines, triethyl phosphite, triethoxyphenylsilane and alkenes and generates the expected coupling products in good to high yields.
- Farrokhi, Alireza,Rouzifar, Majid,Sansano, José Miguel,Sobhani, Sara
-
p. 19963 - 19976
(2021/11/12)
-
- Cu2O-Catalyzed Conversion of Benzyl Alcohols Into Aromatic Nitriles via the Complete Cleavage of the C≡N Triple Bond in the Cyanide Anion
-
Nitrogen transfer from cyanide anion to an aldehyde is emerging as a promising method for the synthesis of aromatic nitriles. However, this method still suffers from a disadvantage that a use of stoichiometric Cu(II) or Cu(I) salts is required to enable the reaction. As we report herein, we overcame this drawback and developed a catalytic method for nitrogen transfer from cyanide anion to an alcohol via the complete cleavage of the C≡N triple bond using phen/Cu2O as the catalyst. The present condition allowed a series of benzyl alcohols to be smoothly converted into aromatic nitriles in moderate to high yields. In addition, the present method could be extended to the conversion of cinnamic alcohol to 3-phenylacrylonitrile.
- Liu, Wenbo,Tang, Peichen,Zheng, Yi,Ren, Yun-Lai,Tian, Xinzhe,An, Wankai,Zheng, Xianfu,Guo, Yinggang,Shen, Zhenpeng
-
p. 3509 - 3513
(2021/10/04)
-
- Switching between mono and doubly reduced odd alternant hydrocarbon: designing a redox catalyst
-
Since the early Hückel molecular orbital (HMO) calculations in 1950, it has been well known that the odd alternant hydrocarbon (OAH), the phenalenyl (PLY) system, can exist in three redox states: closed shell cation (12π e?), mono-reduced open shell neutral radical (13π e?) and doubly reduced closed shell anion (14π e?). Switching from one redox state of PLY to another leads to a slight structural change owing to its low energy of disproportionation making the electron addition or removal process facile. To date, mono-reduced PLY based radicals have been extensively studied. However, the reactivity and application of doubly reduced PLY species have not been explored so far. In this work, we report the synthesis of the doubly reduced PLY species (14π e?) and its application towards the development of redox catalysisviaswitching with the mono-reduced form (13π e?) for aryl halide activation and functionalization under transition metal free conditions without any external stimuli such as heat, light or cathodic current supply.
- Ahmed, Jasimuddin,Datta, Paramita,Das, Arpan,Jomy, Stephy,Mandal, Swadhin K.
-
p. 3039 - 3049
(2021/03/14)
-
- Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp3)?H Bonds**
-
The metal-free activation of C(sp3)?H bonds to value-added products is of paramount importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6-triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal- and cyanide-free conditions. We demonstrate the scope of the method with over 50 examples including late-stage functionalization of drug molecules (celecoxib) and complex structures such as l-menthol, amino acids, and cholesterol derivatives. Furthermore, the presented synthetic protocol is applicable for gram-scale reactions. In addition to methylarenes, selected examples for the cyanation of aldehydes, alcohols and oximes are demonstrated as well. Detailed mechanistic investigations have been carried out using time-resolved luminescence quenching studies, control experiments, and NMR spectroscopy as well as kinetic studies, all supporting the proposed catalytic cycle.
- Murugesan, Kathiravan,Donabauer, Karsten,K?nig, Burkhard
-
supporting information
p. 2439 - 2445
(2020/12/07)
-
- Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
-
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
- Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
-
supporting information
p. 3723 - 3728
(2021/04/07)
-
- Immobilization of a Pd(ii)-containing N-heterocyclic carbene ligand on porous organic polymers: efficient and recyclable catalysts for Suzuki-Miyaura reactions
-
Palladium coordinated with N-heterocyclic carbene-functionalized porous organic polymers (Pd@POPs) was successfully preparedviaScholl coupling reaction and a successive immobilization method. The protocol features simple reaction conditions, easy separation, high yield and low cost. The structure and composition of Pd@POPs were characterized by N2sorption, TGA, FT-IR, SEM, EDX, TEM, XPS and ICP. Then the obtained heterogeneous catalysts were applied in Suzuki-Miyaura coupling reaction to evaluate their catalytic performance. The Pd@POPs displayed high catalytic activity for the Suzuki-Miyaura coupling reaction in an EtOH/H2O solvent. A 0.03 mol% Pd loading was sufficient for the reaction with a high turnover number (TON) of 3220. Moreover, the catalyst was easily recovered and reused for at least six consecutive cycles without obvious loss of its initial activity.
- Gao, Xiyue,Lin, Hongwei,Liu, Cijie,Luo, Qionglin,Ouyang, Yuejun,Xiang, Bailin,Xiang, Dexuan,Yao, Huan,Zhou, Nonglin
-
p. 3676 - 3680
(2021/06/17)
-
- C(acyl)-C(sp2) and C(sp2)-C(sp2) Suzuki-Miyaura cross-coupling reactions using nitrile-functionalized NHC palladium complexes
-
Application of N-heterocyclic carbene (NHC) palladium complexes has been successful for the modulation of C-C coupling reactions. For this purpose, a series of azolium salts (1a-f) including benzothiazolium, benzimidazolium, and imidazolium, bearing a CN-substituted benzyl moiety, and their (NHC)2PdBr2 (2a-c) and PEPPSI-type palladium (3b-f) complexes have been systematically prepared to catalyse acylative Suzuki-Miyaura coupling reaction of acyl chlorides with arylboronic acids to form benzophenone derivatives in the presence of potassium carbonate as a base and to catalyse the traditional Suzuki-Miyaura coupling reaction of bromobenzene with arylboronic acids to form biaryls. All the synthesized compounds were fully characterized by Fourier Transform Infrared (FTIR), and 1H and 13C NMR spectroscopies. X-ray diffraction studies on single crystals of 3c, 3e and 3f prove the square planar geometry. Scanning Electron Microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), metal mapping analyses and thermal gravimetric analysis (TGA) were performed to get further insights into the mechanism of the Suzuki-Miyaura cross coupling reactions. Mechanistic studies have revealed that the stability and coordination of the complexes by the CN group are achieved by the removal of pyridine from the complex in catalytic cycles. The presence of the CN group in the (NHC)Pd complexes significantly increased the catalytic activities for both reactions.
- ?akir, Sinem,Karabiyik, Hande,Kavukcu, Serdar Batikan,Rethinam, Senthil,Türkmen, Hayati
-
p. 37684 - 37699
(2021/12/09)
-
- Aerobic Cu and amine free Sonogashira and Stille couplings of aryl bromides/chlorides with a magnetically recoverable Fe3O4@SiO2 immobilized Pd(II)-thioether containing NHC
-
Two value added C–C cross coupling reactions; Sonogashira and Stille couplings were achieved at milder conditions in the catalytic presence of a magnetically recoverable heterogeneous catalyst Fe3O4@SiO2@NHC^SPh-Pd(II). The catalyst was earlier reported for Suzuki-Miyaura reaction, and as an extension of its catalytic efficiency, the Stille and Sonogashira cross coupling reactions under aerobic condition has been explored in present report. The Sonogashira coupling of aryl bromides and terminal alkynes produced an excellent yield (~96% at 0.25 mol% Pd) of the desired coupling product under copper and amines free conditions. Moreover, an excellent Stille coupling of readily available and more latent aryl chlorides and trialkylstannane was obtained (yields up to 95% at 0.25 mol% Pd) in absence of toxic fluorides additives. The broad substrate scope of the catalyst for both the coupling reactions and the magnetically recoverable feature of catalyst make this reaction highly desirable for industrial applications of present heterogeneous catalysis.
- Khandaka, Himanshu,Sharma, Kamal Nayan,Joshi, Raj Kumar
-
supporting information
(2021/02/20)
-
- Pyrazole-Mediated C-H Functionalization of Arene and Heteroarenes for Aryl-(Hetero)aryl Cross-Coupling Reactions
-
Herein we introduce a transition-metal-free protocol that involves a commercially available, inexpensive pyrazole molecule to conduct C-C cross-coupling reactions at room temperature via a radical pathway. Using this method, an aryldiazonium salt has been coupled to a wide range of arenes and heteroarenes including benzene, mesitylene, thiophene, furan, benzoxazole to result the corresponding biaryl products. The full reaction mechanism is elucidated along with the crystallographic probation of an active initiator species. A potassium-stabilized deprotonated pyrazole steers single-electron transfer to the substrate and behaves as an initiator for the reaction.
- Kundu, Abhishek,Dey, Dhananjay,Pal, Subhankar,Adhikari, Debashis
-
p. 15665 - 15673
(2021/11/16)
-
- Development and Molecular Understanding of a Pd-Catalyzed Cyanation of Aryl Boronic Acids Enabled by High-Throughput Experimentation and Data Analysis
-
A synthetic method for the palladium-catalyzed cyanation of aryl boronic acids using bench stable and non-toxic N-cyanosuccinimide has been developed. High-throughput experimentation facilitated the screen of 90 different ligands and the resultant statistical data analysis identified that ligand σ-donation, π-acidity and sterics are key drivers that govern yield. Categorization into three ligand groups – monophosphines, bisphosphines and miscellaneous – was performed before the analysis. For the monophosphines, the yield of the reaction increases for strong σ-donating, weak π-accepting ligands, with flexible pendant substituents. For the bisphosphines, the yield predominantly correlates with ligand lability. The applicability of the designed reaction to a wider substrate scope was investigated, showing good functional group tolerance in particular with boronic acids bearing electron-withdrawing substituents. This work outlines the development of a novel reaction, coupled with a fast and efficient workflow to gain understanding of the optimal ligand properties for the design of improved palladium cross-coupling catalysts.
- De Jesus Silva, Jordan,Bartalucci, Niccolò,Jelier, Benson,Grosslight, Samantha,Gensch, Tobias,Schünemann, Claas,Müller, Bernd,Kamer, Paul C. J.,Copéret, Christophe,Sigman, Matthew S.,Togni, Antonio
-
-
- Cobalt-Catalyzed Coupling of Aryl Chlorides with Aryl Boron Esters Activated by Alkoxides
-
The cobalt-catalyzed Suzuki biaryl cross-coupling of aryl chloride substrates with aryl boron reagents, activated with more commonly used bases, remained a significant unmet challenge in the race to replace platinum group metal catalysts with Earth-abundant metal alternatives. We now show that this highly desirable process can be realized using alkoxide bases, provided the right counterion is employed, strict stoichiometric control of the base is maintained with respect to the aryl boron reagent, and the correct boron ester is selected. Potassium tert-butoxide works well, but any excess of the base first inhibits and then poisons the catalyst. Lithium tert-butoxide performs very poorly, while even catalytic amounts of lithium additives also poison the catalyst. Meanwhile, a neopentane diol-based boron ester is required for best performance. As well as delivering this sought-after transformation, we have undertaken detailed mechanistic and computational investigations to probe the possible mechanism of the reaction and help explain the unexpected experimental observations.
- Tailor, Sanita B.,Manzotti, Mattia,Smith, Gavin J.,Davis, Sean A.,Bedford, Robin B.
-
p. 3856 - 3866
(2021/04/07)
-
- Synthesis of arylboronates via the Pd-catalyzed desulfitative coupling reaction of sodium arylsulfinates with bis(pinacolato)diboron
-
The desulfitative borylation reaction of sodium arylsulfinates with bis(pinacolato)diboron or bis(neopentylglycolato)diboron under palladium catalysis has been developed, allowing selective C-B bond formation to give arylboronates with a range of functional groups in moderate to good yields under mild reaction conditions. A gram-scale preparation as well as the cascade Suzuki-Miyaura cross-coupling of arylboronates demonstrated the potential practical utility in organic synthesis.
- Qiu, Di,Li, Songyi,Yue, Guanglu,Mao, Jinshan,Xu, Bei,Yuan, Xinyu,Ye, Fei
-
-
- Synthesis of biaryl ketones and biaryl diketones via carbonylative Suzuki-Miyaura coupling reactions catalyzed by bridged bis(N-heterocyclic carbene)palladium(II) catalysts
-
This disclosure relates to bridged bis(N-heterocyclic carbene)palladium(II) complexes, methods of preparing the complexes, and methods of using the complexes in Suzuki-Miyaura coupling reactions.
- -
-
Page/Page column 20; 25-26; 29-30
(2021/12/23)
-
- CuO-catalyzed conversion of arylacetic acids into aromatic nitriles with K4Fe(CN)6 as the nitrogen source
-
Readily available CuO was demonstrated to be effective as the catalyst for the conversion of arylacetic acids to aromatic nitriles with non-toxic and inexpensive K4Fe(CN)6 as the nitrogen source via the complete cleavage of the C[tbnd]N triple bond. The present method allowed a series of arylacetic acids including phenylacetic acids, naphthaleneacetic acids, 2-thiopheneacetic acid and 2-furanacetic acid to be converted into the targeted products in low to high yields.
- Ren, Yun-Lai,Shen, Zhenpeng,Tian, Xinzhe,Xing, Ai-Ping,Zhao, Zhe
-
-
- A new palladium heterogeneous complex (Pd-Gu@BOEH): chemoselective, phosphine-free and practical nanocatalyst in carbon–carbon cross-coupling reaction
-
Herein, boehmite nanoparticles were synthesized via combination of Al(NO3)3·9H2O and NaOH in aqueous solution. This nanomaterial converted to Pd-Gu@BOEH in several sequences. Pd-Gu@BOEH was used as efficient and recoverable nanocatalyst for the chemoselective C–C band formation such as Mizoroki–Heck and Suzuki–Miyaura reactions without any phosphine ligands or inert atmosphere. This catalyst has been characterized by several analyses such as EDS, WDX, SEM, XRD, FT-IR, TEM, TGA, AAS and BET. Also, obtained products from C–C coupling reactions were identified by NMR spectroscopy and their melting points. This catalyst was recycled in described reactions without palladium leaching. The reused catalyst was characterized by EDS, WDX, XRD, FT-IR and AAS analysis, which showed good stability during reaction process.
- Jafari, Fariba,Ghorbani-Choghamarani, Arash,Hasanzadeh, Neda
-
p. 1033 - 1049
(2020/11/05)
-
- Copper-promoted cyanation of aryl iodides with N,N-dimethyl aminomalononitrile
-
A copper-promoted cyanation of aryl iodides has been successfully developed by using N,N-dimethyl aminomalononitrile as the cyanide source with moderate toxicity and better stability. This reaction features broad substrate scope, excellent reaction yields, readily available catalyst, and simple reaction conditions.
- Liu, Si-Zhan,Li, Jing,Xue, Cao-Gen,Xu, Xue-Tao,Lei, Lin-Sheng,Huo, Chen-Yu,Wang, Zhen,Wang, Shao-Hua
-
supporting information
(2021/02/01)
-
- Efficient photocatalytic chemoselective and stereoselective C-C bond formation over AuPd@N-rich carbon nitride
-
Heterogeneous chemoselective or stereoselective C-C coupling reactions remain extremely challenging in traditional organic synthesis. Here, we constructed a AuPd@N-rich carbon nitride (NRCN) photocatalyst through simple ammonia solution heat treatment of carbon nitride and then AuPd NP loading. AuPd@NRCN exhibited extraordinary light color promoted catalytic performance in C-C bond formation under visible light in air. Surprisingly, both high chemoselectivity to unsymmetrical Ullmann biaryl products and satisfactory stereoselectivity to Z-type Heck reaction products could be achieved by changing the light source color. Various substrates exhibited great potential for the economical synthesis of unsymmetrical biaryl products and Z-type olefins. Efficient visible light promoted C-I bond activation accompanied with improved photocatalytic coupling reaction efficiency over AuPd@NRCN was verified firstly by in situ DRIFTS. Considering that the Ullmann cross-coupling reaction is a multi-photon reaction, the improved photocatalytic performance in the Ullmann cross-coupling reaction using a combination of light sources with different colors might be due to the activation of different substrates and/or steps requiring different energies, and the combination of the two energy sources was beneficial for improving the activation efficiency of different substrates and/or steps. The activation of iodobenzene and styrene in the Heck reaction with light was also beneficial to the formation of the stilbene product. The light color promoted chemoselectivity and stereoselectivity are expected to have profound impact on organic synthetic methodology improvement. This journal is
- Jiang, Heyan,Xu, Jie,Zhang, Sishi,Cheng, Hongmei,Zang, Cuicui,Bian, Fengxia
-
p. 219 - 229
(2021/01/28)
-
