- Microwave-assisted copper-catalyzed Sonogashira reaction in PEG solvent
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A catalytic system composed of copper salt, potassium carbonate and appropriate poly(ethylene glycol) (PEG; liquid or solid, various molecular weight: 300 MW 3400) was developed to perform a Sonogashira arylation under microwave activation. In the prese
- Colacino, Evelina,Da?ch, Latifa,Martinez, Jean,Lamaty, Frédéric
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- Palladium nanoclusters in Sonogashira cross-coupling: A true catalytic species?
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The question of whether palladium nanoclusters are the actual catalysts in the so-called 'cluster-catalyzed Sonogashira cross-coupling' is investigated, using the coupling of phenylacetylene with 4-bromobenzonitrile as a model reaction. By combining a detailed kinetic analysis with transmission electron microscopy (TEM), we show that a soluble species must be present in the system when Pd nanoclusters are used as catalysts. Various Pd clusters show similar kinetic profiles to that of a homogeneous Pd(dba)2 complex. Most importantly, TEM analysis of samples taken before, during, and after the reaction shows that the cluster size decreases during the reaction. Based on these findings, we present a possible two-path mechanism for Sonogashira cross-coupling reactions in the presence of Pd nanoclusters.
- Thathagar, Mehul B.,Kooyman, Patricia J.,Boerleider, Romilda,Jansen, Eveline,Elsevier, Cornelis J.,Rothenberg, Gadi
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- Zeolitic imidazolate frameworks-67 (ZIF-67) supported PdCu nanoparticles for enhanced catalytic activity in Sonogashira-Hagihara and nitro group reduction under mild conditions
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A bimetallic PdCu supported on amine functionalized ZIF-67 is shown to be efficient catalyst in Sonogashira-Hagihara coupling reaction of aryl iodides at room temperature and aryl bromides at 40 oC. In addition, the catalyst is used in the reduction of 4-
- Gholinejad, Mohammad,Naghshbandi, Zhwan,Sansano, Jose M.
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- 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
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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
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p. 3030 - 3047
(2021/02/16)
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- Pd supported on clicked cellulose-modified magnetite-graphene oxide nanocomposite for C-C coupling reactions in deep eutectic solvent
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Cellulose-modified magnetite-graphene oxide nanocomposite was prepared via click reaction and utilized for immobilization of palladium (Pd) nanoparticles without using additional reducing agent. The abundant OH groups of cellulose provided the uniform dispersion and high stability of Pd nanoparticles, while magnetite-graphene oxide as a supporting material offered high specific surface area and easy magnetic separation. The as-prepared nanocomposite served as a heterogeneous catalyst for the Heck and Sonogashira coupling reactions in various hydrophilic and hydrophobic deep eutectic solvents (DESs) as sustainable and environmentally benign reaction media. Among the fifteen DESs evaluated for coupling reactions, the hydrophilic DES composed of dimethyl ammonium chloride and glycerol exhibited the best results. Due to the low miscibility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES can be readily recovered by evaporating water and retrieved eight times with negligible loss of catalytic performance.
- Karimi, Sabah,Masteri-Farahani, Majid,Niakan, Mahsa,Shekaari, Hemayat
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- Co3O4 nanoparticles embedded in triple-shelled graphitic carbon nitride (Co3O4/TSCN): a new sustainable and high-performance hierarchical catalyst for the Pd/Cu-free Sonogashira–Hagihara cross-coupling reaction
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Inspired by the synthesis of triple-shelled periodic mesoporous organosilica hollow spheres, a straightforward and controllable approach for the preparation of Co3O4 NPs embedded in triple-shelled graphitic carbon nitride has been es
- Ghodsinia, Sara S. E.,Akhlaghinia, Batool,Jahanshahi, Roya
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p. 3217 - 3244
(2021/05/17)
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- Selective Phosphoranation of Unactivated Alkynes with Phosphonium Cation to Achieve Isoquinoline Synthesis
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We herein develop a selective phosphoranation of alkynes with phosphonium cation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols that largely rely on the utilization of highly functionalized imines/oximes and/or highly polarized alkynes.
- Cui, Hong,Bai, Jinku,Ai, Tianyu,Zhan, Ye,Li, Guanzhong,Rao, Honghua
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supporting information
p. 4023 - 4028
(2021/05/26)
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- Glycosyl Triazole Ligand for Temperature-Dependent Competitive Reactions of Cu-Catalyzed Sonogashira Coupling and Glaser Coupling
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Glycosyl triazoles have been introduced as efficient ligands for the Cu-catalyzed Sonogashira reaction to overcome the challenges of sideways homocoupling reactions in Cu catalysis in this reaction. The atmospheric oxygen in a sealed tube did not affect t
- Mishra, Nidhi,Singh, Sumit K.,Singh, Anoop S.,Agrahari, Anand K.,Tiwari, Vinod K.
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p. 17884 - 17895
(2021/12/17)
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- 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
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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
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supporting information
(2021/02/20)
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- Immobilized Pd on a NHC-functionalized metal-organic FrameworkMIL-101(Cr): An efficient heterogeneous catalyst in the heck and copper-free Sonogashira coupling reactions
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A heterogeneous palladium catalyst system based on immobilization of palladium moieties on a N-heterocyclic carbene (NHC) modified metal organic framework (MOF) was developed for the Heck and copper-free Sonogashira coupling reactions. In order to prepare this catalyst system, first, MIL-101(Cr) was functionalized with NHC moieties through a post synthetic modification (PSM) approach, and then Pd metal was stabilized on the prepered MIL-101(Cr)-NHC substrate. This material was characterized using various microscopic and spectroscopic techniques and then was used as an efficient heterogeneous Pd catalyst system in the Heck and copper-free Sonogashira reactions. Results of the heterogeneity tests showed that the Pd-NHC-MIL-101(Cr) catalyst can efficiently catalyzed these coupling reactions heterogeneously and no remarkable changes observed in the morphology and structure of MIL-101(Cr) template during the reaction progress. Also, existence of palladium nanoparticles immobilized on the MOF structure affirmed by the TEM and XPS analysis confirmed the oxidation state of Pd. A variety of alkene and alkyne derivatives were synthesized in good to excellent yields using this heterogeneous Pd catalyst system under normal conditions. More importantly Pd-NHC-MIL-101(Cr) catalyst was simply recovered from the reaction medium without remarkable decreasing in its catalytic activities after five times of reusability. The ICP analysis showed the very low Pd and Cr metals leaching, representing high stability and applicability of this catalyst in Pd coupling reactions.
- Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
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supporting information
(2021/01/12)
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- Palladium-catalyzed decarbonylative sonogashira coupling of terminal alkynes with carboxylic acids
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A direct decarbonylative Sonogashira coupling of terminal alkynes with carboxylic acids was achieved through palladium catalysis. This reaction did not use overstoichiometric oxidants, thus overcoming the homocoupling issue of terminal alkynes. Under the reaction conditions, a wide range of carboxylic acids including those bioactive ones could couple readily with various terminal alkynes, thus providing a relative general method for preparing internal alkynes.
- Chen, Tieqiao,Huang, Tianzeng,Li, Chunya,Li, Wenhui,Li, Xinyi,Li, Zhaohui,Liu, Long,Tang, Zhi,Zhang, Tao
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supporting information
p. 3304 - 3309
(2021/05/31)
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- Copper-mediated conversion of alkynes into nitriles via iodotriazoles
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We disclose our studies on a copper-mediated reaction of alkynes with trimethylsilyl azide to afford nitriles, and proposed a reaction mechanism, which involves an iodoalkyne and an iodotriazole as intermediates.
- Kori, Ryosuke,Murakami, Keigo,Nishiyama, Yoshitake,Toma, Tatsuya,Yokoshima, Satoshi
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p. 278 - 280
(2021/03/08)
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- Ligand-Promoted Alkynylation of Aryl Ketones: A Practical Tool for Structural Diversity in Drugs and Natural Products
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Conversion of the numerous aryl ketones into aryl electrophiles via Ar-C(O) cleavage remains a challenging yet highly desirable transformation in Sonogashira-type coupling. Herein, we report a palladium-catalyzed ligand-promoted alkynylation of unstrained aryl ketones. The protocol allows the alkynylation to be carried out in a one-pot procedure with broad functional-group tolerance and substrate scope. The potential applications of this protocol in drug discovery and chemical biology are further demonstrated by late-stage diversification of a number of pharmaceuticals and natural products. More importantly, two different biologically important fragments derived from a pharmaceutical and natural product could be connected by the consecutive alkynylation of ketones. Distinct from aryl halides in conventional Sonogashira reactions, the protocol provides a practical tool for the 1,2-bifunctionalization of aryl ketone by merging ketone-directed ortho-C-H activation with ligand-promoted ipso-Ar-C(O) alkynylation.
- Xu, Hui,Ma, Biao,Fu, Zunyun,Li, Han-Yuan,Wang, Xing,Wang, Zhen-Yu,Li, Ling-Jun,Cheng, Tai-Jin,Zheng, Mingyue,Dai, Hui-Xiong
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p. 1758 - 1764
(2021/02/09)
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- Xantphos-coordinated palladium dithiolates: Highly efficient catalyst for decarboxylative Sonogashira reaction into corresponding alkynes
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This work reports Xantphos-coordinated palladium dithiolate complexes as catalysts for decarboxylative Sonogashira coupling reaction of phenyl propiolic acid and 2-butynoic acid with various iodoarenes. These palladium aryl dithiolate complexes were synthesized and characterized by 1H and 31P nuclear magnetic resonance (NMR) spectroscopy, melting point, and elemental analysis (CHNS). Synthetic utility for the reported protocol is explored for the effect of various functional groups on the yield of corresponding heteroaryl alkynes. The current protocol showed excellent catalytic activity towards decarboxylative alkynylation reaction with high turn-over number (TON) up to 105 and turn-over frequency (TOF) up to 104 h?1. The catalyst could be recycled up to six recycles without losing its catalytic activity. The in situ generation of palladium nanoparticles (PdNPs) was observed after the third recycle, and the amount was significant after the sixth recycle, which were confirmed and characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray (EDX) analysis and high-resolution transmission electron microscopy (HR-TEM). The catalytic activity of the reaction is attributed to the formation of PdNPs.
- Lokolkar, Manjunath S.,Mane, Pravin A.,Dey, Sandip,Bhanage, Bhalchandra M.
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- Synthesis of a Cellulosic Pd(salen)-Type Catalytic Complex as a Green and Recyclable Catalyst for Cross-Coupling Reactions
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Abstract: A green recyclable cellulose-supported Pd(salen)-type catalyst was synthesized through sequential three steps: chlorination with thionyl chloride, modification by ethylenediamine, and the formation of Schiff base with salicylaldehyde to immobilize palladium chloride through multiple binding sites. This novel heterogeneous cellulosic Pd(salen)-type catalytic complex was fully characterized by FT-IR, SEM, TEM, XPS, ICP-AES and TG. The traditional cross-coupling chemistry, such as Suzuki, Heck, Sonogashira, Buchwald–Hartwig amination and etherification, was then investigated in the presence of the above cellulose-palladium nanoparticle. Studies have shown that the synthesized catalyst shows high activity and efficiency for all types of transformations, providing the corresponding carbon–carbon or carbon–heteroatom coupling products in a general and mild manner. Furthermore, the catalyst demonstrates high to excellent yields and is easily recycled by simple filtration for up to twelve cycles without any significant loss of catalytic activity. Graphic Abstract: [Figure not available: see fulltext.]
- Sun, Peng,Yang, Jiaojiao,Chen, Chunxia,Xie, Kaijun,Peng, Jinsong
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p. 2900 - 2910
(2020/03/31)
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- A Pd confined hierarchically conjugated covalent organic polymer for hydrogenation of nitroaromatics: Catalysis, kinetics, thermodynamics and mechanism
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Herein, we propose a fast and scalable synthesis of a triazine based hierarchically conjugated covalent organic polymer under solvent and additive free conditions through a single step process. The synthesized material CCTP (Cyanuric Chloride-Thiourea-Polymer) was thoroughly characterized by various physicochemical techniques. The CCTP exhibited regular sponginess and excellent chemical as well as thermal stability. The solvent and additive free approach for CCTP synthesis provides a sustainable alternative for classical solvothermal methods. The CCTP was immobilized with Pd (0) and subsequently a heterogeneous material Pd&at;CCTP was obtained, which was used as an efficient catalyst for the hydrogenation of nitroarenes. The rate constant and Ea were measured to be 2.08 × 10-2 s-1 and 15.67 kJ mol-1 respectively and thereafter other thermodynamic parameters like ΔH, ΔS and ΔG for the hydrogenation of p-nitrophenol were also calculated. The obtained results indicate that the catalytic hydrogenation of p-nitrophenol is a non-spontaneous and endothermic process. We have also investigated the effect of surfactants (NH4OH, FA, and N2) on the reaction performance, and consequently NH4OH and FA both slow down the reaction while N2 doesn't affect the reaction medium. Further, we calculated the rate constant for the hydrogenation of 2,4-dinitrophenol and 2,4,6-trinitrophenol. An array of nitroarenes were further reduced to extend the substrate scope at RT; high TOFs were observed. Besides, Pd&at;CCTP showed excellent reusability in hydrogenation reactions without evident performance falloff.
- Awasthi, Satish Kumar,Yadav, Deepika
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supporting information
p. 4295 - 4303
(2020/07/30)
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- A Pd NP-confined novel covalent organic polymer for catalytic applications
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A novel unsymmetrical covalent organic polymer, COP (1), was designed and characterized using several analytical and spectroscopic techniques. COP (1) was synthesized via the nucleophilic substitution reaction of 2,4,6-trichloro-1,3,5-triazine with p-amin
- Yadav, Deepika,Awasthi, Satish Kumar
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p. 1320 - 1325
(2020/02/04)
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- Monosubstituted, Anionic Imidazolyl Ligands from N?H NHC Precursors and Their Activity in Pd-Catalyzed Cross-Coupling Reactions
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We report that treatment of several 2-diphenylphosphinoimidazoles with Pd(II) salts generates monosubstituted N?H NHC?Pd complexes via insertion into the C?P bond. Removal of the N?H proton in situ leads to anionic (X-type) or imidazolyl-Pd complexes that are highly stable and catalytically active, achieving up to 340,000 turnovers at 1 ppm catalyst loading in Suzuki-Miyaura reactions. DFT-calculated Tolman electronic parameters for the sterically small ligands suggest that these ligands are significantly more donating than traditional NHCs, which provides a rationale for rapid cross-coupling catalysis. Excellent reactivity is also demonstrated in Sonogashira reactions. (Figure presented.).
- Clark, Kyle J.,Ess, Daniel H.,Jensen, Christopher A.,Kenney, Karissa C.,Larson, Alexandra J. S.,Martinez, Erin E.,Michaelis, David J.,Nazari, S. Hadi,Smith, Stacey J.,Valdivia-Berroeta, Gabriel A.
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supporting information
(2020/07/06)
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- A Study of Polarization and Directing Effects of Unsymmetrical Alkynes Using Regioselective Pd-Catalyzed Bromoallylation
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Herein is disclosed the first comprehensive study of factors that affect the regioselectivity of PdBr2(PhCN)2-catalyzed bromoallylation of unsymmetrically substituted internal alkynes. The study was performed on a wide array of electronically and structurally diverse alkynes with aryl-aryl, aryl-ferrocenyl, and aryl-alkyl substitutions. The regioselective formation of bromoallylation products was mostly driven by the polarization of the triple bond in aryl-aryl and aryl-ferrocenyl-substituted ethynes. On the other hand, directing effect, which arises from the presence of a directing group in the side-chain of aryl-alkyl-substituted alkynes, was the dominating factor that determined the regioselectivity of these reactions.
- Topolov?an, Nikola,Hara, Shuto,Císa?ová, Ivana,To?ner, Zdeněk,Kotora, Martin
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supporting information
p. 234 - 240
(2020/01/22)
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- A Co-Cu bimetallic magnetic nanocatalyst with synergistic and bifunctional performance for the base-free Suzuki, Sonogashira, and C-N cross-coupling reactions in water
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A novel magnetically recyclable bimetallic catalyst was prepared by anchoring imidazolium moiety and PEG chains on Fe3O4 NPs and named as Fe3O4?PEG/Cu-Co. It was found to be a powerful catalyst for the Sonogashira, Suzuki, and C-N cross-coupling reactions in water as a green solvent without the need for any external base. Fe3O4?PEG/Cu-Co was well characterized with FT-IR, FE-SEM, TEM, VSM, EDX, ICP, UV-visible, CV, and XPS analyses. Optimum ranges of parameters such as time, temperature, and amount of catalyst were investigated by Design-Expert 10.0.7 software for C-C Suzuki, Sonogashira, and C-N cross-coupling reactions to find the optimum conditions. The catalyst was compatible with a variety of aryl halides and N-arenes and gave favorable coupling products with good to high yields for all of them. Hot filtration and Hg poisoning tests involving the nanocatalyst revealed the stability, low metal leaching, and heterogeneous nature of the catalyst. Reaction mechanisms were proposed by study of the UV-visible spectra in situ as well as hydroquinone tests during the progress of reactions. In situ XPS analysis was also used to study the reaction mechanism. To prove the synergistic performance of Co and Cu in the catalyst, its various homologues were synthesized and applied to a model reaction separately, and then their catalytic activities were investigated. Finally, the catalyst could be recovered from the reaction mixture simply, and reused for several cycles with a minimum loss in catalytic activity and performance.
- Allahresani, Ali,Kazemnejadi, Milad,Nasseri, Mohammad Ali,Rezazadeh, Zinat
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p. 10645 - 10660
(2020/09/18)
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- Palladium(II) phthalocyanines efficiently promote phosphine-free Sonogashira cross-coupling reaction at room temperature
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Herein we report that exceptionally simple and inexpensive Pd(II) complexes of phthalocyanines efficiently catalyze direct formation of diphenylacetylenes at ambient conditions with low loading of catalyst (0.5 mol%). Results of this study demonstrate that terminal alkynes reacted mildly with p-substituted aryl bromides at room temperature under Pd and Cu-cocatalysis to give the corresponding phenylacetylenes in yields up to 98%. Also we have examined this catalyst in Sonogashira cross-coupling with aryl chlorides and it was very effective and this reaction at room temperature that there is no examples in recent articles. This protocol represents the first use of palladium phthalocyanine as homogeneous catalyst in the Pd/Cu-promoted Sonogashira reaction. The palladium(II) phthalocyanine complex is significantly more active in Sonogashira cross-coupling between aryl halides and terminal alkynes as compared with traditional catalysts because of absence of palladium black formation through agglomeration of metal particles and deactivation of catalyst.
- Platonova, Yana B.,Tomilova, Larisa G.,Volov, Alexander N.
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p. 224 - 228
(2020/09/17)
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- Nickel-Catalyzed Sonogashira C(sp)-C(sp2) Coupling through Visible-Light Sensitization
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An efficient method for visible-light-initiated, nickel-catalyzed Sonogashira C(sp)-C(sp2) coupling has been developed via an energy-transfer mode. Thioxanthen-9-one as a photosensitizer could significantly accelerate the arylation of alkynes with a wide
- Zhu, Da-Liang,Xu, Ruijie,Wu, Qi,Li, Hai-Yan,Lang, Jian-Ping,Li, Hong-Xi
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p. 9201 - 9212
(2020/08/14)
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- Palladium anchored on guanidine-terminated magnetic dendrimer (G3-Gu-Pd): An efficient nano-sized catalyst for phosphorous-free Mizoroki-Heck and copper-free Sonogashira couplings in water
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In this research, a novel type of Fe3O4&at;silica-supported dendrimer capped by guanidine groups for immobilization of palladium was reported. This novel nano-sized catalyst was characterized by FTIR, TGA, XRD, FESEM, EDX, VSM, XPS and HRTEM methods. Enhanced catalytic activity of the prepared catalyst in Mizoroki-Heck and copper-free Sonogashira coupling reactions were evaluated in water as a green solvent. The influence of the various reaction parameters such as catalyst dosage, time and temperature on two mentioned C–C coupling reactions were studied. Results showed that the catalyst could be easily recovered by simple separation by an external magnet and reused for five cycles of recovery without considerable losing of its activity.
- Khalafi-Nezhad, Ali,Moaddeli, Ali,Niknam, Esmaeil
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- Palladium(II) complexes containing sterically bulky O, N donor ligands: Synthesis, characterization and catalytic activity in the Suzuki-Miyaura and Sonogashira coupling reactions
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A new class of palladium(II)1-(arylazo)naphtholate complexes of the type [Pd(L1-4)2] containing sterically bulky O, N donor functionalized arylazo ligands has been synthesized. These palladium(II) complexes were characterized by elemental analysis and spectral (FT-IR, UV–Vis, 1H NMR and 13C NMR) studies. The molecular structure of the Palladium(II) complexes [Pd(L1)2] and [Pd(L2)2] were established by X-ray crystallography. These complexes were found to efficiently catalyze the Suzuki-Miyaura coupling of arylboronic acids and aryl halides, and the Sonogashira reaction of aryl halides and phenylacetylene in DMF and i-PrOH media to afford the corresponding C–C coupling products in high yields.
- Nandhini, Raja,Vijayan, Paranthaman,Venkatachalam, Galmari
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- Ni(acac)2/2,6-bis(diphenylphosphino)pyridine/CuI: A highly efficient palladium-free homogeneous catalyst for the Sonogashira cross-coupling reaction
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A highly efficient palladium-free homogeneous catalyst involving Ni(acac)2/2,6-bis(diphenylphosphino)pyridine ((Ph2P)2py)/CuI components was used for the Sonogashira cross-coupling reaction. The Sonogashira reaction was in
- Ataei, Ali,Daryanavard, Marzieh,Joshaghani, Mohammad,Rafiee, Ezzat
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- Gold(I)-Catalyzed Cross-Coupling Reactions of Arenediazonium Salts with Alkynoic Acids
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Abstract: The reaction of simple alkynoate salts with isolated arenediazonium tetrafluoroborate salts that had been pre-conditioned with the gold(I) catalyst AuCl(Me2S) led to the formation of cross-coupled products via a decarboxylative Sonogashira reaction process in modest yield and under mild conditions. The major by-product is a defunctionalized aryl moiety stemming from the diazonium salt, which competitively forms via hydrodediazonation. Good functional group tolerance and reaction site selectivity were attained in this limited investigation.
- Abrams, J. N.,Chi, B. K.
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p. 1236 - 1244
(2020/09/17)
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- Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes: Synthesis of unsymmetrical diarylethynes
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Palladium/copper-cocatalyzed decarbonylative alkynylation of acyl fluorides with alkynylsilanes is described. This reaction not only effectively inhibits the formation of undesired homocoupled products by avoiding the addition of a base, but also exhibits a wide substrate scope to provide a general access to diverse unsymmetrical diarylethynes.
- Chen, Qiang,Fu, Liyan,Nishihara, Yasushi
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supporting information
p. 7977 - 7980
(2020/09/09)
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- Internal alkyne derivative and preparation method thereof
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The invention belongs to the technical field of organic synthesis, and in particular relates to an internal alkyne derivative and a preparation method thereof. The first aspect of the application provides the internal alkyne derivative, wherein the struct
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Paragraph 0068-0073
(2020/01/25)
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- A BODIPY-functionalized PdII photoredox catalyst for Sonogashira C-C cross-coupling reactions
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We report for the first time a BODIPY-functionalized dichloro(1,10-phenanthroline)palladium(ii) complex as an efficient photoredox catalyst for the Sonogashira C-C cross-coupling between phenylacetylene derivatives and iodobenzene derivatives with yields
- Dissanayake, Komadhie C.,Ebukuyo, Peters O.,Dhahir, Yasser J.,Wheeler, Kraig,He, Hongshan
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p. 4973 - 4976
(2019/05/21)
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- Porous organic polymer with: In situ generated palladium nanoparticles as a phase-transfer catalyst for Sonogashira cross-coupling reaction in water
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A new Pd nanoparticle loaded and imidazolium-ionic liquid decorated organic polymer of Pd@PTC-POP was readily fabricated via a Pd(PPh3)4 catalysed in situ one-pot Suzuki cross-coupling reaction between imidazolium attached dibromoben
- Dong, Ying,Chen, Yun-Qi,Jv, Jing-Jing,Li, Yue,Li, Wen-Han,Dong, Yu-Bin
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p. 21671 - 21678
(2019/07/30)
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- Conjugated mesoporous polyazobenzene–Pd(II) composite: A potential catalyst for visible-light-induced Sonogashira coupling
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We herein report the direct harnessing of visible light energy by a novel semiconducting azobenzene-based colloidal porous organic polymer, B3-Azo4 amenable to post-synthetic Pd(II)-complexation for photo-induced Sonogashira coupling using polymer → metal energy transfer process. Completely mesoporous nano-sized particles of the obtained organic network manifested excellent Pd(II) coordinating ability and afforded desired catalytic products at room temperature under aerobic condition in aqueous medium. The protocol remained valid for different aromatic and aliphatic substrates as well. A possible reaction mechanism for photo-mediated Sonogashira coupling catalyzed by Pd-B3-Azo4 is also proposed.
- Nath, Ipsita,Chakraborty, Jeet,Khan, Anish,Arshad, Muhammad N.,Azum, Naved,Rab, Malik A.,Asiri, Abdullah M.,Alamry, Khalid A.,Verpoort, Francis
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p. 183 - 189
(2019/08/07)
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- Functionalized graphene oxide anchored to Ni complex as an effective recyclable heterogeneous catalyst for Sonogashira coupling reactions
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The Sonogashira cross coupling reaction is an applied method for preparation of diarylethyne compounds from readily available aryl halide derivatives and phenyl acetylene. The coupling reaction using nickel complex of N,N′-Bis(2-hydroxyethyl)ethylenediami
- Naeimi, Hossein,Kiani, Fatemeh
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- Rate Enhancement in CAN-Promoted Pd(PPh3)2Cl2-Catalyzed Oxidative Cyclization: Synthesis of 2-Ketofuran-4-carboxylate Esters
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Stoichiometric ceric ammonium nitrate (CAN) and a catalytic amount of Pd(PPh3)2Cl2 (5 mol %) can rapidly produce multisubstituted 2-ketofuran-4-carboxylate esters from 2-propargylic 1,3-ketoesters via oxidative O-cyclization reaction. Pd(PPh3)2Cl2 was found to be the crucial catalyst as its inclusion greatly enhanced the rate of the reaction and cleanly afforded the products within minutes. Over 30 substrates were successfully converted to the desired compounds in mostly moderate to good yields.
- Ruengsangtongkul, Sureeporn,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
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supporting information
p. 2514 - 2517
(2019/04/30)
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- Enhanced catalytic activity of CuI/diethoxyphosphoryl-1,10-phenanthrolines in ‘on water’ Cu-catalyzed Sonogashira reaction
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The use of CuI/diethoxyphosphoryl-1,10-phenanthrolines and ‘on water’ conditions in the Cu-catalyzed Sonogashira reaction of aryl iodides with terminal alkynes significantly increases the reaction rate as compared to that in organic solvents.
- Mitrofanov, Alexander Yu.,Beletskaya, Irina P.
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p. 378 - 379
(2019/08/16)
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- Synthesis and characterization of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd magnetic nanoparticles: A new and highly active catalyst for the Heck/Sonogashira coupling reactions
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In this research, the synthesis and characterization of a novel catalyst is reported based on the preparation of the Pd complex of (pyridin-2-ylmethyl)dithiocarbamate (PDTC) supported on γ-Fe2O3@SiO2 magnetic nanoparticles (γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd). The catalyst is characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, inductively coupled plasma analysis, X-ray powder diffraction, X-ray photoelectron spectroscopy, and vibrating-sample magnetometer measurements. The catalytic performance of γ-Fe2O3@SiO2-(CH2)3-PDTC-Pd was evaluated in the Heck/Sonogashira coupling reactions of various aryl halides with various alkenes/phenylacetylene in water. The synthesized nanocatalyst showed a high catalytic activity even in very small amounts (5 mg, less than 0.1 mol%), was easily separated using magnetic decantation and was reused for ten cycles without any appreciable loss of its reactivity.
- Tashrifi, Zahra,Bahadorikhalili, Saeed,Lijan, Hossein,Ansari, Samira,Hamedifar, Haleh,Mahdavi, Mohammad
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p. 8930 - 8938
(2019/06/17)
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- Dihalogen-bridged NHC-palladium(i) dimers: Synthesis, characterisation and applications in cross-coupling reactions
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A di-iodo-bridged PdI dimer bearing an N-heterocyclic carbene ligand was made accessible via the reduction of [(IPr)PdI2]2 in basic methanol solution. The structural features of [(IPr)PdI]2 were explored by single-crystal X-ray analysis. It was found to be a convenient one-component precatalyst with high activity in Suzuki-Miyaura, Buchwald-Hartwig, and Sonogashira reactions.
- Pirkl, Nico,Del Grosso, Alessandro,Mallick, Bert,Doppiu, Angelino,Goo?en, Lukas J.
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supporting information
p. 5275 - 5278
(2019/05/08)
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- Imidazolium chloride-Co(iii) complex immobilized on Fe3O4@SiO2 as a highly active bifunctional nanocatalyst for the copper-, phosphine-, and base-free Heck and Sonogashira reactions
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A heterogeneous, magnetically recoverable Fe3O4@SiO2@Im[Cl]Co(iii)-melamine nanocomposite was prepared by immobilization of a novel Co(iii) Schiff base complex on Fe3O4@SiO2 nanoparticles followed by treatment with melamine, and was found to be an efficient catalyst for the Heck and Sonogashira reactions. The reactions were performed in the presence of the catalyst (0.5 mol% Co) along with Mn additive in the absence of any base, phosphine ligand, or Cu/co-catalyst in ethanol under reflux conditions. The nanocatalyst was well studied by FTIR, CHN, XRD, XPS, TGA, EDX, VSM, ICP, NMR, FE-SEM, TEM, BET, CV, and DLS analyses. The catalyst was compatible with a variety of substrates, with which all the Heck and Sonogashira coupling products were obtained in high to excellent yields. Also, protocols such as hot filtration, three-phase testing, and mercury poisoning provided a complete insight into the nature of the heterogeneous catalyst. The recycling and reuse of the catalyst were studied for both coupling reactions several times. Moreover, the mechanism of the coupling reactions was entirely investigated.
- Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh G.,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
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p. 1718 - 1734
(2019/04/08)
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- Arylation of Terminal Alkynes by Aryl Iodides Catalyzed by a Parts-per-Million Loading of Palladium Acetate
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Arylation of terminal alkynes (16 varieties) by aryl iodides (28 varieties) was achieved with a mol ppm loading level of palladium catalyst, where a variety of functional groups including heteroarenes were tolerated. Thus, the arylations were carried out in the presence of palladium acetate at ppm loadings and potassium carbonate in ethanol at 80 °C to give the corresponding internal alkynes in good to excellent yields. Synthesis of 2-phenyl-3-(phenylalkynyl)benzofuran was achieved by iterative use of the alkyne arylation under mol ppm catalytic conditions. Reaction-rate analysis, transmission electron microscopic (TEM) examination of the reaction mixture, and mercury-amalgamation test were performed to gain insight into the active species of the highly active ppm catalytic species. TEM examination of the reaction mixture revealed that palladium nanoparticles were generated in situ under the reaction conditions, and their cluster size was variable during the catalytic reaction. A variation in size of palladium particles suggested that the composition-decomposition process of Pd aggregates should take place in situ via monomeric palladium(0) species and/or fine palladium(0) clusters, which might be real catalytic species in this reaction.
- Hamasaka, Go,Roy, David,Tazawa, Aya,Uozumi, Yasuhiro
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p. 11640 - 11646
(2019/12/02)
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- Sequentially Pd/Cu-Catalyzed Alkynylation-Oxidation Synthesis of 1,2-Diketones and Consecutive One-Pot Generation of Quinoxalines
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We report a simple and efficient one-pot synthesis of 1,2-diketones by concatenation of two Pd/Cu-catalyzed processes: Pd0/CuI-catalyzed Sonogashira coupling of terminal alkynes with aryl (pseudo)halides furnishes internal alkynes, which are directly transformed by PdII/CuII-catalyzed Wacker-type oxidation with DMSO and oxygen as dual oxidants to furnish 1,2-diketones. With this efficient, catalyst economical process, various aryl iodides and triflates are efficiently transformed in high yields into symmetrically and unsymmetrically substituted 1,2-diketones with various functional groups. This process can be readily extended to a consecutive one-pot synthesis of quinoxalines in a diversity-oriented fashion.
- Niesobski, Patrik,Martínez, Ivette Santana,Kustosz, Sebastian,Müller, Thomas J. J.
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supporting information
p. 5214 - 5218
(2019/07/31)
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- Benzimidazolyl Palladium Complexes as Highly Active and General Bifunctional Catalysts in Sustainable Cross-Coupling Reactions
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A family of air- A nd moisture-stable dinuclear palladium complexes bearing 2-benzimidazolyl ligands is reported and shown to be a highly effective and general catalytic platform in diverse cross-coupling reactions. The rigidity and conformation of the ligand scaffold was readily modified via tethering of the 2-benzimidazolyl moiety to diamine ligands, resulting in significant changes in catalytic activity. Under optimal conditions, Suzuki, Heck, and Sonogashira-type couplings of aryl bromides can all be performed efficiently with good functional group compatibility using only 0.1 mola?% of catalyst, in aqueous or alcohol solvents. Experimental evidence highlights the importance of the bifunctional character of the ligand for catalytic activity, where the basic N-functionality in the ligand framework is proposed to accelerate (trans)metalation steps via intramolecular assistance.
- Zhu, Jiancheng,Lindsay, Vincent N. G.
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p. 6993 - 6998
(2019/08/26)
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- Magnetic Cu–Schiff base complex with an ionic tail as a recyclable bifunctional catalyst for base/Pd-free Sonogashira coupling reaction
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Abstract: A Cu(II)–Schiff base complex containing imidazolium ionic phase was prepared and decorated on γ-Fe2O3 magnetic nanoparticles (γ-Fe2O3@Cu(II)IL-SB) and found to be an efficient catalyst for the Pd- and base-free Sonogashira coupling reaction. The heterogeneous catalyst was characterized by FTIR spectroscopy, UV–visible spectroscopy, FE-SEM, TEM, XRD spectroscopy, EDX spectroscopy, VSM, ICP spectroscopy, and atomic absorption spectroscopy. The coupling reactions were performed using the catalyst under mild and base-free conditions, and high-to-excellent yields were obtained for a variety of substrates. The catalyst demonstrates a dual-functionality arising from metal sites and imidazolium moieties and that the later plays a base role. Reusability and stability of γ-Fe2O3@Cu(II)IL-SB were studied several times, which can be reused up to eight consecutive runs with at least reduction in catalytic activity. Also, the mechanism of this bifunctional catalytic system was thoroughly investigated. Graphic abstract: A new and efficient method has been developed for the base- and Pd-free Sonogashira cross-coupling reactions of aryl halides with phenyl acetylene using a bifunctional γ-Fe2O3@Cu(II)IL-SB catalyst with imidazolium moiety under mild conditions[Figure not available: see fulltext.].
- Nasseri, Mohammad Ali,Rezazadeh, Zinat,Kazemnejadi, Milad,Allahresani, Ali
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p. 2693 - 2705
(2019/07/23)
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- Green, cost-effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active, durable and reusable catalyst
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A novel heterogenized organometallic catalyst was synthesized by coordinating palladium with polyvinyl alcohol-functionalized Fe3O4@SiO2 nanospheres. This novel catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscope, field emission scanning electron microscope, dynamic light scattering, UV–vis spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, thermogravimetric analysis and inductively coupled plasma analysis. The prepared palladium nanoparticles supported on polyvinyl alcohol functionalized Fe3O4@SiO2 nanoparticles were successfully applied as a magnetically recyclable catalyst in Heck and Sonogashira coupling reactions in water. They showed remarkable activity toward aryl halides (I, Br, Cl) using very low palladium loading in excellent yields and demonstrated high TONs (mmol of product per mmol of catalyst). Also, the catalyst could be magnetically separated and reused seven times without any appreciable loss of catalytic activity.
- Sardarian, Ali Reza,Eslahi, Hassan,Esmaeilpour, Mohsen
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- The CuFe2O4@SiO2@ZrO2/SO42-/Cu nanoparticles: An efficient magnetically recyclable multifunctional Lewis/Br?nsted acid nanocatalyst for the ligand- and Pd-free Sonogashira cross-coupling reaction in water
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Herein, the synthesis and application of copper-incorporated sulfated zirconium oxide supported on CuFe2O4 NPs (CuFe2O4@SiO2@ZrO2/SO42-/Cu NPs) as a novel Lewis/Br?nsted acid nanocatalyst were studied for the Sonogashira C-C cross-coupling reaction. The fabricated CuFe2O4@SiO2@ZrO2/SO42-/Cu catalyst exhibited efficient activity for a large variety of aryl iodides/bromides and, most importantly, aryl chlorides in water and in the presence of NaOH as a base in short reaction times. The catalyst was fully characterized by FTIR, TG-DTG, VSM, XRD, EDX, FE-SEM and TEM analyses. A synergetic effect could be considered to have arisen from the various Lewis acid and Br?nsted acid sites present in the catalyst. The efficient incorporation of copper into zirconia provided a robust highly stable hybrid, which prevented any metal leaching, whether from the magnetite moiety and/or Cu sites in the reaction mixture. Moreover, the catalyst was successfully recovered from the mixture by a simple external magnet and reused for at least 9 consecutive runs. Zero metal leaching, stability, consistency with a variety of substrates, fast performance, cost-effectiveness, environmental friendliness, and preparation with accessible and cheap materials are some of the advantages and highlights of the current protocol.
- Nasseri, Mohammad Ali,Alavi, Seyyedeh Ameneh,Kazemnejadi, Milad,Allahresani, Ali
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p. 20749 - 20759
(2019/07/12)
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- Gold-Catalyzed Oxidation of Internal Alkynes into Benzils and its Application for One-Pot Synthesis of Five-, Six-, and Seven-Membered Azaheterocycles
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Internal alkynes have been shown to undergo oxidation to substituted benzils (1,2-diarylethane-1,2-diones) by α-picoline N-oxide in the presence of Ph3PAuNТf2 (5 mol-%). In addition to the unsubstituted benzil, the method allows preparing, under markedly mild conditions (50 °C in chlorobenzene), various non-symmetrical products, including heteroaromatic versions thereof which are much more difficult to obtain otherwise. This gold(I)-catalyzed transformation was integrated into one-pot reaction sequence delivering a range of 5- to 7-membered ring systems (imidazoles, quinoxalines, 1,2,4-triazines, pyrazines, and 1,4-diazepines), thus linking these important heterocyclic motifs to the internal alkyne reagent space.
- Dubovtsev, Alexey Yu.,Dar'in, Dmitry V.,Krasavin, Mikhail,Kukushkin, Vadim Yu.
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supporting information
p. 1856 - 1864
(2019/02/19)
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- Preparation method of aryl alkyne catalyzed by visible light
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The invention discloses a simple and convenient method for directly synthesizing an aryl alkyne compound through photoredox catalysis. Aryl fluoroborate diazoate is used as an aryl free radical source, and different types of aryl alkyne are synthesized in situ through a decarboxylation process. A reaction has good functional group tolerability, and a simple domestic visible light source can be used for synthesizing the aryl alkyne of different functional groups under mild, neutral and transition-free metal reaction conditions.
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Paragraph 0050-0053
(2019/11/13)
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- Visible Light-Catalyzed Decarboxylative Alkynylation of Arenediazonium Salts with Alkynyl Carboxylic Acids: Direct Access to Aryl Alkynes by Organic Photoredox Catalysis
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A convenient method mediated by photoredox catalysis is developed for the direct construction of aryl alkynes. Readily available aromatic diazonium salts have been utilized as the aryl radical source to couple alkynyl carboxylic acids to feature the decarboxylative arylation. A wide range of substrates are amenable to this protocol with broad functional group tolerance, and diversely-functionalized aryl alkynes could be synthesized under mild, neutral and transition metal-free reaction conditions using visible light irradiation. Alongside synthetic sustainability associated with the photocatalytic and transition metal-free operation, another key point of this method is that the organic dye catalyst acts as an excited-state reductant, thus establishing the quenching cycle for radical addition and decarboxylative elimination. (Figure presented.).
- Yang, Liangfeng,Li, Haifeng,Du, Yijun,Cheng, Kai,Qi, Chenze
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p. 5030 - 5041
(2019/11/03)
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- Involving Single-Atom Silver(0) in Selective Dehalogenation by AgF under Visible-Light Irradiation
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The dehalogenation-arylation and the hydrodehalogenation of various types of organic halides are selectively realized using AgF and visible light without any organic additives under mild conditions. Single-atom silver(0) (denoted as SAAg) serves as the catalytically active center, and the TOF of SAAg reaches 6000 h-1. This elusive activity of Ag is beyond that expected from its ionic, nano, or bulk forms.
- Wu, Wenli,Cui, Enxin,Zhang, Yun,Zhang, Chen,Zhu, Feng,Tung, Chen-Ho,Wang, Yifeng
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p. 6335 - 6341
(2019/07/04)
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- Cobalt catalyzed stereodivergent semi-hydrogenation of alkynes using H2O as the hydrogen source
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Cobalt-catalyzed stereodivergent semi-hydrogenation of internal alkynes to alkenes is developed. The reaction proceeded through transfer hydrogenation under mild conditions using a base metal CoI2 as the catalyst, and H2O/MeOH as the hydrogen source with Zn as the reductant. The E/Z-selectivity of the product could be switched by changing the solvent and by inclusion/exclusion of a bidentate phosphine ligand (dppe). This method provides a simple and cost effective pathway for the synthesis of 1,2-dideuterioalkenes.
- Li, Kangkui,Khan, Ruhima,Zhang, Xuexin,Gao, Yang,Zhou, Yongyun,Tan, Heng,Chen, Jingchao,Fan, Baomin
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supporting information
p. 5663 - 5666
(2019/05/21)
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- Facile Access to Diverse Libraries of Internal Alkynes via Sequential Iododediazoniation/Decarboxylative Sonogashira Reaction in Imidazolium ILs without Ligand or Additive
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Convenient access to diverse libraries of internal alkynes via decarboxylative Sonogashira reaction of alkynyl-carboxylic acids with iodoarenes, employing imidazolium-ILs as solvent, along with piperidine-appended imidazolium [PAIM][NTf2] as task-specific basic IL is demonstrated, without the need for any ligand or additive. The feasibility to perform these reactions by sequential one-pot iododediazoniation/decarboxylative Sonogashira reaction is also shown, and the scope of the methods is underscored by providing 29 examples. The potential for recycling and reuse of the IL solvent is also examined.
- Prabhala, Pavankumar,Savanur, Hemantkumar M.,Kalkhambkar, Rajesh G.,Laali, Kenneth K.
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p. 2061 - 2064
(2019/03/07)
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- SO2F2-Mediated Oxidative Dehydrogenation and Dehydration of Alcohols to Alkynes
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Direct synthesis of alkynes from inexpensive, abundant alcohols was achieved in high yields (greater than 40 examples, up to 95% yield) through a SO2F2-promoted dehydration and dehydrogenation process. This straightforward transformation of sp3-sp3 (C-C) bonds to sp-sp (C=C) bonds requires only inexpensive and readily available reagents (no transition metals) under mild conditions. The crude alkynes are sufficiently free of impurities to permit direct use in further transformations, as illustrated by regioselective Huisgen alkyne-azide cycloaddition reactions with PhN3 to give 1,4-substituted 1,2,3-traiazoles (16 examples, up to 92% yield) and Sonogashira couplings (10 examples, up to 77% yield).
- Zha, Gao-Feng,Fang, Wan-Yin,Li, You-Gui,Leng, Jing,Chen, Xing,Qin, Hua-Li
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supporting information
p. 17666 - 17673
(2019/01/04)
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- Recyclable cellulose-palladium nanoparticles for clean cross-coupling chemistry
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Cheap, recyclable, and robust cellulose-palladium nanoparticles were developed and fully characterized by FTIR, TEM, XPS, TGA, and NMR. The nanoparticles enabled cross-coupling chemistry in a truly general fashion i.e., Suzuki-Miyaura, Heck, Sonogashira, and C-H activation. Notably, all types of transformations were achieved with a single type of nanocatalyst. Complete recyclability of the catalyst and low traces of palladium in the product demonstrates the greenness of the protocol.
- Lu, Zhichao,Jasinski, Jacek B.,Handa, Sachin,Hammond, Gerald B.
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supporting information
p. 2748 - 2752
(2018/04/27)
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- Novel oxime-palladacycle supported on clay composite as an efficient heterogeneous catalyst for Sonogashira reaction
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A novel supported catalyst formed by an oxime-derived palladacycle supported on clay OxPdCy@clay is synthesized and characterized. This palladium composite promotes the Sonogashira reaction of aryl iodides, bromides and chlorides with terminal alkynes in polyethylene glycol200 at 85 or 130 °C using 0.05–0.1 mol% of palladium loading under copper and phosphine free conditions. This supported palladacycle, OxPdCy@clay, showed a superior catalytic activity than dimeric oxime-palladacycles. Mechanistic studies about the heterogeneous or homogeneous nature of the catalyst show that catalyst is working mainly under heterogeneous conditions. This supported palladacycle OxPdCy@clay can be recycled by simple centrifugation and reused for at least nine consecutive runs with small decrease in activity.
- Gholinejad, Mohammad,Dasvarz, Neda,Nájera, Carmen
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p. 262 - 270
(2018/09/06)
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