- Palladium-catalyzed decarboxylative coupling reaction with alkynyl carboxylic acids and arylsiloxanes
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A decarboxylative coupling reaction for alkynyl carboxylic acids and arylsiloxanes was developed using a palladium catalyst. This method provided the desired coupled products in moderate to good yields by reacting the alkynyl carboxylic acids and arylsiloxanes with Pd(dba)2(1.0?mol?%), 1,1-bis(diphenylphosphino)methane (1.0?mol?%), and AgF2(2.0?equiv) at 60?°C for 6?h.
- Jang, Jisun,Raja, Gabriel Charles Edwin,Lee, Ju-Hyeon,Son, Yujeong,Kim, Jimin,Lee, Sunwoo
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- Sonogashira reactions catalyzed by a new and efficient copper(I) catalyst incorporating N-benzyl DABCO chloride
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A new and effective catalytic system using [N-benzyl DABCO] +[Cu4Cl5]- was developed for the palladium-free Sonogashira cross-coupling reactions of phenylacetylene with a variety of aryl halides. In this homogeneous catalytic system, 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride, a quaternary ammonium salt containing a coordinating center, plays an important role and increases the efficiency of Cu(I) species during the reaction. A number of internal alkynes were produced in moderate to excellent yields, in short reaction times in DMF at 135 °C.
- Hajipour, Abdol R.,Mohammadsaleh, Fatemeh
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- Aggregates of a hetero-oligophenylene derivative as reactors for the generation of palladium nanoparticles: a potential catalyst in the Sonogashira coupling reaction under aerial conditions
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The utilization of Pd nanoparticles stabilized by aggregates of hetero-oligophenylene derivative 3 as an excellent catalyst in a copper/amine free Sonogashira coupling reaction under aerial conditions at room temperature has been demonstrated.
- Walia, Preet Kamal,Pramanik, Subhamay,Bhalla, Vandana,Kumar, Manoj
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- Ligand-free palladium-catalyzed decarboxylative coupling reactions of aryl iodides and alkynyl carboxylic acids
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Pd-CNT nanocomposite was prepared from the composite of thiolated MWNT and Na2PdCl4. The palladium nanoparticles possess an average diameter of 2.9 nm with a narrow size distribution for the Pd-CNT. This Pd-CNT showed good activities in the coupling reactions of aryl iodides and aryl alkynyl carboxylic acids to produce the diaryl alkynes in good yields without any additional ligand.
- Pyo, Ayoung,Kim, Ji Dang,Choi, Hyun Chul,Lee, Sunwoo
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- Copper(I) complexes of 2-(benzen-1-yl)methyleneamino-3-aminomaleonitrile and triphenylphosphine ligands: synthesis, characterization, luminescence and catalytic properties
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Some mixed ligand copper(I) complexes of general formula [Cu(L)(PPh3)3]X (X?=?Cl (1), ClO4 (2), BF4 (3) or PF6 (4); L?=?2-(benzen-1-yl)methyleneamino-3-aminomaleonitrile) were prepared and characterized by physicochemical and spectroscopic methods. A single-crystal X-ray diffraction study of [Cu(L)(PPh3)3]CIO4 (2) revealed that the copper atom is four coordinated in a distorted tetrahedral geometry. Electrochemical studies of complexes 1–4 show quasireversible redox behavior corresponding to the Cu(I)/Cu(II) couple. Room temperature luminescence is observed for all four complexes. These complexes proved to be effective catalysts for the Sonogashira coupling of terminal alkynes with aryl halides at 90?°C.
- Devkule,Chavan
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- Synthesis and spectral properties of novel iminophosphoranes
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Three new iminophosphoranes coded as FPZ1 (Ph–C≡C–C6H4–N = PPh3), FPZ2 (Ph–N = P(C6H4–C≡C–Ph)3) and FPZ3 (Ph–C≡C–C6H4–N = P(C6H4–C≡C–Ph)3) were designed and synthesized by introducing different numbers of phenylene acetylene units to FPZ0 (Ph–N = PPh3). The effect of structural modification was studied in detail analyzing the absorption spectra, the emission spectra, and the distributions of the electron density. The absorption spectra of the new iminophosphoranes are shown to be a linear combination of the spectra of each part by the artificial combinatorial absorption spectrum, which coincides with the real one. Most probably the individual parts can’t conjugate due to the tetrahedral structure. The probably formed excimer of FPZ0 and FPZ1 causes in their solid emission spectra an obvious bathochromic shift as compared to that of FPZ2 and FPZ3. The melting point data also showed that long branches of FPZ2 and FPZ3 will attenuate the interactions between the molecules. The results of quantum chemical calculations show that the electronic density in the HOMO of FPZ1, FPZ2, and FPZ3 is delocalized over the iminoaryl moieties. The electron density in the LUMO is delocalized over the triaryl phosphine moieties, but only concentrated on two branches, which directly determines the main direction of intramolecular charge transfer.
- Fang, Jing-Kun,Xu, Zhimin,Sun, Tengxiao,Fang, Yu,Yin, Zhengxi,Wang, Shijun
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- Synthesis and optical properties of cationic cyclopentadienyl iron complexes with diphenylacetylene chromophores
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Cationic cyclopentadienyl iron complexes of arenes are applied in photopolymerization and photocatalysis because of their good photophysical and photochemical properties. In this study, a series of cationic cyclopentadienyl iron complexes with diphenylace
- Shi, Yizhong,Li, Guanglei,Zhao, Baodong,Chen, Yu,Chao, Pengjie,Zhang, Huiqing,Wang, Xiaoning,Wang, Tao
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- Pd(II)–acylthiourea complex and its immobilized counterpart catalyzed condensation of phenylacetylene with aryl halides
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New Pd(II) complex, trans-[PdCl2L2] (1) (L = N-carbamothioylthiophene-2-carboxamide), was prepared and characterized. Its heterogeneous counterpart, trans-[PdCl2(L-SNPs)2] (2) (L-SNPs = ligand immobilized on silica nanoparticles), was also prepared through covalent modification of the ligand using silica nanoparticles and characterized. Both 1 and 2 were exploited for their catalytic activity towards condensation of phenylacetylene with aryl halides. The complexes exhibited good activity when aryl halide bears I? or Br? group. Further, catalyst 2 can be reused for four cycles.
- Sindhuja,Vasanthakumar,Karvembu
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- Synthesis of internal alkynes by Pd(PPh3)4/TMEDA-catalyzed Kumada cross-coupling of alkynyl halides with grignard reagents
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Alkynes serve as prevalent intermediates in the synthesis of natural products and pharmaceuticals. We here described a new and efficient route to internal alkynes by Pd-catalyzed Kumada cross-coupling reactions of alkynyl halides with Grignard reagents. In the presence of Pd(PPh3)4 and N 1,N 1,N 2,N 2-tetramethylethane-1,2-diamine (TMEDA), a variety of alkynyl halides underwent Kumada coupling with Grignard reagents, giving the corresponding internal alkynes in moderate to good yields. A new Pd-catalyzed Kumada cross-coupling reaction of alkynyl halides with Grignard reagents has been developed. This transformation provides a new, experimentally simple access to internal alkynes in good yields, and it can accommodate a broad range of substrates with excellent functional group tolerance and good levels of selectivity control.
- Zhang, Mao-Mei,Gong, Jun,Song, Ren-Jie,Li, Jin-Heng
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- DNA-Decorated, Helically Twisted Nanoribbons: A Scaffold for the Fabrication of One-Dimensional, Chiral, Plasmonic Nanostructures
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Crafting of chiral plasmonic nanostructures is extremely important and challenging. DNA-directed organization of nanoparticle on a chiral template is the most appealing strategy for this purpose. Herein, we report a supramolecular approach for the design of DNA-decorated, helically twisted nanoribbons through the amphiphilicity-driven self-assembly of a new class of amphiphiles derived from DNA and hexaphenylbenzene (HPB). The ribbons are self-assembled in a lamellar fashion through the hydrophobic interactions of HPB. The transfer of molecular chirality of ssDNA into the HPB core results in the bias of one of the chiral propeller conformations for HPB and induces a helical twist into the lamellar packing, and leads to the formation of DNA-wrapped nanoribbons with M-helicity. The potential of the ribbon to act as a reversible template for the 1D chiral organization of plasmonic nanomaterials through DNA hybridization is demonstrated.
- Golla, Murali,Albert, Shine K.,Atchimnaidu, Siriki,Perumal, Devanathan,Krishnan, Nithiyanandan,Varghese, Reji
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- A hexaphenylbenzene based AIEE active probe for the preparation of ferromagnetic α-Fe2O3 nanoparticles: Facile synthesis and catalytic applications
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Fluorescent aggregates formed by self-assembly of a hexaphenylbenzene based derivative 3 serve as a reactor and a stabilizer for the formation of ferromagnetic iron oxide (α-Fe2O3) nanoparticles in aqueous medium at room temperature. These α-Fe2O3 nanoparticles showed excellent catalytic activity in palladium, copper and amine free Sonogashira cross coupling reactions and also in photocatalytic degradation of rhodamine B dye.
- Pramanik, Subhamay,Bhalla, Vandana,Kumar, Manoj
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- An efficient and recyclable magnetic-nanoparticle-supported palladium catalyst for the suzuki coupling reactions of organoboronic acids with alkynyl bromides
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A highly active, air- and moisture-stable and easily recoverable magnetic-nanoparticle-supported palladium catalyst has been developed for the Suzuki cross-coupling reaction of organoboron derivatives with alkynyl bromides. In the presence of palladium catalyst (0.5 mol%), organoboron derivatives including aromatic and aliphatic boronic acids, potassium aryltrifluoroborates, and sodium tetraphenylborate reacted smoothly with 1-bromo-2-substituted acetylenes to generate the corresponding cross-coupling products in good to excellent yields in ethanol. In addition, it is possible to recover and reuse the supported palladium catalyst at least 16 times without significant loss of its catalytic activity. Georg Thieme Verlag Stuttgart - New York.
- Zhang, Xiuli,Li, Pinhua,Ji, Yong,Zhang, Lei,Wang, Lei
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- Green synthesis of Pd/Fe3O4 nanoparticles using Euphorbia condylocarpa M. bieb root extract and their catalytic applications as magnetically recoverable and stable recyclable catalysts for the phosphine-free Sonogashira and Suzuki co
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This work reports on the green synthesis of Pd/Fe3O4 nanoparticles using Euphorbia condylocarpa M. biebroot extract as reducing agents and stabilizers and their catalytic applications in ligand- and copper-free Sonogashira and Suzuki
- Nasrollahzadeh, Mahmoud,Mohammad Sajadi,Rostami-Vartooni, Akbar,Khalaj, Mehdi
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- DABCO-functionalized silica-copper(i) complex: A novel and recyclable heterogeneous nanocatalyst for palladium-free Sonogashira cross-coupling reactions
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A DABCO-functionalized silica supported copper(i)-based nanocatalyst was successfully prepared using a novel and simple route, in which the DABCO as an important functional entity acts as both a stable linker and an excellent chelator. Initially, Cu(ii) i
- Hajipour, Abdol Reza,Hosseini, Seyed Mostafa,Mohammadsaleh, Fatemeh
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- Synthesis, characterization, and nonlinear optical (NLO) properties of truxene-cored diphenylamine derivatives
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Three star-shaped compounds based on a truxene core (FS11, FS12 and FS13) were prepared. The truxene core is incorporating with asymmetric diphenylamines, including one phenyl of diphenylamine substituted by methoxy group and the other phenyl substituted by tolyl, fluorophenyl and phenylethynyl for FS11, FS12 and FS13, respectively. Their one-photon, two-photon absorption, geometric structures, electrochemical behavior and thermal properties were investigated. The absorption maxima of charge transfer band for FS11, FS12 and FS13 are 375?nm, 373?nm and 383?nm, and the corresponding molar extinction coefficients of FS11, FS12 and FS13 is 79,950?M??1?cm??1, 67,220?M??1?cm??1 and 108,780?M??1?cm??1. The “pull-push” structure promotes charge transfer between asymmetric diphenylamine branches and the truxene core. Their two-photon absorbtion property is measured by two-photon induced fluorescence. The maximum two-photon cross-sections values of FS11, FS12 and FS13 are excited at 750?nm, which are 260 GM, 204GM and 367 GM, respectively.
- Li, Fusheng,Zhao, Baodong,Chen, Yu,Zhang, Yufei,Wang, Tao,Xue, Song
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- Microwave irradiated solventless Sonogashira reaction on nickel(0) powder doped KF/Al2O3
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A microwave irradiated solventless Sonogashira coupling reaction catalyzed by nanosize nickel(0) powder on potassium fluoride-alumina mixture has been developed. Terminal alkynes couple with aryl, alkenyl iodide, and aryl bromide in the presence of cuprou
- Wang, Min,Li, Pinhua,Wang, Lei
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- Palladium Niacin Complex Immobilized on Starch-Coated Maghemite Nanoparticles as an Efficient Homo- and Cross-coupling Catalyst for the Synthesis of Symmetrical and Unsymmetrical Biaryls
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Abstract: In this work, catalytic efficiency of palladium niacin complex immobilized on starch-coated maghemite nanoparticles successfully exploited for homo- and cross-coupling reactions such as Suzuki–Miyaura, Sonogashira-, and Ullmann coupling reactions. The solid catalyst characterized by different methods such as FT-IR, TGA, XPS, EDS and ICP-AES. TEM images revealed a nanosize structure for catalyst and vibrating sample magnetometer (VSM) demonstrated its magnetic property. The reactions proceeded well in the absence of commonly used additives with high selectivity. Potential reusability of magnetically separable palladium catalyst and performing the reactions at environmentally conditions are notable features of the present methods making great potential for practical applications. Graphical Abstract: [Figure not available: see fulltext.].
- Rezapour, Elham,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza
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- A novel imidazolium-supported palladium-chloroglycine complex: Copper- and solvent-free high-turnover catalysts for the Sonogashira coupling reaction
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A novel, effective 1-glycyl-3-methyl imidazolium chloride-palladium(II) complex ([Gmim]Cl-Pd(II)) was synthesized and studied as an organocatalyst for the Sonogashira coupling reaction under solvent-free conditions at 25 °C. The hydrophobic group on amino acid favors reagent diffusion toward the chloroglycine moiety, increasing the catalytic activity of supported palladium complex. By this protocol, different aryl halides (Cl, Br and I) were reacted with phenylacetylene in good to excellent yields with turnover number 8.0 × 102 to 9.6 × 102. The catalyst was recycled for the reaction of bromobenzene with phenylacetylene for eight runs without appreciable loss of its catalytic activity and negligible metal leaching. Copyright
- Karthikeyan, Parasuraman,Muskawar, Prashant Narayan,Aswar, Sachin Arunrao,Bhagat, Pundlik Rambhau,Sythana, Suresh Kumar
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- Supramolecular photocatalyst of Palladium (II) Encapsulated within Dendrimer on TiO2 nanoparticles for Photo-induced Suzuki-Miyaura and Sonogashira Cross-Coupling reactions
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In this study, synthesis, characterization and catalytic performance of a novel supramolecular photocatalytic system including palladium (II) encapsulated within amine-terminated poly (triazine-triamine) dendrimer modified TiO2 nanoparticles (Pd (II) [PTATAD] @ TiO2) is presented. The obtained nanodendritic catalyst was characterized by FT-IR, ICP-AES, XPS, EDS, TEM, TGA and UV-DRS. The as-prepared nanodendritic catalyst was shown to be highly active, selective, and recyclable for the Suzuki–Miyaura and Sonogashira cross-coupling of a wide range of aryl halides including electron-rich and electron-poor and even aryl chlorides, affording the corresponding biaryl compounds in good to excellent yields under visible light irradiation. This study shows that visible light irradiation can drive the cross-coupling reactions on the Pd (II) [PTATAD] @ TiO2 under mild reaction conditions (27–30?°C) and no additional additives such as cocatalysts or phosphine ligands. So, we propose that the improved photoactivity predominantly benefits from the synergistic effects of Pd (II) amine-terminated poly (triazine-triamine) dendrimer on TiO2 nanoparticles that cause efficient separation and photogenerated electron–hole pairs and photoredox capability of nanocatalyst which all of these advantages due to the tuning of band gap of catalyst in the visible light region.
- Eskandari, Ameneh,Jafarpour, Maasoumeh,Rezaeifard, Abdolreza,Salimi, Mehri
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- Palladium(II)eSchiff base complex supported on multi-walled carbon nanotubes: A heterogeneous and reusable catalyst in the Suzukie Miyaura and copper-free SonogashiraeHagihara reactions
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The air-moisture stable and recyclable palladium(II) Schiff base complex anchored to multi-walled carbon nanotubes (PdeSchiff base@MWCNTs) behaves as a very efficient heterogeneous catalyst in the SuzukieMiyaura coupling of arylboronic acids and aryl halides, and the SonogashiraeHagihara reaction of aryl iodides and terminal alkynes in aqueous media to afford the corresponding CeC couplings in high yields.
- Navidi, Mozhgan,Rezaei, Nasrin,Movassagh, Barahman
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- A novel and highly efficient polyaniline-functionalized multiwall carbon nanotube-supported cu(I) complex for Sonogashira coupling reactions of aryl halides with phenylacetylene
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A polyaniline-functionalized multiwall carbon nanotube-supported Cu(I) complex was developed as an efficient catalyst for the Sonogashira reactions of aryl halides with phenylacetylene in the presence of potassium hydroxide in dimethylformamide at 135?°C under nitrogen atmosphere. The corresponding products were generated in good to excellent yields using this catalytic system. Moreover, the multiwall carbon nanotube-supported Cu(I) catalyst was simply recycled and reused for six consecutive runs.
- Hajipour, Abdol R.,Jajarmi, Saeideh
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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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- 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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- Bimetallic Ni/Cu mesoporous silica nanoparticles as an efficient and reusable catalyst for the Sonogashira cross-coupling reactions
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A bimetallic mesoporous system (Ni/Cu-MCM-41) has been developed and evaluated as an efficient catalyst for the Sonogashira cross-coupling reaction, under palladium-free conditions. In this new methodology, a wide range of aryl halides react with phenylacetylene to give the corresponding disubstituted alkynes in good yields. Moreover, the present catalytic system is desired because of its high efficiency, easy preparation, low cost, high activity, and good recyclability.
- Nasresfahani, Zahra,Kassaee, Mohamad Z.
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supporting information
(2021/02/12)
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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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- Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organotitanium reagents
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A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by nickel catalyzed cross-couplings of alkynyl halides with aryl titanium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 92 %. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or aryltitanium substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives.
- Li, Qing-Han,Wu, Chuan
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supporting information
(2021/08/25)
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- Facile one-pot synthesis of diarylacetylenes from arylaldehydes: Via an addition-double elimination process
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A practical one-pot protocol has been developed to synthesize diarylacetylenes from arylaldehydes by treatment with 1-(arylmethyl)benzotriazoles and LiN(SiMe3)2. The reaction proceeded through imine formation, Mannich-type addition and double elimination to deliver products in up to 99% yields with broad substrate scope. In addition, gram-scale synthesis of 1-bromo-4-(phenylethynyl)benzene has been demonstrated.
- Chen, Jianyang,Zhang, Xuan,Wu, Jiajun,Wang, Rui,Lei, Chunlin,An, Yanan
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p. 4701 - 4705
(2021/06/11)
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- Simple and efficient diaryl alkyne synthesis method
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The embodiment of the invention discloses a simple and efficient diaryl alkyne synthesis method. The method comprises the steps of by taking arylmethylbenzotriazole and aromatic aldehyde as raw materials, carrying out addition and double-beta-elimination reaction under the action of bis (trimethylsilyl) amino salt MN (SiMe3) 2 to synthesize diaryl alkyne by a one-pot method. The raw materials and chemical reagents used in the method are easy to obtain, the reaction conditions are mild, the operation is simple, the substrate universality is good, the product yield is high, and the method is a simple and efficient diaryl alkyne synthesis method.
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Paragraph 0026; 0029-0031
(2021/04/14)
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- PALLADIUM ACYCLIC DIAMINOCARBENE COMPLEXES AS PRECATALYSTS FOR HIYAMA COUPLING AND THE TANDEM ONE-POT FLUORIDE FREE HIYAMA COUPLING/CYCLIZATION FOR THE SYNTHESIS OF BIOLOGICALLY RELEVANT
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The present invention provides Acyclic diaminocarbene complex of formula (I): Wherein, M is palladium; X is monoanionic ligand selected from Cl, Br or I; Where R1 is different from R2; R1 is selected from the group consisting of alkyl or aryl, each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms; R2 is selected from the group consisting of alkyl, or aryl each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms. The said palladium diamino carbine complex of the present invention are particularly useful as catalyst from Hiyama cross-coupling reaction.
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Paragraph 0090; 0091; 0104-0105
(2020/05/06)
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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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- Utilizing a copper-free Sonogashira reaction in the synthesis of the leukotriene a4 hydrolase modulator batatasin IV
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Batatasin IV is a dihydrostilbenoid isolated from Chinese yams which was shown to have inhibitory activities against plant growth. Later studies showed that this compound may exhibit anti-inflammatory properties by inhibiting the epoxide hydrolase activity of the leukotriene A4 hydrolase enzyme. To access the dihydrostilbenoid skeleton, a copper-free SPhos-mediated Sonogashira reaction was conceived and the substrate scope was explored. Our results indicate that the reaction can tolerate the presence of free alcohols, aldehydes, nitro groups, and anilinyl groups. However, a substituent with an acidic phenol or carboxylic acid group gave significantly lower yields. Next, a total synthesis of batatasin IV was accomplished in 16% overall yield incorporating the reported copper-free Sonogashira reaction. Finally, we show that batatasin IV inhibits the hydrolysis of alanine p-nitroanilide by leukotriene A4 hydrolase with an IC50 of 91.4 μM.
- Petruncio, Greg,Girgis, Michael,Moummi, Sanae,Jayatilake, Meth,Lee, Kyung Hyeon,Paige, Mikell
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supporting information
(2020/10/27)
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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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- Integrating CuO?Fe2O3 Nanocomposites and Supramolecular Assemblies of Phenazine for Visible-Light Photoredox Catalysis
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A photoredox catalytic ensemble consisting of CuO-Fe2O3 nanocomposites and oligomeric derivative of phenazine has been developed. The prepared system acts as an efficient photoredox catalyst for C?N bond formation reaction via SET mechanism under ‘green’ conditions (aerial environment, mixed aqueous media, recyclable), requiring less equivalents of base and amine substrate. The present study demonstrates the significant role of supramolecular assemblies as photooxidants and reductants upon irradiation and their important contribution towards the activation of the metallic centre through energy transfer and electron transfer pathways. The potential of oligomer 4: CuO-Fe2O3 has also been explored for C?C bond formation reactions via the Sonogashira protocol.
- Kaur, Lovjot,Deol, Harnimarta,Kumar, Manoj,Bhalla, Vandana
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supporting information
p. 892 - 898
(2020/03/04)
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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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- 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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- A palladium catalyzed aryl alkyne preparation method
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The invention discloses a palladium catalyzed aryl alkyne of the preparation method, comprises the following steps: in the catalyst, under the action of the ligand and alkali, substituted with aryl sulfonyl chloride alkynoic occurs in the organic solvent escapes suosuo the coupling reaction, after the reaction is finished after treatment to obtain the aryl alkyne. Used in the preparation method of the cheap raw material, the reaction and simple post treatment operation, at the same time, the reaction less side reaction, high yield of the product.
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Paragraph 0037; 0038; 0039
(2019/05/21)
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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 0046-0049
(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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- In Situ Generation of Alkynylzinc and Its Subsequent Negishi Reaction in a Flow Reactor
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A highly efficient and convenient Negishi cross-coupling reaction has been developed for the synthesis of unsymmetrical alkynes and enynes in a continuous-flow process. The reaction proceeds through an in situ generated alkynylzinc reagent by the reaction of lithium acetylide with zinc halide at room temperature followed by a cross-coupling reaction with aryl or vinyl iodides. The notable features of this work compared to the conventional benchtop method are mild reaction conditions, good to excellent yields, broad functional-group compatibility, short residence time (73 sec) and especially desilylation of TMS group with the residence time of only 10.5 sec.
- Kandasamy, Mohanraj,Huang, Yu- Hsuan,Ganesan, Balaji,Senadi, Gopal Chandru,Lin, Wei-Yu
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p. 4349 - 4356
(2019/07/03)
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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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- 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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- Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids
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It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.
- Orha, László,Tukacs, József M.,Kollár, László,Mika, László T.
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supporting information
p. 2907 - 2913
(2019/12/14)
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- Proton-Coupled Electron Transfer: Transition-Metal-Free Selective Reduction of Chalcones and Alkynes Using Xanthate/Formic Acid
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Highly chemoselective reduction of α,β-unsaturated ketones to saturated ketones and stereoselective reduction of alkynes to (E)-alkenes has been developed under a transition-metal-free condition using a xanthate/formic acid mixture through proton-coupled electron transfer (PCET). Mechanistic experiments and DFT calculations support the possibility of a concerted proton electron-transfer (CPET) pathway. This Birch-type reduction demonstrates that a small nucleophilic organic molecule can be used as a single electron-transfer (SET) reducing agent with a proper proton source.
- Prasanna, Ramanathan,Guha, Somraj,Sekar, Govindasamy
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supporting information
p. 2650 - 2653
(2019/04/17)
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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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- Zinc-Catalysed Hydroboration of Terminal and Internal Alkynes
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A regioselective hydroboration of alkynes has been developed by using commercially available zinc triflate as a catalyst, in the presence of catalytic amount of NaBHEt3. The reaction tolerates a wide range of terminal alkynes having several synthetically useful functional groups and proceeds regioselectively to furnish hydroborated products in moderate to excellent yields. This system shows moderate chemoselectivity towards terminal C≡C bond over terminal and internal C=C bond and internal C≡C bond.
- Mandal, Souvik,Mandal, Sayantan,Geetharani
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supporting information
p. 4553 - 4556
(2019/08/20)
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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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- Pd-Catalyzed decarboxylative alkynylation of alkynyl carboxylic acids with arylsulfonyl hydrazides via a desulfinative process
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In the presence of a Pd(ii)/P-ligand catalytic system, decarboxylative alkynylation of alkynyl carboxylic acids and arylsulfonyl hydrazides by desulfinative coupling could provide aryl alkynes in satisfactory yields by either judiciously selecting palladium catalysts or modulating phosphine ligands under mild conditions. The reported coupling reactions are very practical as they do not require the protection of inert gas or oxygen and are tolerant to many functional groups.
- Chang, Sheng,Liu, Ying,Yin, Shu Zhu,Dong, Lin Lin,Wang, Jian Feng
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supporting information
p. 5357 - 5362
(2019/04/04)
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- Highly efficient synthesis of 1,2-disubstituted acetylenes derivatives from the cross-coupling reactions of 1-bromoalkynes with organoalane reagents
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A Highly efficient route for the synthesis of 1,2-disubstituted acetylene derivatives has been developed by palladium catalyzed cross-couplings of alkynyl halides with (hetero)aryl aluminium reagents under mild conditions. This has given corresponding cross-coupling products good to excellent isolated yields of up to 99%. The aryls bearing electron-donating or electron-withdrawing groups in either alkynylhalides or arylaluminum substrates gave cross-coupling products good yields. This process was simple and easily performed, which provides an efficient method for the synthesis of 1,2-disubstituted acetylenes derivatives. On the basis of the experimental results, a possible catalytic cycle has been proposed.
- Shao, Xue-Bei,Jiang, Xin,Li, Qing-Han,Zhao, Zhi-Gang
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p. 6063 - 6070
(2018/09/12)
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- Sonogashira-type cross-coupling reactions catalyzed by copper complexes of pincer N-heterocyclic carbenes
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Copper complexes of N-heterocyclic carbenes (NHC) have recently received great attention in catalysis, however, the application scope has been limited to neutral complexes bearing monodentate ligands. Herein, we report the synthesis and full characterization of a cationic Cu-pincer bis(NHC) complex with bulky tert-butyl wingtips that serves as catalyst for the coupling of aryl iodides and phenylacetylene, alongside its analogs with small alkyl substituents. Unlike other copper catalysts that require an inert atmosphere to prevent alkyne homocoupling, a competing side reaction to Sonogashira reaction, the Cu-pincer bis(NHC) complexes provide good to excellent cross-coupling yields in air. Interestingly, the reaction under argon affords substantially reduced cross-coupling, indicative of the oxygen involvement and its facilitating effect in the mechanism. In our controlled studies, the air-assisted cross-coupling reaction came to a complete stop when using a radical trap, suggesting the presence of a radical in the mechanism. Examining the reaction of Cu-pincer bis(NHC) complexes with oxygen via UV–vis spectroscopy reveals a dark green chromophore formation at ?40 °C with strong absorbance (ε > 400 M?1cm?1) at 460 nm and 500 nm, likely due to a high-valent copper-oxygen adduct.
- Domyati, Doaa,Latifi, Reza,Tahsini, Laleh
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supporting information
p. 98 - 105
(2018/03/06)
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- Recyclable heterogeneous metal foil-catalyzed cyclopropenation of alkynes and diazoacetates under solvent-free mechanochemical reaction conditions
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Silver and copper foil were found to be effective, versatile and selective heterogeneous catalysts for the cyclopropenation of terminal and internal alkynes under mechanochemical reaction conditions. This methodology enables the functionalization of a wide range of terminal or internal alkynes under ambient, aerobic, and solvent-free conditions. Finally, we have demonstrated a unique and versatile one-pot domino Sonogashira-cyclopropenation mechanochemical reaction for the formation of complex cyclopropenes.
- Chen, Longrui,Leslie, Devonna,Coleman, Michael G.,Mack, James
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p. 4650 - 4661
(2018/05/30)
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- Tri(1-naphthyl)phosphine as a ligand in palladium-free Sonogashira cross-coupling of arylhalogenides with acetylenes
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Tri(1-naphthyl)phosphine (Np3P) has been easily prepared in 34% yield from red phosphorus and 1-bromonaphthalene in the superbasic system t-BuONa/DMSO. The expedient procedures for the synthesis of aryl acetylenes by Sonogashira coupling of aryl iodides with terminal alkynes using Np3P as a ligand have been developed. For the first time, it is found that the reaction with compounds containing electron-donating substituents preferably affords buta-1,3-diynes.
- Govdi, Anastasiya I.,Vasilevsky, Sergey F.,Malysheva, Svetlana F.,Kazheva, Olga N.,Dyachenko, Oleg A.,Kuimov, Vladimir A.
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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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- Palladium nanoparticles immobilized on EDTA-modified Fe3O4@SiO2 nanospheres as an efficient and magnetically separable catalyst for Suzuki and Sonogashira cross-coupling reactions
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In this study, a novel heterogeneous palladium catalyst was synthesized by anchoring palladium onto ethylenediaminetetraacetic acid (EDTA)-coated Fe3O4@SiO2 magnetic nanocomposite and used for the Suzuki and Sonogashira cross-coupling reactions. The properties of the magnetic catalyst were characterized by FT-IR, XRD, TEM, FE-SEM, DLS EDX, XPS, N2 adsorption-desorption isotherm analysis, TGA, VSM, elemental analysis and the loading level of Pd in catalyst was measured to be 0.51?mmol/g by ICP. The catalyst was used in Suzuki cross-coupling reactions of various aryl halides, including less reactive chlorobenzenes with phenylboronic acid without any additive or ligand under green conditions. Furthermore, we have reported this recyclable catalytic system for Sonogashira cross-coupling reactions of various aryl halides (I, Br, Cl) under copper and ligand-free conditions in the presence of DMF/H2O (1:2/v:v) as a solvent. The magnetic catalyst could also be separated by an external magnet and reused six times without any significant loss of activity.
- Esmaeilpour, Mohsen,Zahmatkesh, Saeed,Fahimi, Nafiseh,Nosratabadi, Mehran
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- Direct Access to Aryl Bis(trifluoromethyl)carbinols from Aryl Bromides or Fluorosulfates: Palladium-Catalyzed Carbonylation
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A palladium-catalyzed carbonylative approach for the direct conversion of (hetero)aryl bromides into their α,α-bis(trifluoromethyl)carbinols is described, and it employs only stoichiometric amounts of carbon monoxide and trifluoromethyltrimethylsilane. In addition, aryl fluorosulfates proved highly compatible with these reaction conditions. The method is tolerant of a diverse set of functional groups, and it is adaptable to late-stage carbon-isotope labeling.
- Domino, Katrine,Veryser, Cedrick,Wahlqvist, Benjamin A.,Gaardbo, Cecilie,Neumann, Karoline T.,Daasbjerg, Kim,De Borggraeve, Wim M.,Skrydstrup, Troels
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supporting information
p. 6858 - 6862
(2018/05/08)
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- Nickel-Catalyzed Highly Regioselective Hydrocyanation of Terminal Alkynes with Zn(CN)2 Using Water as the Hydrogen Source
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The first efficient and general nickel-catalyzed hydrocyanation of terminal alkynes with Zn(CN)2 in the presence of water has been developed. The reaction provides a regioselective protocol for the synthesis of functionalized vinyl nitriles with a range of structural diversity under mild reaction conditions while obviating use of the volatile and hazardous reagent of HCN. Deuterium-labeling experiments confirmed the role of water as the hydrogen source in this hydrocyanation reaction.
- Zhang, Xingjie,Xie, Xin,Liu, Yuanhong
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supporting information
p. 7385 - 7389
(2018/06/11)
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- Transition-Metal-Free Highly Chemoselective and Stereoselective Reduction with Se/DMF/H2O System
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A novel metal-free reduction system, in which H2Se (or HSe-) produced in situ from Se/DMF/H2O acts as the active reducing species, has been developed. By using water as an inexpensive, safe, and environmentally friendly surrogate as the hydrogen donor, this new reduction system incorporating Se/DMF/H2O displayed high selectivity and good activity in the reduction of α,β-unsaturated ketones and alkynes. Therefore, this reduction system has great potential to be a general and practical reduction methodology in organic transformation.
- Li, Hong-Chen,An, Cui,Wu, Ge,Li, Guo-Xing,Huang, Xiao-Bo,Gao, Wen-Xia,Ding, Jin-Chang,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
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supporting information
p. 5573 - 5577
(2018/09/12)
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- Palladium-Catalyzed Decarboxylative Coupling Reactions of Propiolic Acid Derivatives and Arylsulfonyl Hydrazide
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Arylsulfonyl hydrazides were employed as coupling partners for the decarboxylative coupling reaction of propiolic acid derivatives. When the reaction was conducted using Pd(TFA) 2 (1.0 mol%), dppp (1.0 mol%), and Cu(OAc) 2 (2.4 equiv
- Park, Jaerim,Song, Kwang Ho,Lee, Sunwoo
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p. 3197 - 3204
(2018/08/12)
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- Synthesis of Internal Alkynes through an Effective Tandem Elimination-Hydrodebromination-Cross-Coupling of gem-Dibromoalkenes with Halobenzenes
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Carbon-carbon couplings are among the most important strategies for constructing functional molecules in organic synthetic chemistry, and cheap, diverse, and readily available coupling partners are crucial to these diverse reactions. In this contribution, we report the first palladium-catalyzed C-C cross-coupling reaction of two kinds of organic halide, a gem -dibromoalkene and a halobenzene, as the starting materials. Terminal alkynes were generated in situ through a tandem elimination-hydrodebromination process, and the internal alkyne final products were synthesized in one pot. The reaction proceeded under simple, facile, and classic copper-free Sonogashira coupling reaction conditions in good to excellent yields.
- Ji, Yuan,Zhong, Ning,Kang, Zinan,Yan, Guobing,Zhao, Ming
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supporting information
p. 209 - 214
(2018/03/26)
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- Synthesis of α-fluoroimines by copper-catalyzed reaction of diarylacetylenes and n-fluorobenzenesulfonimide
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Difunctionalization of unsaturated bonds with fluorinating reagents has been regarded as an efficient route to vicdifunctional organic fluorides. Here we report a coppercatalyzed synthesis of α-fluoroimines from diarylacetylenes and N-fluorobenzenesulfonimide. Mechanistically, the reaction initiates from the generation of imidyl radical, which reacts with alkyne to give the product. The resulting α-fluoroimine can easily be transformed into other organic fluorides such as fluoroketone and fluoroamines.
- Yip, Shu Jan,Yoshidomi, Tetsushi,Murakami, Kei,Itami, Kenichiro
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supporting information
p. 329 - 331
(2018/03/01)
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- Cross-coupling reactivity of 1,1-dichloroalkenes under palladium catalysis: Domino synthesis of diarylalkynes
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An efficient synthesis of diarylalkynes was achieved from the domino cross-coupling reaction of 1,1-dichloroalkenes with triarylbismuth reagents under palladium-catalyzed conditions. Under the established palladium protocol, 1,1-dichloroalkenes demonstrated hitherto unknown remarkable cross-coupling reactivity with organometallic triarylbismuth reagents to furnish functionalized diarylalkynes.
- Maddali, L. N. Rao,Meka, Suresh
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p. 4412 - 4418
(2018/03/21)
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- Development of highly electron-deficient and less sterically-hindered phosphine ligands possessing 1,3,5-triazinyl groups
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Highly electron-deficient and less sterically-hindered phosphine ligands with two or three 1,3,5-triazinyl groups on the phosphorus atoms have been synthesized and examined in transition metal-catalyzed reactions for the first time. Due to the lack of any hydrogens or substituents at ortho-positions of the 1,3,5-triazine towards the phosphorous atom, it is considered that the steric hindrance of the tris(triazinyl)phosphine ligand to a metal center is least among triarylphosphine ligands. In the Stille coupling of aryl iodides, these electron-poor phosphine ligands provided good product yields compared to hitherto well-known phosphine ligands.
- Abe, Kazumi,Kitamura, Masanori,Fujita, Hikaru,Kunishima, Munetaka
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- New transmetalation reagents for the gold-catalyzed visible light-enabled C(sp or sp2)-C(sp2) cross-coupling with aryldiazonium salts in the absence of a photosensitizer
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The scope of photosensitizer-free visible light-driven gold-catalyzed cross-coupling was evaluated by a wide variety of organoboron and organosilicon species using four equivalents of aryldiazonium salts and (4-CF3-C6H4)3PAuCl in MeOH. In addition, a C(sp or sp2)-C(sp2) cross-coupling of organotrimethylsilanes and aryldiazonium salts was investigated. The reactions can be conducted under very mild reaction conditions, with a reduced amount of aryldiazonium salt (1.2 equiv.) by using a catalytic amount of Ph3PAuNTf2 in MeCN under irradiation with blue LEDs at room temperature.
- Witzel, Sina,Sekine, Kohei,Rudolph, Matthias,Hashmi, A. Stephen K.
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p. 13802 - 13804
(2018/12/14)
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- Method for synergistically catalyzing Sonogashira cross-coupling reaction with carbonyl iron cluster compounds and trace palladium
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The invention discloses a method for synergistically catalyzing a Sonogashira cross-coupling reaction with carbonyl iron cluster compounds and trace palladium. According to the method, palladium chloride and triiron dodecarbonyl are taken as catalysts, acetylenic ketone is taken as a ligand, methanol is taken as a solvent, aryl halide, terminal alkyne and K2CO3 are subjected to a reaction , and arylethynylene compounds are obtained. With the adoption of the method, the use amount of palladium metal is reduced obviously, reaction operation is simple, the condition is mild (the temperature is commonly about 60 DEG C), compatibility of functional groups is good, the yield is high, the use quantity of the catalysts is low, and the productivity is high.
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Paragraph 0024; 0025; 0026; 0027; 0028-0047; 0072; 0073
(2017/07/19)
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- External oxidant-free cross-coupling of arylcopper and alkynylcopper reagents leading to arylalkyne
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External oxidant-free oxidative cross-coupling between arylcopper and alkynylcopper has been performed, which provides a new way for the formation of arylalkyne with high selectivity.
- Wang, Sheng,Min, Yaosen,Zhang, Xiaowei,Xi, Chanjuan
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p. 28308 - 28312
(2017/07/07)
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- A phosphine-free, atom-efficient cross-coupling of aryl iodides with triarylindiums or trialkynylindiums catalyzed by immobilization of palladium(0) in MCM-41
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The first phosphine-free heterogeneous atom-efficient cross-coupling reaction of aryl iodides with triarylindiums or trialkynylindiums was achieved in THF at 68 °C by using 1 mol% of MCM-41-immobilized palladium(0)-Schiff base complex [MCM-41-N,N-Pd(0)] as catalyst, yielding a variety of unsymmetrical biaryls and arylalkynes in good to excellent yields. The heterogeneous palladium(0) catalyst could easily be prepared via a simple procedure from commercially readily available reagents, and recovered by filtration of the reaction solution and recycled at least 10 times without significant loss of activity.
- Lei, Zhiwei,Liu, Haiyi,Cai, Mingzhong
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