The Experts below are selected from a list of 1725 Experts worldwide ranked by ideXlab platform
Yanguang Wang - One of the best experts on this subject based on the ideXlab platform.
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copper mediated Cyanation reactions
Tetrahedron Letters, 2014Co-Authors: Qiaodong Wen, Jisong Jin, Lianpeng Zhang, Yan Luo, Yanguang WangAbstract:Abstract Aryl nitriles can be efficiently synthesized through transition-metal-mediated Cyanation of aryl halides, arenes, aryl boronic acids, and so on. Among those most commonly used transition-metals, copper catalysts are surely much more inexpensive and easier to handle, compared to any other metal catalysts. Considering the high-efficiency of copper catalysts in the activation of C–X, C–H, and C–B bond as well as in the formation of C–CN bond, this Letter summarizes various copper-mediated Cyanations based on the different kinds of cyanide reagents, such as metal cyanides, potassium hexacyanoferrate(II), acetone cyanohydrins, DDQ, AIBN, benzyl cyanide, malononitrile, nitromethane, and DMF. Our group’s recent contributions to this area are also demonstrated.
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palladium catalyzed cyanide metathesis utilization of benzyl cyanide as an operator benign reagent for aryl halide Cyanations
ChemInform, 2012Co-Authors: Binbin Hu, Ping Lu, Yanguang WangAbstract:Benzyl cyanide (II) is a safe and effective Cyanation reagent for palladium-catalyzed Cyanation of haloarenes, affording the corresponding aryl nitriles in moderate to good yields.
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palladium catalyzed cyanide metathesis utilization of benzyl cyanide as an operator benign reagent for aryl halide Cyanations
RSC Advances, 2012Co-Authors: Binbin Hu, Ping Lu, Yanguang WangAbstract:Benzyl cyanide was disclosed to be a safe and effective Cyanation reagent for palladium-catalyzed Cyanation of haloarenes, which afforded aryl nitriles in moderate to good yields.
Stephen L Buchwald - One of the best experts on this subject based on the ideXlab platform.
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mild palladium catalyzed Cyanation of hetero aryl halides and triflates in aqueous media
ChemInform, 2015Co-Authors: Daniel T Cohen, Stephen L BuchwaldAbstract:The scalable procedure is applied to the Cyanation of complex molecules and natural products such as steroids, chiral amino acids and the reverse transcriptase inhibitor lersivirine (XI).
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mild palladium catalyzed Cyanation of hetero aryl halides and triflates in aqueous media
Applied Categorical Structures, 2015Co-Authors: Daniel T Cohen, Stephen L BuchwaldAbstract:A mild, efficient, and low-temperature palladium-catalyzed Cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed Cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the Cyanation of a general scope of (hetero)aryl halides and triflates at 2–5 mol % catalyst loadings with temperatures ranging from rt to 40 °C. This mild method was applied to the synthesis of lersivirine, a reverse transcriptase inhibitor.
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copper catalyzed domino halide exchange Cyanation of aryl bromides
ChemInform, 2003Co-Authors: Jacopo Zanon, Artis Klapars, Stephen L BuchwaldAbstract:An efficient copper-catalyzed domino halogen exchange-Cyanation procedure for aryl bromides was developed utilizing 10 mol % CuI, 20 mol % KI, 1.0 equiv of the inexpensive N,N'-dimethylethylenediamine as ligand, and 1.2 equiv of NaCN in toluene at 110 degrees C. The new method represents a significant improvement over the traditional Rosenmund-von Braun reaction: the reaction conditions are much milder, and the use of stoichiometric amounts of copper(I) cyanide and polar solvents is avoided; therefore the isolation and purification of the aromatic nitrile products is greatly simplified. In addition, the new method exhibits excellent functional group compatibility comparable to that of the analogous Pd-catalyzed Cyanation methodology.
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copper catalyzed domino halide exchange Cyanation of aryl bromides
Journal of the American Chemical Society, 2003Co-Authors: Jacopo Zanon, Artis Klapars, Stephen L BuchwaldAbstract:An efficient copper-catalyzed domino halogen exchange-Cyanation procedure for aryl bromides was developed utilizing 10 mol % CuI, 20 mol % KI, 1.0 equiv of the inexpensive N,N‘-dimethylethylenediamine as ligand, and 1.2 equiv of NaCN in toluene at 110 °C. The new method represents a significant improvement over the traditional Rosenmund−von Braun reaction: the reaction conditions are much milder, and the use of stoichiometric amounts of copper(I) cyanide and polar solvents is avoided; therefore the isolation and purification of the aromatic nitrile products is greatly simplified. In addition, the new method exhibits excellent functional group compatibility comparable to that of the analogous Pd-catalyzed Cyanation methodology.
Sukbok Chang - One of the best experts on this subject based on the ideXlab platform.
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catalytic Cyanation of aryl iodides using dmf and ammonium bicarbonate as the combined source of cyanide a dual role of copper catalysts
ChemInform, 2014Co-Authors: Amit B Pawar, Sukbok ChangAbstract:It is assumed that copper is involved both in the generation of “CN” units from DMF-ammonia and in the Cyanation of aryl iodides (I).
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catalytic Cyanation of aryl iodides using dmf and ammonium bicarbonate as the combined source of cyanide a dual role of copper catalysts
Chemical Communications, 2014Co-Authors: Amit B Pawar, Sukbok ChangAbstract:Cu(II)-catalyzed Cyanation of aryl iodides has been developed using DMF and ammonium bicarbonate as the combined source of cyanide. It is assumed that copper is involved both in the generation of “CN” units from DMF–ammonia and in the Cyanation of aryl halides. A range of electron-rich and fused (hetero)aryl iodides underwent Cyanation resulting in moderate to good yields.
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copper mediated transformation of organosilanes to nitriles with dmf and ammonium iodide
Organic Letters, 2013Co-Authors: Zhen Wang, Sukbok ChangAbstract:Cyanation of aryl-, diaryldimethyl-, and styrylsilanes was developed for the first time under copper-mediated oxidative conditions using ammonium iodide and DMF as the combined source of nitrogen and carbon atom of the introduced cyano unit, respectively. The reaction was observed to proceed in a two-step process: initial conversion of organosilanes to their iodo intermediates and then Cyanation. This method has a broad substrate scope with high functional group tolerance.
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copper mediated selective Cyanation of indoles and 2 phenylpyridines with ammonium iodide and dmf
ChemInform, 2012Co-Authors: Jinho Kim, Hyunwoo Kim, Sukbok ChangAbstract:Copper-mediated regioselective Cyanation of indoles and 2-phenylpyridines was developed by using ammonium iodide and DMF as the combined source of a cyano unit under "Pd-free" conditions. Mechanistic studies indicate that the reaction of indoles proceeds through a two-step sequence: electrophilic initial iodination and then Cyanation. The Cyanation has a broad substrate scope, high functional group tolerance, and excellent regioselectivity.
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synthesis of aromatic nitriles using nonmetallic cyano group sources
Angewandte Chemie, 2012Co-Authors: Sukbok ChangAbstract:: Aromatic nitriles are prepared efficiently through transition-metal-mediated Cyanation of aryl (pseudo)halides with metallic cyano-group sources, such as CuCN, KCN, NaCN, Zn(CN)(2), TMSCN, or K(4) [Fe(CN)(6)]. However, this approach often suffers from drawbacks, such as the formation of stoichiometric amounts of metal waste, the poisoning of the metal catalysts, or the generation of toxic HCN gas. As a result, a range of "nonmetallic" organic cyano-group sources have been explored for the Cyanation of aryl halides and arene C-H bonds. This Minireview summarizes types of nonmetallic cyano-group sources and their applications in the preparation of aryl nitriles.
Rene M Koenigs - One of the best experts on this subject based on the ideXlab platform.
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visible light photoredox catalyzed oxidative strecker reaction
ChemInform, 2012Co-Authors: Magnus Rueping, Shaoqun Zhu, Rene M KoenigsAbstract:The efficient aerobic, photocatalytic oxidative Cyanation of tertiary amines (I) and (IV) employing KCN (II) as cyanide source is described.
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visible light photoredox catalyzed oxidative strecker reaction
Chemical Communications, 2011Co-Authors: Magnus Rueping, Shaoqun Zhu, Rene M KoenigsAbstract:An aerobic photocatalytic oxidative Cyanation of tertiary amines providing valuable α-aminonitriles in good to excellent yields was developed. Mild reaction conditions and low catalyst loading are attractive features of the protocol.
Rui Wang - One of the best experts on this subject based on the ideXlab platform.
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a unique combined source of cn from 1 2 dichloroethane and tmsn3 in the copper catalyzed Cyanation of a c sp3 h bond adjacent to a nitrogen atom
Organic Letters, 2014Co-Authors: Gen Zhang, Guangbin Cheng, Dabin Liu, Rui WangAbstract:A novel combined metal-free “CN” source from trimethylsilyl azide and 1,2-dichloroethane has been developed and successfully applied to copper-catalyzed oxidative Cyanation of α-C–H tertiary amines for the synthesis of C1-Cyanation tetrahydroisoquinoline derivatives with good to excellent yields for the first time.
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rhodium i catalyzed n cn bond cleavage intramolecular β Cyanation of styrenes
ChemInform, 2013Co-Authors: Rui Wang, John R FalckAbstract:The first examples of an intramolecular Cyanation of styrene derivatives via a Rh-Catalyzed N—CN cleavage reaction are given.
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rhodium i catalyzed n cn bond cleavage intramolecular β Cyanation of styrenes
Chemical Communications, 2013Co-Authors: Rui Wang, John R FalckAbstract:We report herein the first example of intramolecular Cyanation of a styrene by a rhodium(I)-catalyzed N–CN cleavage reaction. Substituents on the arenes or the styrene alpha-position are tolerated. Our results demonstrate that alkene Cyanation can indeed be atom economical.
