Amide-Directed Catalytic Asymmetric Hydroboration of Trisubstituted Alkenes
作者:Sean M. Smith、James M. Takacs
DOI:10.1021/ja908257x
日期:2010.2.17
rhodium-catalyzed reaction is stereospecific. In addition, simple TADDOL-derived phenyl monophosphite ligands in combination with Rh(nbd)(2)BF(4) afford highly enantioselective catalysts (seven examples, 91-98% ee). These catalysts provide an alternative methodology to prepare Felkin or anti-Felkin acetate-aldol products and related derivatives that are obtainable from the intermediate chiral organoboranes
Copper-Mediated Selective Cross-Coupling of 1,1-Dibromo-1-alkenes and Heteronucleophiles: Development of General Routes to Heterosubstituted Alkynes and Alkenes
site-selective, double, or alkynylative cross-coupling, therefore providing divergent and straightforward entries to numerous building blocks such as bromoenamides, ynamides, ketene N,N-acetals, bromoenol ethers, ynol ethers, keteneO,O-acetals, or vinylphosphonates and further expanding the copper catalysis toolbox with useful and versatile processes.
Copper-Catalyzed Coupling of 1,1-Dibromo-1-alkenes with Phenols: A General, Modular, and Efficient Synthesis of Ynol Ethers, Bromo Enol Ethers, and Ketene Acetals
An efficient and general copper-catalyzed method is reported for the synthesis of phenol-derived 1-bromoenol ethers, ynol ethers, and ketene acetals by chemodivergent copper-catalyzed cross-coupling between readily available 1,1-dibromo-1-alkenes and phenols.
Stereoselective Synthesis of (Z)-1,2-Dithio-1-alkenes via Copper-Catalyzed Thiolation of (Z)-2-Bromovinyl Sulfides
作者:Wanzhi Chen、Huayue Wu、Hui Xu、Jiuxi Chen
DOI:10.1055/s-0031-1290067
日期:2012.2
We describe a new method for the stereoselective synthesis of (Z)-1,2-dithio-1-alkenes via copper-catalyzed cross-coupling of (Z)-2-bromovinyl sulfides and thiols. The desired products are obtained in good to excellent yields. The double bond geometry of the starting (Z)-2-bromovinyl sulfides is retained under these reaction conditions.
An efficient synthesis of trisubstituted alkenes including 1,2-heterodisubstituted alkenes has been described. Reactions of thiols and amines with 1,1-dibromo-1-alkenes in the presence of TBAF·3H2O afford (Z)-2-bromovinyl sulfides and (Z)-2-bromovinyl amines regio- and stereoselectively. The reaction proceeds under catalyst-free conditions with high efficiency. The coupling reactions of the obtained