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
铑催化的三取代烯烃的硼氢化反应通常很慢并且经常受到竞争性烯烃异构化的影响。相比之下,β,γ-不饱和酰胺框架内包含的三取代烯烃部分容易发生反应,这可能是由羰基导向效应和底物与铑催化剂的两点结合促进的。立体异构底物,例如 (E)- 和 (Z)-3,干净地产生非对映异构产物,因此铑催化的反应是立体有择的。此外,简单的 TADDOL 衍生的苯基单亚磷酸酯配体与 Rh(nbd)(2)BF(4) 结合可提供高度对映选择性的催化剂(七个实例,91-98% ee)。