Expanding the Utility of Brønsted Base Catalysis: Biomimetic Enantioselective Decarboxylative Reactions
作者:Yuanhang Pan、Choon Wee Kee、Zhiyong Jiang、Ting Ma、Yujun Zhao、Yuanyong Yang、Hansong Xue、Choon-Hong Tan
DOI:10.1002/chem.201100687
日期:2011.7.18
of simple esters, the use of them as nucleophiles in directasymmetric transformations is a long‐standing challenge in synthetic organic chemistry. Nature approaches this difficulty through a decarboxylative mechanism, which is used for polyketide synthesis. Inspired by nature, we report guanidine‐catalyzed biomimetic decarboxylative CC and CN bond‐formation reactions. These highly enantioselective
Cr-Catalyzed Asymmetric Cross Aza-Pinacol Couplings for β-Amino Alcohol Synthesis
作者:Hui Hu、Zhaobin Wang
DOI:10.1021/jacs.3c08493
日期:2023.9.27
proceeds in a radical-polar crossover manner from the intermediacy of an α-amino radical instead of a ketyl radical. Key to the success is using a chiral chromium catalyst, which plays a triple role in the chemoselective single-electron reduction of the imine, fast radical interception to inhibit radicaladdition to imines, and chemo- and stereoselectiveaddition to aldehydes instead of imines. This method