Chiral Phosphoric Acid Catalyzed Highly Enantioselective Desymmetrization of 2-Substituted and 2,2-Disubstituted 1,3-Diols via Oxidative Cleavage of Benzylidene Acetals
作者:Shan-Shui Meng、Yong Liang、Kou-Sen Cao、Lufeng Zou、Xing-Bang Lin、Hui Yang、K. N. Houk、Wen-Hua Zheng
DOI:10.1021/ja507332x
日期:2014.9.3
A highly enantioselective catalytic protocol for the desymmetrization of a wide variety of 2-substituted and 2,2-disubstituted 1,3-diols is reported. This reaction proceeds through the formation of an "ortho ester" intermediate via oxidation of 1,3-diol benzylidene acetal by dimethyldioxirane (DMDO) and the subsequent proton transfer catalyzed by chiral phosphoric acid (CPA). The mechanism and origins
Enantioselective Desymmetrization of 1,3-Diols by a Chiral DMAP Derivative
作者:Hiroki Mandai、Kosuke Ashihara、Koichi Mitsudo、Seiji Suga
DOI:10.1246/cl.180697
日期:2018.11.5
We developed an enantioselective desymmetrization of 1,3-diols by a chiral N,N-dimethyl-4-aminopyridine (DMAP) derivative containing a 1,1′-binaphthyl with tert-alcohol units. The reactions require...
characteristic Lewis acid catalyst in the regio- and stereoselective rearrangement of epoxides to aldehydes. This Cr(TPP)OTf-catalyzed reaction is an operationally simple and especially convenient method for synthesizing optically active beta-siloxy aldehydes from 2,3-epoxy silyl ethers which are readily available in enantiomerically enriched forms by the Sharpless epoxidation of allylic alcohols followed