Enantioselective Carbonyl–Ene Reactions Catalyzed by Chiral Cationic Dirhodium(II,III) Carboxamidates
作者:Xichen Xu、Xiaochen Wang、Yuxiao Liu、Michael P. Doyle
DOI:10.1021/jo5013674
日期:2014.12.19
An enantioselectivecarbonyl–enereaction of glyoxylate esters with 1,1-disubstituted alkenes catalyzed by chiral cationic dirhodium(II,III) carboxamidates is described. The paddlewheel dirhodium(II,III) carboxamidates having one open coordination site at each rhodium smoothly catalyze the carbonyl–enereaction to afford homoallylic alcohol products in good isolated yields with high enantioselectivities
Significant counterion effect of the In(III)–pybox complex in highly enantioselective carbonyl-ene reactions of ethyl glyoxylate
作者:Jun-Feng Zhao、Teguh-Budiono W. Tjan、Teck-Peng Loh
DOI:10.1016/j.tetlet.2010.06.066
日期:2010.10
A highly efficient enantioselective carbonyl-ene reaction of ethyl glyoxylate catalyzed by an In(III)-pybox complex, which is designed based on the counterion effect, is reported. Reactions of both aliphatic and aromatic 1,1-disubstituted olefins proceed smoothly to give enantioenriched homoallylic alcohols with excellent yields and enantioselectivities. In addition, electron-withdrawing as well as donating groups on the phenyl ring of alpha-methyl styrenes are tolerated in this reaction. (C) 2010 Elsevier Ltd. All rights reserved.