Bifunctional cinchona alkaloid-squaramide-catalyzed highly enantioselective aza-Michael addition of indolines to α,β-unsaturated ketones
作者:Arun K. Ghosh、Bing Zhou
DOI:10.1016/j.tetlet.2013.04.080
日期:2013.7
An enantioselectiveaza-Michael addition of indolines to α,β-unsaturatedketones was achieved using a bifunctional cinchona alkaloid-derived chiral squaramide derivative. Various β-indolinyl ketone derivatives were obtained in good to excellent yields and with high enantioselectivity. DDQ or MnO2 oxidation of indoline derivatives provided convenient access to various enantioenriched N-substituted indole
A comprehensive library of N- or 1-substituted indoles was formed by conjugate additions of indoline with Michael acceptors followed by an oxidation step. Using N-substituted indoles as key Michael donors, the synthesis of 1,3-disubstituted indoles was also accomplished. (c) 2012 Elsevier Ltd. All rights reserved.