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Copper‐Catalyzed Asymmetric Annulation Reactions of Carbenes with 2‐Iminyl‐ or 2‐Acyl‐Substituted Phenols: Convenient Access to Enantioenriched 2,3‐Dihydrobenzofurans
Author(s) -
Liang XinShen,
Li RuiDong,
Wang XiaoChen
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201907943
Subject(s) - enantioselective synthesis , annulation , diazo , chemistry , carbene , oxonium ion , catalysis , stereocenter , ketone , imine , organic chemistry , cyclopropanation , ylide , medicinal chemistry , combinatorial chemistry , ion
Abstract We have developed a method for the highly diastereo‐ and enantioselective construction of 2,3‐dihydrobenzofurans bearing tetrasubstituted carbon stereocenters by means of annulation reactions between carbenes and 2‐iminyl‐ or 2‐acyl‐substituted phenols through catalysis by readily accessible copper(I)/bisoxazoline catalysts under mild conditions. These reactions feature a unique mechanism in which the copper catalyst serves a dual function: first it reacts with the diazo compound to generate a metal carbene, and second, upon formation of an oxonium ylide, it acts as a Lewis acid to activate the imine or ketone for diastereo‐ and enantioselective cyclization.