Vinylogous propargylation of α,α-dicyanoalkenes: construction of an all-carbon quaternary center†
Abstract
The first highly efficient vinylogous propargylation of α,α-dicyanoalkenes catalyzed by a copper catalyst to construct an all-carbon quaternary center with 3-ethynyl-2-oxoindolin-3-yl acetates is reported. The corresponding products with an all-carbon quaternary center were obtained in moderate to excellent yields (up to 92%). In addition, a gram-scale reaction and derivative transformations have also been achieved.