A gold-catalyzed cyclization/nucleophilic addition reaction of o-alkynylanilines with ynamides: stereoselective synthesis of 3-vinylindoles

Abstract

Functionalized 3-vinylindoles were obtained through the cyclization/nucleophilic addition of ynamides and o-alkynylanilines catalyzed by a gold catalyst with high stereoselectivity and site-selectivity. The theoretical research suggested that the C_α of ynamides activated by the gold complex was favorable for the addition at the C3 position of indoles. Additionally, JohnPhosAu(MeCN)SbF₆ could efficiently reduce the activation energy barrier of the addition process compared to PicAuCl₂ and Au(PPh₃)NTf₂, and the steric hindrance effect of JohnPhosAu(MeCN)SbF₆ facilitates the formation of 3-vinylindoles with the E configuration.