Synthesis of Functionalized 3-Bromoindenes via Pd(II)-catalyzed Tandem Reactions of o-(Alkynyl)styrenes: Taking Dioxygen as Sole Oxidant

Abstract

This paper introduced an economic and environmental approach to 3-bromoindenes from simple and readily available o-(alkynyl)styrenes via a Pd-catalyzed cascade cyclization including bromopalladation/Heck cross-coupling/β-H elimination. With O2 as the sole oxidant and KBr as bromide source, a series of poly-substituted 3-bromoindenes were synthesized with high chemoselectivity avoiding the use of CuBr2.