Copper-catalyzed decarboxylative alkenylation of sp3 C–H bonds with cinnamic acidsvia a radical process

Abstract

A copper-catalyzed decarboxylative coupling of vinylic carboxylic acids with simple alcohols, ethers, and hydrocarbons was achieved. In the past decades, most of the sp³ α-C–H activation/C–C bond formation reactions proceeded via an addition of a α-hydroxy carbon-centered radical to heterocycles, alkenes, and alkynes. The present system exhibits a novel pathway for the functionalization of various sp³ C–H bonds via radical addition–elimination of aryl-substituted vinyl carboxylic acids. This strategy allows for rapid and selective access to a variety of (E)-alkenes such as allylic alcohols, allylic ethers, and substituted styrenes. In addition, this procedure could be scaled up to gram level, which would be useful to prepare natural products and pharmaceuticals that contain chromene and its derivatives.