Rapid synthesis of benzofulvenes from α-bromodiarylethylenes based on a 1,4-palladium shift strategy

Abstract

A palladium-catalyzed synthesis of benzofulvenes from α-halo diarylethylenes has been reported. The reaction proceeds through an aryl to vinyl 1,4-palladium shift, followed by the Heck reaction with the second vinyl-substituted benzene. The cyclization may occur through an intramolecular Heck-type of cyclization or an aryl-to-vinyl 1,4-Pd migration and C–H arylation reaction. The reaction accepts a variety of functional groups and affords a wide range of functionalized benzofulvenes up to 93% yields. Additionally, dibenzopentalenes were prepared with excellent yields from the newly synthesized benzofulvenes.