Palladium-catalyzed allylic amination of vinyl bicyclo[1.1.0]butanes: A strain release approach toward alkylidenecyclobutanes

Abstract

A palladium-catalyzed allylic amination of vinyl bicyclo[1.1.0]butanes with amines is described. This protocol is featured with its novel activation model, broad substrate scope and mild reaction conditions, affording a wide variety of alkylidenecyclobutanes in good to excellent yields. DFT calculations suggest that the reaction probably follows a pathway involving palladium-catalyzed C-C bond cleavage, protonation, and nucleophilic allylic substitution. This approach is anticipated to further enrich the BCB chemistry and open new avenues for stereoselective access to bioisosteres of benzenes.