Merging of Light/Dark Palladium Catalytic Cycles Enables Multicomponent Tandem Alkyl Heck/Tsuji-Trost Homologative Amination Reaction toward Allylic Amines.

Abstract

A visible light-induced palladium-catalyzed homologative three-component synthesis of allylic amines has been developed. This protocol proceeds via a unique mechanism involving two distinct cycles enabled by the same Pd(0) catalyst: a visible light-induced hybrid radical alkyl Heck reaction between 1,1-dielectrophile and styrene, followed by the "in dark" classical Tsuji-Trost-type allylic substitution reaction. This method works well with a broad range of primary and secondary amines, aryl alkenes, dielectrophiles, and in complex settings. The regiochemistry of the obtained products is primarily governed by the structure of 1,1-dielectrophile. Involvement of π-allyl palladium intermediates allowed for the control of stereoselectivity, which has been demonstrated with up to 95:5 er.