A Versatile Synthesis of Vinyl-Substituted Heterocycles via Regio- and Enantioselective Pd-Catalyzed Tandem Allylic Substitution

Abstract

We herein report a versatile, regio- and enantioselective palladium-catalyzed tandem allylic substitution powered by a chiral bisphosphorus ligand WingPhos with the palladium loading as low as 0.1 mol %, forming a series of chiral vinyl-substituted heterocycles, including tetrahydroquinoxalines, piperazines, dihydro-2H-benzo[b][1,4]-oxazines, and morpholines, in exellent ee's and yields. The protocol features readily available starting materials, mild reaction conditions, and a broad substrate scope. Mechanistic investigation supports a tandem allylic substitution process.