Visible Light‐Driven, Room Temperature Heck‐Type Reaction of Alkyl Halides with Styrene Derivatives Catalyzed by B12 Complex

Abstract

AbstractA visible light driven Heck‐type coupling reaction of alkyl halides with styrene and its derivatives catalyzed by the cobalamin derivative (B12) with the [Ru(bpy)3]Cl2 photosensitizer at room temperature is reported. The catalytic efficiencies of the B12 catalyst were compared to that of other cobalt complexes such as cobaloxime. Various control experiments supported a radical‐based mechanism similar to those for typical B12 model reactions. A unique coupling reaction combined with 1,2‐migration of the functional group is also reported. Mild reaction conditions using an environmentally benign cobalt catalyst derived from the natural B12 provided a practical protocol for the synthetic organic chemistry of the B12 catalyzed reaction system.magnified image