Iron(II)-Catalyzed Heck-Type Coupling of Vinylarenes with Alkyl Iodides

An iron(II)-catalyzed radical alkyl Heck-type reaction of alkyl iodides with vinylarenes under mild conditions has been reported. t-Butyl peroxybenzoate (TBPB) behaves simultaneously as a radical relay initiator, a precursor for the generation of alkyl radical from alkyl iodides, and an oxidant to recycle iron(II)/iron(III). Unactivated primary, secondary, and tertiary alkyl iodides are compatible with the reaction conditions. The mechanistic studies suggest that a radical-polar-crossover pathway might be involved in the catalytic cycle.