Photoexcited Cobalt Catalysed Endo-Selective Alkyl Heck Reaction

Abstract

Herein we report an intramolecular endo-selective Heck reaction of iodomethylsilyl ethers of phenols and alkenols. The reaction leads to the formation of seven- and eight-membered siloxycycles in excellent yields which could be further converted into the corresponding allylic alcohols upon oxidation. Thus, the method could be used for the selective (Z)-hydroxymethylation of o-hydroxystyrenes and alkenols. Rapid scan EPR experiments and DFT calculations suggests a concerted β-hydrogen elimination event to take place in the triplet state.