Photoexcited cobalt catalysed endo-selective alkyl Heck reaction

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, this method could be used for the selective (Z)-hydroxymethylation of o-hydroxystyrenes and alkenols. Rapid scan EPR experiments and DFT calculations suggest a concerted beta-hydrogen elimination event to take place in the triplet state.

Automated summary

In this study, an intramolecular endo-selective Heck reaction of iodomethylsilyl ethers of phenols and alkenols was reported. The reaction resulted in the formation of seven- and eight-membered siloxycycles in excellent yields, which could be further converted into the corresponding allylic alcohols upon oxidation. This method could be used for the selective (Z)-hydroxymethylation of o-hydroxystyrenes and alkenols. Rapid scan EPR experiments and DFT calculations suggested a concerted beta-hydrogen elimination event to take place in the triplet state.