Ortho-Vinylation Reaction of Phenols with Ethyne

Phenols were vinylated at the ortho-position with ethyne in the presence of SnCl₄−Bu₃N reagent. The reaction was applicable to phenols possessing either electron-donating or electron-withdrawing groups. 2,6-Divinylphenols were synthesized under modified conditions. A reaction mechanism involving carbostannylation of alkynyltin and phenoxytin was discussed.