Rhodium-Catalyzed Homocoupling of γ‑Alkylated tert-Propargylic Alcohols

An unprecedented rhodium-catalyzed homocoupling reaction of γ-alkylated tert-propargylic alcohols is reported, and 2-alkynylated buta-1,3-diene or 2-alkynylated hexa-1,3,5-triene are generated selectively. Multiple β-eliminations, including sequential β-carbon, β-hydrogen, and β-oxygen eliminations from the corresponding rhodium intermediates, are assumed to be involved during the reaction process.