Copper-Catalyzed Cyclization–Fragmentations of Enynols

摘要

Pt and Au are going out of fashion: The [Cu(CH₃CN)₄][BF₄] species effectively catalyzes the cyclization–fragmentation of 5-en-1-yn-3-ols. The reactivity of 6-en-1-yn-4-ols greatly depends on the catalyst used (see scheme). An unusual fragmentation and metathesis reactions of 6-en-1-yn-4-ols have also been detected.