Gold(i)- and platinum(iv)-catalyzed intramolecular annulations of allenes towards furans

Abstract

Intramolecular annulations of allenes towards furans to give six-membered ring fused furans with gold and platinum catalysts have been developed. It was found that allenes can be activated by gold catalysts and attacked by the furan rings to generate six-membered rings. When PtCl₄ was used as a catalyst, the annulation also gives six-membered ring fused furans, but the carbon–carbon double bond in the products shifted to form conjugation with the furan ring with a high Z/E ratio.