Phosphine-Catalyzed Cascade [3 + 2] Cyclization鈭扐llylic Alkylation, [2 + 2 + 1] Annulation, and [3 + 2] Cyclization Reactions between Allylic Carbonates and Enones
文摘
The phosphine-catalyzed annulations between Morita鈭払aylis鈭扝illman adduct carbonates and enones are reported. Under the catalysis of PBu3 (20 mol %), cascade [3 + 2] cyclization鈭抋llylic alkylation, [2 + 2 + 1] annulation, and [3 + 2] cyclization reactions chemoselectively occur depending on the substituent variation of both the carbonate and enone. These reactions provide efficient syntheses of highly functionalized cyclopentenes and cyclopentanes.