Transition Metal-Catalyzed Intermolecular [5+2] and [5+2+1] Cycloadditions of Allenes and Vinylcyclopropanes

摘要

This study provides the first examples of rhodium-catalyzed intermolecular [5+2] and [5+2+1] cycloadditions of allenes incorporating alkynyl, alkenyl, cyano, and cyanoalkyl substituents. These reactions proceed often in good to excellent yields, even at high concentrations, and low catalyst loading. This procedure provides a new strategy for the assembly of seven- and eight-membered rings and the basis for new types of C_2 components for metal-catalyzed processes. Further studies of substrate, catalysts, ligands, conditions, and synthetic applications are in progress.