Ruthenium-Catalyzed Cyclization of Enyne - Dramatic Influence of Substituents on the Alkyne-

摘要

During the course of our study on ruthenium-catalyzed enyne metathesis, we found a novel alkenylative cyclization of enyne using Cp*RuCl(cod). The reaction proceeds via oxidative cyclization of enyne 1 to a ruthenium catalyst followed by insertion of ethylene into ruthenacyclopentene I to give ruthenacycloheptene II. Then beta-hydrogen elimination from II followed by reductive elimination occurs to give cyclized compound 2 having a diene moiety.