Transition metal-catalyzed intramolecular enyne cyclization reaction

This review summarizes the recent developments in transition metal-catalyzed l,n-enyne cyclization reactions that have been reported in the literature from January 1, 2002 to April 30, 2005. The cyclizations described herein include four parts according the reaction mechanism, i.e. cyclization initiated by oxidative cyclometallation; by activation of the triple bond to form a vinyl metal species; by electrophilic activation of the triple bond; and by activation of the double bond. Enyne cyclizations that do not follow the above reaction mechanism are not included.