New cyclizations via catalytic ruthenium vinylidenes

Abstract

New carbocyclizations that proceed via catalytic metal-vinylidenes are presented. Metal-vinylidene catalytic species, which are easily accessible from terminal alkynes and catalytic amounts of transition-metal complexes, can be involved either in pericyclic reactions or in tandem processes triggered by nucleophilic attack at the electrophilic position of the vinylidene. In both cases, a wide variety of valuable cyclic compounds are easily accessible. Some recent carbocyclizations will be described. © 2008 IUPAC.