Olefin metathesis by molybdenum imido alkylidene catalysts

A "well-defined" alkylidene complex of the type Mo(CHCMe2Ph)(N-2,6-i-Pr2C6H3)[OCMe(CF3)(2)](2) has proven to be a useful initiator in catalytic olefin metathesis reactions of interest to organic chemists. A variety of related molybdenum imido alkylidene complexes can be prepared readily from a common precursor. This article is a summary of what is known about the details of the steps in a metathesis reaction catalyzed by complexes of the type Mo(CHR')(NAr)(OR)(2), and how the activity and stability of complexes of this type change upon altering each of the ligands in the pseudo-tetrahedral species. Some recent asymmetric ring-closing metathesis reactions are also discussed briefly. (C) 1999 Elsevier Science Ltd. All rights reserved.