Molybdenum imido alkylidene and tungsten oxo alkylidene N-heterocyclic carbene complexes for olefin metathesis

This mini-review summarizes the latest accomplishments with group 6 metal alkylidene-N-heterocyclic carbene complexes (metal = Mo, W) for use in olefin metathesis. Both the fundamentals and the unique features of this novel class of olefin metathesis catalysts are presented. Also, their use and performance in ring-closing metathesis, cross metathesis, homometathesis, and self-metathesis reactions as well as in ring-opening metathesis polymerization and cyclopolymerization is outlined. [GRAPHICS] .