Description
Bifunctional organometallic catalysts offer unique opportunities for new and improved reactivity and selectivity. The combination of a metal's d electrons and a pendant base or acid in the vicinity of an organometallic active site leads to substantial improvement of reaction rate in many key reactions. Here we report a synthesis of the first example of an imidazol-2-yl substituted bifunctional N-heterocyclic carbene ligand (NHC) and its coordination to a variety of metals. The metal complexes have been characterized by IR, NMR, and X-ray crystallography. The catalytic activity of these new NHC-metal complexes in hydrogenation reactions (e.g. Oppenauer-type alcohol oxidation, β-alkylation of secondary alcohols with primary alcohols, N-alkylation of amines with alcohols), hydroamination, and azide-alkyne cycloaddition reactions is described.
