Synthesis of novel rhodium-xylyl linked N-heterocyclic carbene complexes as hydrosilylation catalysts

Abstract

Reaction of ortho-xylylbis(N-2,4,6-trimethylbenzylimidazolinium);xylylbis(N-butylimidazolinium) and para-xylylbis(N-2,4,6-trimethylbenzylimidazolinium); xylylbis(N-butylimidazolinium) salts with KOBut and [RhCl(COD)](2) yields ortho- and para-xylylbis{(N-alkylimidazolidin-2-ylidene)chloro(eta(4)-1,5-cyclooctadiene) rho dium(I)} complexes (2a-d). All compounds synthesized were characterized by elemental analysis and NMR spectroscopy, and the molecular structures of the 2a and 2d were determined by X-ray crystallography. Triethylsilane reacts with acetophenone derivatives in the presence of catalytic amount of the new rhodium(I)-carbene complexes (2a-d), to give the corresponding silylethers in good yields (83-99%). Copyright (C) 2008 John Wiley & Sons, Ltd.