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)]<inf>2</inf> yields ortho- and paraxylylbis{(N-alkylimidazolidin-2-ylidene)chloro(η4-1, 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 © 2008 John Wiley & Sons, Ltd.