A stable crystalline imino-N-heterocyclic carbene ligand and its corresponding palladium(II) and rhodium(I) complexes

Abstract

The crystalline heteroditopic, acyclic, and nonenolizable imino-N-heterocyclic carbene chelating ligand 1-tert-butyl-3-(1-phenyliminophenylmethylene)imidazol-2-ylidene (designated as C boolean AND imine) has been isolated and structurally characterized. The metal complexes [Pd(C boolean AND imine)Cl-2], [Pd(allyl)(C boolean AND imine)]-PF6, [Rh(COD)(C boolean AND imine)]PF6, and [Rh(CO)(C boolean AND imine)(2)]Cl have been prepared either by Ag transfer or by reaction with the free carbene. The palladiumt(II) complexes have been tested for catalytic application in Suzuki type C-C cross-coupling reactions of aryl bromides and the rhodium(l) complexes for the catalytic hydroformylation of 1-octene. The metal complexes [Pd(C boolean AND imine)Cl-2], [Pd(allyl)(C boolean AND imine)]PF6, and [Rh(CO)(C boolean AND imine)(2)]Cl have been structurally characterized by single-crystal X-ray diffraction.