Ir(I) complexes with oxazoline-thioether ligands: nucleophilic attack of pyridine on coordinated 1,5-cyclooctadiene and application as catalysts in imine hydrogenation
摘要:
Oxazoline-thioether ligands 6-11 react with [Ir(eta(4)-COD)Py-2]PF6 (COD= C8H12 = 1,5-cyclooctadiene) to give [Ir(sigma-eta(2)-C8H12Py-)L] PF6 (L-oxazoline-thioether ligand) (12a-d) complexes resulted from the coordination of ligand to the metal and subsequent nucleophilic attack of pyridine to one of the double carbon bond of COD with concomitant iridium-carbon bond formation. When [Ir(eta(4)-COD)(2)]BF4 was used as starting material, the reaction with ligands 7, 9 afforded the complexes [Ir(eta(4)-COD)L]BF4. Application of these iridium complexes to the reduction of N-(alpha-methyl)benzylidenbenzylamine gave low or negligible enantioselectivity. (C) 2004 Elsevier B.V. All rights reserved.