Synthesis and characterization of {[(COD)Rh(bis-(2R,3R)-2,5-diethylphospholanobenzene)](+)BARF(-)} for use in homogeneous catalysis in supercritical carbon dioxide


Guzel B. , OMARY M., FACKLER J., AKGERMAN A.

INORGANICA CHIMICA ACTA, vol.325, pp.45-50, 2001 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 325
  • Publication Date: 2001
  • Doi Number: 10.1016/s0020-1693(01)00601-6
  • Title of Journal : INORGANICA CHIMICA ACTA
  • Page Numbers: pp.45-50

Abstract

Reaction of [(COD)(2)Cl2Rh] (COD: cyclo-octadiene) with sodium tetrakis((3,5-trifluoromethyl)phenyl)borate (NaBARF) in the presence of an excess of COD yields [(COD)(2)Rh](+)BARF(-). The COD ligands are readily displaced by the bidentate ligand 1,2-bis((2R,5R)-2,5-diethylphosphalono)benzene (Et-DuPHOS) to form [(COD)Rh(Et-DuPHOS)]BARF, the structure of which has been determined by X-ray crystallography. BARF was selected as the counterion in order to achieve solubility in supercritical carbon dioxide for use in asymmetric hydrogenation and hydroformylation reactions. Density-functional theory calculations were used to study the intermediates in asymmetric hydroformylation of styrene. The energies of the two-enantiomer models differ by 11.3 kcal mol(-1). (C) 2001 Elsevier Science B.V. All rights reserved.