Ruthenium(II)-assisted asymmetric hydrogen transfer reduction of acetophenone using chiral tridentate phosphorus-containing ligands derived from (1R, 2R)-1,2-diaminocyclohexane

Flores-Lopez CZ; Flores-Lopez LZ; Aguirre G; Hellberg LH; Parra-Hake M; Somanathan R

Journal of Molecular Catalysis A-Chemical, Vol.215, No.1-2, 73-79, 2004

DOI10.1016/j.molcata.2004.01.013 Export Citation

Ruthenium(II)-assisted asymmetric hydrogen transfer reduction of acetophenone using chiral tridentate phosphorus-containing ligands derived from (1R, 2R)-1,2-diaminocyclohexane

Flores-Lopez CZ, Flores-Lopez LZ, Aguirre G, Hellberg LH, Parra-Hake M, Somanathan R

Several chiral and unsymmetrical tridentate [NNP]-type ligands with sp(2)-N and sp(3)-N were synthesized from monosulfonamide of (1R, 2R)-1,2-diaminocyclohexane and 2-(diphenylphosphino)benzaldehyde. Their ruthenium(II) complexes have been used in the enantioselective asymmetric hydrogen transfer reduction of acetophenone in 2-propanol with selectivities in the range 14-99% e.e. The good enantioselectivity with the ligands with sp(2)-N and sp(3)-N is believed to be due to formation of hexacoordinated complexes with a 2:1 ligand to metal ratio. (C) 2004 Elsevier B.V. All rights reserved.

Keywords:asymmetric;Ruthenium(II);transfer;hydrogenation;Schiff base