ENANTIOSELECTIVE CATALYSIS .66. ENANTIOSELECTIVE CATALYTIC TRANSFER HYDROGENATION OF ALPHA,BETA-UNSATURATED CARBOXYLIC-ACIDS WITH FORMATES CATALYZED BY NOVEL RUTHENIUM PHOSPHINE COMPLEXES
Hydrogen transfer from the formic acid/triethylamine (5:2) azeotrope to alpha,beta-unsaturated carboxylic acids is effectively catalyzed by ruthenium complexes of general formula [Ru(acac-F6)(eta-3 - C3H5)(diphosphine)]. If a chiral diphosphine is employed, the saturated acids are obtained in up to 93% ee, the most active and selective catalyst being formed with BINAP.