OPTICALLY-ACTIVE PHENIRAMINE BY ENANTIOSELECTIVE HYDROGENATION OF UNSATURATED AMINES, ESTERS AND ACIDS USING RU(II)-COMPLEXES WITH BINAP ASCATALYTIC PRECURSORS

Pheniramine (3a) was prepared through enantioselective hydrogenation o f various precursor compounds catalyzed by Ru(II)/BINAP complexes, In the case of N,N-dialkyl-3-phenyl-3-(2-pyridyl)allylamines (1 and 2) on ly the (Z)-isomer shows a satisfactory reactivity; moreover, the chemo selectivity is affected by the hydrogenolysis of the alkylamino group of the substrate. The enantioselectivity did not exceed 50%. 3-Phenyl- 3-(2-pyridyl)acrylic acids (9 and 10) and their ethyl esters (5 and 6) gave good chemical yields only at reaction temperature greater than o r equal to 50 degrees C; also in this case poor enantioselectivities ( up to 35%) were achieved. (C) 1997 Elsevier Science B.V.