Chiral pyridylphosphines and their application in asymmetric catalytic hydrogenation of 2-arylpropenoic acids

Abstract

Novel, optically active phosphorous compounds of the formula [refer to Patent file] wherein R.sup.1 represents hydrogen atoms, straight or branched-chain alkyl groups having from 1 to 6 carbon atoms, R.sup.2 represents hydrogen atoms, halogen atoms, lower alkyl groups (1 to 6 carbon atoms), lower alkoxy groups (1 to 6 carbon atoms), hydroxy group, chiral hydroxyalkyl groups, and amino groups (1.degree., 2.degree., 3.degree.) vinyl groups or allyl groups and R.sup.3 represents phenyl groups, aryl groups, cyclohexyl groups, substituted and unsubstituted cycloalkyl groups, heteroaromatic rings, are described. The compounds of the formula serve as highly useful ligands in the preparation of ruthenium complexes which are effective catalysts for the asymmetric hydrogenation of 2-arylpropenoic acids leading to high valued 2-arylpropionic acids.