The present invention is concerned with a novel process for the preparation of compounds of formula I
comprising catalytic asymmetric hydrogenation of a compound of formula (II)
in the presence of a catalyst comprising ruthenium and a chiral diphosphine ligand or comprising rhodium and a chiral diphosphine ligand, wherein R
1
, R
2
, R
3
and R
4
are as defined in the specification and claims. The compounds of formula I and the corresponding salts and/or esters are pharmaceutically active substances.
本发明涉及一种新颖的方法,用于制备化合物I的过程,包括在催化不对称氢化的条件下,以包含
钌和手性二
膦配体或包含
铑和手性二
膦配体的催化剂的存在下,对式(II)化合物进行氢化,其中R1、R2、R3和R4如规范和声明中定义。化合物I及其相应的盐和/或酯是具有药理活性的物质。