| abstract |
Compounds of formula II ##STR1## wherein the groups (R 1 ) 2 P(CH 2 ) m bzw.n are in o- or m-position to each other and the substituents R 1 are identical or different radicals, m and n are each independently of the other 0 or 1, R 1 is linear or branched C 1 -C 12 alkyl, unsubstituted C 5 -C 6 cycloalkyl or C 5 -C 6 cycloalkyl which is substituted by C 1 -C 4 alkyl or C 1 -C 4 alkoxy, or is phenyl or benzyl, or both substituents R 1 in a group (R 1 ) 2 P together are o,o'-diphenylene, --R 2 --X-- is a bond or --(C x H 2x --O) y --, or X-- is O-- and R 2 is C 1 -C 6 alkylene, x is an integer from 2 to 6 and y is an integer from 2 to 6, R 3 is C 2 -C 18 alkylene, phenylene or benzylene, and R 4 is C 1 -C 6 alkyl or phenyl, can be applied to solid carriers, such as silica gel or aerosils, and complexed with rhodium or iridium compounds. These materials are heterogeneous and separable catalysts for the asymmetrical hydrogenation of prochiral compounds containing carbon double bonds or carbon/hetero atom double bonds, for example ketones and imines. |