Patent ID: 7671225

Claim:
A compound of the formula I or I′, where both R 1 independently are a hydrogen atom or C 1 -C 4 -alkyl and R′ 1 is C 1 -C 4 -alkyl; X 1 and X 2 are each, independently of one another, a secondary phosphine group; R 2 is hydrogen, R 01 R 02 R 03 Si—, C 1 -C 18 -acyl substituted by halogen, hydroxy, C 1 -C 8 -alkoxy or R 04 R 05 N—, or R 06 -X 01 —C(O)—; R 01 , R 02 and R 03 are each, independently of one another, C 1 -C 12 -alkyl, unsubstituted or C 1 -C 4 -alkyl- or C 1 -C 4 -alkoxy-substituted C 6 -C 10 -aryl or C 7 -C 12 -aralkyl; R 04 and R 05 are each, independently of one another, hydrogen, C 1 -C 12 -alkyl, C 3 -C 8 -cycloalkyl, C 6 -C 10 -aryl or C 7 -C 12 -aralkyl, or R 04 and R 05 together are trimethylene, tetramethylene, pentamethylene or 3-oxapentylene; R 06 is C 1 -C 18 -alkyl, unsubstituted or C 1 -C 4 -alkyl- or C 1 -C 4 -alkoxy-substituted C 3 -C 8 -cycloalkyl, C 6 -C 10 -aryl or C 7 -C 12 -aralkyl; X 01 is —O— or —NH—; T is C 6 -C 20 -arylene; v is 0 or an integer from 1 to 4; X 1 is bound in the ortho position relative to the T-C* bond; and * denotes a mixture of racemic or enantiomerically pure diastereomers or pure racemic or enantiomerically pure diastereomers.