Chiral ligands for application in asymmetric syntheses

A compound of the formula (I)

• in which B is a bivalent moiety of the formula —(CHR1)n—(R2C═CR3)—(CHR4)m where R1, R2, R3 and R4 are each independently hydrogen or alkyl, and n and m are each independently zero or an integer from 1 to 8, where, however, the sum of n and m is from 1 to 8, and in which, moreover,
• G is chlorine or hydrogen and
• R′ and R″ are each independently aryl or alkyl or
• in which B is a bivalent moiety of the formula —(CHR1)n—(CR2R3)m—(CHR4)o where R1, R2, R3 and R4 are each independently hydrogen or alkyl, and n, m and o are each independently zero or an integer from 1 to 8, where the sum of n, m and o is from 1 to 8, G is chlorine and
• R′ and R″ are each independently aryl or alkyl.