Novel transition-metal complexes and use thereof in transition-metal catalyzed reactions

Compounds of the formulae (I) and (II)

• 24
• where
• M is a transition metal of the 8th transition group of the Periodic Table,
• X1 and X2 are the same or different and are each an anionic ligand,
• R1, R2, R3 and R4 are the same or different and are each hydrogen, with the proviso that at least one radical R1 to R4 is different to hydrogen, or are each cyclic, straight-chain or branched alkyl radicals having from 1 to 50 carbon atoms or aryl radicals having from 6 to 30 carbon atoms, where at least one hydrogen atom in the radicals mentioned is optionally replaced by an alkyl group or a functional group, and R1 and/or R4 is also halogen, C1-C4-alkoxy, C6-C10-aryloxy, cyano, C1-C4-alkoxycarbonyl, C6-C10-aryloxycarbonyl or aliphatic or aromatic C1-C10-acyloxy, and/or
• R1 and R2 or R2 and R3 or R3 and R4 or R4 and R5 are part of a cyclic system which consists of a carbon framework having from 3 to 20 carbon atoms, not including the carbon atoms in formula (I) and (II), where at least one hydrogen atom is optionally replaced by an alkyl group or a functional group, and/or at least one carbon atom of the cycle is optionally being replaced by a heteroatom from the group of S, P, O and N, and
• R5 is hydrogen or a cyclic, straight-chain or branched alkyl radical having from 1 to 20 carbon atoms or an aryl radical having from 6 to 20 carbon atoms, where at least one hydrogen atom in the radicals mentioned is optionally replaced by an alkyl group or a functional group, and
• R6 and R7 are the same or different and are each cyclic, straight-chain or branched alkyl radicals having from 1 to 30 carbon atoms or are each aryl radicals having from 6 to 20 carbon atoms, where at least one hydrogen atom is optionally replaced by an alkyl group or a functional group.