Synthesis and characterisation of bite angle-dependent (eta~1-allyl)Rh and (eta~3-allyl)Rh complexes bearing diphosphine ligands. Implications for nucleophilic substitution reactions

摘要

Several novel rhodium allyl complexes have been prepared and their structures have been studied using NMR spectroscopy and X-ray crystallography. Depending on the bite angle of the ligand and the substitution pattern of the allyl group, two different coordination modes (eta~1 and eta~3) have been observed for the allyl moiety. The activities for these Rh allyl complexes in the allylic alkylation reaction have been tested. We have shown that both coordination modes give active complexes in this reactin, but that the regioselectivity is dependent on the coordination mode of the allyl group.