Efficient preparation of new rhodium- and iridium-[bis(oxazolinyl)-3,5-dimethylphenyl] complexes by C-H bond activation: Applications in asymmetric synthesis

摘要

The bis(oxazolinyl)-3,5-dimethylphenylrhodium and -iridium complexes were synthesized in high yields by an efficient C-H bond activation method with 4,6-dimethyl-1,3-bis(oxazolinyl)benzene derivatives. The catalytic activity of the complexes was examined for the asymmetric conjugate reduction of (E)-ethyl 3-phenylbut-2-enoate and the asymmetric reductive aldol reaction of tert-butyl acrylate and benzaldehyde. It was found that the rhodium complex of 3,5-dmPhebox showed the higher catalytic activity, whereas the corresponding iridium complexes proved to be less active.