EFFECTS OF RARE-EARTH-METALS ON THE CATALYTIC ASYMMETRIC NITROALDOL REACTION

Various asymmetric rare earth complexes have been prepared from rare earth metal trichlorides such as YCl3, LaCl3, PrCl3, NdCl3, SmCl3, EuCl3, GdCl3, TbCl3 and YbCl3, dilithium (R)-binaphthoxide, NaOH and H2O. The optical purities of nitroaldols obtained using these rare earth complexes as an asymmetric catalyst have been highly dependent on the size of rare earth metals. The application to a catalytic asymmetric synthesis of (S)-metoprolol, a beta1-selective beta-blocker, has been also achieved.