Mixed La-Li heterobimetallic complexes for tertiary nitroaldol resolution

Full details of the kinetic resolution of tertiary nitroaldols derived from simple ketones are described. Mixed BINOL/biphenol La-Li heterobimetallic complexes gave the best selectivity in retro-nitroaldol reactions of racemic tertiary nitroaldols. Using a 2:1 mixture of La-Li-3-(binaphthoxide 1a)(3) complex (LLB) and La-Li-3-(biphenoxide 1e)(3) complex, chiral tertiary nitroaldols were obtained in 80-97% ee and 30-47% recovery yield. Transformations of products were also investigated. (C) 2009 Elsevier Ltd. All rights reserved.