New chiral Ni-II complexes of Schiff's bases of glycine and alanine for efficient asymmetric synthesis of alpha-amino acids

摘要

New modified chiral auxiliaries (S)-N-(2-benzoylphenyl)-1-(2-chlorobenzyl)pyrrolidine-2-carboximide (2-CBPB) and (S)-N-(2-benzoylphenyl)-1-(3,4-dimethylbenzyl)pyrrolidine-2-carboxamide (3,4-DMBPB) and their Ni-11 complexes of Schiffs base with glycine and alanine have been synthesized and tested in asymmetric C-alkylation and aldol condensation reactions of amino acid moietics. The tests proved that both new auxiliaries were efficient with the ee's of the final amino acids as high as 98% even in case of alpha-methyl-alpha-amino acid synthesis. (c) 2006 Elsevier Ltd. All rights reserved.