Combinatorial design of simplified high-performance chiral phase-transfer catalysts for practical asymmetric synthesis of alpha-alkyl- and alpha,alpha-dialkyl-alpha-amino acids

Chem Asian J. 2008 Sep 1;3(8-9):1702-14. doi: 10.1002/asia.200800107.

Abstract

A very efficient, chiral phase-transfer catalyst, (S)-2 Db, was prepared by taking advantage of the combinatorial approach from the readily available (S)-1,1'-binaphthyl-2,2'-dicarboxylic acid. This catalyst exhibited high catalytic performance (0.01-0.1 mol %) in the asymmetric alkylation of N-(diphenylmethylene)glycine tert-butyl ester and N-(p-chlorophenylmethylene)alanine tert-butyl ester relative to other chiral phase-transfer catalysts in current use. This has created a general and highly practical procedure for the enantioselective synthesis of structurally diverse natural and unnatural alpha-alkyl-alpha-amino acids as well as alpha,alpha-dialkyl-alpha-amino acids. A similar simplified catalyst, (S)-2 Fb, is also applicable to the direct asymmetric aldol reaction between glycine Schiff base and aldehydes with moderate syn selectivity and high enantioselectivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Amino Acids / chemical synthesis*
  • Amino Acids / chemistry
  • Catalysis
  • Combinatorial Chemistry Techniques
  • Crystallography, X-Ray
  • Models, Molecular
  • Molecular Structure
  • Stereoisomerism

Substances

  • Amino Acids