Bifunctional iminophosphorane organocatalysts for enantioselective synthesis: application to the ketimine nitro-Mannich reaction

J Am Chem Soc. 2013 Nov 6;135(44):16348-51. doi: 10.1021/ja409121s.

Abstract

The design, synthesis, and development of a new class of modular, strongly basic, and tunable bifunctional Brønsted base/H-bond-donor organocatalysts are reported. These catalysts incorporate a triaryliminophosphorane as the Brønsted basic moiety and are readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general enantioselective organocatalytic nitro-Mannich reaction of nitromethane to unactivated ketone-derived imines allows the enantioselective construction of β-nitroamines possessing a fully substituted carbon atom. The reaction is amenable to multigram scale-up, and the products are useful for the synthesis of enantiopure 1,2-diamine and α-amino acid derivatives.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / chemical synthesis*
  • Amino Acids / chemistry
  • Catalysis
  • Diamines / chemical synthesis*
  • Diamines / chemistry
  • Imines / chemistry*
  • Models, Molecular
  • Molecular Structure
  • Organophosphorus Compounds / chemistry*
  • Stereoisomerism

Substances

  • Amino Acids
  • Diamines
  • Imines
  • Organophosphorus Compounds