An enantioselective biginelli reaction catalyzed by a simple chiral secondary amine and achiral brønsted acid by a dual-activation route

Chemistry. 2008;14(10):3177-81. doi: 10.1002/chem.200701581.

Abstract

An enantioselective Biginelli reaction that proceeds by a dual-activation route has been developed by using a combined catalyst of a readily available trans-4-hydroxyproline-derived secondary amine and a Brønsted acid. Aromatic, heteroaromatic, and fused-ring aldehydes were found to be suitable substrates for this multicomponent reaction. The corresponding dihydropyrimidines were obtained in moderate-to-good yields with up to 98 % ee under mild conditions. Based on the experimental results and the observed absolute configurations of the products, a plausible transition state has been proposed to explain the origin of the activation and the asymmetric induction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetoacetates / chemistry
  • Amines / chemistry*
  • Benzaldehydes / chemistry
  • Catalysis
  • Molecular Structure
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry
  • Stereoisomerism
  • Trifluoroacetic Acid / chemistry*
  • Urea / chemistry

Substances

  • Acetoacetates
  • Amines
  • Benzaldehydes
  • Pyrimidines
  • Urea
  • Trifluoroacetic Acid
  • ethyl acetoacetate