(Diisopinocampheyl)borane-mediated reductive aldol reactions of acrylate esters: enantioselective synthesis of anti-aldols

Org Lett. 2013 Aug 2;15(15):3922-5. doi: 10.1021/ol401679g. Epub 2013 Jul 25.

Abstract

The (diisopinocampheyl)borane promoted reductive aldol reaction of acrylate esters 4 is described. Isomerization of the kinetically formed Z(O)-enolborinate 5Z to the thermodynamic E(O)-enolborinate 5E via 1,3-boratropic shifts, followed by treatment with representative achiral aldehydes, leads to anti-α-methyl-β-hydroxy esters 9 or 10 with excellent diastereo- (up to ≥20:1 dr) and enantioselectivity (up to 87% ee). The results of double asymmetric reactions of 5E with several chiral aldehydes are also presented.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acrylates / chemical synthesis
  • Acrylates / chemistry*
  • Aldehydes / chemical synthesis
  • Aldehydes / chemistry*
  • Boranes / chemistry*
  • Catalysis
  • Esters
  • Oxidation-Reduction
  • Stereoisomerism

Substances

  • (diisopinocampheyl)borane
  • Acrylates
  • Aldehydes
  • Boranes
  • Esters
  • 3-hydroxybutanal
  • acrylic acid