Pyrrolidinyl-camphor derivatives as a new class of organocatalyst for direct asymmetric Michael addition of aldehydes and ketones to beta-nitroalkenes

Chemistry. 2010 Jun 18;16(23):7030-8. doi: 10.1002/chem.201000483.

Abstract

Practical and convenient synthetic routes have been developed for the synthesis of a new class of pyrrolidinyl-camphor derivatives (7 a-h). These novel compounds were screened as catalysts for the direct Michael addition of symmetrical alpha,alpha-disubstituted aldehydes to beta-nitroalkenes. When this asymmetric transformation was catalyzed by organocatalyst 7 f, the desired Michael adducts were obtained in high chemical yields, with high to excellent stereoselectivities (up to 98:2 diastereomeric ratio (d.r.) and 99 % enantiomeric excess (ee)). The scope of the catalytic system was expanded to encompass various aldehydes and ketones as the donor sources. The synthetic application was demonstrated by the synthesis of a tetrasubstituted-cyclohexane derivative from (S)-citronellal, with high stereoselectivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyclic Monoterpenes
  • Aldehydes / chemistry*
  • Alkenes / chemistry*
  • Camphor / chemical synthesis*
  • Camphor / chemistry
  • Catalysis
  • Cyclohexanes / chemistry*
  • Ketones / chemistry*
  • Molecular Structure
  • Monoterpenes / chemistry*
  • Nitro Compounds / chemistry*
  • Pyrrolidines / chemical synthesis*
  • Pyrrolidines / chemistry
  • Stereoisomerism

Substances

  • Acyclic Monoterpenes
  • Aldehydes
  • Alkenes
  • Cyclohexanes
  • Ketones
  • Monoterpenes
  • Nitro Compounds
  • Pyrrolidines
  • Camphor
  • citronellal