Asymmetric Michael addition of a recyclable chiral amine: inversion of stereoselectivity caused by the difference of ethereal solvents

Org Lett. 2008 Jul 3;10(13):2653-6. doi: 10.1021/ol8007793. Epub 2008 Jun 7.

Abstract

The Michael addition of a chiral amine [(-)- 6] to alpha,beta-unsaturated esters ( 4) was attained and the stereoselectivity was inverted by changing the solvent from diethyl ether to tetrahydrofuran when alpha,beta-unsaturated esters having an aromatic ring at the beta-position were employed. In addition, the chiral auxiliary in the Michael adducts ( 9A) was facilely removed with N-iodosuccinimide to afford beta-amino esters ( 10A) and 2-methoxy- d-bornylaldehyde ( 11), which can be reclaimed to the chiral amine ( 6) by reductive amination.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines / chemistry*
  • Ethers / chemistry*
  • Molecular Structure
  • Quaternary Ammonium Compounds / chemistry
  • Solvents / chemistry*
  • Stereoisomerism
  • Sulfites / chemistry

Substances

  • Amines
  • Ethers
  • Quaternary Ammonium Compounds
  • Solvents
  • Sulfites
  • hydrogen sulfite