Asymmetric synthesis of 1,4-amino alcohol ligands with a norbornene backbone for use in the asymmetric diethylzinc addition to benzaldehyde


Tanyeli C. , SÜNBÜL M.

TETRAHEDRON-ASYMMETRY, vol.16, no.11, pp.2039-2043, 2005 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 16 Issue: 11
  • Publication Date: 2005
  • Doi Number: 10.1016/j.tetasy.2005.04.019
  • Title of Journal : TETRAHEDRON-ASYMMETRY
  • Page Numbers: pp.2039-2043

Abstract

The asymmetric synthesis of cis-1,4-amino alcohols with a norbornene backbone was performed starting with (2S,3R)(-)-cis-hemiester 2 (98% ee). Chemoselective amination with NH4OH and HMPTA followed by LAH reduction afforded 5 and 7. respectively. Amido ester 6 was transformed into chiral ligand 9 with Grignard reaction followed by LAH reduction. The chiral ligands 5. 7. and 9 were subjected to asymmetric diethylzinc addition to examine their effectiveness as chiral catalysts. Among these, c chiral ligand 7 exhibited the highest enantioselectivity (88% ee). (c) 2005 Elsevier Ltd. All rights reserved.