Asymmetric synthesis of novel 1,4-aminoalcohol ligands with norbornene and norbornane backbone: use in the asymmetric diethylzinc addition to benzaldehyde


TANYELİ C., Odabas S., ERDEM M., ÇAKIR E., KESKİN E.

TETRAHEDRON-ASYMMETRY, vol.18, no.19, pp.2349-2357, 2007 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 19
  • Publication Date: 2007
  • Doi Number: 10.1016/j.tetasy.2007.09.019
  • Journal Name: TETRAHEDRON-ASYMMETRY
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.2349-2357

Abstract

The asymmetric synthesis of cis-1,4-aminoalcohols with norbornene and norbornane backbone was performed starting with (2S, 3R)-(-)-cis-hemiester 1 (98% ee). Chemoselective amination with HMPTA followed by Grignard reactions and subsequent LAH reductions afforded compounds 5a-d. cis-Hemiester 1 was also transformed into chiral ligands 7a-f and 9a-d with the DCC coupling method followed by LAH reduction using acyclic, heterocyclic amines and various aniline derivatives and p-toluenesulfonamide, respectively. The chiral ligands were subjected to asymmetric diethylzinc addition to examine their effectiveness as chiral catalysts. Among these, arylamine and tosyl substituted chiral ligands 9a-d exhibited the highest selectivities (up to 97% ee). (c) 2007 Elsevier Ltd. All rights reserved.