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, cilt.18, ss.2349-2357, 2007 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 18 Konu: 19
  • Basım Tarihi: 2007
  • Doi Numarası: 10.1016/j.tetasy.2007.09.019
  • Dergi Adı: TETRAHEDRON-ASYMMETRY
  • Sayfa Sayıları: ss.2349-2357

Özet

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.