Stereoselective synthesis of optically active cyclopenta[c]pyridines and tetrahydropyridines


Sezer S. , Gumrukcu Y., Bakirci I., Unver M. Y. , TANYELİ C.

TETRAHEDRON-ASYMMETRY, cilt.23, ss.662-669, 2012 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 23 Konu: 9
  • Basım Tarihi: 2012
  • Doi Numarası: 10.1016/j.tetasy.2012.04.016
  • Dergi Adı: TETRAHEDRON-ASYMMETRY
  • Sayfa Sayıları: ss.662-669

Özet

The intramolecular Pauson-Khand and ring closing metathesis (RCM) reactions of nitrogen containing chiral enynes and dienes are described. The enyne and diene systems comprised of N-propargylated and N-allylated units are constructed on chiral homoallylic or homopropargylic alcohol backbones, respectively, via S(N)2 and/or modified Mitsunobu reactions. The racemic homoallylic and homopropargylic alcohol derivatives were successfully resolved in high ee (93-99%) by applying chemoenzymatic methods using various lipases such as PS-C II, Lipozyme, and CAL-B. Each enantiomerically enriched enyne afforded the most conformationally stable diastereomeric cyclopenta[c]pyridine ring system as the sole product, whereas enantiomerically enriched dienes gave tetrahydropyridine derivatives as a result of intramolecular Pauson-Khand and RCM reactions, respectively. (C) 2012 Elsevier Ltd. All rights reserved.