Towards Stapling of Helical Alleno-Acetylene Oligomers - Synthesis of an Enantiopure Bis(ethynylvinylidene)-Substituted Cyclohexadeca-1,3,9,11-tetrayne


MUELLER I. -. S. , BERNET B., Dengiz C. , SCHWEIZER W. B. , DIEDERICH F.

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, cilt.2014, ss.941-953, 2014 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 2014 Konu: 5
  • Basım Tarihi: 2014
  • Doi Numarası: 10.1002/ejoc.201301529
  • Dergi Adı: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
  • Sayfa Sayıları: ss.941-953

Özet

We are interested in developing strategies to bridge (staple) enantiomerically pure acyclic alleno-acetylenic oligomers to enhance their conformational preferences for helical secondary structures, which are postulated to be at the origin of their exceptional chiroptical properties. We found that ring-closing metathesis (RCM), which has been used for the stapling of peptide helices, failed with an acyclic alleno-acetylene dimer decorated with lateral olefinic side chains. Instead, enyne RCM to an enantiomerically pure dienyne occurred. We switched to the introduction of diacetylene-containing bridges and report here the 15-step synthesis of a moderately strained, enantiomerically pure cyclohexa-1,3,9,11-tetrayne with an oxidative acetylenic coupling in the key step. The chiroptical properties of the new compounds are discussed.