Activation and regioselectivity of five-membered cyclic thionocarbamates to nucleophilic attack


Awheda I., SAYGILI N. , Garner A. C. , Wallis J. D.

RSC ADVANCES, vol.3, no.47, pp.24997-25009, 2013 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 3 Issue: 47
  • Publication Date: 2013
  • Doi Number: 10.1039/c3ra41074a
  • Title of Journal : RSC ADVANCES
  • Page Numbers: pp.24997-25009

Abstract

The cyclic thionocarbamate of alaninol undergoes nucleophilic attack by sulfur nucleophiles at 5-C to give 1-thiopropyl-2-amine derivatives when derivatised on nitrogen with a Boc group. Iodide under microwave conditions causes a rearrangement to the isomeric thiazolidinone, while "hard" nucleophiles react at the thione group to yield a variety of product types by subsequent C-N or C-O cleavage. X-ray crystallography studies showed that the N-Boc group reduces delocalisation of electron density from nitrogen into the thione group, and thus promotes activation of the ring to nucleophilic attack.