Internal nucleophilic catalyst mediated cyclisation/ring expansion cascades for the synthesis of medium-sized lactones and lactams

Aggie Lawer, James A Rossi-Ashton, Thomas C Stephens, Bradley J Challis, Ryan G Epton, Jason M Lynam, William Paul Unsworth

Research output: Contribution to journalArticlepeer-review


A strategy for the synthesis of medium-sized lactones and lactams from linear precursors is described in which an amine acts as an internal nucleophilic catalyst to facilitate a novel cyclisation/ring expansion cascade sequence. This method obviates the need to use high-dilution conditions usually associated with medium-ring cyclisation protocols, as the reactions operate exclusively via kinetically favourable 'normal' sized cyclic transition states. This same feature also enables biaryl-containing medium-sized rings to be prepared with complete atroposelectivity via point-to-axial chirality transfer.

Original languageEnglish
Pages (from-to)13942-13947
JournalAngewandte Chemie International Edition
Issue number39
Early online date13 Aug 2019
Publication statusPublished - 24 Sept 2019

Bibliographical note

© 2019 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.


  • atropisomers
  • axial chirality
  • medium-sized rings
  • pyridines
  • ring expansion

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