DOI

Substrates that are insufficiently activated towards the hydrated imidazoline ring expansion (HIRE) process have been previously found to deliver exclusively the products of aminoalkyl side-chain ring expansion. Attempted reversal of the process by thermal activation towards HIRE failed. We have found that for such problematic substrates the HIRE-type ring expansion can be effectively achieved by applying lithium hexamethyldisilazide (LHMDS) in toluene. LHMDS is thought to promote intramolecular transamidation, which leads to ring-expanded 10- and 11-membered heterocyclic products in modest to good yields. The process significantly broadens the substrate scope amenable to the HIRE strategy.

Original languageEnglish
Article numberss-2021-t0715-op
Pages (from-to)2494-2510
Number of pages17
JournalSynthesis (Germany)
Volume54
Issue number10
Early online date10 Feb 2022
DOIs
StatePublished - 1 May 2022

    Research areas

  • aminoalkyl sidechain incorporation, facilitated intramolecular transamidation, fused imidazolinium moiety, hydrated imidazoline ring expansion, lithium hexamethyldisilazide, [1,4]diazepinones, [1,4]ox(thi)azepinones, aminoalkyl sidechain- incorporation, CARBOXAMIDES, 4]diazepinones, 4]ox(thi)azepinones, [1, LACTAMS, TRANSAMIDATION

    Scopus subject areas

  • Catalysis
  • Organic Chemistry

ID: 93077628