A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1- b]oxazol-6-ium salts

Andrew D Gillie; Matthew G Wakeling; Bethan L Greene; Louise Male; Paul W Davies

doi:10.3762/bjoc.20.54

A laterally-fused N-heterocyclic carbene framework from polysubstituted aminoimidazo[5,1- b]oxazol-6-ium salts

Beilstein J Org Chem. 2024 Mar 18:20:621-627. doi: 10.3762/bjoc.20.54. eCollection 2024.

Authors

Andrew D Gillie¹, Matthew G Wakeling^#¹, Bethan L Greene^#¹, Louise Male¹, Paul W Davies¹

Affiliation

¹ School of Chemistry, University of Birmingham, Birmingham, B15 2TT, UK.

^# Contributed equally.

Abstract

A polysubstituted 3-aminoimidazo[5,1-b]oxazol-6-ium framework has been accessed from a new nitrenoid reagent by a two-step ynamide annulation and imidazolium ring-formation sequence. Metalation with Au(I), Cu(I) and Ir(I) at the C2 position provides an L-shaped NHC ligand scaffold that has been validated in gold-catalysed alkyne hydration and arylative cyclisation reactions.

Keywords: NHC; annulation; carbene; gold; imidazolium.

Grants and funding

We thank EPSRC and the School of Chemistry at the University of Birmingham for studentship support (ADG, MGW, BLG). P.W.D. is grateful to the Royal Society and Leverhulme Trust for the award of a Senior Research Fellowship (SRF\R1\191033).