A novel and versatile method for the synthesis of 2H-imidazoles via iron-catalyzed [3 + 2] annulation from readily available oxime acetates with vinyl azides has been developed. This denitrogenative process involved N–O/N–N bond cleavages and two C–N bond formations to furnish 2,4-substituted 2H-imidazoles. This protocol was performed under mild reaction conditions and needed no additives or ligands
Deoximation of Oxime<i>O</i>-Acetates, Oximes, and Oxime Ethers by Nonacarbonyldiiron or Pentacarbonyliron. An Electronic Effect for the N–O Bond Cleavage
The reaction of [Fe2(CO)9] or [Fe(CO)5] with oxime O-acetates, oximes, and oxime ethers under photoirradiation or thermal conditions undergoes deoximation to give the corresponding ketones. The oxime O-acetate was found to be the most reactive class of these compounds. A proposed mechanism involves an initial complexation of the [Fe(CO)4] species to the nitrogen atom of the oxime group, and the subsequent
acetates and xanthates for the synthesis of thiazol-2-yl ethers with remarkable regioselectivity has been developed. Various oxime acetates, whether derived from aryl ketones or alkyl ketones, or natural product cores are suitable for this conversion. Unique dihydrothiazoles were also obtained when both reaction sites were methine. Mechanistic studies indicated that imino copper(III) intermediates were involved
Chemoselective [3 + 2] annulation of oxime acetate with 2-aryl-3-ethoxycarbonyl-pyrroline-4,5-dione: an entry to pyrrolo[2,3-<i>b</i>]pyrrole derivatives
A novel chemoselective [3 + 2] annulation reaction of easily accessible ketoxime acetate with 2-aryl-3-ethoxycarbonyl pyrroline-4,5-dione has been developed for the synthesis of unknown pyrrolo[2,3-b]pyrrole frameworks. This method involves copper-mediated N–O bond cleavage followed by the formation of carbon–carbon and carbon–nitrogen bonds. This operationally simple protocol provides broader functional