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Updated: Mar 11, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Umpolung synthesis of branched α-functionalized amines from imines via photocatalytic three-component reductive
Angel L Fuentes de Arriba1, Felix Urbitsch1, Darren J Dixon1
1Department of Chemistry, Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford, UK. Darren.dixon@chem.ox.ac.uk.
Abstract:
A three component reductive coupling reaction of a (hetero)aromatic amine, a (hetero)aromatic aldehyde and an electron deficient olefin catalysed by eosin Y under green LED light irradiation, for the direct generation of γ-amino acid derivatives, is described. This new umpolung synthesis of amines, which exploits the high nucleophilicity of a putative α-amino radical intermediate, generated via single electron reduction of the in situ generated imine from the Hantzsch ester terminal reductant, is efficient, operationally simple, broad in scope and offers a complementary strategy to existing synthetic approaches.
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