Amine gas treating

Radical

Enantioselective synthesis

Catalysis

Organic chemistry

Nucleophile

Chemistry

Amination

Combinatorial chemistry

Imine

Iminium

Reductive amination

Photoredox catalysis

Electrophile

Photocatalysis

Organocatalysis

Photochemistry

Umpolung

Radical ion

ACS Catalysis

The construction and manipulation of amine-containing architectures is of importance to academic and industrial development and discovery programs. The photochemical single-electron reduction of imine derivatives to generate α-amino radical intermediates has emerged as a powerful umpolung strategy for opening up underexplored routes to such amine motifs. Furthermore, these radicals have been shown to engage in a wide variety of chemistry, including radical–radical coupling, addition to electrophiles, and reductive amination chemistry. The concept has also begun to see application to iminium ion intermediates and the extension to enantiocontrolled C–C bond formation. This Perspective covers recent efforts in this synthetic strategy to simple and complex amine structures alike.

α-Amino Radicals via Photocatalytic Single-Electron Reduction of Imine Derivatives