Convergent paired photocatalyzed hydroarylation of β-alkenyl ketones with cyanoaromatics enabled by radical anion sorting

Abstract

A regioselective C(sp³)–C(sp²) coupling of unactivated β-alkenyl ketones with cyanoaromatics by synergetic convergent paired photoredox/CO₂˙⁻ reductive catalysis through radical anion sorting-enabled decyanative hydroarylation for producing β-aryl alkylketones with sterically congested carbons is developed. This reaction achieves regioselective β-arylation of carbonyl compounds via radical anion sorting. It works with a broad range of β-alkenyl ketones and cyano(hetero)aromatics, showing excellent functional group compatibility and exquisite regioselectivity. Mechanistic studies suggest that a radical anion sorting pathway proceeds via sequential single electron reductions by synergetic convergent paired photoredox and CO₂˙⁻ reductive catalysis, wherein an initial alkene radical anion protonation event is followed by a subsequent isomerization, single electron reduction, radical anion–radical anion coupling, decyanation and protonation cascade.