Visible-Light-Activated Enantioselective Perfluoroalkylation with a Chiral Iridium Photoredox Catalyst

Abstract

A visible-light-activated enantioselective radical perfluoroalkylation of 2-acyl imidazoles with perfluoroalkyl iodides (CF₃I, C₃F₇I, C₄F₉I, C₆F₁₃I, C₈F₁₇I and C₁₀F₂₁I) and perfluorobenzyl iodide at the α-position of the carbonyl group is reported. Enantioselectivities with up to >99.5% ee are achieved. The process uses a dual-function chiral Lewis acid/photoredox catalyst at loadings of 2–4 mol% and constitutes a redox-neutral, electron-catalyzed reaction that proceeds via intermediate perfluoroalkyl radicals.

Key words

photoredox catalysis - asymmetric catalysis - visible light - perfluoroalkylation - radical reaction - electron catalysis

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