Photoredox-catalyzed redox-neutral difluoroalkylation to construct perfluoroketones with difluoroenoxysilanes

Abstract

A mild and facile approach to construct various perfluoroketones via photo-catalyzed difluoroalkylation of difluoroenoxysilanes is accomplished. The reaction includes the strategy of combination of two fluorine-containing functional groups, which confers...

Visible‐Light Promoted Radical Fluoroalkylation of O‐ and N‐Substituted Alkenes

“…They are obtained from α,α,α‐trifluoro‐substituted ketones by reductive silylation [55] . Their reaction with bromodifluoroacetic ester and amide, as well as with perfluorinated alkyl iodides, was performed under standard photocatalytic conditions [56] (Scheme 9). Here, the reaction was best performed with water as a cosolvent and using sodium hydrogen bisulfite as a scavenger of the silylating agent by‐product.…”

Photoredox-Catalyzed N-Directed Regioselective Difluoroalkylation of Unactivated C(sp3)–H Bonds

“…Cai and co-workers reported the first successful radical addition reaction of difluoro­enoxysilanes with arene diazonium tetrafluoroborates, generating a series of α-aryl-α,α-difluoroketones . Subsequently, cost-effective and environmentally friendly photoredox approach was developed for the reactions of difluoro­enoxysilanes with various radical precursors including Katritzky salts, alkyl carboxylic redox esters, and fluoroalkyl bromides . Inspired by these advances and our continued interest in organofluorine chemistry and remote C­(sp 3 )–H functionalization, we envision the possibility of regioselectively introducing α,α-difluoroketone fragments at unactivated sp 3 -hybridized carbon centers using mild photoredox catalysis.…”