Visible-Light-Mediated α-Ketoacylations of NH-Sulfoximines with gem-Difluoroalkenes

Abstract

A photochemical approach for the preparation of α-keto-N-acyl sulfoximines from NH sulfoximines and gem-difluoroalkenes has been developed. In the presence of NBS, the reactions proceed in air without the need of a photocatalyst or additional oxidant. Results of mechanistic studies suggest that the two oxygens in the products stem from water and dioxygen.

Ligand-to-Copper Charge-Transfer-Enabled C–H Sulfoximination of Arenes

“…But direct sulfoximination of electron-neutral or deficient arenes has not been established. Conventionally, sulfoximinyl radicals generated from preactivated sulfoximines typically engage in HAT reactions, or addition reactions to highly reactive radicophiles, such as styrenes, that can outcompete HAT . No N - arylation has been reported via addition reactions of sulfoximinyl radicals to a diverse set of arenes.…”

N-Haloimide-enabled halogenationviahalogen-bond-assisted C–C activation of alkanols

“…Based on these experimental findings and previous work, 26 a reaction pathway was proposed to form the alkoxy radical, which was assumed to be a crucial intermediate, as outlined in Scheme 7h. The halogen bonding interaction between alkanol and NIS could generate the reactive hypohalite intermediate VI under photo-irradiation.…”

Visible-light-mediated C–F bond cleavage for the synthesis of polyfluorinated compounds

“…1 Among the variety of polyfluorinated compounds, gem -difluoroalkenes, which have highly similar spatial and electronic distribution to carbonyl groups (such as aldehydes, ketones, and esters), have been recognized as a special class of fluorine-containing moieties that have drawn intense attention from chemists. 2 The conventional synthesis method is the direct gem -difluoromethylenation of carbonyl or diazo compounds. 3 In recent years, a new strategy for the synthesis of different gem -difluoroolefins has been successfully established by using the β-F elimination of α-trifluoromethyl alkenes (Scheme 1a).…”