Fluorinated Sulfilimino Iminiums: Efficient and Versatile Sources of Perfluoroalkyl Radicals under Photoredox Catalysis

Abstract

Reported herein is the use of S-perfluoroalkyl sulfilimino iminiums as a new source of R radicals under visible-light photoredox catalysis (R =CF , C F , CF Br, CFCl ). These shelf-stable perfluoroalkyl reagents, readily prepared on gram scale from the corresponding sulfoxide using a one-pot procedure, allow the efficient photoredox-induced oxyperfluoroalkylation of various alkenes using fac-Ir(ppy) as the photocatalyst. Importantly, spin-trapping/electron paramagnetic resonance experiments were carried out to characterize all the radical intermediates involved in this radical/cationic process.

Merging hypervalent iodine and sulfoximine chemistry: a new electrophilic trifluoromethylation reagent

“…11 One year later, one of our groups extended this methodology to other peruoroalkyl radicals including the triuoromethyl group. 12 One important property of these compounds is the ease with which they can be structurally diversied and their properties nely tuned for targeted applications.…”

Integrated redox-active reagents for photoinduced regio- and stereoselective fluorocarboborylation

“…Along these lines, cascade radical addition of unsaturated hydrocarbons in the absence of metallo-intermediate has been realized through careful manipulation of the radical reactivities [9][10][11] . A single process to achieve radical difunctionalization with extensive functionality tolerance, especially fluorine-containing moieties, is of great value in altering the physical and biological properties of the unsaturated hydrocarbons 4,[12][13][14][15][16][17][18] . Studer and co-workers 19 have reported a radical 1,2-trifluoromethylboration of unactivated alkenes using gaseous CF 3 I.…”

Metal‐Free Visible‐Light‐Mediated Hydrotrifluoromethylation of Unactivated Alkenes and Alkynes in Continuous Flow

“…Based on this analysis and on previous Electron Paramagnetic Resonance experiments with sulfilimino iminiums 1 , a plausible mechanism is depicted in Scheme b. After irradiation with visible light, the formed excited state 4* oxidizes HE 3 .…”