Visible-Light-Induced Monofluoroalkenylation and gem-Difluoroallylation of Inactivated C(sp³)–H Bonds via 1,5-Hydrogen Atom Transfer (HAT)

Abstract

The direct monofluoroalkenylation of C(sp3)–H bonds is of great importance and quite challenging. Current methods have been restricted to the monofluoroalkenylation of activated C(sp3)–H bonds. Here, we reported the photocatalyzed C(sp3)–H monofluoroalkenylation of inactivated C(sp3)–H bonds with gem-difluoroalkenes via 1,5-hydrogen atom transfer. This process shows good functional group tolerance, such as halides (F, Cl), nitrile, sulfone, ester, and pyridine, and good γ-selectivity. Moreover, this method succeeds in the photocatalyzed gem-difluoroallylation of inactivated C(sp3)–H with α-trifluoromethyl alkenes.

Two-in-One Role of Benzophenone in Photoinduced C(sp3)–H Monofluoralkenylation: Hydrogen-Atom Transfer and Single-Electron Transfer

“…As we know, significant progress has been made in this field through nucleophilic addition–elimination reaction or transition-metal-catalyzed cross-coupling reaction . In recent years, the direct monofluoroalkenylation of C­(sp 3 )–H bonds with gem -difluoroalkenes has offered an atom- and step-economical route to multisubstituted monofluoroalkenes . The advantage of visible-light-induced photoredox catalysis has simplified access to C­(sp 3 )-centered radical intermediates from C­(sp 3 )–H bonds, enabling their subsequent radical–radical cross-coupling to produce monofluoroalkenes of C­(sp 3 )–H bonds (Scheme a) .…”

Lewis Acid Promoted Vicinal Oxytrifluoromethylselenolation of Alkenes

“…Consequently, compared with well developed difunctional trifluoromethylthiolation of alkenes, the development of difunctional trifluoromethyl­selenolation of alkenes with diverse nucleophiles is still in great demand. Recently, we have developed a new type of trifluoromethyl­selenolation reagents, trifluoromethyl selenoxides, which were successfully applied to metal-free C–H trifluoromethyl­selenolation of a series of (hetero)­arenes. , In continuation of our interest in the development of trifluoromethylselenolation reagents , and the synthesis of fluoro-containing compounds, herein, we present a metal-free three-component 1,2-oxytrifluoromethyl­selenolation and 1,2-aminotrifluoromethyl­selenolation of various alkenes (Scheme , 2).…”