Photocatalytic Difluoromethylation Reactions of Aromatic Compounds and Aliphatic Multiple C–C Bonds

Abstract

Among the realm of visible light photocatalytic transformations, late-stage difluoromethylation reactions (introduction of difluoromethyl groups in the last stages of synthetic protocols) have played relevant roles as the CF2X group substitutions exert positive impacts on the physical properties of organic compounds including solubility, metabolic stability, and lipophilicity, which are tenets of considerable importance in pharmaceutical, agrochemical, and materials science. Visible-light-photocatalyzed difluoromethylation reactions are shown to be accomplished on (hetero)aromatic and carbon–carbon unsaturated aliphatic substrates under mild and environmentally benign conditions.

Rose Bengal-photocatalyzed perfluorohexylation reactions of organic substrates in water. Applications to late-stage syntheses

“…However, a vast majority of photocatalyzed perfluoroalkylation transformations of organic substrates are carried out in MeCN or DMSO, or mixtures of these latter solvents with MeOH or acetone [9,18]. In particular, a few visible light photocatalyzed fluoroalkylation reactions of organic substrates in aqueous media have recently been reported [17,[19][20][21][22][23][24][25][26], and some are illustrated in Scheme 1.…”

Visible-Light-Driven Direct 2,2-Difluoroacetylation Using an Organic Pigment Catalyst

“…Recently, gem -difluorinated compounds have gained considerable interest within the synthetic community because the CF 2 motif of the molecules allows drastic changes in their chemical, physical, and biological properties, including chemical reactivity of the neighboring functional groups, metabolic stability, and bioavailability . In addition, there are limited means to access the corresponding gem -difluorinated molecules compared to those of the monofluorinated or trifluoromethyl-substituted compounds. − Molecules, which contain a CF 2 CO 2 R group, are attractive building blocks for gem -difluoromethylene groups because they allow easy functional group modification of the appended alkyl group. − CF 2 CO 2 R-containing compounds have traditionally been prepared by the fluorination of carbonyl or thiocarbonyl groups. − However, the most striking means to realize the 2,2-difluoroacetylation is the introduction of CF 2 CO 2 R to organic compounds (Figures – ). − …”

Progress in Visible Light‐Induced Difluroalkylation of Olefins

“…The subsequent radical addition to the olefinic bond with further transformation would produce the corresponding fluorinated products. Several researchers have reviewed the photoinduced fluoroalkylation chemistry even covered the area of difluoroalkylation chemistry [64–68] . However, the present review focused only on the recent development of the photocatalytic difluoroalkylation of olefin.…”

“…Several researchers have reviewed the photoinduced fluoroalkylation chemistry even covered the area of difluoroalkylation chemistry. [64][65][66][67][68] However, the present review focused only on the recent development of the photocatalytic difluoroalkylation of olefin. Examples involving combinational strategies of difluroalkylation of olefin with intramolecular functional group migration, cascade difluoroalkylation and CÀ H annulation reactions/ring expansion, threecomponent alkynyl-difluoroalkylation of olefin, visible-light induced catalyst/oxidant-free difluoroalkylation, fluoroalkylsulfonylation and difluoromethylcarboxylation with CF 2 RSO 2 M are also reviewed.…”