Trifluoromethylation of alkenes with concomitant introduction of additional functional groups

Metal-free di- and tri-fluoromethylation of alkenes realized by visible-light-induced perylene photoredox catalysis

Regioselective amino-difluoromethylation of aromatic alkenes via C(sp³)-CF₂H and C(sp³)-N bond formation with the C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 C moiety has been achieved in a single operation by visible-light photoredox catalysis. The combination of a shelf-stable and easy-to-handle sulfonium salt, S-difluoromethyl-S-di(p-xylyl)sulfonium tetrafluoroborate, and perylene catalysis is the key to the successful transformation. Furthermore, this noble metal-free protocol allows for the photocatalytic trifluoromethylation of alkenes.

Palladium-Catalyzed Synthesis of 3-Trifluoromethyl-Substituted 1,3-Butadienes by Means of Directed C-H Bond Functionalization

A palladium-catalyzed C-H bond functionalization of acrylamides was developed to build up stereoselectively trifluoromethylated 1,3-butadienes. Using a tertiary amide as a directing group, olefins were selectively functionalized with 2-bromo-3,3,3-trifluoropropene to access these important fluorinated compounds. The methodology was extended to the construction of pentafluoroethyl-substituted 1,3-dienes. Mechanistic studies supported by density functional theory calculations suggested a redox neutral mechanism for this transformation.

Catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes to versatile enantioenriched-fluoroalkyl amines

Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive radical species. Here we report a catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical sources, providing a versatile platform to access four types of enantioenriched α-tertiary pyrrolidines bearing β-perfluorobutanyl, trifluoromethyl, difluoroacetyl and even difluoromethyl groups in excellent yields and with excellent enantioselectivity. The key to success is not only the introduction of the CuBr/chiral phosphoric acid dual-catalytic system but also the use of silver carbonate to suppress strong background and side hydroamination reactions caused by a stoichiometric amount of the in situ generated HCl. Broad substrate scope, excellent functional group tolerance and versatile functionalization of the products make this approach very practical and attractive.

Methods for the asymmetric introduction of organofluorine groups are often limited by the lack of variability in the starting materials. Here the authors report an asymmetric radical process for the introduction of fluoroalkyl groups using readily available fluoroalkylated sulfonyl chlorides.

Synthesis of Trifluoromethylated Naphthoquinones via Copper-Catalyzed Cascade Trifluoromethylation/Cyclization of 2-(3-Arylpropioloyl)benzaldehydes

A novel copper-catalyzed cascade trifluoromethylation/cyclization of 2-(3-arylpropioloyl)benzaldehydes is described, allowing a direct access to structurally diverse trifluoromethylated naphthoquinones under mild reaction conditions. It represents the first trans-acyltrifluoromethylation of internal alkynes.

An Unconventional Mechanistic Insight into SCF3 Formation from Difluorocarbene: Preparation of 18 F-Labeled α-SCF3 Carbonyl Compounds

Trifluoromethylthiolation by sulfuration of difluorocarbene with elemental sulfur is described for the first time, which overrides long-standing trifluoromethyl anion-based theory. Mechanistic elucidation reveals an unprecedented chemical process for the formation of thiocarbonyl fluoride and also enables transition-metal-mediated trifluoromethylthiolation and [¹⁸ F]trifluoromethylthiolation of α-bromo carbonyl compounds with broad substrate scope and compatibility.

Fluorinative ring-opening of cyclopropanes by hypervalent iodine reagents. An efficient method for 1,3-oxyfluorination and 1,3-difluorination

A new method is presented for 1,3-difluorination and 1,3-oxyfluorination reactions. The process is based on iodonium mediated opening of 1,1-disubstituted cyclopropanes. The reaction proceeds with high chemo- and regioselectivity under mild reaction conditions typically at room temperature in a couple of hours. The reaction probably occurs via electrophilic ring-opening of cyclopropanes.

Ruthenium(II)-Catalyzed meta C-H Mono- and Difluoromethylations by Phosphine/Carboxylate Cooperation

Ruthenium(II)-catalyzed meta-selective C-H (di)fluoromethylation was accomplished by phosphine and carboxylate cooperation. The remote C-H functionalization was characterized by ample substrate scope, thereby setting the stage for meta-(di)fluoromethylation through facile C-H cleavage.

Copper-Mediated Domino Cyclization/Trifluoromethylation/Deprotection with TMSCF3: Synthesis of 4-(Trifluoromethyl)pyrazoles

A copper-mediated synthesis of 4-(trifluoromethyl)pyrazoles is described. In one step from readily accessible α,β-alkynic tosylhydrazones, a remarkable domino sequence of cyclization, trifluoromethylation, and detosylation takes place to furnish the 4-CF₃ N-H pyrazole cores with good functional group compatibility. The reaction conditions are mild and convenient, at room temperature in air, using the commercially available trifluoromethyltrimethylsilane (TMSCF₃) as the CF₃ source. The method can be applied to the synthesis of a 4-CF₃ analogue of the anti-inflammatory drug celecoxib.

Phosphine-catalyzed remote α-C–H bond activation of alcohols or amines triggered by the radical trifluoromethylation of alkenes: reaction development and mechanistic insights

An efficient radical protocol for concomitant functionalization of both alkenes and remote α-C–H bonds of alcohols or amines via 1,5(6,7)-HAT was realized in a highly controlled site-selective manner.

Photoredox-catalyzed oxytrifluoromethylation of allenes: stereoselective synthesis of 2-trifluoromethylated allyl acetates

A novel stereoselective synthesis of 2-CF₃-allyl acetates by photocatalytic oxytrifluoromethylation of allenes has been developed.

Photoredox-catalysed chloro-, bromo- and trifluoromethylthio-trifluoromethylation of unactivated alkenes with sodium triflinate

A convenient and practical protocol is developed for radical vicinal difunctionalization of unactivated alkenes under transition-metal-free conditions.

Efficient trifluoromethylation via the cyclopropanation of allenes and subsequent C–C bond cleavage

Trifluoromethyl has been efficiently incorporated into organic skeletons via allene cyclization and C–C bond cleavage.

Highly shape- and regio-selective peroxy–trifluoromethylation of styrene by metal–organic framework Cu3(BTC)2

The peroxy and trifluoromethyl groups play important roles in pharmacy, but it is challenging to introduce both of them selectively into the target molecules in a homogeneous catalytic system.

The direct decarboxylative allylation of N-arylglycine derivatives by photoredox catalysis

The direct decarboxylative allylation of N-arylglycine derivatives has been accomplished via visible-light photoredox catalysis.

Highly efficient and versatile synthesis of α,α-difluoro-γ-lactams via aminodifluoroalkylation of alkenes

An efficient approach to α,α-difluoro-γ-lactam derivatives was developed using a copper/amine catalyst via a tandem radical cyclization pathway.

Copper-catalyzed acyltrifluoromethylation of alkenes: rapid access to trifluoroethyl indanones and related compounds

Copper-catalyzed acyltrifluoromethylation of alkenes is described, affording trifluoroethyl indanones and related cyclic ketones in promising yields with excellent diastereoselectivity.

Silver-catalyzed formal [3+2]-cycloaddition of α-trifluoromethylated methyl isocyanides: a facile stereoselective synthesis of CF3-substituted heterocycles

An Ag-catalyzed formal [3+2]-cycloaddition of α-trifluoromethylated methyl isocyanides with polar double bonds has been developed for the expeditious synthesis of trifluoromethylated oxazolines, imidazolines and pyrrolines under mild conditions.

Regioselective synthesis of difluoroalkyl/perfluoroalkyl enones via Pd-catalyzed four-component carbonylative coupling reactions

The first example of Pd-catalyzed four-component carbonylative difluoroalkylation/perfluoroalkylation through the alkyne difunctionalization process is achieved.

Photoredox-catalysed redox-neutral trifluoromethylation of vinyl azides for the synthesis of α-trifluoromethylated ketones

A redox-neutral, mild, and simple protocol is developed for the synthesis of α-trifluoromethylated ketones from vinyl azides upon visible-light irradiation.

1,2-Difunctionalization-type (hetero)arylation of unactivated alkenes triggered by radical addition/remote (hetero)aryl migration

A novel (hetero)arylation of unactivated alkenes has been developed via 1,4(5)-(hetero)aryl migration triggered by radical alkene azidation, trifluoromethylation, or phosphonylation.

Copper-catalyzed trifluoromethylazidation and rearrangement of aniline-linked 1,7-enynes: access to CF3-substituted azaspirocyclic dihydroquinolin-2-ones and furoindolines

A set of reactions involving copper-catalyzed trifluoromethylazidation and then rearrangement of aniline-linked 1,7-enynes was developed, and provided facile access to azaspirocyclic dihydroquinolin-2-ones, furoindolines and functionalized aziridines.

Electronic halocyclization and radical haloazidation of benzene-linked 1,7-dienes for the synthesis of functionalized 3,1-benzoxazines

Electronic halocyclization and radical haloazidation of benzene-linked 1,7-dienes by using TMSN₃ as an azidyl source and NBS as a halogen source has been disclosed in this paper, producing a series of functionalized 3,1-benzoxazines in moderate to good yields.