An electrochemical trifluoromethylation/spirocyclization of N-benzylacrylamides with CF₃SO₂Na as the source of trifluoromethyl group has been developed. This approach is carried out in a simple undivided cell at room temperature without relying on metal-reagents and oxidants, which provides a green and efficient route to construct a series of CF₃-containing 2-azaspiro[4.5]decanes. Furthermore, the gram-scale synthesis and transformation can be easily performed.

A [3+2] cyclization of difluoromethyl nitrile imines generated in situ from difluoroacetohydrazonoyl bromides with β-(N,N-dimethylamino)enones/enoates/enamides in the presence of base is described. The cycloaddition reaction pro- duced the pyrazoline intermediates, from which 3,4-disubstituted-3-difluoromethylpyrazoles were obtained in moderate to good yields via spontaneous elimination of the Me₂NH molecule. The reaction is fully regioseclective by the interaction of lowest unoccupied molecular orbital (LUMO) of the 1,3-dipoles and highest occupied molecular orbital (HOMO) of electron-rich alkenes (inverse-electron-demand). This approach expands the types of [3+2] cyclization involved difluoro- methyl nitrile imines, which provides a simple, efficient and novel method for the synthesis of 3-difluoromethylpyrazoles.

A novel three-component cascade radical reaction involving non-activated olefins, quinoxalin-2(1H)-ones, and AgSCF₃ was proposed. Under the action of the oxidizing agent K₂S₂O₈, 40 quinoxaline derivatives containing SCF₃ were obtained with the highest yield of 78%. This method provides a mild and environmentally friendly approach to prepare trifluoromethylthio-substituted quinoxalines, offering advantages such as high yield, broad substrate scope, atom economy, and environmental efficiency.

Palladium-catalyzed C(sp³)—Si bonds transformation of commercially available polyalkoxy trifluorosilane reagents has been developed through C(sp³)—C(sp²) cross-coupling reactions. This Hiyama cross-coupling reaction shows good functional group tolerance and provides a series of trifluoropropyl (hetero)arenes. The fluoride source and alkyl tether of bisphosphine ligand play important roles in improving yields.

Perovskite solar cells (PSCs) are of significant importance in the fields of environment, ecology, and energy structure adjustment due to their exceptional performance, cost-effectiveness, and straightforward preparation process. Among them, hole transport materials (HTMs) play a crucial role in PSCs by effectively regulating the battery interface barrier, facilitating hole transport and collection, reducing charge recombination, optimizing the perovskite layer-electrode interface, and enhancing the properties of perovskite light absorption layer. Fluorine-substituted materials possess unique charge transport and photoelectric properties. The introduction of fluorine atoms into organic molecules through induction and conjugation effects can lower molecular energy levels, improve HTM hole mobility thereby enhancing PSCs performance. This paper provides a comprehensive review and summary on the impact of fluorine-substituted organic hole transport materials on the photoelectric properties of PSCs as well as their underlying mechanisms.

An efficient method for the construction of C(sp²)—S bond has been developed. The stable N-heterocyclic carbene 1,3-bis(2,6-dissopropylphenyl)-imidazole-2-ylidene can activate the C—Si bond of pentafluorophenyl trimethylsilicon effectively to initiate the nucleophilic substitution reaction with thiosulfonic ester, producing pentafluorophenyl sulfide products in 34%~98% yields.

Benzoxazines are important motif in pharmaceuticals and functional molecules. A visible-light induced photocatalytic strategy for the synthesis of difluoroethyl benzoxazines with organo-photocatalyst was developed. In the present protocol, a series of olefinic amides can be transferred to difluoroethylated benzoxazines via oxydifluoromethylation with CF₂HSO₂Na as difluoromethylating reagent, which is easily operated and good functional group tolerant.

The unique properties of difluorinated compounds have attracted widespread attention in the fields of medicine and material sciences. The conversion of inexpensive and easily available trifluoromethyl groups into difluoro groups is of great importance in organic synthesis. However, there still exist great challenges in the selective cleavage of C—F bonds, because the dissociation energy of single C—F bond in trifluoromethyl group is much higher than that of the C—F bond in the difluoro unit of the generated product. Thus, the selective cleavage of C—F bond is difficult to control, which can easily lead to excessive defluorination. Compared with the traditional thermal reaction, the visible-light irradiated reaction provides an alternative pathway to achieve C—F cleavage more efficiently and selectively. The research progress on the selective cleavage of C—F bonds mediated by visible light in the past three years is summarized and its future perspective is prospected.

Bromodifluoromethyl trimethylsilane (TMSCF₂Br) has proved to be an important difluoromethyl(alkyl)ation reagent that is widely applied in organic synthesis over the past decade, since it was used as a difluorocarbene precursor in 2011. This review aims to provide a briefly summary for the synthesis of TMSCF₂Br, and to introduce the recent advances in the applications of TMSCF₂Br as a difluorocarbene or trimethylsilyldifluoromethyl radical precursor for developing various difluoromethyl(alkyl)ations of different kinds of substrates. Meanwhile, the activation ways of TMSCF₂Br and the possible mechanism, as well as its advantages and disadvantages in each kind of reactions are detailedly disccussed, which might provide some references and inspiration for researchers engaged in organic synthesis and organic fluorine chemistry.

A novel photoredox/Lewis base dual-catalytic defluorinative silylation reaction of trifluoromethylsubstituted alkenes for the synthesis of gem-difluoroallylsilanes is reported, where silylboranes are employed as the silyl donor reagents. The protocol proceeds via the catalytic activation of Si—B bond by a Lewis base quinuclidine and the formation of silyl radical, making it easy to scale up. It features mild and green reaction conditions, simple reaction system, broad substrate scope and good functional group compatibility. Furthermore, the potential of this class of building blocks in the construction of various gem-difluoromethyl-containing structures has been also demostrated.

The last decade has witnessed the great development of SuFEx reactions. The synthetic value of SuFEx reactions in the preparation of small molecules and polymers is reviewed. The paper is arranged based on the types of substrates and the possible direction of the reaction is discussed.

A supporting electrolyte-free method for the electrochemical synthesis of trifluoromethylated oxindoles in conti- nuous flow was developed. Various N-arylacrylamides reacted with CF₃SO₂NHNHBoc smoothly to provide the corresponding products in moderate yields. The reaction scale-up was easily realized without changing the reaction conditions, which showed the application potential of continuous flow electrochemical synthesis.

The [3+2] cycloaddition reactions of trifluoroacetohydrazonoyl bromides with ynones, alkynoates and aynamides have been developed, and a series of 3-trifluoromethylpyrazole derivatives were obtained in medium to excellent yields. The noble features of this protocol include excellent regioselectivity, good functional group tolerance, mild reaction conditions and simple operation. It provides an efficient and practical method for the synthesis of 3-trifluoromethylpyrazoles.

In this study, a visible-light photoredox-catalyzed difluoroalkylation of newly designed functionalized aromatic isocyanides with commercially available CF₂ precursors was reported. A series of CF₂-containing indole-1,2-fused diazepanones were constructed in cascade reaction through a sequence of radical addition/cyclization processes under mild conditions. This reaction not only generated a class of polycyclic indole fused seven-membered nitrogen heterocycles but also expanded the reactions of functionalized isocyanides.

Based on the main skeleton of fluoroboron dipyrrole (BODIPY), two near-infrared fluorescent probes Azo-BDP1 and Azo-BDP2 were rationally designed and synthesized with large Stokes shift of 217 and 224 nm, respectively. As two visualized probes for Na₂S₂O₄, Azo-BDP1 and Azo-BDP2 exhibited high sensitivity and selectivity. The reaction-based recognition mechanism was confirmed by mass spectral analysis, in addition, fluorescence imaging studies in zebrafish embryos and zebrafish proved that the probe Azo-BDP1 is suitable for the detection of Na₂S₂O₄ in vivo.

In order to meet the demand of data storage security in the rapid development of information, a π-conjugated triphenylamine-based difluororboron compound (PyTPABF₂) was designed and successfully synthesized. PyTPABF₂ held positive solvatochromism behavior, intramolecular charge transfer property, aggregation-induced emission behavior and high contrast mechanofluorochromic performance. The as-prepared powders PyTPABF₂ exhibited bright green fluorescence (533 nm), which luminescent color switching to khaki (556 nm) under external mechanical stimulation, meanwhile, the color could recover to original state after fuming. The X-ray diffraction (XRD) measurement demonstrated that this phenomenon originated from the process of phase transformation between crystalline and amorphous. More importantly, PyTPABF₂-based data secu-rity paper could be achieved rewritable storage of information. It was of assistance in the rational design of smart luminescent materials.

Deuterated mono- and difluoroalkyl groups have attracted increasing attention in medicinal and biological studies. Controllable snipping one or two fluorine atoms from widely accessible trifluoromethyl groups followed by deuteration is an attractive method to access these molecules, whereas this has been hindered by the challenges associated with the chemoselectivity control during the defluoriantion process. Herein, a strategy for chemoselective deuterodefluorination reaction of trifluoro- and difluoroalkylacetamides via spin-center shifts is reported. The reaction starts with the attack of a deuterated 4-dimethylaminopyridine-boryl radical (DMAP-BD₂) to the amide oxygen atom, followed by a spin-center shift process to trigger the C—F bond scission. The resulting α,α-difluorocarbonyl radicals undergo deuterium atom transfer to afford the CF₂D-products in high yields and high levels of D-incorporation. Notably, increasing the amount of DMAP-BD₃ enables the selective cleavage of the two C—F bonds, leading to CFD₂-products in good yields meanwhile maintaining good levels of D-incorporation.

The synthesis and transformation of fluorine-containing organic molecules has experienced vigorously development and has become one of the most important frontier topics of fluorine chemistry, which profoundly affects life science and material science. Among them, carbonylative transformation of fluorocarbon-containing substrates is a carbonylation reaction developed in recent years which still has many challenges. This review summarized the progresses on fluorocarbon-containing substrates carbonylation reactions based on transition metal palladium, nickel and copper catalysis. In order to understand the mechanism of these reactions, representative reactions were selected for detailed discussion.

Fluoride ion is closely related to human life activities. Excessive or too little fluoride ions in human body will cause pathological changes. Therefore, it is necessary to develop appropriate measures to detect the fluoride ion content in human body and environment. Colorimetry and fluorescence detection have attracted much attention due to their high selectivity, high sensitivity and fast response. Herein, reaction-based fluoride ion probes are introduced. According to the reaction mechanisms, these probes can be divided into five types: interactions between fluoride ion and boronic acid derivatives, fluoride ion-promoted cleavage of Si—C bond, fluoride ion-promoted cleavage of Si—O bond, fluoride ion-induced dehydrogenation, fluoride ion-promoted cleavage of P—O bond. Not only the detection method of the probe is introduced, but also the action mechanism of some examples is described.

Polycyclic indoles are widely found in natural products and pharmaceutical molecules, and have a wide range of applications in the pharmaceutical, pesticide and dye industries. Although considerable development has been made in the synthesis of indole polycycles, it is still of great scientific interest and value to explore more efficient and milder experimental strategies for the synthesis of highly-functionalized polycyclic indoles. Herein, a one-step radical tandem cyclization reaction to synthesize difluoroalkylindoles with quaternary carbon centers by using difluorobromoesters as the fluorine source and 3-alkenyl indoles as the substrates under visible light-catalyzed conditions was developed. The method is easy-to-operate and mild in conditions, with a wide range of substrate adaptability and good yields, providing a green and efficient synthetic route for fluorine-containing polycyclic indoles.

Ir(III)-catalyzed three-component cascade reaction to construct unique trifluoroethoxylation amide compounds has been developed, meanwhile the fluorinated compounds could continue to react with alcohols to prepare complex spiro isoindolinone derivatives in one-pot. The highly efficient approaches produce various amide compounds by condition- controlled.

Photocatalytic heterogeneous chlorotrifluoromethylation and iodoperfluoroalkylation of unactivated terminal alkenes have been achieved under the catalysis of phenylphenothiazine-based porous organic polymer (PTH-POP). This method offers a transition-metal-free and recyclable platform to access valuable perfluoroalkylated compounds in a highly efficient fashion.

A protocol for the copper-catalyzed decarboxylative cross-coupling of α‑fluoroacrylic acids with N-tosyl oxaziridines was reported. A series of substituted α-fluoroacrylic acids, and primary, secondary and tertiary substituted oxaziridines were suitable reaction substrates. The decarboxylation reaction exhibited good functional group compatibility and excellent Z-stereoselectivity. This method provides a novel and practical strategy for the construction of monofluoroalkenes, which are key functional groups in the pharmaceutical and material sciences. In addition to α-fluoroacrylic acids, β- fluoroacrylic acid could also participate in the reaction smoothly, which provides a protocol to access various substituted monofluoroalkenes. This methodology also provides a platform for the modification of complex biologically active molecules.

A novel transition-metal-free protocol for the synthesis of 1-alkyl-3-(2-oxo-2-aryl/alkyl-ethyl)indolin-2-ones is developed. This work reveals that oxoindole skeletons can be directly constructed from ortho-vinylanilines and commercially available halogenated difluoroalkyl reagents via a C—N cleavage/new C—N bonds and C—C bond formation cascade. This reaction portrays high efficiency and excellent functional group compatibility, and has great potential in the late-stage modifications of pharmaceutical molecules and natural products.

Photoredox-catalyzed 2∶2 coupling of styrene and BrCF₂CO₂Me is reported, which undergoes a homo-coupling of in situ generated β-CF₂CO₂Me substituted benzyl radical. The reaction features a wide substrate scope and functional group tolerance to afford bis-difluoroacetylated hexestrol derivatives with high yields.

N-Fluoroallyl hydrazones with four-ring structure were effectively synthesized using cyclobutanone hydrazones and gem-difluorocyclopropanes as raw materials through palladium catalyzed ring opening of difluorocyclopropanes and nucleophilic capture process of nitrogen nucleophile. This protocol shows broad substrate scope and good functional group tolerance, which can be applied for gram-scale preparation.

A photosensitizer-free visible-light-promoted method for site-selective trifluoromethylation of tryptophan- containing oligopeptides using YlideFluor as the trifluoromethyl radical source under mild conditions was developed. Mechanistic studies showed that a donor-acceptor between 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and YlideFluor is generated. Upon irradiation with blue LEDs, the S—CF₃ bond in the adduct undergoes homolytic cleavage to give trifluoromethyl radical, which attacks the electron-rich C-2 position of the indole moiety in the tryptophan-containing oligopeptide.

Selective C-F bond activation of the trifluoromethyl group is an important approach for the synthesis of gem-difluoro compounds. Given the importance of trifluoromethyl alkenes in synthetic chemistry as well as their diversity in selectivity, the research on selective C-F bond activation of these compounds has received considerable interest. To this end, The research progress is summarized, including nucleophilic addition/defluorination (S_N2' type), acid-promoted defluorinative Friedel-Crafts arylation, (formal) ipso-defluorinative functionalization, and transition-metal-catalyzed migratory insertion/ defluorination.