Free-Radical Bromotrifluoromethylation of Olefin via Single-Electron Oxidation of NaSO2CF3 by NaBrO3

10-Phenylphenothiazine-Organophotocatalyzed Bromo-Perfluoroalkylation of Unactivated Olefins

In this study, we have developed a smooth metal-free visible-light-induced bromo-perfluoroalkylation of unactivated olefins with the aid of 10-phenylphenothiazine (PTH) as an organic photoredox catalyst. The reaction is 100% atom-economic redox-neutral and proceeds with stoichiometric amounts of olefin and perfluoroalkyl bromide. To show the potential of these unexplored motifs, we carried out various postfunctionalizations taking advantage of the bromine atom, including gram-scale experiments.

Recent advances in the application of Langlois' reagent in olefin difunctionalization

In this review, we summarise the recent applications of Langlois' reagent in the radical-mediated difunctionalization of alkenes. Among the various trifluoromethylation reagents, Langlois' reagent is an exceptional compound, and many important organic transformations have been realized by employing such reagents. Various organic transformations of Langlois' reagent, especially in radical chemistry, have been developed in recent years. This review describes several key activation methods for Langlois' reagent in the difunctionalization of alkenes by showcasing selected cornerstone research areas and related mechanisms to stimulate the interest of readers in promoting the wider development and application of Langlois' reagent.

A straightforward access to trifluoromethylated natural products through late-stage functionalization

This review summarizes the applications of late-stage strategies in the direct trifluoromethylation of natural products in the past ten years, with particular emphasis on the reaction model of each method.

Recent Advances on the Halo- and Cyano-Trifluoromethylation of Alkenes and Alkynes

Incorporation of fluorine into organic molecules is a well-established strategy in the design of advanced materials, agrochemicals, and pharmaceuticals. Among numerous modern synthetic approaches, functionalization of unsaturated bonds with simultaneous addition of trifluoromethyl group along with other substituents is currently one of the most attractive methods undergoing wide-ranging development. In this review article, we discuss the most significant contributions made in this area during the last decade (2012−2021). The reactions reviewed in this work include chloro-, bromo-, iodo-, fluoro- and cyano-trifluoromethylation of alkenes and alkynes.

Vicinal halo-trifluoromethylation of alkenes

Both trifluoromethyl and halide groups are widely found in medicinally and pharmaceutically important compounds and, moreover, organohalides are commonly used as versatile intermediates in synthetic organic chemistry. Due to their prevalence and easy accessibility, alkene halo-trifluoromethylation provides a convenient way to install these valuable functionalities in complex targets. In this review, we summarize recent advances and achievements in this fast-growing research field. For clarity, the reactions were classified according to the type of halogen atom.

Copper-catalyzed one-pot amine-alkylation of quinones with amines and alkanes

A copper-catalyzed one-pot amine-alkylation of quinones with amines and alkanes in the presence of di-tert-butyl peroxide (DTBP) was developed via a radical reaction process. Various alkanes and aromatic or aliphatic amines with diverse structures and electronic properties are suitable substrates, and the chirality of amines can be maintained for the transformation. This method has high step and atom economy for straightforward access to aminated and alkylated quinones from readily available starting materials.

Zinc–Brønsted acid mediated practical hydrotrifluoromethylation of alkenes with CF3Br

Hydrotrifluoromethylation of alkenes was developed through a novel generation of CF3˙ via the combination of Zn and PhCO2H with CF3Br.

Mn(OAc)3-Mediated Addition Reactions of NaSO2CF3 and Perhalogenated Carboxylic Acids with Unactivated Alkenes Conjectured by a Single Electron Transfer and Halogen Abstraction Mechanism

A free-radical halotrifluoromethylation of olefins by using Mn(OAc)₃·2H₂O, CF₃SO₂Na, and perhalogenated carboxylic acids has been achieved. Perhalogenated carboxylic acids act as a halogen source and CF₃SO₂Na acts as a CF₃ source. The reaction displayed good tolerance of functional groups in the substrates under mild conditions. The radical clock experiment and TEMPO inhibition experiment support a radical process. The halogen reagent competition experiment shows that the last step of halogenation process is mainly through a halogen abstraction mechanism.

Transition-metal-free trifluoromethylative difunctionalization of olefins and alkynes: approaches and challenges ahead

Transition metal free trifluoromethylative difunctionalization of olefins and alkynes represents one of the most efficient methods to generate pharmaceutically and agrochemically important organofluoride compounds.

Dual Roles of tert-Butyl Nitrite in the Transition Metal- and External Oxidant-Free Trifluoromethyloximation of Alkenes

By employing tert-butyl nitrite as both nitrogen source and oxidant, the trifluoromethyloximation of alkenes proceeds smoothly in a free-radical process. The developed difunctionalization reaction enables practical and efficient synthesis of a wide range of α-CF₃ ketoximes in moderate yields with excellent regioselectivity. This method features the use of readily available and stable alkenes as substrates and inexpensive CF₃ SO₂ Na as a CF₃ reagent, no involvement of transition metals or external oxidant, and room-temperature conditions. Moreover, a scale-up of the reaction, further transformation of the products into various valuable CF₃ -containing compounds, and removal of the trifluoromethyl group are readily achieved.

Bond-Forming and -Breaking Reactions at Sulfur(IV): Sulfoxides, Sulfonium Salts, Sulfur Ylides, and Sulfinate Salts

Organosulfur compounds have long played a vital role in organic chemistry and in the development of novel chemical structures and architectures. Prominent among these organosulfur compounds are those involving a sulfur(IV) center, which have been the subject of countless investigations over more than a hundred years. In addition to a long list of textbook sulfur-based reactions, there has been a sustained interest in the chemistry of organosulfur(IV) compounds in recent years. Of particular interest within organosulfur chemistry is the ease with which the synthetic chemist can effect a wide range of transformations through either bond formation or bond cleavage at sulfur. This review aims to cover the developments of the past decade in the chemistry of organic sulfur(IV) molecules and provide insight into both the wide range of reactions which critically rely on this versatile element and the diverse scaffolds that can thereby be synthesized.

Electrochemically Promoted Fluoroalkylation-Distal Functionalization of Unactivated Alkenes

Difunctionalization of olefins represents a powerful synthetic tool and yet a challenging task. This work describes an electrochemically enabled fluoroalkylation-migration reaction of unactivated olefins in the absence of a strong oxidant or heavy metal catalyst, affording fluorinated (hetero)aryl ketones in good yields and excellent regioselectivities. The efficient and sustainable electrochemical strategy provides a rapid access to a dual functionalized fluorine-containing heterocyclic manifold.

Electrochemical vicinal aminotrifluoromethylation of alkenes: high regioselective acquisition of β-trifluoromethylamines

A high-regioselective electrochemical aminotrifluoromethylation of alkenes leading to β-trifluoromethylamines using CF₃SO₂Na as a trifluoromethyl precursor and acetonitrile as an N-nucleophile was achieved.

K2S2O8-Mediated Selective Trifluoromethylacylation and Trifluoromethylarylation of Alkenes under Transition-Metal-Free Conditions: Synthetic Scope and Mechanistic Studies

A practical and efficient method for selective intramolecular radical trifluoromethylacylation and -arylation of alkenes with inexpensive CF₃SO₂Na and K₂S₂O₈ in aqueous media has been developed, respectively, affording the highly chemoselective synthesis of CF₃-functionalized chroman-4-ones and chromanes in satisfactory yields. Control experiments and DFT calculations indicate that the CF₃SO₂Na/K₂S₂O₈ system is capable of trifluoromethylating the substrate of alkenes without a transition metal catalyst and the oxidation of CF₃SO₂Na to ·CF₃ by K₂S₂O₈ is involved in the rate-determining step.

A NaSO2CF3/NaBrO3-mediated bromotrifluoromethylation of enyne via free-radical cascade processes

A NaBrO₃-induced radical bromotrifluoromethylation of enynes with NaSO₂CF₃ was developed. This method allows a transition-metal free, highly selective and step-economic access to diverse bromotrifluoromethylated five- and six-membered heterocycles.

Copper(i) reagent-promoted hydroxytrifluoromethylation of enamides: flexible synthesis of substituted-3-hydroxy-2-aryl-3-(2,2,2-trifluoro-1-arylethyl)isoindolin-1-one

A novel CuBr-catalyzed hydroxytrifluoromethylation reaction was investigated. Substituted 3-benzylidene-2-arylisoindolin-1-ones were reacted with sodium trifluoromethanesulfinate to afford substituted-3-hydroxy-2-aryl-3-(2,2,2-trifluoro-1-arylethyl)isoindolin-1-one.

Transition metal free decarboxylative fluoroalkylation of N-acrylamides with 3,3,3-trifluoro-2,2-dimethylpropanoic acid (TFDMPA)

1,1-Dimethyl-2,2,2-trifluoroethyl substituted oxindoles were prepared by a novel transition metal-free decarboxylative fluoroalkylation of activated alkenes and C–H functionalization cascade process.

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

Sodium trifluoromethanesulfinate, CF3SO2Na, and trifluoromethanesulfonyl chloride, CF3SO2Cl, are two popular reagents that are widely used for the direct trifluoromethylation of a large range of substrates. Further, these two reagents are employed for the direct trifluoromethylsulfenylation and trifluoromethylsulfinylation, the introduction of the SCF3 and the S(O)CF3 group, respectively. In addition to the aforementioned reactions, the versatility of these two reagents is presented in other reactions such as sulfonylation and chlorination. This first part is dedicated to sodium trifluoromethanesulfinate.

Transition-metal-free radical tri-/difluoromethylation of N,N-dialkylhydrazones with sodium sulfinates

An operationally simple and scalable protocol has been developed for radical tri-/difluoromethylation of N,N-dialkylhydrazones under transition-metal-free conditions.

Visible-light-induced thiotrifluoromethylation of terminal alkenes with sodium triflinate and benzenesulfonothioates

An unconventional reductive quenching cycle was developed to realize the visible-light-induced thiotrifluoromethylation of terminal alkenes.