495406-19-4Relevant academic research and scientific papers
Visible light-mediated radical fluoromethylation: Via halogen atom transfer activation of fluoroiodomethane
Deneny, Patrick J.,Gaunt, Matthew J.,Kumar, Roopender
, p. 12812 - 12818 (2021/10/19)
Incorporation of the fluoromethyl group can profoundly influence the physicochemical properties of organic molecules, offering a promising strategy for the discovery of novel pharmaceutical agents. Direct fluoromethylation of unfunctionalized C(sp2) centres can be achieved using fluoromethyl radicals, but current methods for their generation usually rely on the activation of non-commercial or expensive radical precursors via inefficient single electron transfer pathways, which limits their synthetic application. Here we report the development of a fluoromethylation strategy based on the generation of fluoromethyl radicals from commercially available fluoroiodomethane via halogen atom transfer. This mode of activation is orchestrated by visible light and tris(trimethylsilyl)silane, which serves as both a hydrogen- and halogen atom transfer reagent to facilitate the formation of C(sp3)-CH2F bonds via a radical chain process. The utility of this metal- and photocatalyst-free transformation is demonstrated through the multicomponent synthesis of complex α-fluoromethyl amines and amino acid derivatives via radical addition to in situ-formed iminium ions, and the construction of β-fluoromethyl esters and amides from electron-deficient alkene acceptors. These complex fluoromethylated products, many of which are inaccessible via previously reported methods, may serve as useful building blocks or fragments in synthetic and medicinal chemistry both in academia and industry. This journal is
Hydrofluoromethylation of alkenes with fluoroiodomethane and beyond
Chen, Xuanxiao,Gouverneur, Véronique,Hell, Sandrine M.,Meyer, Claudio F.,Ortalli, Sebastiano,Sap, Jeroen B. I.
, p. 12149 - 12155 (2021/09/28)
A process for the direct hydrofluoromethylation of alkenes is reported for the first time. This straighforward silyl radical-mediated reaction utilises CH2FI as a non-ozone depleting reagent, traditionally used in electrophilic, nucleophilic and carbene-type chemistry, but not as a CH2F radical source. By circumventing the challenges associated with the high reduction potential of CH2FI being closer to CH3I than CF3I, and harnessing instead the favourable bond dissociation energy of the C-I bond, we demonstrate that feedstock electron-deficient alkenes are converted into products resulting from net hydrofluoromethylation with the intervention of (Me3Si)3SiH under blue LED activation. This deceptively simple yet powerful methodology was extended to a range of (halo)methyl radical precursors including ICH2I, ICH2Br, ICH2Cl, and CHBr2F, as well as CH3I itself; this latter reagent therefore enables direct hydromethylation. This versatile chemistry was applied to18F-,13C-, and D-labelled reagents as well as complex biologically relevant alkenes, providing facile access to more than fifty products for applications in medicinal chemistry and positron emission tomography.
An aryne triggered ring-opening fluorination of cyclic thioethers with potassium fluoride
Fan, Rong,Liu, Binbin,Zheng, Tianyu,Xu, Kun,Tan, Chen,Zeng, Tianlong,Su, Shuaisong,Tan, Jiajing
, p. 7081 - 7084 (2018/07/05)
Herein, we report an aryne triggered ring-opening fluorination protocol of a great variety of saturated sulfur heterocycles. A key factor for the success is the identification of a suitable mediator. Compared to previous methods, this transition-metal free protocol employs low-cost potassium fluoride as the fluorine source. The operational simplicity and mild reaction conditions allow for the rapid synthesis of a wide range of aliphatic fluoride compounds in good yields.
Hypervalent Iodine(III)-Mediated Oxidative Fluorination of Alkylsilanes by Fluoride Ions
Xu, Peng,Wang, Feng,Fan, Guilan,Xu, Xiufang,Tang, Pingping
, p. 1101 - 1104 (2017/01/18)
The first example of a hypervalent iodine(III)-mediated oxidative fluorination of alkylsilanes by fluoride ions without the use of transition metals is demonstrated. This reaction is operationally simple, scalable, and proceeds under mild reaction conditions. Mechanistic studies suggest the involvement of a single-electron transfer resulting from the interaction of an organopentafluorosilicate and aryliodonium difluoride, which were generated in situ from the corresponding alkylsilane and iodosobenzene, respectively, in the presence of fluoride ions.
Fluorine-18 Radiolabeling and Radiopharmacological Characterization of a Benzodioxolylpyrimidine-based Radiotracer Targeting the Receptor Tyrosine Kinase EphB4
Mamat, Constantin,Mosch, Birgit,Neuber, Christin,K?ckerling, Martin,Bergmann, Ralf,Pietzsch, Jens
, p. 1991 - 2003 (2013/01/15)
Members of the Eph receptor tyrosine kinase family play essential roles in the pathogenesis of cancer and are therefore promising candidates for molecular imaging by positron emission tomography (PET), for example. In this regard, radiochemical access to
Cocatalysis in phase-transfer catalyzed fluorination of alkyl halides and sulfonates
Ma?kosza,Bujok
, p. 209 - 216 (2007/10/03)
Phase-transfer catalyzed (PTC) fluorination of alkyl halides and sulfonates with solid KF proceeds efficiently when cocatalyst triphenyltin fluoride is used. The cocatalytic action of the tin compound consists in continuous formation of difluorotriphenylstannate anion that as the tetraalkyloammonium salt enter the solution where it reacts with alkyl halides to produce alkyl fluorides. The cocatalytic system was used to synthesis of 1,1-difluoroalkanes in two steps from aldehydes. A new kind of PTC was elaborated in which Ph 3SnF acts as phase transfer catalyst via continuous formation of potassium salts of diflurotriphenylstannate anions soluble in dipolar aprotic solvents. A new, simple and general method of synthesis of tetraalkylammonium and potassium salts of difluorotriorgano-tin, silicon and germanium anions is reported.
