558-22-5Relevant academic research and scientific papers
1,2-(Bis)trifluoromethylation of Alkynes: A One-Step Reaction to Install an Underutilized Functional Group
Guo, Shuo,AbuSalim, Deyaa I.,Cook, Silas P.
, p. 11704 - 11708 (2019)
Modifying the electronic properties of olefins is the quintessential approach to tuning alkene reactivity. In this context, the exploration of trifluoromethyl groups as divergent electronic modifiers has not been considered. In this work, we describe a copper-mediated 1,2-(bis)trifluoromethylation of acetylenes to create E-hexafluorobutenes (E-HFBs) under blue light in a single step. The reaction proceeds with high yield and E/Z selectivity. Since the alkyne captures two trifluoromethyl groups from each molecule of bpyCu(CF3)3, mechanistic studies were conducted to illuminate the role of the reactants. Interestingly, E-HFBs exhibit remarkable stability to standard olefin functionalization reactions in spite of the pendant trifluoromethyl groups. This finding has significant implications for medicine, agroscience, and materials.
Integrated infrared intensities and atomic polar tensors in fluoroform
Kim, Kwan,King, W. T.
, p. 5591 - 5597 (1980)
The integrated intensities of the fundamental modes in HCF3 and DCF3 have been measured by Wilson-Wells-Penner-Weber method, and the atomic polar tensors were derived.The effective atomic charge for fluorine was found to be χF/e=0.598+/-0.018, in good agreement with that in other fluorocarbons.The effective atomic charge for hydrogen was found to be χH/e=0.049+/-0.006, a value somewhat lower than that found in other hydrocarbons and their derivatives.
Hydrogen isotope exchange between fluoroform (CF3H) and water. 2. Catalysis by hydroxide ion in the presence of added dimethyl sulfoxide
Symons, E. Allan,Clermont, Michel J.,Coderre, Lorraine A.
, p. 3131 - 3135 (1981)
Hydroxide ion catalyzed isotope exchange between CF3D or CF3T and Me2SO/water has been studied as a function of solvent composition and temperature in a stirred reactor. The solubility of CF3H gas in the catalyst solutions has been measured over a range of temperatures to enable conversion of the experimental exchange rate constants to in-solution values The resultant kobsd (CF3D) for 0.011 mol·L-1 -OH at 49.1°C increases by a factor of 106 on changing from water to 70 mol % Me2SO. The heat of solution of CF3H at 50°C passes through a minimum in the region of 30-35 mol % Me2SO; the "salting-out" effect on CF3H solubility is also strongest in this region of greatest Me2SO/H2O association. Hydrolysis of CF3H is a factor of ca. 600 slower than isotope exchange at 50°C in 30 mol % Me2SO. The slopes of linear plots of log kobsd(CF3D) vs H- and vs. Cox and Stewart's excess basicity function are 0.80 and 0.99, respectively; their significance is discussed. The Arrhenius activation parameters (CF3D) determined as a function of solvent composition have been broken down to enthalpy, entropy, and free energy of transfer functions for the reactants and transition state. Comparisons are made with similar data available for chloroform and molecular hydrogen. The primary kinetic isotope effect kD/kT, calculated from rate constant data for CF3D and CF3T exchange, increases smoothly from an inverse value in 20 mol % Me2SO (ca. 0.4) to ca 1.5 in 70 mol % Me2SO. The above results are consistent with a product-like transition state for CF3D isotope exchange.
Mechanistic study of nucleophilic fluorination for the synthesis of fluorine-18 labeled fluoroform with high molar activity fromN-difluoromethyltriazolium triflate
Chai, Jin Young,Cha, Hyojin,Lee, Sung-Sik,Oh, Young-Ho,Lee, Sungyul,Chi, Dae Yoon
, p. 6099 - 6106 (2021/02/12)
The synthesis of fluorine-18 labeled fluoroform with high molar activity has grown in importance for the development of fluorine-18 labeled aryl-CF3radiopharmaceuticals that are useful as diagnostic radiotracers for the powerful technique of positron emission tomography (PET). We designed a strategy of synthesizing fluorine-18 labeled fluoroform fromN1-difluoromethyl-N3-methyltriazolium triflate (1)viaSN2 fluorination without stable fluorine isotope scrambling. Fluoroform was generated at rt in 10 min by fluorination of the triazolium precursor with TBAF (6 equiv.). We propose three routes (a), (b), and (c) for this fluorination. Quantum chemical calculations have been carried out to elucidate the mechanism of experimentally observed nucleophilic attack of fluoride at difluoromethyl groupviaroute (a), notN3-methylviaroute (b).1H and19F NMR studies using deuterium source have been performed to examine the competition between SN2 fluorination (route (a)) and the formation of difluorocarbene (route (c)). The observed superiority of SN2 pathway to formation of difluorocarbene in the reaction of the precursor using CsF in (CD3CN/(CD3)3COD (17.8?:?1)) gives the possibility of preparing the fluorine-18 labeled fluoroform in high molar activity.
Carbon-Carbon Bond-Forming Reductive Elimination from Isolated Nickel(III) Complexes
Bour, James R.,Camasso, Nicole M.,Meucci, Elizabeth A.,Kampf, Jeff W.,Canty, Allan J.,Sanford, Melanie S.
supporting information, p. 16105 - 16111 (2016/12/22)
This manuscript describes the design, synthesis, characterization, and reactivity studies of organometallic NiIII complexes of general structure TpNiIII(R)(R1) (Tp = tris(pyrazolyl)borate). With appropriate selection of th
Copper(I)-photocatalyzed trifluoromethylation of alkenes
Beniazza,Molton,Duboc,Tron,McClenaghan,Lastécouères,Vincent
supporting information, p. 9571 - 9574 (2015/06/08)
Using the photoreducible CuII precatalyst 2, trifluoromethylation reactions of alkenes are conducted effectively at low copper loading (0.1-0.5 mol%) on exposing the reaction mixture to sunlight/ambient light.
Nucleophile-catalyzed, facile, and highly selective C-H activation of fluoroform with Pd(II)
Takemoto, Shin,Grushin, Vladimir V.
supporting information, p. 16837 - 16840 (2013/12/04)
Exceedingly facile (23 C) and chemoselective H-CF3 activation with [(dppp)Pd(Ph)(OH)] in the presence of a Lewis base promoter such as n-Bu3P leads to Pd-CF3 bond formation in nearly quantitative yield. A combined experimental and computational study points to a new mechanism that involves H-bonding Pd-O(H)···H-CF 3 and nucleophilic attack of the promoter on the metal, followed by a push-pull-type collapse of the resultant five-coordinate Pd(II) intermediate via a polar transition state.
Trifluoromethide as a strong base: [CF3-] mediates dichloromethylation of nitrones by proton abstraction from the solvent
Behr, Jean-Bernard,Chavaria, Dani,Plantier-Royon, Richard
, p. 11477 - 11482 (2013/12/04)
An unprecedented reactivity of CF3-TMS has been revealed, which exploits the basic character of the generated [CF3-] capable of delivering dichloromethide from dichloromethane with subsequent transfer to nitrones under smooth conditions. The proton-abstraction pathway was demonstrated through isotopic labeling experiments in CD2Cl2. The same reaction was achieved in acetonitrile with the introduction of a cyanomethyl group onto the nitrones.
Silver-mediated trifluoromethylation-iodination of arynes
Zeng, Yuwen,Zhang, Laijun,Zhao, Yanchuan,Ni, Chuanfa,Zhao, Jingwei,Hu, Jinbo
supporting information, p. 2955 - 2958 (2013/04/10)
An unprecedented silver-mediated vicinal trifluoromethylation-iodination of arynes that quickly introduces CF3 and I groups onto aromatic rings in a single step to give o-trifluoromethyl iodoarenes has been developed. A new reactivity of AgCF3 has been revealed, and 2,2,6,6-tetramethylpiperidine plays an important role in this difunctionalization reaction.
Simple, stable, and easily accessible well-defined CuCF3 aromatic trifluoromethylating agents
Tomashenko, Olesya A.,Escudero-Adan, Eduardo C.,Martinez Belmonte, Marta,Grushin, Vladimir V.
body text, p. 7655 - 7659 (2011/10/02)
Give me an F: Exceptionally easy to make in over 90 yield (see scheme) and air-stable in the solid state, [(Ph3P)3Cu(CF3)] is a remarkable example of a rarely encountered well-defined Cu(I) trifluoromethylating agent and a convenient starting material for the synthesis of other CuCF3 complexes, such as [(phen)Cu(PPh3)(CF 3)]. Copyright
