340-04-5Relevant articles and documents
Kinetic study on photocatalytic hydrogenation of acetophenone derivatives on titanium dioxide
Kohtani, Shigeru,Kamoi, Yuna,Yoshioka, Eito,Miyabe, Hideto
, p. 1084 - 1091 (2014)
Acetophenone (AP) derivatives were photocatalytically hydrogenated to afford the corresponding secondary alcohols with excellent chemical efficiencies on titanium dioxide (Degussa P25, TiO2) under UV light irradiation. Maximum reaction rates (kmax) and apparent adsorption constants (KLH) under irradiation were obtained from the Langmuir-Hinshelwood kinetic analysis. The kmax values showed a tendency to decrease with the decreasing reduction potentials (Ered) of the AP derivatives, while the KLH values were distributed in the range of 280-780 L mol-1. Among these, simple AP exhibited the greatest adsorptivity upon the UV irradiated TiO2 surface. Additionally, it was demonstrated that the electrons trapped at surface defect Ti (Tist) sites on the TiO2 actually hydrogenated the AP derivatives. The amount of reacted electrons also showed a tendency to decrease with decreasing Ered values, in accord with the dependence on kmax. These results indicate that the electrons accumulated at shallow Tist states easily participate in the hydrogenation of AP derivatives, whereas those trapped at deeper states hardly react with the substrates. The results strongly support the electron transfer reaction model via the Tist sites in the photocatalytic hydrogenation on TiO2. This journal is the Partner Organisations 2014.
Trifluoromethylation of carbonyl compounds with sodium trifluoroacetate
Chang, Ying,Cai, Chun
, p. 937 - 940 (2005)
In the presence of copper(I) iodide as catalyst, a variety of carbonyl compounds, such as aldehydes, ketones and acid anhydrous, could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields, and a possible mechanism was proposed to explain the roles of catalyst and solvent in the reaction system.
Hemiaminals of trifluoroacetaldehyde, as trifluoromethylating agents
Mispelaere, Clotilde,Roques, Nicolas
, p. 6411 - 6414 (1999)
Hemiaminals of trifluoroacetaldehyde are new trifluoromethylating agents. These reagents are synthesised from amines and gaseous trifluoroacetaldehyde. tBuONa is able to deprotonate the hemiaminals to form trifluoromethyl anion equivalents CF3CH(O-)NMe2. The trifluoromethyl anion has been transferred from such intermediates to benzaldehyde yielding phenyl (trifluoromethyl) methanol.
Piano-stool d6-rhodium(III) complexes of chelating pyridine-based ligands and their papain bioconjugates for the catalysis of transfer hydrogenation of aryl ketones in aqueous medium
Madern, Nathalie,Queyriaux, Nicolas,Chevalley, Alice,Ghasemi, Mahsa,Nicolotti, Orazio,Ciofini, Ilaria,Mangiatordi, Giuseppe Felice,Salmain, Michèle
, p. 314 - 322 (2015)
Two half-sandwich d6-rhodium(III) complexes of the general formula [(η5-Cp?)Rh(N^N)Cl]Cl where N^N is a phenanthroline or a bispyridine methane derivative carrying a thiol-targeting maleimide or chloroacetamide function were synthesized and characterized. Both complexes were able to catalyse the transfer hydrogenation of 2,2,2-trifluoroacetophenone in aqueous medium using formate or phosphite as hydrogen donor. Covalent anchoring of these complexes to the cysteine endoproteinase papain yielded hybrid metalloproteins with transfer hydrogenase properties. Under optimized conditions of pH, hydrogen donor concentration and catalyst load, conversion of substrate was nearly quantitative within 24 h at 40 °C and the (S)-enantiomer was obtained preferably albeit with a modest enantiomeric excess of 7-10%. Covalent docking simulations complemented the experimental findings suggesting a molecular rationale for the observed low enantioselectivity. The harmonious use of experimental and theoretical approaches represents an unprecedented starting point for driving the rational design of artificial metalloenzymes built up from papain with higher catalytic efficiency.
Trifluoromethylketones chemistry: Efficient access to silyl enol ethers or silyl carbinols using lithium diisopropylamide
Provot, Olivier,Berrien, Jean-Francois,Moskowitz, Henri,Mayrargue, Joelle
, p. 185 - 187 (1997)
Lithium diisopropylamide, reacts with trifluoromethylketones either as a base in polar solvents or as a hydride donor in hexane. In the presence of terf-Butyldimethylsilyl chloride, Lithium diisopropylamide allows the transformation of trifluoromethylketo
Molecular structures and reactivity of trifluoromethyltris(dialkylamino)phosphonium bromides
Chernega, Alexander N.,Kolomeitsev, Alexander A.,Yagupolskij, Yurij L.,Gentzsch, Andreas,Roeschenthaler, Gerd Volker
, p. 271 - 276 (1995)
Hexa-alkylphosphorus triamides and trifluoromethyl bromide react to give trifluoromethyltris(dialkylamino)phosphonium bromides which were used for the trifluoromethylation of benzaldehyde and copper(I) iodide in the presence of fluoride anions with different counterions; tris(diethylamino)difluorophosphorane proved to be a masked fluoride anion donor.The structures of (1+)Br(1-) and (1+)Br(1-) have been determined by single-crystal X-ray investigations and shown to exhibit a distorted tetrahedral bond configuration with a rather long (F3)C-P bond of 1.866(9) or 1.896(6) Angstroem, respectively. - Keywords: Molecular structures; Reactivity; Trifluoromethyltris(dialkylamino)phosphonium bromides; Single-crystal X-ray determination; NMR spectroscopy
TRIFLUOROMETHYLATION OF CARBONYL COMPOUNDS WITH TRIFLUOROMETHYLZINC IODIDE UNDER ULTRASONIC IRRADIATION
Kitazume, Tomoya,Ishikawa, Nobuo
, p. 1679 - 1680 (1981)
The trifluoromethylation of carbonyl compounds with trifluoromethylzinc iodide, prepared from trifluoromethyl iodide with ultrasonically dispersed zinc, smoothly proceeded to give corresponding α-trifluoromethyl carbinols in good yields.
1H, 13C, and 19F Nuclear Polarizations in the Photochemistry of α,α,α-Trifluoroacetophenone
Wagner, Peter J.,Thomas, Michael J.
, p. 4173 - 4182 (1980)
CIDNP effects are observed during irradiation of α,α,α-trifluoroacetophenone (TFA) and several of its ring-substituted derivatives.In cyclohexane, the major CIDNP involves disproportionation of PhC(OH)CF3 radicals, although some 19F emission (E) is also o
Noncyclic [10-S-5] sulfuranide dioxide salts with three S-C bonds: A new class of stable hypervalent compounds
Sevenard, Dmitri V.,Kolomeitsev, Alexander A.,Hoge, Berthold,Lork, Enno,Roeschenthaler, Gerd-Volker
, p. 12366 - 12367 (2003)
Phenyl triflate reacts with CF3SiMe3/Q+F- (Q+ = [K(18-crown-6)]+, Me4N+) and (Me2N)3S+Me3SiF2- to afford the first noncyclic [10-S-5] sulfuranide dioxide salts, [(CF3)3SO2]-Q+, with three S-C bonds, whose molecular structure was determined by X-ray crystallography. Copyright
Synthesis, Reactivity and Structural Properties of Trifluoromethylphosphoranides
Shyshkov, Oleg O.,Kolomeitsev, Alexander A.,Hoge, Berthold,Lork, Enno,Haupt, Axel,Ke?ler, Mira,R?schenthaler, Gerd-Volker
supporting information, (2022/02/19)
Phosphoranides are interesting hypervalent species which serve as model compounds for intermediates or transition states in nucleophilic substitution reactions at trivalent phosphorus substrates. Herein, the syntheses and properties of stable trifluoromet
