Search results for "trifluoromethyl"
showing 10 items of 288 documents
Divulging the various chemical reactivity of trifluoromethyl-4-vinyl-benzene as well as methyl-4-vinyl-benzene in [3+2] cycloaddition reactions.
2020
Abstract In the present paper, an investigation about the [3 + 2]cycloaddition (32 C A) reactions of benzonitrile oxide with 1-trifluoromethyl-4-vinyl-benzene, and with 1-methyl-4-vinyl-benzene, using the Molecular Electron Density Theory (MEDT) through DFT/B3LYP/6–311++G (d,p), is performed. A deep mechanistic study beside an accurate electronic description of different stationary points along the IRC paths of the two 32 C A reactions have performed by examining the two competitive regioisomericortho/metareaction pathways, and providing the mechanism associated with them. The presence of the CF3 group reduces the activation energy, which makes it possible to increase the experimental yield…
Synthesis and application of β-substituted Pauson-Khand adducts: trifluoromethyl as a removable steering group.
2013
The reaction between alkynes (I) and norbornadiene (II) affords the β-substituted Pauson—Khand adducts (III) as single regioisomers and the trifluoromethyl steering group can be easily removed in the presence of DBU and water.
CCDC 780593: Experimental Crystal Structure Determination
2011
Related Article: M.Karna, M.Lahtinen, A.Kujala, P.-L.Hakkarainen, J.Valkonen|2010|J.Mol.Struct.|983|82|doi:10.1016/j.molstruc.2010.08.036
Competitive interaction of three peroxidizing herbicides with the binding of 3H acifluorfen to corn etioplast membranes
1990
AbstractThe specific binding of the herbicide acifluorfen 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid to corn etioplast membranes is competitively inhibited by protoporphyrinogen IX, the substrate of protoporphyrinogen oxidase. Three other peroxidizing molecules, oxadiazon [5-ter-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazol-2-one], LS 82556 [(S)3-N-(methylbenzyl)carbamoyl-5-propionyl-2,6-lutidine], and M&B 39279 [5-amino-4-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)pyrazol], also compete with acifluorfen for its binding site. The four herbicides thus bind to the same site, or to closely located sites, on the enzyme protoporphyrinogen oxidase.
Enantioselective Addition of Nitromethane to 2-Acylpyridine N-Oxides. Expanding the Generation of Quaternary Stereocenters with the Henry Reaction
2014
[EN] The direct asymmetric Henry reaction with prochiral ketones, leading to tertiary nitroaldols, is an elusive reaction so far limited to a reduced number of reactive substrates such as trifluoromethyl ketones or alpha-keto carbonyl compounds. Expanding the scope of this important reaction, the direct asymmetric addition of nitromethane to 2-acylpyridine N-oxides catalyzed by a BOX-Cu(II) complex to give the corresponding pyridine-derived tertiary nitroaldols having a quaternary stereogenic center with variable yields and good enantioselectivity, is described.
Green phosphorescence and electroluminescence of sulfur pentafluoride-functionalized cationic iridium(III) complexes
2015
EZ-C acknowledges the University of St Andrews for financial support. We report four cationic iridium(III) complexes [Ir(C^N)2(dtBubpy)](PF6) that have sulfurpentafluoride-modified 1-phenylpyrazole and 2-phenylpyridine cyclometalating (C^N) ligands (dtBubpy = 4,4'-di-tert-butyl-2,2'-bipyridyl). Three of the complexes were characterized by single-crystal X-ray structure analysis. In cyclic voltammetry, the complexes undergo reversible oxidation of iridium(III) and irreversible reduction of the SF5 group. They emit bright green phosphorescence in acetonitrile solution and in thin films at room temperature, with emission maxima between 482–519 nm and photoluminescence quantum yields of up to 7…
Unexpected metal-free synthesis of trifluoromethyl arenes via tandem coupling of dicyanoalkenes and conjugated fluorinated sulfinyl imines
2021
A novel strategy for the synthesis of policyclic trifluoromethyl arenes has been devised. It involves a DBU-promoted tandem cycloaromatization reaction of dicyanoalkenes and fluorinated conjugated sulfinyl imines. This unprecedented transformation is a metal-free and air-tolerant process that takes place from readily available starting materials under mild reaction conditions.
One electron transfer chain decomposition of trifluoroacetone diperoxide: The first 1,2,4,5-tetroxane with O-transfer capability
1992
Abstract Reaction of 1,1,1-trifluoropropanone (trifluoroacetone) ( 1a ) with 30% hydrogen peroxide in the presence of conc. sulfuric acid afforded in good yield 3,6-bis(trifluoromethyl)-3,6-dimethyl-1,2,4,5-tetroxane or trifluoroacetone diperoxide ( 2a ). Peroxide 2a is quantitatively converted into trifluoroacetone ( 1a ) and dioxygen by a catalytic amount of tetrabutylammonium iodide through a reductive electron transfer chain reaction carried out by the superoxide ion. Trifluoroacetone diperoxide ( 2a ) is capable of O-atom transfer to alkenes and sulfides.
Oxygenation of Alkane C−H Bonds with Methyl(trifluoromethyl)dioxirane: Effect of the Substituents and the Solvent on the Reaction Rate
2005
[Chemical reaction: See text] The mechanism of the oxygenation of alkane C-H bonds with methyl(trifluoromethyl)dioxirane (1a) is studied through the effect of the substituent and solvent on the rate of oxygenation of 2-substituted adamantanes (2). The results suggest a remarkable electron deficiency at the reacting carbon atom in the transition state leading to the regular oxygenation products. The linearity of the Hammett plot reveals that the reaction mechanism does not change within a range of 0.15-0.67 units of sigma(I). A change in the solvent does not affect the distribution of the products, indicating a through-bond transmission of the substituent effect as the origin of the deactiva…
CCDC 1581155: Experimental Crystal Structure Determination
2018
Related Article: Sarah Keller, Fabian Brunner, José M. Junquera‐Hernández, Antonio Pertegás, Maria‐Grazia La‐Placa, Alessandro Prescimone, Edwin C. Constable, Henk J. Bolink, Enrique Ortí, Catherine E. Housecroft|2018|ChemPlusChem|83|217|doi:10.1002/cplu.201700501