Search results for "trifluoromethyl"
showing 10 items of 288 documents
CCDC 1564495: Experimental Crystal Structure Determination
2017
Related Article: Fernando Rabasa-Alcañiz, Javier Torres, María Sánchez-Roselló, Tomás Tejero, Pedro Merino, Santos Fustero, Carlos del Pozo|2017|Adv.Synth.Catal.|359|3752|doi:10.1002/adsc.201700975
Implication of three isoforms of PLA2in human T-cell proliferation
2002
We observed that human (Jurkat) T-cells constitutively expressed the mRNA, encoding for the four isoforms of phospholipase A(2) (PLA(2)), i.e. two secretory (type IB and type V), and two cytosolic (type IV, Ca(2+)-dependent and type VI, Ca(2+)-independent). In order to assess whether these PLA(2) isoforms are active, we labeled Jurkat T-cells with [(3)H]arachidonic acid ([(3)H]AA) and determined its release into the extracellular medium in the presence of phorbol 12-myristate 13-acetate (PMA) and ionomycin. The three PLA(2) isoforms seem functional as aristolochic acid and bromoenol lactone (BEL), the respective inhibitors of type IB/type V and type VI PLA(2)s, significantly inhibited the r…
Pauson-Khand reaction of internal dissymmetric trifluoromethyl alkynes. Influence of the alkene on the regioselectivity.
2014
Abstract: The scope of the Pauson-Khand reaction (PKR) of internal trifluoromethyl alkynes, previously described with norbornadiene, is expanded to norbornene and ethylene. A thorough structural analysis of the resulting PK adducts has been carried out to unveil that α-trifluoromethylcyclopentenones are preferred in all cases, independently of the electronic properties of the alkyne. The regioselectivity observed with norbornadiene and ethylene is higher than in the case of norbornene.
Thiourea Organocatalysts as Emerging Chiral Pollutants: En Route to Porphyrin-Based (Chir)Optical Sensing
2021
Environmental pollution with chiral organic compounds is an emerging problem requiring innovative sensing methods. Amino-functionalized thioureas, such as 2-(dimethylamino)cyclohexyl-(3,5-bis(trifluoromethyl)phenyl)thiourea (Takemoto’s catalyst), are widely used organocatalysts with virtually unknown environmental safety data. Ecotoxicity studies based on the Vibrio fischeri luminescence inhibition test reveal significant toxicity of Takemoto’s catalyst (EC50 = 7.9 mg/L) and its NH2-substituted analog (EC50 = 7.2–7.4 mg/L). The observed toxic effect was pronounced by the influence of the trifluoromethyl moiety. En route to the porphyrin-based chemosensing of Takemoto-type thioureas, their s…
Light-controlled reversible modulation of frontier molecular orbital energy levels in trifluoromethylated diarylethenes
2017
Among bistable photochromic molecules, diarylethenes (DAEs) possess the distinct feature that upon photoisomerization they undergo a large modulation of their π-electronic system, accompanied by a marked shift of the HOMO/LUMO energies and hence oxidation/reduction potentials. The electronic modulation can be utilized to remote-control charge- as well as energy-transfer processes and it can be transduced to functional entities adjacent to the DAE core, thereby regulating their properties. In order to exploit such photoswitchable systems it is important to precisely adjust the absolute position of their HOMO and LUMO levels and to maximize the extent of the photoinduced shifts of these energ…
The synthesis of fluorinated heteroaromatic compounds. Part 2. Five-membered rings with two heteroatoms. A review
2007
CCDC 894411: Experimental Crystal Structure Determination
2013
Related Article: S.Fustero, P.Bello, J.Miro, M.Sanchez-Rosello, M.A.Maestro, J.Gonzalez, C.del Pozo|2013|Chem.Commun.|49|1336|doi:10.1039/c2cc37796a
Electron-deficient trifluoromethyl-substituted sub-components affect the properties of M4L4 tetrahedral cages
2017
Two supramolecular tetrahedral cages based on a new electron-deficient trifluoromethyl-substituted pyridylimine ligand are synthesised by sub-component self-assembly. Their structures are characterised by NMR und UV-Vis spectroscopy, high-resolution mass spectrometry and single crystal X-ray diffraction. The iron(II) complex shows host–guest chemistry, complex-to-complex transformations and novel electronic properties.
Reactions at Interfaces: Oxygenation of n-Butyl Ligands Anchored on Silica Surfaces with Methyl(trifluoromethyl)dioxirane
2011
The oxygenation of n-butyl and n-butoxy chains bonded to silica with methyl(trifluoromethyl)dioxirane (1) revealed the ability of the silica matrix to release electron density toward the reacting C(2)-H σ-bond through the Si-C(1) and Si-O(1) σ-bonds connecting the alkyl chain to the surface (silicon β-effect). The silica surface impedes neither the alkyl chain adopting the conformation required for the silicon β-effect nor dioxirane 1 approaching the reactive C(2) methylene group. Reaction regioselectivity is insensitive to changes in the solvation of the reacting system, the location of organic ligands on the silica surface, and the H-bonding character of the silica surface. Reaction rates…
Synthesis and induction of G0–G1 phase arrest with apoptosis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazep…
2007
The multistep synthesis of 3,5-dimethyl-6-phenyl-8-(trifluoromethyl)-5,6-dihydropyrazolo[3,4-f][1,2,3,5]tetrazepin-4(3H)-one 15 has been carried out. The compound showed antiproliferative and apoptotic effects against K562, K562-R (imatinib mesilate resistant), HL60 and multidrug resistant (MDR) HL60 cell lines. Compound 15 showed a pro-apoptotic activity against HL60 and K562 resistant cell lines markedly higher than etoposide and busulfan, respectively. Flow cytometry studies carried out on K562 cells allowed to establish that 15 induces G0-G1 phase arrest followed by apoptosis.