Search results for "Trifluoromethyl"
showing 10 items of 288 documents
CCDC 1040203: Experimental Crystal Structure Determination
2016
Related Article: Markus Albrecht, Yi Hai, Okan Köksal, Gerhard Raabe, Fangfang Pan, Arto Valkonen and Kari Rissanen|2016|Chem.-Eur.J.|22|6596|doi:10.1002/chem.201600249
CCDC 2051302: Experimental Crystal Structure Determination
2021
Related Article: Irina Osadchuk, Nele Konrad, Khai-Nghi Truong, Kari Rissanen, Eric Clot, Riina Aav, Dzmitry Kananovich, Victor Borovkov|2021|Symmetry|13|275|doi:10.3390/sym13020275
The introduction of fluorine atoms or trifluoromethyl groups in short cationic peptides enhances their antimicrobial activity
2006
The effect of introducing fluorine atoms or trifluoromethyl groups in either the peptidic chain or the C-terminal end of cationic pentapeptides is reported. Three series of amide and ester peptides were synthesised and their antimicrobial properties evaluated. An enhanced activity was found in those derivatives whose structure contained fluorine, suggesting an increase in their hydrophobicity.
Synthesis of tritiated derivatives of the diphenylether herbicides acifluorfen and acifluorfen methyl
1992
Acifluorfen 1 and acifluorfen methyl 2, two herbicides of the diphenylether family, are inhibitors of protoporphyrinogen oxidases. Two tritiated derivatives of these compounds, namely 3-[3H]-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid [3H]-1, and methyl 3-[3H]-5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid [3H]-2, have been synthesised from 3-[3H]-5-hydroxybenzoic acid, in order to probe their interactions with the target enzymes.
The role of fluorine in the stereoselective tandem Aza-Michael addition to acrylamide acceptors: An experimental and theoretical mechanistic study
2007
Aza-Michael additions of alpha-amino esters to fluorinated acceptors take place in a highly stereoselective manner, to give partially modified Psi-[NHCH2]retropeptides incorporating a hydrolytically stable trifluoroalanine mimic. The reaction mechanism has been investigated experimentally and theoretically, in order to explain the effect of the trifluoromethyl group on the reactivity and the origins of the experimentally observed stereocontrol. The reaction is a two-step process, involving a tandem aza-Michael addition followed by a stereoselective hydrogen transfer. Both steps are base-catalyzed. The high level of stereocontrol is the result of a combination of electrostatic interactions a…
Palladium-Catalysed CH Bond Electrophilic Fluorination of Highly Substituted Arylpyrazoles: Experimental and DFT Mechanistic Insights
2015
A general protocol for palladium-catalysed CH mono- and di-fluorination of highly substituted arylpyrazoles is reported. Coupling pathways and substrate limitations are discussed in the light of complementary mechanistic experimental and density functional theory (DFT) studies. The mono- and di-ortho-fluorination of arylpyrazoles having substituted pyrazole groups and ortho-, meta-, or para-substituted arene moieties is achieved. Various pyrazole groups can efficiently promote the direct CH activation/fluorination of substrates bearing valuable reactive ester, cyano, halide and nitro functions. The presence of methoxy, methyl and trifluoromethyl is tolerated on the pyrazole directing groups…
Stacking of Sterically Congested Trifluoromethylated Aromatics in their Crystals – The Role of Weak F···π or F···F Contacts
2020
European journal of organic chemistry : EurJOC 2020(38), 6073-6077 (2020). doi:10.1002/ejoc.202001008
Intramolecular Nitrone Cycloaddition of α-(Trifluoromethyl)styrenes. Role of the CF3 Group in the Regioselectivity
2017
The intramolecular 1,3-dipolar cycloaddition of ortho-substituted 1,1,1-trifluoromethylstyrene-derived nitrones is described. Tricyclic fused isoxazolidines were obtained as major or exclusive products, in contrast to the case for nonfluorinated substrates, which rendered the bridged derivatives. This change in the regioselectivity was attributed to the electronic and, particularly, steric requirements of the trifluoromethyl group in comparison to the methyl group. It is worth mentioning that trifluoromethylstyrenes have been employed for the first time as dipolarophiles in a 1,3-dipolar intramolecular cycloaddition reaction, leading to the corresponding isoxazolidines bearing a quaternary …
On the Reaction of 3-Bromo-2-nitrobenzo[b]thiophene 13C-Labeled at C-2 with 3-(Trifluoromethyl)aniline: A Preliminary Insight into a Nucleophilic Su…
1997
The results of the title reaction have furnished proofs against a rearrangement of the carbon-atom skeleton and for a nitro group shift in the relevant nucleophilic substitution.
Discovering Copper for Methane C–H Bond Functionalization
2015
The copper complex Tp(CF3)2,BrCu(NCMe) (1, Tp(CF3)2,Br = hydrotris((3,5-bis(trifluoromethyl)-4-bromo)-pyrazol-1-yl)borate) catalyzes the insertion of the CHCO2Et group (from ethyl diazoacetate N2CHCO2Et, EDA) into the C–H bonds of methane, in a homogeneous process that uses supercritical carbon dioxide (scCO2) as the reaction medium. Other light alkanes such as ethane, propane, and butane have been also functionalized with this copper-based catalyst, in the first example of the derivatization of the series of C1–C4 alkanes with this metal and a soluble catalyst.