17337-12-1Relevant articles and documents
Trifluoroethylation of olefins with trichlorotrifluoroethane
Puy, Michael Van Der
, p. 133 - 140 (1993)
1,1,1-Trichlorotrifluoroethane was added to seven different olefins using a redox system, giving adducts having the CF3CCl2-C-CCl- subunit.Selective addition to the exocyclic double bond in limonene was observed.The adducts were dechlorinated by catalytic reduction or with tri-n-butyltin hydride.The two-step sequence thus provided a method for appending the trifluoroethyl group (CF3CH2-) to olefins.
Direct C(sp3)?H Trifluoromethylation of Unactivated Alkanes Enabled by Multifunctional Trifluoromethyl Copper Complexes
Choi, Geunho,Lee, Geun Seok,Park, Beomsoon,Kim, Dongwook,Hong, Soon Hyeok
supporting information, p. 5467 - 5474 (2021/01/20)
A mild and operationally simple C(sp3)?H trifluoromethylation method was developed for unactivated alkanes by utilizing a bench-stable CuIII complex, bpyCu(CF3)3, as the initiator of the visible-light photoinduced reaction, the source of a trifluoromethyl radical as a hydrogen atom transfer reagent, and the source of a trifluoromethyl anion for functionalization. The reaction was initiated by the generation of reactive electrophilic carbon-centered CF3 radical through photoinduced homolytic cleavage of bpyCu(CF3)3, followed by hydrogen abstraction from an unactivated C(sp3)?H bond. Comprehensive mechanistic investigations based on a combination of experimental and computational methods suggested that C?CF3 bond formation was enabled by radical–polar crossover and ionic coupling between the resulting carbocation intermediate and the anionic CF3 source. The methylene-selective reaction can be applied to the direct, late-stage trifluoromethylation of natural products and bioactive molecules.
HYDROFLUOROCARBON REFRIGERANT COMPOSITIONS AND USES THEREOF
-
, (2008/06/13)
Disclosed herein are hydrofluorocarbon refrigerant or heat transfer fluid compositions that are useful in refrigerain or air conditioning apparatus or as heat transfer fluids. The compositions of the present invention are also useful in centrifugal compressor apparatus that employ two-stage compressors or single slab.single pass heat exchangers.
Fluorine substitution effects on the alkyl coupling reaction on a Ag(111) surface
Paul, Anumita,Gellman, Andrew J.
, p. 9056 - 9066 (2007/10/03)
We have investigated fluorine substitution effects on the rate of coupling of adsorbed alkyl groups on a Ag(111) surface. Alkyl groups are formed by thermal dissociation of the C-I bond in adsorbed alkyl iodides. Variable heating rate temperature programmed reaction (TPR) studies were used to determine the kinetic parameters for the coupling of ethyl groups and propyl groups. They are Ea = 15.1 ± 0.6 kcal/mol, v = 1016.7±0.8 s-1 and Ea = 16.9 ± 0.4 kcal/mol, v = 1017.1±0.4 s-1, respectively. Substitution of fluorine for hydrogen in the adsorbed alkyl groups systematically raises the coupling reaction temperature. For example, trifluoropropyl groups self-couple at temperatures ～70 K higher than propyl groups on Ag(111). Coadsorbed propyl and trifluoropropyl groups cross-couple at temperatures ～10 K higher than the propyl self-coupling reaction. The kinetic parameters evaluated from the results of this study and from results of earlier studies by X.-L. Zhou, J. M. White, and co-workers [Surf. Sci. 1989, 219, 294; Catal. Lett. 1989, 2, 375; J. Phys. Chem. 1991, 95, 5575] are used to plot linear free energy relationships (LFER) which provide insight into the electronic nature of the reaction center. The implication of the LFER plots for the surface alkyl coupling reaction is that the reaction center in the transition state is electron deficient with respect to the initial state.
Sodium Perfluoroalkane Carboxylates as Sources of Perfluoroalkyl Groups
Carr, Gillian E.,Chambers, Richard D.,Holmes, Thomas F.,Parker, David G.
, p. 921 - 926 (2007/10/02)
Sodium trifluoroacetate, in the presence of copper(I) iodide, is used as a source of trifluoromethyl to replace halogen by trifluoromethyl in benzenoid and heterocyclic aromatic systems, as well as in alkenyl and alkyl halogen compounds.The mechanism of this interesting copper-assisted process has been explored and an intermediate of the form - is proposed.Introduction of higher perfluoroalkyl groups from their respective sodium perfluoroalkane carboxylates has been demonstrated and the machanistic features are compared with those of the trifluoromethylation process.
