422-41-3Relevant academic research and scientific papers
Radical addition reactions of fluorinated species part 6. Regioselectivity of the addition of nucleophilic radicals to halogenopropenes and evidence for a steric effect of the chlorine substituent
Paleta, Oldrich,Cirkva, Vladimir,Budkova, Zuzana,Boehm, Stanislav
, p. 155 - 171 (1997)
Nucleophilic radicals derived from alkanols and cyclic ethers (oxolane, 1,3-dioxolane, 2,2-dimethyl-1,3-dioxolane) were employed to test the regioselectivity of addition to 3-chloro-1,1,2,3,3-pentafluoropropene (1), 1,3-dichloro-1,2,3,3-tetrafluoropropene (2), 1,1,3-trichloro-2,3,3-trifluoropropene (3) and 1,3-dichlord-2,3,3-trifluoropropene (4). The regioselectivity was strongly dependent on the number of chlorine atoms at the terminal position and on the character of the additive. Thus the two chlorine atoms in 3 completely reversed the regioselectivity to an anti-Kharasch mode. The relative reaction rates were dramatically decreased with increasing number of terminal chlorine atoms in olefins 1-3. The allylic chlorine atom in 1 appeared to mimic a longer perfluoroalkyl chain. Experimental results were compared with the shapes of frontier orbitals and electron densities calculated using PM3 and ab initio (3-12G and 6-311 + G**) methods. The transformations of the adducts to chlorofluoroalkyl methacrylates and fluorinated pentane-1,2-diol are reported.
Synthesis of > and Some Chlorofluoropropenes
Paleta, Oldrich,Kvicala, Jaroslav,Guenter, Jaroslav,Dedek, Vaclav
, p. 920 - 924 (2007/10/02)
The starting substances C3Cl5F3 (1) and C3Cl4F4 (2) prepared earlier by the addition of CCl3F with CClF=CClF and/or CF2=CClF were utilized for the synthesis of chlorofluoropropenes by means of fluorination, reduction of C-Cl bonds in halogenopropanes, and final dehalogenation, all the reactions being performed at atmospheric pressure.The reaction conditions permit laboratory scale production.The contents of the isomeric admixtures in the resultant products were determined by NMR spectroscopy.The starting halogenopropanes 1, 2 represent mixtures of isomers, but in course of the individual synthetic steps the content of the main isomer was generally increased.In comparison with previously used syntheses, our procedure proves advantageous for the synthesis of "perfluoroallylchloride" (9a, isomer purity 95percent).Using this procedure a number of halogenopropanes were prepared and dechlorinated to give the corresponding halogenopropenes (isomer purity percent): CClF2-CClF-CCl2F (2a, 87), CF3-CClF-CCl3 (2b, 78), CClF2-CClF-CClF2 (3a, 87), CF3-CClF-CCl2F (3b, 90), CF3-CClF-CHCl2 (5a, 90), CF3-CClF-CHClF (6a, 73), CClF2-CF=CClF (8a, 93), CF3-CF=CCl2 (8b, 84), 9a, CF3-CF=CClF (9b, 86) and CF3-CF=CHCl (11a, 84).The minor isomers in substance 2 yielded products which were isolated after being combined from several preparations: CClF2-CF2-CHCl2 (5b, 84); CClF2-CF=CHCl (10a, 98), which by addition of chlorine yielded CClF2-CClF-CHCl2 (4a, 95).The NMR spectra of all the major and minor products, excluding perhalogenopropanes, are listed.
