- A convenient and practical method for the selective preparation of deuterofluorocarbons
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A detailed study of the development of efficient and practical conditions for the selective synthesis of 1-deuterononafluorobutane from 1-iodononafluorobutane is reported. The optimal conditions involve treatment of the iodo-precursor in D2O at ~170 °C in the presence of metallic zinc in a sealed Schlenk tube to give a 59% yield of 1-deutero-1,1,2,2,3,3,4,4,4-nonafluorobutane. The same method was applied successfully to two higher homologues to produce 1-deutero-1,1,2,2,3,3,4,4,5,5,5-undecafluoropentane and 1-deutero-1,1,2,2,3,3,4,4,5,5,6,6,6-tridecafluorohexane in yields of 64% and 56%, respectively. Surprisingly, even the non-perfluorinated product 6-deutero-1,1,1,2,2,3,3,4,4-nonafluorohexane could be synthesized in 69% yield with this method.
- Richardson, David P.,Bauer, Gordon S.,Bravo, Andrew A.,Drzyzga, Michael,Motazedi, Tina,Pelegri-O'Day, Emma M.,Poudyal, Shirish,Suess, Daniel L.M.,Thoman, John W.
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p. 208 - 215
(2015/11/02)
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- Reactions of FeCH2(+) and CoCH2(+) with Aliphatic Alkanes in the Gas Phase. Activation of C-H and C-C Bonds by Naked Transition-Metal Carbene Ions
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Gas-phase reactions of the title carbenes with several aliphatic alkanes using Fourier transform mass spectrometry (FTMS) ,are described.CoCH2(+) reacts with alkanes larger than methane whereas FeCH2(+) reacts with alkanes larger than ethane.Both FeCH2(+) and CoCH2(+) react predominantly by initial C-H bond insertion with some C-C bond insertion also observed.As a consequence of facile carbene-alkyl coupling, C-C bond cleavage processes proceed predominantly with elimination of the original carbene incorporated into the departing alkane neutral.In addition a small amount of C-C bond formation product is also observed.Finally, a greater degree of H/D scrambling is observed for CoCD2(+) than for FeCD2(+).
- Jacobson, D. B.,Freiser, B. S.
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p. 4373 - 4378
(2007/10/02)
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- Rate constants and Arrhenius parameters for the reactions of primary, secondary, and tertiary alkyl radicals with tri-n-butyltin hydride
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Rate constants for the title reactions have been measured over a range of temperatures by using laser flash photolytic techniques. At 300 K the rate constants are 10.8, 2.01, 2.34, 1.35, 2.47, and 1.84 × 106 M-1 s-1 for methyl, ethyl, n-butyl, isopropyl, cyclohexyl, and tert-butyl, respectively. The Arrhenius preexponential factors range from 109.39 M-1 s-1 for methyl to 108.43 M-1 s-1 for tert-butyl and activation energies from 3.97 kcal/mol for cyclohexyl to 2.95 kcal/mol for tert-butyl. The rate constant (k10) for the 1,5-cyclization of 5-hexenyl radical to cyclopentylmethyl radical can be represented by log k10/s-1 = (10.37 ± 0.32) - (6.85 ± 0.42)/θ, where θ = 2.3RT kcal/mol.
- Chatgilialoglu,Ingold,Scaiano
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p. 7739 - 7742
(2007/10/02)
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