- 31P, 19F AND 1H NMR SPECTROSCOPIC STUDY OF THE REACTION OF BIS(TRIFLUOROMETHYL)PHOSPHINE AND SOLID KOH. SYNTHESIS OF THE PHOSPHAALKENE CF3P=CF2
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The formation and subsequent reaction of the phosphaalkene CF3P=CF2 obtained via dehydrofluorination of (CF3)2PH with KOH pellets at room temperature has been studied by multinuclear NMR spectroscopy.
- Hosseini, Hossein E.,Kroto, Harold W.,Nixon, John F.,Ohashi, Osamu
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- FLUOROPHOSPHAALKENES - PREPARATION AND REACTIVITY
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A novel preparative route to perfluoroheteroalkenes F3CE=CF2 (E=P, As) and E'=CF2 (E'=S, Se) has been developed using the trimethyltin compounds Me2SnE(CF3)2 and Me3SnE'CF3 as precursors.After a short information about the characterization of these heteroalkenes, the results of self-addition, HX-addition and cycloaddition reactions of F3CP=CF2 (1) are presented and discussed.A one-pot procedure could be developed for the Diels-Alder type reactions of 1 and 2, keeping a mixture of Me3SnE(CF3)2 and the corresponding diene at 70 deg C until the 19F signals of the tin compound disappeared.The enthalpy of dissociation of the dimer (CF3PCF2)2 as well as that of the retrodiene cleavage of the cycloadduct, formed from 1 and cyclopentadiene, are deduced from appearance potentials and used for an estimate of the PC ?- and ?-bond energy of 1.A one-pot process for the production of the labile diphosphene F3P=PCF3 (23) and its trapping by dienes are reported.The observed reactivity of 1 and 23 support the view that these compounds show a remarkable similarity to alkenes.
- Grobe, J.,Van, D. Le,Schulze, J.,Szameitat, J.
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p. 239 - 252
(2007/10/02)
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- Reactive E=C (p-p)?-Systems, IV: Retro Diene Cleavage of Diels-Alder Adducts of the Phosphaalkene F3CP=CF2
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Pyrolysis of the Diels-Alder adducts 2-4 yields F3CP=CF2 (1) and the corresponding dienes.For the thermal cleavage of 3 an alternative pathway in addition to the retro-diene reaction is observed, giving the new phosphetane F3CP-CF2 and C4H4 dimers.The enthalpy of the cyclo-reversion reaction of 2 as well as estimated bond energies for the phosphorus-carbon ?- and ?-bond have been determined from appearance potentials and thermochemical literature data.The products were characterized by mass and NMR spectra. - Keywords: Retro Diene Reactions, Phospha-Heterocycles, Mass Spectra, Thermochemical Data, NMR Spectra
- Binnewies, Michael,Grobe, Joseph,Van, Duc Le
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p. 927 - 933
(2007/10/02)
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