67884-63-3Relevant academic research and scientific papers
THERMAL AND PHOTOCHEMICAL DEAZETATIONS OF FLUORINE-SUBSTITUTED 4-METHYLENEPYRAZOLINES. THE KINETIC BEHAVIOR OF TRIMETHYLENEMETHANES.
Dolbier Jr.,Burkholder
, p. 2139 - 2142 (2007/10/02)
4-(Difluoromethylene)-1-pyrazoline and 4-(fluoromethylene)-1-pyrazoline were observed to undergo thermal and photochemical deazetation in the gas phase as well as in solution to form mixtures of methylenecyclopropanes. The gas-phase and solution-phase, thermal, and photochemical results are contrasted, and the observed kinetically controlled product ratios are compared with the very different equilibrium values. As a result, mechanisms involving trimethylenemethane diradicals are proposed for both processes. The photochemical reactions seem to be dominated by 'hot' reactions of vibrationally excited TMMs, while the thermal reactions show interesting selectivity in their cyclization processes.
CYCLOPROPANE CHEMISTRY. PART 5 . HEXAFLUOROCYCLOPROPANE AS A SOURCE OF DIFLUOROCARBENE
Birchall, J. Michael,Fields, Roy,Haszeldine, Robert N.,McLean, Reginald J.
, p. 487 - 496 (2007/10/02)
Thermolysis of hexafluorocyclopropane in the presence of ethylene, propene, vinyl chloride, and vinyl bromide gives good yields of the corresponding 1,1-difluorocyclopropanes, formed by addition of difluorocarbene to the olefin.The tetrafluoroethylene formed dimerises to octafluorocyclobutane, co-dimerises with the olefin, or survives, depending on the reaction conditions.With allene, hexafluorocyclopropane gives 1-(difluoromethylene)cyclopropane, 2,2,3,3-tetrafluorospiropentane, and products derived from tetrafluoroethylene and allene.
CARBENE CHEMISTRY. PART 13 . PREPARATION OF SOME FLUOROALLENES BY A CARBENE ROUTE, AND THE REACTION OF ALLENES WITH HALOGENOCARBENES
Bunegar, Michael J.,Fields, Roy,Haszeldine, Robert N.
, p. 497 - 510 (2007/10/02)
Fluoroallene and 1,3-difluoroallene are prepared in good overall yield by the addition of dichlorocarbene to vinyl fluoride and 1,2-difluoroethylene respectively, followed by pyrolysis of the dichlorocyclopropanes and treatment of the resulting dichloropropenes with zinc.Pyrolysis of 1,1-dichloro-2-fluorocyclopropane over zinc gives fluoroallene directly.The reaction of allene with 2,2,3-trifluoro-3-trifluoromethyloxiran at 180 deg C as a source of difluorocarbene gives both 1,1-difluoro-2-methylenecyclopropane and its rearrangement product 1-(difluoromethylene)cyclopropane, the latter reacting more readily with a second difluorocarbene to give 2,2,3,3-tetrafluorospiropentane.In an analogous way, fluoroallene reacts with dichlorocarbene, generated from trifluoro(trichloromethyl)silane at 140 deg C, to give E- and Z-1,1-dichloro-2-(fluoromethylene)cyclopropane, 1-(dichloromethylene)-2-fluorocyclopropane, and 2,2,3,3-tetrachloro-4-fluorospiropentane.
