67884-63-3Relevant articles and documents
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.
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.