1891-96-9Relevant academic research and scientific papers
Thermal cyclopropyl—allyl rearrangement of gem-chlorofluorocyclopropanes under gas-phase pyrolysis conditions. Formation of chlorofluoroalkenes and 2-fluorobuta-1,3-dienes
Volchkov,Lipkind,Nefedov
, p. 1391 - 1401 (2019/08/12)
The gas-phase pyrolysis of isomeric 2-chloro-2-fluoro-1-phenylcyclopropanes in a flow reactor at 250–430 °С gives 1-phenyl- and 3-phenyl-3-chloro-2-fluoropropenes. Under similar conditions, methyl-substituted gem-chlorofluorocyclopropanes undergo cyclopropyl—allyl isomerization accompanied by dehydrochlorination to form chlorofluoroalkenes and 2-fluoro-buta-1,3-dienes.
Copper(I)-catalyzed solvolysis of gem-chlorofluoro- and gem-bromofluorocyclopropanes. Preparation of 2-fluoroallylic ethers, esters and alcohols
Novikov, Maxim A.,Volchkov, Nikolai V.,Lipkind, Maria B.,Nefedov, Oleg M.
, p. 131 - 143 (2015/10/05)
Copper(I)-catalyzed solvolysis of gem-chlorofluoro- and gem-bromofluorocyclopropanes in MeOH, NaOAc/AcOH, NaOAc/DMF, HCO2Na/HCO2H or water/dioxane affords 2-fluoroallylic ethers, esters or alcohols in moderate to excellent yields. Th
Gas-phase pyrolysis of 1-chloro-1-fluoro-2-methylcyclopropanes in the presence of SiO2 or Al2O3 with the formation of 2-chloro- or 2-fluorobuta-1,3-dienes
Volchkov,Lipkind,Novikov,Nefedov
, p. 2250 - 2254 (2015/06/22)
Gas-phase pyrolysis of of 1-chloro-1-fluoro-2-methylcyclopropanes in an empty or filled with quartz pieces flow-tube reactor at 430 - 460 °C gives 2-fluorobuta-1,3-dienes (in 42 - 75% yields), whereas pyrolysis in the presence of Al2O3 at 150 - 250 °C gives 2-chlorobuta-1,3-dienes as the major products (in 58 - 68% yield).
CuCl-catalyzed isomerization of gem-Chlorofluoro-cyclopropanes into chlorofluoroalkenes
Volchkov, Nikolai V.,Novikov, Maksim A.,Lipkind, Mariya B.,Nefedov, Oleg M.
, p. 19 - 21 (2013/08/24)
CuCl-catalyzed isomerization of gem-chlorofluorocyclopropanes into chlorofluoroalkenes occurs as a result of the ring opening accompanied by the migration of chlorine atom. In the case of vinyl- or cyclopropyl-containing substrates, chlorofluoroalkadienes
Unprecedented chemistry of an aryloxychlorodiazirine: Generation of a dihalodiazirine and diazirinone
Moss, Robert A.,Chu, Gaosheng,Sauers, Ronald R.
, p. 2408 - 2409 (2007/10/03)
The reaction of p-nitrophenoxychlorodiazirine with tetrabutylammonium fluoride follows three channels: (1) ～17% of p-nitrophenoxide/fluoride exchange to chlorofluorodiazirine and p-nitrophenol, (2) ～28% of Cl/F exchange to p-nitrophenoxyfluorodiazirine, and (3) ～55% of ipso fluoride attack, affording p-nitrofluorobenzene and the previously unknown diazirinone (diazacyclopropenone). Copyright
Catalytic cyclopropanation of fluorine-containing alkenes and dienes with diazomethane and methyl diazoacetate
Guseva, Ekaterina V.,Volchkov, Nikolay V.,Tomilov, Yury V.,Nefedov, Oleg M.
, p. 3136 - 3144 (2007/10/03)
The reactivities of various double bonds in fluorine-containing unsaturated compounds toward cyclopropanation with diazomethane and methyl diazoacetate with catalysis by copper, rhodium and palladium compounds were studied. In general, the presence of fluorine atoms attached to the double bond or arranged at neighbouring positions exerted a suppressive effect on the cyclopropanation of this bond. As would be expected, diazomethane in the presence of palladium compounds primarily cyclopropanated less highly substituted double bonds. In the case of 2-fluoro-3-methylbutadiene, the reaction took place at both of the double bonds. When methyl diazoacetate was used, [Rh2(OAc) 4] was an efficient catalyst, yielding cyclopropanation products on monofluoro-substituted double bonds in alkenes and cycloalkenes. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Selectivity of Dihalocarbenes in Cycloaddition Reactions
Giese, Bernd,Lee, Woo-Bung,Meister, Juergen
, p. 725 - 735 (2007/10/02)
Dihalocarbenes 1a-e yield in the 2-methyl-2-butene/2-methylpropene competition system the cyclopropanes 2a-e and 3a-e.Whereas selectivity increases at 293 K in the sequence CBr2 CClBr CCl2 CFCl CF2, at 393 K the order of carbene selectivity is reversed: CF2 CFCl CCl2 CClBr CBr2 (Table 1).At 360 K (isoselective temperature) the carbenes 1a-e react with equal selectivity.The reason for this is that activation enthalpies and activation entropies are changed in the same direction with variation of carbene substituents from fluorine to bromine (Table 2).Thereby the selectivities of CClBr and CBr2 increase with increasing temperature (Figure 2). - Above and below 360 K the order of the slopes of carbenes 1a-e are reversed in the Skell-Moss diagram (Figure 3).
