Isomerization of Halogenated Cyclopentene over a NH4F Catalyst

摘要

The mechanism of the halogen-transfer isomerization of halogenated cyclopentene was investigated over a NH4F catalyst in DMF. This catalytic system was to have the unique ability to isomerize halogenated cyclopentene selectively. The process of migration of the F atom in the 3-position on the C(sp(3)) atom to the 4-position on the C(sp(3)) atom is in chemical equilibrium, whereas the process of migration of the F atom in the 2-position on the C(sp(2)) atom to the 3-position on the C(sp(3)) atom is not. Therefore, halogenated cyclopentene containing fluorine on either the C(sp(3)) or C(sp(2)) atom could be prepared selectively in terms of the NH4F catalyst.