REACTION OF 1-CHLOROPERFLUOROCYCLOALKENE DERIVATIVES WITH NUCLEOPHILES

1-Acetyl-2-chloroperfluorocycloalkenes and 1-benzoyl-2-chloroperfluoro cycloalkenes have been prepared by the coupling of 2-chloroperfluorocy cloalkenyl copper reagent with acetyl chloride and benzoyl chloride, r espectively. Similarly, 1-chloro-2-(p-nitrophenyl)perfluoro-cyclopente ne and -cyclohexene were prepared by the reaction of 2-chloroperfluoro cyclo-pentenyl and -hexenyl copper reagent with p-nitroiodobenzene. Th e compounds contain not only highly activated double bands but also ch arge-stabilizing groups in vinylic positions. The reaction of these co mpounds has been studied with various nucleophiles. They were very sus ceptible to nucleophilic attack at the chlorine-bonded carbon atom. Cy clobutene and cyclopentene derivatives underwent interesting nucleophi lic displacement reactions of vinylic chlorine with alkoxide, amine an d triethyl phosphite without allylic rearrangement under mild conditio ns. The stabilization effect to the generated carbanion intermediate b y the acyl or p-nitrophenyl group undoubtedly dictates selectivity. Ho wever, additional factors must be considered in cyclohexene derivative s in which both 'inward' and 'outward' eliminations occur from methoxi de ion attack on perfluoroacyclohexene derivatives. Also the order of activating power for a double bond has been found to be benzoyl > acet yl >> p-nitrophenyl and 1-chlorotetrafluorocyclobutene derivatives wer e more reactive than 1-chlorohexafluorocyclopentene derivatives toward s the various nucleophiles.