Ⅰ, Synthesis and reactions of 2-chlorohexafluorocyclopentenyl zinc and copper reagent

Abstract

I. Synthesis and Reactions of 2-Chlorohexafluorocyclopentenyl Zinc and Copper Reagent 1-Chloro-2-iodohexafluorocyclopentene reacted with activated zinc powder in DMF solvent at room temperature to give 2-chloro-hexafluorocyclopentenyl zinc reagent in 96\% yield. Treatment of this organozinc reagent with cuprous bromide at room temperature for one hour provided a simple route to the 2-chlorohexafluorocyclopentenyl copper reagent in quantitative yield. 2-Chlorohexafluorocyclopentenyl copper reagent exhibited good thermal stability at room temperature in the absence of oxygen and/or moisture and formed a wide variety of new carbon-carbon and carbon-heteroatom bonds via reactions with alkyl halides, vinyl halides, acyl halides, and heteroatomic halides. Alkylation and coupling reactions of this organocopper reagent were performed, and the reaction of this organocopper reagent with acyl halides and heteroatomic halides gave the previously inaccessible substituted polyfluorocyclopentene derivatives. II. Reaction of 1-Chlorohexafluorocyclopentene Derivatives with Various Nucleophiles 1-Acetyl-2-chloro-, 1-benzoyl-2-chloro-, and 1-chloro-2-p-nitrophenylhexafluorocyclopentene were prepared by the reaction of 2-chlorohexafluorocyclopentenyl copper reagent with acetyl chloride, benzoyl chloride, and pnitroiodobenzene, respectively. These compounds contain not only highly activated double bonds but also charge stabilizing groups in vinylic position. These compounds reacted readily with alkoxide, amine, and phosphite to undergo interesting nucleophilic displacement reactions of vinylic chlorine without allylic rearrangement. In reaction of 1-acetyl-and 1-benzoyl-2-chlorohexafluorocy-clopentene with Grignard reagent, nucleophilic attack occurred at the carbonyl carbon rather than at the beta-carbon to give tertiary alcohol product.