Bifunctional solvent-driven hydrodechlorination of 1,2-dichlorohexafluorocyclopentene and mechanism study

The hydrodechlorination of 1,2-dichlorohexafluorocyclopentene (F6) with Zn in the mixed solvents of water and amide was taken into investigation. It was proposed that the hydrodechlorination reaction involved the following steps: (1) the reaction of Zn insertion into carbon-chlorine bond of F6 in amide; (2) the hydrolysis reaction of 2-chlorohexafluorocyclopentenyl zinc chloride with water into 1-chloro-3,3,4,4,5,5-hexafluorocyclpentene (F6E-1Cl); (3) A small amount of F6E-1Cl could undergo the above-mentioned hydrodechlorination reaction similar to F6, thereby generating 3,3,4,4,5,5-hexafluorocyclopentene (F6E). Besides, it was also found when the molecular polarity index (MPI) of the amide was greater than or equal to 11.94 kcal/mol, it was conducive to the hydrodechlorination reaction, and the conversion was close to 100%. The molecular electrostatic potential (ESP) analysis results showed that F6 was easier to hydrolyze than F6E-1Cl, which was consistent with the experimental results and was beneficial to improve the selectivity of F6E-1Cl.