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

•F6E-1Cl and F6E were formed in the hydrodechlorination of F6 with Zn in bifunctional solvent of water and amide.•The amide favors the formation of the insertion product.•And the water favors the hydrolysis of the insertion product.•The larger the molecular polarity index of the amide, the more favorable the reaction was.•F6E-1Cl is synthsyzed with high selectivity sicne F6 is easier to hydrodechlorinate than F6E-1Cl. 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. [Display omitted]