Syntheses and Reactions of Functional Polymers. XL. Enhanced Reactivity of Poly(vinyl chloride) by Neighboring-Group Participation of the N,N-Disubstituted Dithiocarbamate Function

In order to demonstrate that neighboring-group participation of the N,N-disubstituted dithiocarbamate function is involved in the substitution reaction of poly (vinyl chloride) (PVC) with the dithiocarbamate anion, the rates of reactions of PVC and the copolymer (vinyl chloride-S-vinyl N,N-diethyldithiocarbamate) with −SCS-NEt2 were compared under the same conditions. These polymer reactions were undertaken in dimethylformamide or tetrahydrofuran at 45°C. The rate enhancements with the copolymer were observed in both solvents. From these observations, it was concluded that the chloromethylene groups in PVC neighboring the dithiocarbamate function were activated .toward the nucleophile via neighboring-group participation. This is the first time that neighboring-group participation involving the polymer main chain might be observed in the polymer reaction. The difference in reaction mechanism between the polymer reaction and the model reaction was discussed.