A selective continuous-flow (CF) deuterodehalogenation approach is described performed
in propylene carbonate, which is considered as one of the greenest solvents. Various
CF technologies are known for hydrodehalogenation reactions; however, they are not
directly transferable for deuteration transformations. A novel spherical activated
carbon-supported palladium catalyst has been found to be useful for the catalytic
deuterodehalogenation of haloarenes. After careful reaction parameter optimization,
complete conversion was achieved for bromine-and chlorine-substituted haloarenes.
Nonetheless, no deuterium exchange was observed for the fluorine substituent, while
iodine-substituted compounds poisoned the catalyst. Importantly, deuterated compounds
were obtained with a rate of 3 mg min-1 and the catalyst showed reasonable reusability.
Moreover, benzylic amides were also deuterated without any debenzylation side-reaction.
