Solvent-Free Mechanoradical-Mediated Minisci-Type C-H Alkylation of N-Heteroarenes

An environmentally friendly new C-H alkylation method of N-heteroarenes facilitated by mechanochemistry is described. Under solvent-free ball-milling, mechanoradicals (SO4 center dot -) were generated from persulfate via in situ homolysis in the solid state, at as low as -50 C-degrees. These highly oxidizing radicals readily transform alkyl trifluoroborate salts to their corresponding carbon-based radicals for subsequent C-C bond formation with N-heterocycles. Mechanistic studies unambiguously confirmed the involvement of both oxygen- and alkyl-radical-based intermediates.

Automated summary

An environmentally friendly C-H alkylation method of N-heteroarenes facilitated by mechanochemistry is described. Mechanoradicals generated from persulfate via in situ homolysis in the solid state can readily transform alkyl trifluoroborate salts to carbon-based radicals for subsequent C-C bond formation with N-heterocycles.