Direct alkylation of quinoxalinones with electron-deficient alkenes enabled by a sequential paired electrolysis

Paired Electrolysis-Enabled Arylation of Quinoxalin-2(1H)-ones

The first paired electrolysis-enabled arylation of quinoxalin-2(1H)-ones was achieved using cyanoarenes as the arylation reagents. A variety of 3-arylquinoxalin-2(1H)-ones with various important functional groups were obtained in moderate to good yields under metal- and chemical oxidant-free conditions. With a pair of reductive and oxidative processes occurring among the substrates and reaction intermediates, the power consumption can be dramatically reduced.

Paired Electrolysis Enabled Trifluoromethylheteroaromatization of Alkenes and Alkyne with Trifluoromethyl Thianthrenium Triflate (TT-CF3+OTf-) as a Bifunctional Reagent

We report a strategic exploitation of trifluoromethyl thianthrenium triflate (TT-CF3+OTf-) as both electromediator and CF3 radical precursors for paired electrolysis. Enabled by this strategy, the three-component trifluoromethylheteroaromatization of alkenes and alkynes was realized. The superiority of TT-CF3+OTf- to other electrophilic CF3 reagents is attributed to the cathodic generation of thianthrene (TT) as a mediator, which shifts the heterogeneous oxidation of interest to a homogeneous one.