Electrocatalytic C(sp3)-H/C(sp)-H cross-coupling in continuous flow through TEMPO/copper relay catalysis.

Electrocatalytic dehydrogenative C(sp3)-H/C(sp)-H cross-coupling of tetrahydroisoquinolines with terminal alkynes has been achieved in a continuous-flow microreactor through 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)/copper relay catalysis. The reaction is easily scalable and requires low concentration of supporting electrolyte and no external chemical oxidants or ligands, providing straightforward and sustainable access to 2-functionalized tetrahydroisoquinolines.