Tethered photocatalyst-directed palladium-catalysed C-H allenylation of N -aryl tetrahydroisoquinolines.

Harnessing radical intermediates in regioselective reactions presents a substantial challenge. Here, we report a novel control strategy through engineering covalently tethered transition metal-photocatalysts that conjoin Pd-phosphine and Ru/Ir photoredox units. This strategy allows us to override the innate regioselectivity of the Pd-catalysed C-H allenylation of N -aryl tetrahydroisoquinolines.