Efficient merging of copper and photoredox catalysis for the asymmetric cross-dehydrogenative-coupling of alkynes and tetrahydroisoquinolines

A highly efficient catalytic asymmetric alkynylation of prochiral CH₂ groups in tetrahydroisoquinoline was developed using copper catalyzed cross-dehydrogenative-coupling of sp³ and sp C–H bonds with the assistance of a photocatalyst and visible light.