Visible-Light-Catalyzed Tandem Borylation/Cyclization of 1,7-Enynes with NHC-Boranes for the Synthesis of Boron-Embedded Polycyclic 3,4-Dihydroquinolin-2(1 H )-ones

A visible-light-catalyzed cascade cyclization of 1,7-enynes with N -heterocyclic carbene boranes has been developed, enabling the one-step construction of 1 H -borolo[3,4- c ]quinoline skeletons via a sequential inter- and intramolecular C–B, C–C, and C–B bond-forming process. This protocol provides rapid access to structurally diverse boron-containing polycyclic products (25 examples, up to 92% yield) under mild conditions. The reaction features broad functional group tolerance and excellent scalability, with gram-scale experiments proceeding without erosion of yield.