Site-selective desaturation of C(sp3)-C(sp3) bonds via photoinduced ruthenium catalysis

Ruthenium(ii) photocatalysis has emerged as one of the most advanced tools in modern synthetic chemistry, but its catalytic mode is generally limited to single-electron transfer and triplet energy transfer events. Herein, we introduce a dual function ruthenium(ii) catalytic system by intertwining single-electron transfer with its innate transition metal catalytic activity. This approach allows for the efficient desaturation of various amide and alcohol derivatives in a highly regio- and stereoselective fashion under mild conditions. Further, an interesting radical-triggered cascade 1,5-HAT/Heck-type coupling could also be achieved through this photoinduced Ru catalysis.