Visible-Light-Promoted Radical Spirocyclization of 1,7-Enynes and α-Bromocarbonyl Compounds to Access Spirooxindole Derivatives

A novel visible-light-induced radical cascade spirocyclization of 1,7-enynes with diverse α-bromocarbonyl compounds is developed for the efficient construction of functionalized spirooxindole derivatives. This protocol features mild reaction conditions and simple operation, enabling the one-step assembly of complex spirocyclic skeletons with high diastereoselectivity. Scale-up synthesis and diversified product derivatizations further demonstrate the synthetic utility of this methodology. A series of control experiments confirm a radical-involved reaction pathway involving key 1,5-hydride shift and radical rearrangement processes.