Visible-Light-Mediated O–H Functionalization Reactions of Acetylenic alcohols with 3-diazooxindoles: Facile Access to Spirooxindole-Fused Oxacycles

Visible-light-mediated O–H functionalization reactions of acetylenic alcohols with 3-diazooxindoles were first described. Various substituted acetylenic alcohols were well tolerated and the O–H functionalization products were delivered in moderate to high yields. More importantly, these ether products could be easily transformed into spirooxindole-fused oxacycles. A preliminary study of the mechanism revealed that this reaction probably proceeded through a carbene transfer instead of a proton transfer pathway.