Photocatalytic Annulation-Carbohalogenation of 1,7-Enynes for Atom-Economic Synthesis of Functionalized 3,4-Dihydronaphthalen-1(2H)-ones

A general and efficient photocatalytic annulation-carbohalogenation of 1,7-enynes with a wide variety of alkyl halides was reported, which led to the atom-economic synthesis of functionalized 3,4-dihydronaphthalen-1(2H)-ones with good yields and high stereoselectivity under the mild and oxidant-free conditions. The reaction demonstrated remarkable compatibility regarding alkyl halides as bifunctional reagents, such as ethyl 2-bromo-2,2-difluoroacetate, ethyl 2,2-difluoro-2-iodoacetate, perfluorobutyl iodide, bromotrichloromethane, and diethyl 2-bromomalonate, and enabled wide substrate scope, high functional group tolerance, and 100% atom utilization. (Figure presented.).