A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions

A practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions has been developed.In the presence of PhI(OAc)_(2) as promoter and under ambient conditions,the reactions of styrenes and triiodomethane undergo the transformation smoothly to deliver the corresponding a-iodoketones without additional photocatalyst in good yields under sunlight irradiation.Mea nwhile,the reactions of styrenes with tribromomethane and trichloromethane generate the desiredα-bromoketones and a-chloroketones in high yields by using Ru(bpy)_(3)Cl_(2) as a photocatalyst under blue LED(450-455 nm) irradiation.