LAUSR

We have developed a visible light-induced oxidative a-keto-dichlorination of terminal and internal aryl alkynes to form dichloroacetophenones (DCAPs) and dichlorophenyl-acetophenones (DCPAPs), respectively, by using CuCl 2 as a photoredox catalyst in the presence of air at room temperature (without using any exogenous photocatalyst). Here, photoexcited CuCl 2 undergoes LMCT to generate Cl radical, which readily adds to the alkynes to form DCAPs or DCPAPs in the presence of O 2 . This a-keto-dichlorination reaction is a green and mildest protocol as it produces water as the only by-product. Moreover, the evaluation of green chemistry metrics indicates that the E-factor (= mass of wastes/mass of products) of the current a-keto-chlorination method is ~10.1 times lower than that of a literature reported photochemical method. The Eco Scale value (scores 55, on a scale of 0-100 indicates an acceptable synthesis) signifies that this process is simple, highly efficient, eco-friendly and cost-effective.