Visible Light-Promoted Friedel-Crafts-Type Chloroacylation of Alkenes to β-Chloroketones.

The photoredox chloroacylation of alkenes has been developed as a substitute for the Friedel-Crafts acylation of alkenes to β-chloroketones. The direct generation of acyl radical species from acid chlorides under the photoredox conditions allows the formation of β-chloroketones without dehydrochlorination with the help of KHCO3. The synthetic utility of the current method is demonstrated in the one-pot synthesis of dihydroisoxazole, dihydropyrazole, and dihydropyrimidine-2-thione in 1 mmol scale.