Use of Hypervalent Iodine Reagents in Visible Light-Promoted α-Ketoacylations of Sulfoximines with Aryl Alkynes

In visible light, sulfoximidoyl-containing hypervalent iodine reagents react with aryl alkynes to give N-alpha-ketoacylated sulfoximines in good to high yields. The process is metal- and base-free, providing the diketonic products without the use of highly oxygenated reagents such as peroxides. Results from mechanistic investigations suggest the intermediacy of radicals and reveal the importance of molecular oxygen.