Abstract Alkyl aryl ketones on treatment with SiCl4/urea–hydrogen peroxide (UHP) or SiCl4/iodosylbenzne reagent systems afforded α-chloroketones in excllent yields, while ketones with higher enol content provide exclusively α, α-dichloroketones under exceedingly mild conditions. The reaction proceeds via the initial formation of silyl enol ethers. A polarized chlorine intermediate that resulted from the coordination of SiCl4 with ...
