DMSO Enabled Selective Radical O-H Activation of 1,3(4)-Diols.

Selectivity control is one of the central topics in organic chemistry. Although the alkoxyl radical induced unprecedented transformations have drawn more attentions, compared to the booming selective C-H activation, the selective radical O-H activation remains less explored. Herein, we report a novel selective radical O-H activation strategy of diols by combining spatial effect with proton coupled electron transfer (PCET). The common molecule DMSO is found to be an essential reagent that enables the regioselective transformation of diols. Mechanistic studies indicated the existence of the alkoxyl radical and the selective interaction between DMSO and hydroxyls. Moreover, the distal C-C cleavage is realized by this selective alkoxyl radical initiation protocol.