Direct access to alpha-sulfenylated amides/esters via sequential oxidative sulfenylation and C-C bond cleavage of 3-oxobutyric amides/esters

An efficient, environmentally benign and unprecedented synthesis of various alpha-sulfenylated amides/esters has been developed under oxygen atmosphere. The reaction shows good functional group tolerance and excellent chemo/regioselectivity. All the desired products were obtained in moderate to excellent yields, even on the gram scale. Practically, the related alpha-thiol Weinreb amide can be readily transferred to a series of prospective compounds, and selenium atom can be introduced to the alpha-sites of the amides in high yields.