Copper-Catalyzed Selective C(sp³)-H Esterification Using Azidobenziodoxole Derivatives as the Mediator

An efficient and selective copper-catalyzed secondary C(sp³)-H esterification has been developed. The reaction of various alkane substrates with azidobenziodoxole derivatives, in the presence of a cuprous iodide catalyst and trifluoromethanesulfonic acid additive, afforded inert aliphatic C-H esterification products. These reactions are selective and compatible with a wide range of functional groups. Mechanistic studies suggest that the azidobenziodoxole derivatives not only function as hydrogen-abstracting reagents to selectively activate C(sp³)-H bonds but also serve as ester donors in the esterification reaction.