Thioamide‐Directed Cobalt(III)‐Catalyzed Selective Amidation of C(sp 3 )−H Bonds

A mild, oxidant‐free, and selective Cp*Co III ‐catalyzed amidation of thioamides with robust dioxazolone amidating agents via C(sp 3 )−H bond activation to generate the desired amidated products is reported. The method is efficient and allows for the C−H amidation of a wide range of functionalized thioamides with aryl‐, heteroaryl‐, and alkyl‐substituted dioxazolones under the Cp*Co III ‐catalyzed conditions. The observed regioselectivity towards primary C(sp 3 )−H activation is supported by computational studies and the cyclometalation is proposed to proceed by means of an external carboxylate‐assisted concerted metalation/deprotonation mechanism. The reported method is a rare example of the use of a directing group other than the commonly used pyridine and quinolone classes for Cp*Co III ‐catalyzed C(sp 3 )−H functionalization and the first to exploit thioamides.