General α‐Amino 1,3,4‐Oxadiazole Synthesis via Late‐Stage Reductive Functionalization of Tertiary Amides and Lactams**

An iridium-catalyzed reductive three-component coupling reaction for the synthesis of medicinally relevant α-amino 1,3,4-oxadiazoles from abundant tertiary amides or lactams, carboxylic acids, and (N-isocyanimino) triphenylphosphorane, is described. Proceeding under mild conditions using (<1 mol %) Vaska's complex (IrCl(CO)(PPh3)2) tetramethyldisiloxane to access key reactive iminium ion intermediates, a broad range 1,3,4-oxadiazole architectures were accessed acid feedstock partners. Extension heterodiazole was readily achieved by exchanging partner C-, S-, N-centered Brønsted provided rapid modular these desirable, yet difficult-to-access, heterocycles. The high chemoselectivity catalytic activation step allowed late-stage functionalization 10 drug molecules, including heterodiazole-fused drug–drug conjugates.