Internal Atom Exchange in Oxazole Rings: A Blueprint for Azole Scaffold Evaluation

Abstract In this article, we provide a route to transform isoxazoles and oxadiazoles into the corresponding pyrazoles and 1,2,4-triazoles in one step using catalytic amounts of an air-stable Ni(0) complex. The reaction is a formal atom-exchange process at the internal heteroatoms of the aromatic cycle. This work provides a blueprint for reactivity that permits the rapid evaluation of different five-membered azole scaffolds, thus avoiding de novo synthesis of the molecule of interest.