Gold-catalyzed synthesis of oxazoles from alkynyl triazenes and dioxazoles

Abstract

A gold-catalyzed regioselective [3 + 2] cycloaddition of alkynyl triazenes with 1,2,4-dioxazoles was developed. The triazene group in the products could be replaced to obtain iodo-oxazoles, providing potential transformations to diverse oxazole structures. This protocol features readily available starting materials, mild reaction conditions and scalability. A plausible mechanism involving a nitrene transfer process was proposed.