Transition‐Metal‐Free N ‐Arylation of Pyrazoles with Diaryliodonium Salts

A new synthetic method was developed for the N ‐arylation of pyrazoles using diaryliodonium salts. The transformation does not require any transition‐metal catalyst and provides the desired N ‐arylpyrazoles rapidly under mild reaction condition in the presence of aqueous ammonia solution as a mild base without the use of inert atmosphere. The chemoselectivity of unsymmetric diaryliodonium salts was also explored with large number of examples.