Modular Synthesis of Alkylarylazo Compounds via Iron(III)-Catalyzed Olefin Hydroamination

A novel Fe-catalyzed olefin hydroamination with aryldiazo sulfones for accessing alkylarylazo compounds has been successfully developed. Aryldiazo sulfones are used as radical acceptors, and N–N double bonds will be regenerated when an arene sulfonyl group leaves. The reaction features mild reaction conditions and a broad substrate scope, allowing access to many azo compounds that would be difficult or perhaps impossible to access using other methods.