Iron‐Catalyzed Oxidative C−C and N−N Coupling of Diarylamines and Synthesis of Spiroacridines

We describe iron-catalyzed intermolecular oxidative coupling reactions of diarylamines to form substituted 2,2′-bis(arylamino)biaryl compounds, tetraarylhydrazines, and 5,6-dihydrobenzo[c]cinnolines with the same hexadecafluorinated iron–phthalocyanine catalyst. The mild formation of C−C or N−N bonds was controlled by the use of acidic or basic additives. In contrast to most iron-catalyzed dehydrogenative coupling reactions, ambient air could be used as the sole oxidant. Moreover, iron(III) chloride hexahydrate promoted a one-pot coupling and subsequent intramolecular dearomative coupling to give 10H-spiro[acridine-9,1′-cyclohexa-2′,5′-dien-4′-ones].