Reductive Molybdenum‐Catalyzed Direct Amination of Boronic Acids with Nitro Compounds

C−N coupling: A new electrophilic amination of boronic acids with simple and inexpensive nitro compounds has been developed allowing the preparation of a variety of highly substituted and functionalized aromatic secondary amines. The process employs affordable PPh₃ as reducing agent, in the presence of an easily available and highly stable dioxomolybdenum(VI) complex as catalyst.

Abstract

The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C−N coupling. Our methodology has proven to be scalable, air and moisture tolerant, highly chemoselective and engages both aliphatic and aromatic nitro compounds. Moreover, this general and step‐economical synthesis of aromatic secondary amines showcases orthogonality to other aromatic amine syntheses as it tolerates aryl halides and carbonyl compounds.

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