Practical Iridium-Catalyzed Direct α-arylation of N-heteroarenes with (Hetero)arylboronic Acids by H₂O-Mediated H₂ Evolution

Liang Cao,¹ He Zhao,¹ Rongqing Guan,¹ Huanfeng Jiang,¹ and Min Zhang^1,*

ABSTRACT: Despite the widespread applications of 2-(hetero)aryl N-heteroarenes in numerous fields of science and technology, universal access to such compounds is easily hampered due to the lack of a general method for their synthesis. Herein, by a H₂O-mediated H₂-evolution cross-coupling strategy, we report a new iridium(III)-catalyzed facile method to direct α-arylation of N-heteroarenes with both aryl and heteroaryl boronic acids, proceeding with broad substrate scope and excellent functional compatibility, oxidant and reductant-free conditions, operational simplicity, easy scalability, and no need for prefunctionalization of N-heteroarenes. This method offers applicability for structural modification of biomedical molecules, but also a practical route for direct access to 2-(hetero)aryl N-heteroarenes, a class of potential cyclometalated C^N ligands and N^N bidentate ligands that are difficult to prepare with the existing α-C-H arylation methods, thus filling an important gap in the capabilities of synthetic organic chemistry.

Nat. Commun., 2021, DOI:10.1038/s41467-021-01378-3