Diarylation of N- and O-nucleophiles through a metal-free cascade reaction

Abstract

The arylation of heteroatom nucleophiles is a central strategy to reach diarylated compounds that are key building blocks in agrochemicals, materials and pharmaceuticals. Nucleophilic aromatic substitution is a classical tool for such arylations, and hypervalent iodine-mediated arylations are modern alternatives to achieve a wider scope of products. Herein, we combine the benefits of those strategies to enable an atom-efficient and transition metal-free functionalization of N- and O- nucleophiles with two structurally different aryl groups, to provide di- and triarylamines and diaryl ethers in one single step (> 100 examples). The core of this strategy is the unique reactivity discovered with certain fluorinated diaryliodonium salts, which unveils novel reaction pathways in hypervalent iodine chemistry. The method is suitable for aliphatic amines, anilines, ammonia and even water and tolerates a wide variety of functional and protecting groups. Furthermore, the retained iodine substituent is easily accessible for derivatization of the products.

A one-pot cascade protocol for diarylation of amines and water

“…In this step, the diaryliodonium salts are synthesized by a one-pot method following a literature procedure developed by our group ( Bielawski et al., 2007 ). This procedure is depicted in Scheme 2 and can be used without modifications for other electron-deficient fluorinated iodoarenes and the full scope of diaryliodonium salts is available at Linde et al. (2022) .…”

“…The preparation of the diaryliodonium salts is described within this protocol as well as the diarylation of amines and water. We have used similar conditions to prepare triarylamines from anilines, and diarylamines from ammonia, as depicted in Scheme 1 and described in Linde et al. (2022) .…”

“…Degass the solvents prior to every reaction by argon bubbling for 15 min.

Scheme 1 Diarylation of N- and O- nucleophiles Adapted with permission from Linde et al. (2022) .

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“…The protocol is limited to use of unhindered amines and diaryliodonium salts with certain substituents. For complete details on the use and execution of this protocol, please refer to Linde et al. (2022) .…”

“…For complete details on the use and execution of this protocol, please refer to Linde et al. (2022) .…”