Aqueous pulsed electrochemistry promotes C-N bond formation via a one-pot cascade approach.

He, Meng; Wu, Yongmeng; Li, Rui; Wang, Yuting; Liu, Cuibo; Zhang, Bin · Nat Commun · 2023

basic_science · Level V

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Abstract

Electrocatalytic C - N bond formation from inorganic nitrogen wastes is an emerging sustainable method for synthesizing organic amines but is limited in reaction scope. Integrating heterogeneous and homogeneous catalysis for one-pot reactions to construct C - N bonds is highly desirable. Herein, we report an aqueous pulsed electrochemistry-mediated transformation of nitrite and arylboronic acids to arylamines with high yields. The overall process involves nitrite electroreduction to ammonia over a Cu nanocoral cathode and subsequent coupling of NH<sub>3</sub> with arylboronic acids catalyzed by in situ dissolved Cu(II) under a switched anodic potential. This pulsed protocol also promotes the migration of nucleophilic ArB(OH)<sub>3</sub><sup>-</sup> and causes the consumption of OH<sup>-</sup> near the cathode surface, accelerating C - N formation and suppressing phenol byproducts. Cu(II) can be recycled via facile electroplating. The wide substrate scope, ready synthesis of <sup>15</sup>N-labelled arylamines, and methodological expansion to cycloaddition and Click reactions highlight the great promise.