Ni-Mediated High-Spin Iron(III) for Boosting Electrocatalytic NO to Oxime Conversion.

Abstract

Oximes serve as indispensable intermediates in synthetic chemistry, owing to their distinctive C═N─OH structure, conferring highly versatile reactivity. Synthesis of oxime via the electrochemical method has potential advantages, accompanied by the upgrading of industrialization. Herein, we propose a novel strategy by introducing nickel (Ni) mediation to obtain high-spin iron (Fe)(III) in phthalocyanine structure for synthesizing glyoxylate oxime via electrocatalytic nitric oxide (NO) coupling with keto acid. The optimized pFeNiPc catalyst achieved a Faradaic efficiency of 84.3% and a long-term stability for glyoxylate oxime electrosynthesis. Moreover, the oxime could be directly cyclized to synthesize a gram-level agrochemical isoxazoline molecule. The enriched amounts of high-spin Fe(III) sites promote the accumulation of NO on the catalyst surface and further accelerate reduction, which enables the efficient adsorption-conversion of NO to oxime. This work devises an innovative strategy to selectively engineer the activation of catalytic sites by tailoring electronic configuration and presents a method to facilitate NO valorization in organonitrogen synthesis.