Electrosynthesis of a nylon-6 precursor from cyclohexanone and nitrite under ambient conditions.

Wu, Yongmeng; Zhao, Jinghui; Wang, Changhong; Li, Tieliang; Zhao, Bo-Hang; Song, Ziyang; Liu, Cuibo; Zhang, Bin · Nat Commun · 2023

basic_science · Level V

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Abstract

Cyclohexanone oxime, an important nylon-6 precursor, is conventionally synthesized through cyclohexanone-hydroxylamine (NH<sub>2</sub>OH) and cyclohexanone ammoxidation methodologies. These strategies require complicated procedures, high temperatures, noble metal catalysts, and toxic SO<sub>2</sub> or H<sub>2</sub>O<sub>2</sub> usage. Here, we report a one-step electrochemical strategy to synthesize cyclohexanone oxime from nitrite (NO<sub>2</sub><sup>-</sup>) and cyclohexanone under ambient conditions using a low-cost Cu-S catalyst, avoiding complex procedures, noble metal catalysts and H<sub>2</sub>SO<sub>4</sub>/H<sub>2</sub>O<sub>2</sub> usage. This strategy produces 92% yield and 99% selectivity of cyclohexanone oxime, comparable to the industrial route. The reaction undergoes a NO<sub>2</sub><sup>-</sup> → NH<sub>2</sub>OH→oxime reaction pathway. This electrocatalytic strategy is suitable for the production of other oximes, highlighting the methodology universality. The amplified electrolysis experiment and techno-economic analysis confirm its practical potential. This study opens a mild, economical, and sustainable way for the alternative production of cyclohexanone oxime.