Electrocatalytic Synthesis of Pyridine Oximes using in Situ Generated NH₂OH from NO species on Nanofiber Membranes Derived from NH₂‐MIL‐53(Al)

Abstract

Pyridine oximes producing from aldehyde or ketone with hydroxylamine (NH2OH) have been widely applied in pharmaceutics, enzymatic and sterilization. However, the important raw material NH2OH, exhibits corrosive and unstable properties, leading to substantial energy consumption during storage and transportation. Herein, this work presents a novel method for directly synthesizing highly valuable pyridine oximes using in situ generated NH2OH from electrocatalytic NO reduction with well‐design nanofiber membranes (Al‐NFM) derived from NH2‐MIL‐53(Al). Particularly, 2‐pyridinealdoxime, the precursor of antidote pralidoxime (2‐PAM) for nerve agents suffering from scarcity and high cost, was achieved with a Faraday efficiency up to 49.8 % and a yield of 92.1%, attributing to the high selectivity of NH2OH production on Al‐NFM, further easily reacted with iodomethane to produce 2‐PAM. This study proposes a creative approach, having wide universality for synthesizing pyridine and other oximes with a range of functional groups, which not only facilitates the conversion of exhaust gas (NO) and waste water (NO2‐) into valuable chemicals especially NH2OH production and in‐situ utilization through electrochemistry, but also holds significant potential for synthesis of neuro detoxifying drugs to humanity security.

Recent research progress on building C–N bonds via electrochemical NOx reduction

“…Li's group has also reported a similar method to synthesize a wide range of pyridine oximes via the *NH 2 OH intermediate generated in NO x RR. 73 In the meantime, the groups of Zou and Wang have also developed an electrosynthesis method for cyclohexanone oxime by utilizing the in situ generated *NH 2 OH in NO x RR. 51 Compared to Zhang's work, they used a 10-times higher concentration of cyclohexanone (0.1 M) and therefore the side reaction of cyclohexanone reduction into cyclohexanol must be considered.…”

Electrocatalytic Systems for NOx Valorization in Organonitrogen Synthesis

“…Through DFT calculations and in situ characterizations, the ability of Fe to accumulate adsorbed NH 2 OH and cyclohexanone was proved to be response for the high efficiency (Figure 6c). [54] Similarly, Li group [55] designed a catalyst (Al−NFM) with Al−O/N unsaturated coordination sites, synthesizing pyridine oximes by coupling electrochemistry with pyridine aldehydes, and pralidoxime iodide (an efficient antidote for organophosphorus poisoning) was further synthesized by a simple nucleophilic addition reaction. Through this method, other 5 kinds of pyridine oximes and additional 14 kinds of oximes featuring diverse functional groups, are successful synthesized (Figure 6d).…”

“… (a) Oxime production in the electro‐synthesizing leucine process using CoFe‐SSM at various potentials, [30] Copyright 2023, Wiley‐VCH GmbH; (b) the schematic diagram of a pathway for NO and cyclohexanone to produce CHO, [54] Copyright 2023, Wiley‐VCH GmbH; (c) Experimental amplification for the electrocatalytic synthesis of cyclohexanone oxime toward caprolactam production, [54] Copyright 2023, Wiley‐VCH GmbH; (d) the FE of various as synthesized pyridine oximes over Al‐NFM with Al−O/N unsaturated coordination sites from pyridine aldehyde [55] . Copyright 2023, Wiley‐VCH GmbH; (e) Yield and selectivity of different substrates over Cu−S electrocatalyst [56] .…”

Electrocatalytic Systems for NOx Valorization in Organonitrogen Synthesis

“…Through DFT calcula-tions and in situ characterizations, the ability of Fe to accumulate adsorbed NH 2 OH and cyclohexanone was proved to be response for the high efficiency (Figure 6c). [54] Similarly, Li group [55] designed a catalyst (AlÀ NFM) with AlÀ O/N unsaturated coordination sites, synthesizing pyridine oximes by coupling electrochemistry with pyridine aldehydes, and pralidoxime iodide (an efficient antidote for organophosphorus poisoning) was further synthesized by a simple nucleophilic addition reaction. Through this method, other 5 kinds of pyridine oximes and additional 14 kinds of oximes featuring diverse functional groups, are successful synthesized (Figure 6d).…”