GREEN CHEMISTRY
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2026
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IF 10.6
Yingxuan Zhao,Chenyang Shen,Qing Liu,Siyuan Zhao,Ruiyao Zhao,Xiangke Guo,Nianhua Xue,Luming Peng,Xuefeng Guo,Yan Zhu,Weiping Ding
Olefin functionalization is a powerful approach for accessing a wide range of value-added compounds with broad applications. Advanced electrosynthesis offers streamlined upgrades over traditional methods by employing electrons as traceless agents and is extremely attractive for promoting olefin functionalization, but achieving high efficiency and selectivity remains a major challenge. Here, we report a conceptually new electrochemical strategy that precisely controls the reactivity of olefin-derived carbocations, the key intermediates of functional transformations, through asymmetric electrolyte design. Using cyclohexene as a model substrate, we reveal that while the local electrode microenvironment steers surface-generated carbocations toward either electrochemical oxidation or Ritter-type amidation in water/acetonitrile mixed electrolytes, the intrinsic competition between water and acetonitrile fundamentally dictates the reaction outcome. By creating a controlled molecular imbalance under overall charge neutrality through selective semipermeable membranes, the asymmetric electrolyte system decouples these competing pathways, enabling exclusive oxidation or 98% selective amidation—the highest Ritter-type amidation efficiency reported under electrochemical conditions. This work establishes electro-driven carbocation control as a powerful principle for resolving intrinsic selectivity challenges in multicomponent systems and provides a broadly applicable, sustainable strategy for selective olefin electro-conversion.
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DOI
高影响因子
ACS Catalysis
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2025
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IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
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DOI
高影响因子
Catalysis Science & Technology
·
2025
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IF 4.2
Yu-Le Wang,Songhai Wu,Yu-Zhen Xu,Yu-Dong Shan,Yong Liu,Xu Han
The selective oxidation of cyclohexene (Cy) to cyclohexene oxide (Cy-ep) using O2 remains challenging due to low epoxidation selectivity. In this work, a series of Mo-doped TS-1 (Mo-TS-1) catalysts were successfully synthesized for the epoxidation of Cy under solvent- and initiator-free conditions with O2 as the oxidant. Among them, 5Mo-TS-1 exhibited high catalytic performance, achieving 43.5% Cy conversion and 50.6% selectivity toward Cy-ep. Additionally, valuable byproducts such as 2-cyclohexen-1-ol (Cy-ol) and 2-cyclohexen-1-one (Cy-one) were obtained with yields of 28.0% and 21.4%, respectively. Since both Cy-ol and Cy-one are valuable intermediates in fragrance synthesis, over 43.5% of Cy was effectively converted into high-value products. Quenching experiments and Raman spectroscopy revealed that surface oxygen vacancies (Ov) facilitate the activation of O2 to form ≡Ov‑superoxo species, which abstract hydrogen from the allylic C-H bond of Cy to generate 3-cyclohexenyl radicals (Cy•). These radicals subsequently react with O2 to form Cy-OO•, followed by hydrogen abstraction from another Cy molecule to yield 2-cyclohexene-1-hydroperoxide (Cy-OOH). A positive correlation between Cy-OOH and Cy-ep formation underscores the critical role of Cy-OOH in the epoxidation process. Furthermore, Raman spectroscopy confirmed the presence of ≡Mo-(η2-O2) peroxo species on the catalyst surface, which preferentially attack the C=C bond of Cy to form Cy-ep. DFT calculations elucidated two distinct O2 activation pathways: In Pathway I, O2 is activated at Ov sites to form ≡Ov‑superoxo, which subsequently reacts with Cy to generate ≡Ov‑peroxo, Cy-OOH, and Cy•. In Pathway II, Mo(V/VI) sites either directly activate O2 or react with peroxo intermediates (≡Ov‑peroxo or Cy-OOH) to form ≡Mo-(η2-O2). This species selectively epoxidizes the alkene bond in Cy to Cy-ep. Notably, the direct activation of O2 at Mo(V/VI) sites bypasses the allylic oxidation route, thereby enhancing the epoxidation selectivity beyond the theoretical limit of 50.0%. This study provides new insight on the importance of surface superoxo and peroxo mediated by Ov and Mo(V/VI) in the epoxidation processes.
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2025
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IF 6.2
Zehao Li,Wanying Wang,Lulu Zhang,Jinchu Yang,Yongming Xu,Zhenzhen Huang,Wanzeng Li,Shiying Wang,Jingwen Yang,Zhifeng Zhang
Dihydrocarvone is extensively utilized in food, pharmaceutical, and cosmetic fields because of its pleasant odor, high economic value, and diverse pharmacological properties. In this study, an ene reductase KlebER3, which catalyzed the conversion of carvone to dihydrocarvone using NAD(P)H as a cofactor, was identified from Klebsiella sp. O852 through genome sequencing. This enzyme displayed optimal activity at 30 °C and pH 7 and maintained appreciable stability at 20–50 °C and pH 6–8. Besides, KlebER3 had good resistance to dimethyl sulfoxide and glycerine and exhibited wide-ranging substrate acceptance for α,β-unsaturated compounds. Furthermore, a Q26A mutant with enhanced activity, stability, and stereoselectivity was obtained by molecular docking, alanine scanning, and site-directed mutagenesis. Molecular dynamics simulations revealed that these improvements may be attributed to increased nonpolar interactions, elevated flexibility of the active pocket, reduced binding free energy, and strengthened rigidity of protein conformation. This study established a basis for further investigations of the function and modification of ene reductase as well as the efficient biosynthesis of dihydrocarvone.
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）