Key Laboratory of Cardiovascular and Cerebrovascular Disease Prevention and Control, Ministry of Education, Gannan Medical University, Ganzhou, Jiangxi 341000, P.R. China.
Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, P.R. China.
Dalton Trans. 2021 Sep 21;50(36):12413-12418. doi: 10.1039/d1dt01967h.
A highly efficient method to oxidize methylarenes to their corresponding acids with a reusable Cr catalyst was developed. The reaction can be carried out in water with 1 atm oxygen and KSO as cooxidants, proceeds under green and mild conditions, and is suitable for the oxidation of both electron-deficient and electron-rich methylarenes, including heteroaryl methylarenes, even at the gram level. The excellent result, together with its simplicity of operation and the ability to continuously reuse the catalyst, makes this new methodology environmentally benign and cost-effective. The generality of this methodology gives it the potential for use on an industrial scale. Differing from the accepted oxidation mechanism of toluene, GC-MS studies and DFT calculations have revealed that the key benzyl alcohol intermediate is formed under the synergetic effect of the chromium and molybdenum in the Cr catalyst, which can be further oxidized to afford benzaldehyde and finally benzoic acid.
开发了一种将甲基芳烃高效氧化为相应酸的方法，使用可重复使用的 Cr 催化剂。该反应可以在 1 个大气压氧气和 KSO 作为共氧化剂的水中进行，在绿色温和的条件下进行，适用于电子缺电子和富电子的甲基芳烃的氧化，包括杂芳基甲基芳烃，甚至在克级水平。优异的结果，加上其操作简单和催化剂可连续重复使用的能力，使这种新方法具有环境友好和经济高效的特点。该方法的通用性使其具有在工业规模上应用的潜力。与甲苯的公认氧化机制不同，GC-MS 研究和 DFT 计算表明，关键的苄醇中间体是在 Cr 催化剂中铬和钼的协同作用下形成的，它可以进一步氧化生成苯甲醛，最终生成苯甲酸。
