A Magnetic Heterogeneous Biocatalyst Composed of Immobilized Laccase and 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) for Green One-Pot Cascade Synthesis of 2-Substituted Benzimidazole and Benzoxazole Derivatives under Mild Reaction Conditions
作者:Mehdi Mogharabi-Manzari、Mahshid Kiani、Sima Aryanejad、Somaye Imanparast、Mohsen Amini、Mohammad Ali Faramarzi
DOI:10.1002/adsc.201800459
日期:2018.9.17
reagent. The prepared catalyst was used to synthesize 12 benzoxazole and benzimidazole derivatives. The one‐pot, two‐step enzymatic aerobic oxidation reaction included the condensation of in situ‐produced salicylaldehyde derivatives with aromatic amines, followed by an enzymatic dehydrogenation process. Optimal reaction conditions consisted of a citrate buffer (10 mM, pH 4.5) at 40 °C for an incubation
通过将化学和生化物种固定在磁性纳米颗粒上,可重复使用的高性能多相催化剂的设计可简化,快速且清洁的分离过程,从而提高了催化系统的效率。使用戊二醛作为偶联剂,将漆酶和4-氨基-2,2,6,6-四甲基哌啶-1-氧基分别固定在胺官能化的氧化铁(II,III)纳米粒子上。所制备的催化剂用于合成12个苯并恶唑和苯并咪唑衍生物。一锅,两步酶促好氧氧化反应包括原位缩合反应。用芳族胺制备水杨醛衍生物,然后进行酶促脱氢过程。最佳反应条件包括在40°C下柠檬酸缓冲液(10 mM,pH 4.5)孵育10 h和包含固定化漆酶(80 mg,100 U)和固定化2,2,6,6-的非均相催化剂四甲基哌啶-1-氧基(TEMPO)(40 mg,2 mol%)。10次运行后,催化剂保留了其初始活性的85%以上。除了可以重复使用而不会对性能造成重大损失外,该催化系统的环保特性还包括其高催化活性和使用外部磁体从反应混合物中回收的便捷性。