- 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
-
The design of reusable high-performance heterogeneous catalysts via the immobilization of chemical and biochemical species on magnetic nanoparticles increases the efficiency of catalytic systems by facilitating easy, fast, and clean separation processes. Laccase and 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl were separately immobilized on amine functionalized iron (II, III) oxide nanoparticles with covalent bonding using glutaraldehyde as a coupling 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 time of 10 h and a heterogeneous catalyst containing immobilized laccase (80 mg, 100 U) and immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) (40 mg, 2 mol%). The catalyst retained more than 85% of its initial activity after 10 runs. In addition to the potential for reuse without significant losses in performance, eco-friendly attributes of this catalytic system include its high catalytic activity and the ease with which it can be recovered from the reaction mixture using an external magnet. (Figure presented.).
- Mogharabi-Manzari, Mehdi,Kiani, Mahshid,Aryanejad, Sima,Imanparast, Somaye,Amini, Mohsen,Faramarzi, Mohammad Ali
-
p. 3563 - 3571
(2018/09/22)
-
- Synthesis, characterization and DPPH scavenging activity of some benzimidazole derivatives
-
A base-catalyzed conversion of aldehydes to benzimidazoles has been achieved. The compounds have been characterized by IR, NMR, micoranalysis, and GC-MS. The reaction for the formation of benzimidazoles has been monitored with 1H NMR and IR. Th
- Odame, Felix,Krause, Jason,Hosten, Eric C.,Betz, Richard,Lobb, Kevin,Tshentu, Zenixole R.,Frost, Carminita L.
-
p. 271 - 284
(2018/09/06)
-
- Conventional and microwave-assisted synthesis of benzimidazole derivatives and their in vitro inhibition of human cyclooxygenase
-
A large series of 1,2-diaryl-benzimidazole and 2-aryl-1H-benzimidazole derivatives were synthesized with slight differences using both microwave irradiation and conventional heating methods. Usually higher yields and time reactions reduction were obtained
- Secci, Daniela,Bolasco, Adriana,D'Ascenzio, Melissa,Della Sala, Flavio,Yanez, Matilde,Carradori, Simone
-
p. 1187 - 1195
(2013/01/15)
-