Jacobsen catalyst as a P450 biomimetic model for the oxidation of an antiepileptic drug

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 2007-08, Vol.273 (1), p.259-264
• Main Authors: Leod, T.C.O. Mac, Barros, V.P., Faria, A.L., Schiavon, M.A., Yoshida, I.V.P., Queiroz, M.E.C., Assis, M.D.
• Format: Article
• Language: English
• Subjects: Biomimetic models; Carbamazepine; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Salen complex; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2007.04.003

The carbamazepine oxidation by 3-chloroperoxybenzoic acid ( m-CPBA), tert-butyl hydroperoxide ( t-BuOOH) or H 2O 2, mediated by a salen complex was investigated in homogeneous medium or encapsulated in a matrix based on poly(dimethylsiloxane). The product carbamazepine 10,11-epoxide is dependent on the oxidant, pH, solvent and co-catalyst. The encapsulated complex was an efficient catalyst for carbamazepine oxidation using t-BuOOH and m-CPBA as oxidant. ▪ In this work, we investigated carbamazepine (CBZ) oxidation by 3-chloroperoxybenzoic acid ( m-CPBA), tert-butyl hydroperoxide 70 wt.% ( t-BuOOH) or hydrogen peroxide 30 wt.%, mediated by a salen complex in homogeneous medium or encapsulated in a polymeric matrix based on poly(dimethylsiloxane) (PDMS). The formation of carbamazepine 10,11-epoxide (CBZ-EP) is highly dependent on the oxidant, pH, solvent and co-catalyst. CBZ oxidation by m-CPBA, t-BuOOH and H 2O 2 is more efficient at low pH values, although the pH influence is small in the case of m-CPBA and t-BuOOH, in the entire pH range. This shows that the presence of substituents linked to the −OOH group of m-CPBA and t-BuOOH affects the catalytic activity of the studied system significantly. The encapsulated Jacobsen catalyst proved to be an efficient catalyst for carbamazepine oxidation by the oxidants t-BuOOH and m-CPBA. However, the hybrid polymeric membrane acted as a barrier against the oxidant H 2O 2, preventing it from reaching the bulk of the membrane, making substrate oxidation impossible in this case.