Artigo Produção Nacional Revisado por pares

Porphyrin−Kaolinite as Efficient Catalyst for Oxidation Reactions

2009; American Chemical Society; Volume: 1; Issue: 11 Linguagem: Inglês

10.1021/am900556b

ISSN

1944-8252

Autores

Natalia Bizaia, Emerson H. de Faria, Gustavo Pimenta Ricci, Paulo S. Calefi, Eduardo J. Nassar, Kelly A. D. F. Castro, Shirley Nakagaki, Kátia J. Ciuffi, Raquel Trujillano, Miguel Á. Vicente, A. Gil, S.A. Korili,

Tópico(s)

Metal-Catalyzed Oxygenation Mechanisms

Resumo

The preparation, characterization, and application in oxidation reactions of new biomimetic catalysts are reported. Brazilian São Simão kaolinite clay has been functionalized with [meso-tetrakis(pentafluorophenyl)porphinato]iron(III), Fe(TPFPP). To obtain the functionalized clay, the natural clay was purified by dispersion−sedimentation, expanded by insertion of dimethyl sulfoxide (DMSO), and functionalized with amino groups by substitution of DMSO with ethanolamine. These previous steps allowed clay functionalization with Fe(TPFPP), leading to a layered material with a basal spacing of 10.73 Å. Clay functionalization with the porphyrin was confirmed by formation of the secondary amine, as demonstrated by FTIR bands at 3500−3700 cm−1. UV−vis spectroscopy revealed a red shift in the Soret band of the iron porphyrin in the functionalized material as compared to the parent iron porphyrin catalyst in solution, indicating FeIIIP → FeIIP reduction. The catalytic performance of the functionalized clay was evaluated in the epoxidation of cyclooctene, with complete selectivity for the epoxide (100% epoxide yield), and ketonization of cyclohexane, cyclohexanone being the major product. The novel catalyst was also evaluated in the Baeyer−Villiger (BV) oxidation of cyclohexanone, with 85% conversion of cyclohexanone in ε-caprolactone, with total selectivity to ε-caprolactone.

Referência(s)