The Research on Porphyrins and Analogues in Brazil: A Small Review Covering Catalytic and other Applications since the Beginning at Universidade de São Paulo in Ribeirão Preto until the Joint Venture between Brazilian Researchers and Colleagues from Universidade de Aveiro, Portugal

Shirley Nakagaki,Yassuko Iamamoto,Maria Da Graça Neves,Maria Do Amparo Faustino,Kelly Castro

doi:10.21577/0103-5053.20190153

Abstract

The synthetic versatility and the potential applications of porphyrins and analogues in different fields have aroused special interest in their study, especially to mimic biological systems, such as cytochrome P-450. The ability of the porphyrin tetrapyrrolic core to accommodate metal ions of varying charges can modulate the type of application of these compounds. As a contribution, in this special number in honor to the Brazilian women who have devoted their lives to the growth and dissemination of chemistry knowledge, we report the advances in porphyrin research in Brazil for catalytic purposes and other applications, beginning at the Universidade de Sao Paulo (USP) at Ribeirao Preto. We also discuss some works that have resulted from joint research effort between Brazilian researchers and Portuguese colleagues from the Universidade de Aveiro, Portugal, working in the porphyrin field.

Highlights

In spite of all the different solids used as supports for the immobilization of metalloporphyrins (Table 1), there is an expectation that MPs organized as porous materials, either using a porous solid as support,[85,86,87,89,90,91,99,100,125] or integrated into porous structures, such as metal-organic frameworks (MOFs)[27,80,140,141,145,146,192,193] or porous organic polymers (e.g., PIM = polymers of intrinsic microporosity),[149,153] will have enhanced catalytic performance, mainly regarding the selectivity, relative to non-porous materials, since the confinement effect for reagents and/or products may lead to unusual and unexpected selectivities for the same reaction relative to a homogeneous environment
The results presented by [Fe(TDFSPP)]-3DMMOXLDH after 24 h of catalytic reaction suggested that the immobilization of the FeP on the porous materials containing relatively small cavities or narrow channels was responsible for promoting the interesting regioselectivity in the oxidation of terminal linear alkanes
The results suggested that the longer reaction time (1 h versus 24 h) favors substrate access to the catalytic active species confined in the structure of the solid support, improving the efficiency and selectivity of the catalyst for oxidation in the substrate’s terminal position

Summary

Introduction

In the field of catalysis, synthetic metalloporphyrins, mainly the complexes with MnIII and FeIII ions, proved able to successfully oxidize hydrocarbons and other organic compounds under mild conditions.[25] They are able to act as chemical models of the P-450 enzyme family using oxygen donors, PhIO, as shown by Groves et al.,[25] and H2O2 and PhI(OAc)[2], since they are able to catalyze the transfer of one oxygen atom from these oxidants to a metal complex in various oxidative reactions, leading to the formation of the catalytically active species.[38]. Cooper and Groves[23] studied the oxidation of the diagnostic substrate tetramethylcyclopropane with important drug-metabolizing cytochrome P-450 isozymes and with a model cationic ironporphyrin/iodosylbenzene system and concluded that: “The similarity of the observed behaviour of the model system and the active enzymes indicate that similar mechanisms and similar intermediates are involved in both cases.”[23]

Brief historical events

Uses of Metalloporphyrins for Homogeneous Catalysis

Immobilization of Metalloporphyrins for Heterogeneous Catalysis

Findings

Final Remarks