Uso de argila bentonita como catalisadores em reações orgânicas: uma breve revisão em periódicos internacionais

Abstract

The constant search for synthetic processes that include reagents and reaction conditions in which the desired products are obtained at low cost and with little or no environmental impact has been the focus of many researchers. In this context, catalysts are important allies and are increasingly being used in new approaches to organic synthesis. From this point of view, new synthetic systems involving environmentally friendly catalysts and less toxic solvents are of great interest from the perspective of green chemistry. Heterogeneous catalysts have ensured advantages such as waste reduction, easy recovery of the reaction medium using simple and safe methods, as well as the possibility of reuse in new chemical reactions. Among the various heterogeneous catalysts of natural origin available in the literature, many researchers have been using bentonite, a class of clay belonging to the smectite family, as heterogeneous catalysts. In Brazil, this can be found in several regions, where one of the most studied and known is located in the Northeast Region, state of Paraíba, in the municipality of Boa Vista. Therefore, this work aims to carry out a bibliographical research in international journals about works on organic synthesis catalyzed by bentonite clay in the period from 2017 to 2022. Furthermore, it is important to highlight that the database used in the research was Scifinder, in which The term “bentonite clay catalysts organic synthesis” was used to carry out the search. In summary, 218 articles were reported by the database, among which only 14 articles actually belonged to the topic proposed for study. Therefore, numerous reactions were noticed in which bentonite clay-based catalysts were used. These reactions took place in an aqueous environment, with excellent temperature conditions, relatively short reaction times and excellent yields. Furthermore, from a sustainable point of view, numerous catalysts have been subjected to recycling tests, which have shown that they can be reused in new chemical reactions for several consecutive cycles without significant loss of their catalytic activity.