Brazil is responsible for 1/3 of the world production of oranges (16 million ton), and the oil from its peel contains about 90% limonene. The use of this renewable natural product is an interesting option, in terms of sustainability, as an alternative to the use of oil derivates for the manufacture of high value-added products, useful in pharmaceuticals, cosmetics, fragrances and flavors. Thus, any environmentally correct process of terpene transformation into useful products has strong economic consequence, and the majority of the isolated components from these compounds are ideal starting materials for the synthesis of important new chemicals. The metathesis reaction of olefins, in particular unsaturated ring opening by ethenolysis is an efficient reaction in terms of atom economy, because there is no intrinsic formation of byproducts. When applied to cyclic derivatives of unsaturated terpenes such as, for example, limonene, leads to the formation of non-conjugated trienes. These new molecules obtained from the metathesis can be sequentially used in other reactions catalyzed by transition metal complexes, such as the epoxidation, in order to obtain functionalized molecules of high economic interest. Although the aforementioned reactions can be considered as classical, its application to natural product requires further studies to the development of new and improved catalysts, which involves the synthesis of new ligands and new organometallic complexes. Their implementation should lead to the development of new catalytic systems and new technological route that will allow added value to natural products terpene family which are abundant in Brazil. In this project we intend to conduct the ethenolysis of limonene via homogeneous catalysis (catalyst of ruthenium-ylidene type) and heterogeneous (rhenium oxide supported on mesoporous alumina) to obtain trienes, which will subsequently be epoxidized using a green system based on Al2O3/H2O2. The products obtained have application in organic and organometallic synthesis, allowing obtaining new routes to the promotion of renewable raw materials.
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