Avaliação da atividade catalítica de nanopartículas de Pt e Pt/Sn imobilizadas sobre suporte de carbono na síntese da 3-hexil-1H-isocromen-1-ona

Abstract

Isocoumarins are substances that have great applicability both in the medicine area and agroindustry due to their potential and diversified biological activity. However, these compounds are derived from fungi and plants which makes it difficult to extract them on a large scale for commercial demand. Although there are some synthetic methods for obtaining these substances, most of them result in the formation of by-products, such as phtalides, which are difficult to separate. Therefore, there is great interest in the development of more efficient synthesis methods to produce such compounds selectively. Sonogashira cross-coupling between o-iodobenzoic acid and terminal alkynes has been shown to be an excellent pathway for the synthesis of isocoumarins, although it does not always result in the selective isocoumarin production when conventional catalysts are used. Therefore, the objective of this work was to evaluate the potentiality of the heterogeneous Pt/C nanocatalysts and a Pt/Sn torque supported on carbon with 50%, 65%, 70%, 75% and 100% tin coating for selective extraction of the structure of 3-hexyl-1H-isochromen-1-one by Sonogashira coupling. In this work, 3-hexyl-1H-isochromen-1-one was obtained selectively using Pt-based nanocatalysts, a metal without precedence in cross-coupling reactions. The structural characterization of isocoumarin was performed by 1H and 13C NMR and the morphology of the nanoparticles was determined by MET.