Aplicação do ácido tricloroisocianúrico e disselenetos de diorganoíla para a síntese de compostos organosselenados

Abstract

In the first work of this thesis, a new method was developed for the synthesis of 3-organylselanyl-benzo[b]chalcogenophenes promoted by trichloroisocyanuric acid (TCCA). The reaction between TCCA and diorganoyl diselenides promotes the formation of an electrophilic selenium species in situ, which reacts directly with the 1-(1-alkynil)-2-(chalcogenyl)arenes, favoring an electrophilic cyclization reaction. The developed method proved to be effective in the synthesis of twenty different 3-organylselanyl-benzo[b]chalcogenophenes with yields ranging from 58% to 94% under mild reaction conditions. In addition, the reaction proved to be suitable to produce a molecule of N-methyl-indole with organylselanyl moiety. Similarly, in the second work of this thesis, the system involving TCCA and diorganoyl diselenides was used for the generation of electrophilic selenium species in situ. However, a regioselective reaction of electrophilic aromatic substitution was performed at C-1 of β-naphthol, using ethanol as a solvent at room temperature. With this method, it was possible to obtain 18 compounds that varied between 32% and 90% of yield. In addition, in this second work, was possible to obtain the synthesis of a selenated derivative of naproxen, a drug known and marketed worldwide.