Calcogenação fotoinduzida de organofosfitos - Uma abordagem livre de metais

Abstract

The development of new green methodologies in organic synthesis contributes the clean and safe production of new compounds that are mainly applield in medicinal chemistry. A large portion of medicines are produced by total synthesis, where simple molecules pass through a lot of steps to achieve the final product. Therefore, the continous development of new methodologies in organic synthesis, mainly green approaches, enable the production of new compounds from softer procedures, taking into account the human health, environmental health and less energy comsumption. Recently, many works have brought potentials applications of selenylated organic compounds in medicinal chemistry, for exemple, in aromatic heterocycles functionalization, activated arenes and organophosphites. Phosphoselenoates are compounds formed from organophosphites, where its functionalization creates a P-Se bond, displaying antioxidante and antibacterial properties. Methodologies alreary shown uses transition metals, strong oxidants or high temperature to produce the desired product. The use of visible light is a greener alternative to such synthesis, being a clean and abundant source of energy, mainly when organic dyes are used as catalyst instead transition metal complexes. In this methodology, conditions like solvente, catalyst and stoichiometric quantity are optimized, searching for better yields of products. With the optimized conditions in hand, many different derivatives of products are synthesized, changing the starter materials from organophosphite, diselenide, ditelluride, to check the method coverage, and how do the yields vary in relation to the reactants used. Besides, control reactions are done to elaborate a propoused mechanism, making possible to see the reactants behavior in a photochemical system. The products characterization is done by 1H and 13C NMR.