Síntese de selenoésteres via reação de cloretos de acila com disselenetos na presença de Zn0 catalisado por CoCl2.6H2O

Abstract

Selenium is an essential micronutrient for animal and plant metabolism. Organic selenium molecules have attracted a lot of attention because they are important synthetic intermediates and have several biological activities. Among these molecules, selenoesters stand out for being precursors of anions and acyl radicals, intermediates in protein synthesis, application in chemistry of new technological materials and for exhibiting various pharmacological activities such as antioxidants and antimicrobials, for example. The practical, alternative and efficient synthetic approach to the synthesis of selenol and thiol esters is described through the reaction of acyl chlorides with diselenides or disulfides in the presence of Zn dust catalyzed by inexpensive CoCl2.6H2O. This protocol tolerated a wide range of substrates, such as aromatic and aliphatic acyl chloride with a variety of sensitive functional groups to afford the respective products in good yields. Furthermore, the method was also extended to use anhydrides acid as substrate. In addition, the obtained selenol ester was readily transformed into Z-vinyl selenide ketone by the reaction of selenocarbonylation of terminal alkynes catalyzed by palladium/copper system.