Síntese de organocalcogenilcromenos e 9,10-bis (organocalcogenil)fenantrenos via reação de carbociclização promovida por Oxone®

Abstract

In the present study, a method was developed for the synthesis of 2-(organochalcogenyl)-3H-benzo[f]chromenes and 3-(organoselanyl)-2H-chromenes through intramolecular cyclization of propargylic aryl ethers derivatives. This cyclization was promoted by electrophilic and/or radical species generated in situ from the reaction of diorganyl diselenides and ditellurides with Oxone®, using acetonitrile as solvent at 100 °C in a sealed tube. Thus, through the developed method it was possible to synthesize thirty-one examples of organochalcogenylchromenes in good to excellent yields (50-98%) within reaction times ranging from 0.8-24 h. This includes 3 examples of chalcogenylchromenes derived from natural products. Additionally, a method was developed for the synthesis of 9,10-bis (organochalcogenyl)phenanthrenes and seleno-spiro[cyclohexane-1,1'-indene]-2,2-dien-4-ones via cyclization of (biphenyl-2-alkyne)chalcogenides with diorganyl diselenides in the presence of Oxone® as a green oxidant, in acetonitrile at 80 °C. In this study, 16 examples of 9,10-bis(organochalcogenyl)phenanthrenes were selectively obtained with yields of 50-97% after 1-4 h of reaction time, along with 4 examples of seleno-spiro[cyclohexane-1,1'-indene] -2,5-diene-4-ones in yields of 65-80% after 2 h.