Formação sequencial de ligações carbono-carbono/carbono-selênio mediada por cloreto férrico e dicalcogenetos de diorganoíla: síntese e reatividade de 2-organocalcogenil-naftalenos

Abstract

In the present study, a series of aryl alkynols functionalized was subjected to intramolecular cyclization reaction promoted by iron(III) chloride and diorganyl dichalcogenides allowing the synthesis of 2-organoselenyl-naphthalenes. The mutual action between the diorganyl dichalcogenide and iron (III) chloride, in a 0.6: 0.75 mole ratio, was essential for the achievement of the products in good yields. The cyclization reaction tolerated a variety of functional groups, such as electron-donating group, electron-withdrawing groups and bulky groups. It was obtained the naphthalene derivatives exclusively via 6-endo-dig cyclization, giving thirty new compounds in 45-90% yields. In addition, using these compounds it was possible to carry out a selenium-lithium exchange reaction, giving the lithium intermediate derivatives, which were captured by electrophiles, leading to five new compounds in 45-96% yields.