332017-50-2Relevant articles and documents
Lewis acid catalyzed Nenitzescu indole synthesis
Velezheva, Valeriya S.,Kornienko, Albert G.,Topilin, Sergey V.,Turashev, Ascar D.,Peregudov, Alexander S.,Brennan, Patrick J.
, p. 873 - 879 (2006)
A novel method for Lewis acid catalyzed Nenitzescu indole syntheses of 5-hydroxyindoles bearing different substituents in positions 1 (Alk, Bn, Ar), 2 (Me, Et, Ph), and 3 (COOEt, COMe, CONHPh) as well as tricyclic derivatives are reported. The method is simple, rapid, efficient, and allows preparation of hydroxyindoles from 1,4-benzoquinone and enamines in good to excellent yields with the use of low-polar solvents in the presence of weak Lewis acids catalysts. The formation of 5-hydroxyindoles under such mild conditions is explained in terms of a non-redox mechanism.
