Abstract

RAFIEE, Ezzat; ZOLFAGHARIFAR, Zohreh; JOSHAGHANI, Mohammad  and  EAVANI, Sara. Dodecatungstocobaltate and Sn (IV)-substituted polyoxometalate: Preparation, characterization and catalytic performances in solventless synthesis of bis(indolyl)methanes. S.Afr.j.chem. (Online) [online]. 2012, vol.65, pp.138-144. ISSN 1996-840X.

Electrophilic substitution reaction of indole with various aldehydes and cyclohexanone were carried out in the presence of electron-transfer (K₅CoW₁₂O₄₀.3H₂O) and green Lewis acid ([(n-C₄H₉)₄N]₃PMo₂W₉(Sn⁴+.H₂O)O₃₉) catalysts. These catalysts were characterized by N₂-adsorption measurements, FT-IR, UV-Vis, ³¹P NMR, TGA, cyclic voltammetry and elemental analysis. Mechanisms for their catalytic activity are proposed. Both of these catalysts can be recovered and reused.

Keywords : Dodecatungstocobaltate; Sn (IV)-substituted polyoxometalate; bis(indolyl)methanes; electrophilic substitution; solvent-free conditions.

        · text in English     · English ( pdf )