CeIII-Promoted Oxidation. Efficient Aerobic One-pot Eco-friendly Synthesis of Oxidized Bis(indol-3-yl)methanes and Cyclic Tetra(indolyl)dimethanes

CLAUDIO C. SILVEIRA; SAMUEL R. MENDES; MARCOS A. VILLETTI; DAVI F. BACK ; TEODORO S. KAUFMAN

GREEN CHEMISTRY (PRINT)

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2012 vol. 14 p. 2912 - 2921

1463-9262

Indoles and benzaldehyde derivatives undergo an efficient one-pot smooth condensation and a further atmospheric-pressure aerobic dehydrogenation with CeCl3 in i-PrOH, to afford the corresponding oxidized bis(indol-3-yl)methanes. Use of 2,2-bisindole as the heterocyclic precursor provides cyclic tetra(indolyl)dimethane derivatives, which further undergo partial oxidation to the related calix-shaped macrocycles, carrying an all cis 1,3,7-cyclodecatriene core and supporting a 2,2-biindolylidene moiety. The syntheses of these high value-added compounds is operationally simple and can be performed at room temperature under mild, neutral and environmentally friendly conditions.