Synthesis of Triindolylmethanes Catalyzed by Zeolites.

Various triindolylmethanes were synthesized by condensation of indole (or its derivatives) with indole-3-carboxaldehyde using solid acids as catalysts. Among the valued catalysts, [SO3H]–MSU mesoporous molecular sieve-functionalized MSU with sulfonic acid group gave the most outstanding performance. Electron-donating groups on indoles were favourable to the reaction, whereas electron-withdrawing groups decreased the reactivity of indoles. [ABSTRACT FROM AUTHOR]