Ruthenium-exchanged montmorillonite as an efficient and reusable catalyst for the synthesis of bis(indolyl)methanes

The catalytic efficacy of ruthenium (Ru)-exchanged montmorillonite, a well-established heterogeneous catalyst, was systematically explored to synthesize diverse bis(indolyl)methanes. The developed methodology consistently yielded the desired products with satisfactory to excellent yields, while notable advantages of the proposed approach encompassed minimal reaction times and solvent-free conditions. Furthermore, the method was characterized by its procedural simplicity, facile catalyst synthesis, ready accessibility of the starting materials from commercial sources, and the potential for catalyst recyclability.