Poly(N-vinylimidazole): A biocompatible, efficient, and highly recyclable heterogeneous catalyst for the preparation of bis(3-indolyl)methanes

Poly(N-vinylimidazole) (PVIm), as a biocompatible, efficient, halogen-free, and reusable catalyst, was ‎applied for the solvent-free synthesis of a library of bis(3-indolyl)methanes. The reaction was ‎smoothly carried out under mild conditions, and the crude products were purified easily, and ‎the pure products were obtained in high to excellent yields.‎