p-sulfonic acid calix[4]arene: An efficient reusable organocatalyst for the synthesis of bis(indolyl)methanes derivatives in water and under solvent-free conditions

Seyed Meysam Baghbanian; Yaser Babajani; Hamed Tashakorian; Samad Khaksar; Maryam Farhang

Comptes Rendus. Chimie, Volume 16 (2013) p. 129-134