Green and Efficient Synthesis of Bis(indolyl)methanes in the Presence of Mesoporous acidic Nano-Ordered Catalysts under Ball Milling

In this study, a green and efficient method for the synthesis of biologically-active bis(indolyl)methane compounds (BIMs) has been described through the condensation of indole with different carbonyl compounds in the presence of SO3H-functionalized mesoporous silica materials (MCM-41-SO3H) catalyst under ball milling. Synthesis of BIMs is proceed very well in the presence of nano-ordered MCM-41-SO3H under solvent-free conditions using ball-milling technique at room temperature. The MCM-41-SO3H can be used at least four consecutive times under optimized conditions with a slight decrease in its catalytic activity. High to quantitative yields of the desired products, low loading of the catalyst, short reaction times at ambient temperature, reusability of the catalysts, and avoiding the use of toxic solvents are significant advantages of this green protocol.