KINETICS OF SOLVENTLESS HYDROARYLATION OF STYRENE WITH ANISOLE USING NOVEL HETEROGENEOUS Cs-DTPA CATALYST SUPPORTED ON MESOCELLULAR FOAM (MCF) SILICA

摘要

Hydroarylation is an example of a C-H bond activation reaction. This synthesis strategy is useful in the synthesis of a number of pharmaceutical molecules. The hydroarylated moiety is an important part of biologically active molecules. In the present study, cesium salt (Cs) of dodecatungstophosphoric acid (DTPA) supported on mesocellular foam (MCF) silica was used to carry out a kinetic investigation of the said reaction. The activity of the catalyst was compared with Amberlyst-15, montmorillonite clay K10, and bulk Cs-DTPA catalysts. The novel catalyst showed better performance because of an even distribution of acidic sites on the MCF support and the high surface area of the support used. The catalyst was synthesized by an incipient wetness technique and characterized by various characterization methods. The reaction parameters were studied in detail and a kinetic model for the reaction was developed. The reaction follows the Langmuir-Hinshelwood-Hougen-Watson model with weak adsorption of all species leading to a second-order reaction. The activation energy was found to be 14.3 kcal/mol. The catalyst was active and reusable.