Synthesis of MCM-41 Supported L-proline Copper (I) Complex and Its Catalytic Performance for the Coupling Reaction of p-Iodotoluene with Sodium Methanesulfinate

By sequentially condensing 3-chloropropyltrimethoxysilane and trimethylchlorosilane with MCM-41 in toluene, chloropropyl-functionalized MCM-41 (MCM-41-Cl) is obtained. L-proline sodium functionalized MCM-41 (MCM-41-L-Proline) is successfully prepared by condensation and immobilization of MCM-41-Cl with N-Boc-4-hydroxy-L-proline, followed by deprotection of Boc and acid-base neutralization reaction. The performance of MCM-41-L-Proline in catalyzing the coupling reaction of p-iodotoluene (PIT) with sodium methanesulfinate (CH3SO2Na) is investigated with the synergistic effect of CuI. The results indicate that, under optimized reaction conditions, the MCM-41-L-Proline/CuI catalytic system delivers a 48.5% yield of methylsulfonyl toluene (MST). Interestingly, FT-IR results indicate that MCM-41-L-Proline and CuI in situ formed the MCM41-L-Proline Cu(I) complex during the coupling reaction. This catalyst demonstrates excellent catalytic stability and recyclability, maintaining its activity with no significant decline after six cycles.