Synthesis Of MCM-41-immobilized Bipyridine Copper Complexes And Their Applications In C-Se Bond Formation And Alcohol Oxidation Reactions

1. Bipyridine-functionalized MCM-41 anchored copper iodide complex [MCM-41-bpy-CuI] was prepared from 4,4′-bis[3-(triethoxysilyl)propylamino-methyl]-2,2′-bipyridine via immobilization on MCM-41, followed by reacting with CuI in DMF at room temperature. This supported copper complex was characterized by TEM, nitrogen adsorption/desorption, XRD, ICP, elemental analyses and thermogravimetric analysis(TGA).2. We investigated the carbon-selenium coupling reaction of arylboronic acids with diaryl diselenides catalyzed by MCM-41-bpy-CuI. It was found that the C-Se coupling reaction proceeded very smoothly in the presence of a catalytic amount of MCM-41-bpy-CuI to give the corresponding diaryl selenides in good to excellent yields at 110 ℃ using DMSO/H2O(2/1) as solvent under air atmosphere. This heterogeneous copper catalyst exhibited high catalytic activity and can be recovered and recycled by a simple filtration of the reaction solution and reused for 10 consecutive trials without significant loss of activity.3. A heterogeneous copper(I)-catalyzed aerobic oxidation of primary benzylic and allylic alcohols to aldehydes was achieved under air in EtOH at 50 oC in the presence of 5 mol% of MCM-41-bpy-CuI and 5 mol% of TEMPO using aqueous ammonia as base, yielding a variety of aromatic and α,β-unsaturated aldehydes in good to excellent yields. This heterogeneous copper catalyst can be easily recovered by a simple filtration of reaction solution and reused for at least 10 consecutive trials without any decreases in activity.4. We investigated the carbon-selenium coupling reaction of aryl iodides with diaryl diselenides catalyzed by MCM-41-bpy-CuI. It was found that the C-Se coupling reaction proceeded very smoothly in the presence of a catalytic amount of MCM-41-bpy-CuI and magnesium powder to give the corresponding diaryl selenides in good yields at 120 oC using DMF as solvent under argon atmosphere. This heterogeneous copper catalyst exhibited high catalytic activity and can be reused for 5 consecutive trials without significant loss of activity.