Applications Of Mesoporous MCM-41 Immobilized Copper Complexes In Alcohol Oxidation And Carbon-Heteroatom Bond Formation Reactions

1. 1,10-Phenanthroline-functionalized mesoporous MCM-41(MCM-41-Phen) was first prepared by the addition of 5-amino-1,10-phenanthroline to(3-isocyanatopropyl)triethoxysilane, followed by the condensation with mesoporous material MCM-41. The reaction of the MCM-41-Phen with CuCl in DMF at room temperature afford the MCM-41-immobilized 1,10-phenanthroline copper(I) complex(MCM-41- Phen-CuCl), which then was characterized by XRD, ICP and elemental analysis. We investigated its catalytic characteristics in aerobic oxidation of alcohols into aldehydes or ketones. The results indicated that the new heterogeneous copper catalyst exhibited high catalytic activity, not only benzyl alcohols were oxidized into aromatic aldehydes in high yields, but also allylic alcohols and secondary alcohols were transformed into the corresponding aldehydes and ketones. Moreover, the new copper catalyst could be recycled several times without significant loss of activity, providing a novel and green route to aldehydes and ketones by the aerobic oxidation of alcohols.2. The MCM-41-immobilized 1,10-phenanthroline copper(I) complex(MCM-41-Phen-CuI) was prepared by the reaction of the MCM-41-Phen with Cu I in DMF at room temperature. We investigated its catalytic characteristics in C–P cross-coupling reaction of aryl iodides with diphenylphosphine. The results indicated that this new heterogeneous copper catalyst can efficiently catalyze the C–P cross-coupling of aryl iodides with diphenylphosphine, affording a variety of functionalized triphenylphos- phine compounds in good to excellent yields. The electronic nature of subsitituents has limited influences on the reaction, and both electron-donating and electron-with- drawing were well tolerated. In addition, the new catalyst could be recycled several times without significant loss of activity, providing a novel and practical route to a variety of functionalized triphenylphosphine compounds.3. The MCM-41-immobilized bidentate nitrogen copper(I) complex(MCM-41-2N-Cu I) was prepared by the reaction of the bidentate nitrogen-functionalized MCM-41(MCM-41-2N) with CuI in DMF at room temperature according to a literature procedure. We investigated its catalytic characteristics in aerobic oxidative annulation of 2-aminopyridines with methyl ketones to access imidazo[1,2-a]pyri- dines. The results indicated that this heterogeneous copper catalyst exhibited high catalytic activity, a variety of methyl ketones underwent effectively aerobic oxidative annulation reaction with various 2-aminopyridines, affording a variety of imidazo- [1,2-a]pyridines in good yields. Moreover, the heterogeneous copper catalyst could be recycled several times without significant loss of activity, providing a novel and practical route for the synthesis imidazo[1,2-a]pyridines.