| 초록 |
Knoevenagel reaction is one of the most important organic reactions available to the synthetic chemistry. It is also potentially one of the most environmentally friendly, having water as its co-product. In this work, a series of amine functionalized MCM-41 catalysts were prepared and their catalytic performance in Knoevenagel reaction of selected substrates was investigated. Knoevenagel reaction is very dependent on the efficient removal of water, which leads to faster reaction rates and much higher conversion. Water resistant and catalytically active amine grafted MCM-41 was prepared after silylation using methyltrimethoxsilane. Hydrogen bonding with surface silanol was effectively suppressed and led to high TON. Amine functionalized MCM-41 prepared by coating produced high conversion, but its TON was much lower than the one amine grafted with silylation. In the amine coated catalyst, amine groups were not isolated and large portion of them may be bonded by hydrogen force, which resulted in the reduction in the strength of basicity of the N group. |
