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偶联反应如Suzuki、Heck、Negishi以及Sonogashira等能够形成新的碳-碳键,在有机合成反应中具有重要的意义.通常情况下,这些反应是在均相反应中进行,然而从均相反应体系中分离并且回收贵金属Pd是很困难的.这种困难以及流失的Pd所引起的环境和经济效益严重阻碍了这些催化剂在大规模生产中的应用.为了解决这个问题,将Pd负载在固体载体中,使反应在多相体系中进行.常见的载体有嵌段聚合物、分子筛、碳、水滑石、介孔二氧化硅等.相比有机载体,纳米孔型的无机载体具有较大的比表面积和孔容、三维的孔结构,这些都有利于催化反应中的传质,但是无机载体在碱性条件下的稳定性差,并且难以修饰有机功能基团,因此制备高活性的多相偶联反应催化剂仍然是一个挑战.
Coupling reactions such as Suzuki, Heck, Negishi, and Sonogashira, which are capable of forming new carbon-carbon bonds, are of major importance in organic synthesis reactions. In general, these reactions are performed in a homogeneous reaction, however, It is very difficult to separate and recover the precious metal Pd in the system.The environmental and economic benefits caused by this difficulty and the lost Pd seriously hindered the application of these catalysts in large scale production.In order to solve this problem, Pd was loaded on a solid support , The reaction is carried out in a heterogeneous system.The common carriers are block polymers, molecular sieves, carbon, hydrotalcite, mesoporous silica, etc. Compared to organic carriers, nanoporous inorganic carriers have a larger ratio Surface area and pore volume, three-dimensional pore structure, all of which favor the mass transfer in the catalytic reaction, but the inorganic carrier has poor stability under alkaline conditions and difficult to modify the organic functional groups, thus preparing highly active multi-phase coupling Reaction catalyst remains a challenge.