连续流中介孔二氧化钛负载钯催化Suzuki偶联反应（急）

Suzuki Coupling Reaction Catalyzed by Palladium Supported on Mesoporous Titanium Dioxide in Continuous Flow

摘要:

以氯化钯和钛酸正丁酯为原料，聚乙烯吡咯烷酮为金属保护剂，三嵌段共聚物F127为模板剂，采用溶胶凝胶法制备了钯负载量为0.1 wt%~1.0 wt%的非均相 Pd/m-TiO2催化剂。经BET、XRD和TEM表征,催化剂具有有序介孔结构，孔径分布在8 nm~10 nm，钯金属颗粒均匀分散在载体上，颗粒尺寸为11.3 nm~13.3 nm。在微填充床反应器中进行了连续流Pd/m-TiO2催化Suzuki偶联反应研究，确定了最优工艺条件：混合溶剂N,N-二甲基甲酰胺（DMF）和水（V:V=1:1，400 mL），碱为磷酸钾（n碱:n溴苯=1.5:1），流速为0.20 mL/min，溴苯、苯硼酸和磷酸钾的浓度分别为0.10 mol/L、0.12 mol/L和0.15 mol/L，钯负载量为0.7 wt%，反应温度为80 ℃，6.8 min反应时间内Suzuki偶联反应收率达99%，催化剂重复使用多次后仍保持良好催化活性。

Abstract:

0.1 wt%~1.0 wt% heterogeneous Pd/m-TiO2 catalysts were prepared by Sol-Gel method using PdCl2 and n-butyl titanate as raw materials, PVP as metal protective agent, F127 as template agent. The structure was characterized by BET, XRD and TEM. The results showed that the catalysts had an ordered mesoporous structure with 8 nm~10 nm pore size distribution, 11.3 nm~13.3 nm palladium particle size and good dispersion. Then Pd/m-TiO2 catalyst was fixed by micro-packed reactor to catalyzed Suzuki coupling reaction in continuous flow. The optimal continuous flow process was determined: mixed solvent of DMF and water (V:V=1:1, 400 mL), base K3PO4(n碱:n溴苯=1.5：1) , 0.20 mL/min flow rate, 0.10 mol/L bromobenzene, 0.12 mol/L phenylboronic acid, 0.15 mol/L K3PO4, 0.7 wt% palladium loading and 80 ℃ reaction temperature. The yield of Suzuki coupling reaction was 99% in 6.8 min residence time. The catalyst still maintained good catalytic activity after repeated use.