Abstract:

Heterogeneous cyclopropanation catalysts are classified as metal catalysts, metal-supported catalysts, complex-immobilized catalysts, and MOF-based catalysts. Research progress on the reactive components, supports, immobilization methods and action principles of heterogeneous cyclopropanation catalysts is reviewed in detail. Metal-supported catalysts are easy to prepare and have relatively high activity, selectivity but the stereoselectivity is low, therefore they show better application in fuel-synthesis than medical or pesticide. To improve the stability and expand the reactive components of metal-supported catalysts is the development tendency. Complex-immobilized catalysts have good activity and stereoselectivity with wide adjustability of structure and performance. Nevertheless, optimizing immobilization methods such as using covalent bonding and enhancing synergistic action between supports and ligands by optimizing pore structure and surface group are quite important to promote the catalyst stability and immobilizing strength. MOF-based catalysts exhibit unique properties in cyclopropanation reactions, and the catalytic performance can be improved by defect-engineering (mechanical grind, ligand doping, heat treatment, etc.) which should balance the activity and stability. Furthermore, designing chiral ligands for new MOF-based catalysts to enhance the stereoselectivity is also the important research direction.

Key words: diazo compounds, cyclopropanation, heterogeneous catalysis, immobilization, activity, stereoselectivity

摘要：

从重氮化合物环丙烷化用多相催化剂类型角度，将环丙烷化多相催化剂分为金属催化剂、金属负载型催化剂、络合物固载化催化剂、金属有机骨架（MOF）基催化剂等，详细介绍和评述了催化剂在活性组分、载体、固载方法、性能及作用原理等方面的研究进展。指出金属负载型催化剂制备简单，活性和选择性较高，但立体选择性差，在农药、医药领域适用性有限，更适宜应用于燃料合成领域，因此提升催化剂的稳定性和拓展金属活性组分是其发展趋势。络合物固载化催化剂具有较好的活性和立体选择性，结构与性能易于调控，但制备过程复杂，活性组分易流失，需通过优化固载方法如共价键合提高固载强度，以及优化载体孔道结构与表面基团提升载体-配体的协同作用。MOF基催化剂在环丙烷化中展现出独特的催化性能，通过机械研磨、配体掺杂、热处理等方式引入缺陷可综合提高MOF基环丙烷化催化剂性能，但需平衡活性与骨架结构的稳定性。此外，设计利于环丙烷化的手性配体并引入至MOF结构提高其立体选择性是MOF基环丙烷化催化剂的重要发展方向。

关键词: 重氮化合物, 环丙烷化, 多相催化, 固载化, 活性, 立体选择性