Ullmann偶联反应催化剂研究进展

Ullmann偶联反应是典型的碳碳键偶联反应,反应合成的联苯类化合物是重要有机化工原料,应用前景广阔。初期采用均相Pd催化剂,不能重复利用,工业化生产受到限制。改用多相Pd催化剂催化反应,需要添加剂导致产物分离困难。多相Au催化剂适用性受到限制,反应底物局限于碘代芳烃,双金属催化剂在催化活性与选择性方面均有较好的优势。综述Ullmann-type偶联反应中均相Pd催化体系、多相Pd催化体系、多相Au催化体系以及多相双金属催化体系催化剂的研究进展,阐述反应机理,并对Ullmann偶联反应研究进行展望。

Research advances in the catalysts for Ullmann Coupling Reactions

Ullmann coupling reaction,as an efficient method of C-C bond coupling,is used to synthesize the biaryls.Being crucial organic chemical raw materials,these compounds have broad application prospects.In the early days,the homogeneous Pd catalysts could not be used repeatedly and their commercial application was restricted.Heterogeneous palladium catalysts catalyzed the reaction result in difficult separation of the products because of the addition of additives.The applicability of heterogeneous gold catalysts is restricted and the reaction substrates are confined to aryl iodides.Nevertheless,bimetallic catalysts have advantages in terms of the catalytic activity and selectivity.The research progress in catalyst systems for Ullmann coupling reactions,such as homogeneous palladium,heterogeneous palladium,heterogeneous gold and bimetallic catalysts and possible catalytic pathways were reviewed.The prospects of Ullmann coupling reactions are outlined.