Silica-coated magnetic nanoparticles functionalized cobalt complex: a recyclable and efficient catalyst for the C−C bond formation

Abstract

In this study, the Co-based catalyst was prepared by cobalt immobilization on the surface of functionalized silica-coated magnetic NPs (Fe 3 O 4 @SiO 2 -CT-Co) as a magnetically core-shell nanocatalyst and characterized by FT-IR, TGA, XRD, VSM, SEM, TEM, EDX, EDX mapping, and ICP techniques and appraised in the Suzuki-Miyaura cross-coupling reaction under mild reaction conditions. The results displayed the superparamagnetic behavior of the Fe 3 O 4 NPs core encapsulated by SiO 2 shell, and the size of the particles was estimated about 30 nm. Compared with the previously reported catalysts, the engineered Fe 3 O 4 @SiO 2 -CT-Co catalyst provided perfect catalytic performance for the Suzuki-Miyaura cross-coupling reaction in water as a green solvent and it was much cheaper in the comparison with the traditional Pd-based catalysts. Importantly, the durability of magnetic nanocatalyst was studied and observed that it is stable under the reaction conditions and could be easily reused for at least six successive cycles without any significant decrease in its catalytic activity.

Research on Thia-Michael Addition Tandem Reactions Catalyzed by AlCl3@MNPs

“…因此有必要设计和开发出一种新型、高 效、 易回收的催化剂, 用于催化脂肪胺、 二硫化碳与 α,β-不饱和羰基化合物三组分硫杂 Michael 加成反应. 超顺 磁性纳米颗粒(Fe 3 O 4 )由于其具备高比表面积、超顺磁性 等, 使其兼具了均相催化剂的高催化活性和非均相催化 剂的易回收套用特性 [17][18] , 可以负载各种活性成分催化 有机合成 [19][20][21] 、生物柴油制备 [22][23] 、氯酚类污染物降 解 [24] 和 CO 2 吸附 [25] 等. 本文以超顺磁性纳米粒负载的 氯化铝(AlCl 3 @MNPs)为催化剂, 对脂肪胺、 二硫化碳与 α,β-不饱和羰基化合物的硫杂 Michael 加成串联反应的 条件优化、底物拓展、催化剂回收重复使用等开展相关 研究.…”