Chutimasakul Threeraphat, Na Nakhonpanom Pakamon, Tirdtrakool Warinda, Intanin Apichai, Bunchuay Thanthapatra, Chantiwas Rattikan, Tantirungrotechai Jonggol
Department of Chemistry, Center of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol University Bangkok 10400 Thailand
RSC Adv. 2020 Jun 2;10(35):21009-21018. doi: 10.1039/d0ra03884a. eCollection 2020 May 27.
A nonprecious metal and biopolymer-based catalyst, Cu/chitosan beads, has been successfully prepared by using a software-controlled flow system. Uniform, spherical Cu/chitosan beads can be obtained with diameters in millimeter-scale and narrow size distribution (0.78 ± 0.04 mm). The size and morphology of the Cu/chitosan beads are reproducible due to high precision of the flow rate. In addition, the application of the Cu/chitosan beads as a green and reusable catalyst has been demonstrated using a convenient and efficient protocol for the direct synthesis of imines the oxidative self- and cross-coupling of amines (24 examples) with moderate to excellent yields. Importantly, the beads are stable and could be reused more than ten times without loss of the catalytic performance. Furthermore, because of the bead morphology, the Cu/chitosan catalyst has greatly simplified recycling and workup procedures.
一种基于非贵金属和生物聚合物的催化剂——铜/壳聚糖微球，已通过软件控制的流动系统成功制备。可以获得直径为毫米级且尺寸分布狭窄（0.78±0.04毫米）的均匀球形铜/壳聚糖微球。由于流速的高精度，铜/壳聚糖微球的尺寸和形态具有可重复性。此外，铜/壳聚糖微球作为一种绿色且可重复使用的催化剂的应用已通过一种方便高效的方法得到证明，该方法用于直接合成亚胺——胺的氧化自偶联和交叉偶联（24个实例），产率中等至优异。重要的是，这些微球稳定，可重复使用十多次而不损失催化性能。此外，由于微球的形态，铜/壳聚糖催化剂极大地简化了回收和后处理程序。
