文献类型：期刊文献

英文题名：Highly porous chitosan microspheres supported palladium catalyst for coupling reactions in organic and aqueous solutions

作者：Zeng, Minfeng[1];Zhang, Xin[1];Shao, Linjun[1];Qi, Chenze[1];Zhang, Xian-Man[1]

机构：[1]Shaoxing Univ, Inst Appl Chem, Shaoxing 312000, Peoples R China

年份：2012

卷号：704

起止页码：29

外文期刊名：JOURNAL OF ORGANOMETALLIC CHEMISTRY

收录：SCI-EXPANDED(收录号：WOS:000300638400004)、、EI(收录号：20120914811203)、Scopus(收录号：2-s2.0-84862784797)、WOS、CCR-EXPANDED(收录号：WOS:000300638400004)

基金：The authors acknowledge the financial support from the National Natural Science Foundation of China (No. 21172149) and Key Sci-Tech Innovation Team Project of Zhejiang Province, China (No.2010R50014-12).

语种：英文

外文关键词：Palladium catalyst; Chitosan; Porous microspheres; Coupling reaction

外文摘要：Porous chitosan microspheres (PCMS) were prepared from crosslinking chitosan/polyethylene glycol (PEG) interpenetrating microspheres through selective dissolution of the water-soluble PEG component for the immobilization of palladium catalyst. The resultant Pd/PCMS supported palladium has been demonstrated as a highly active and easily recyclable heterogeneous catalyst for the Ullmann-type reductive homocoupling of aromatic halides and the Heck cross-coupling of aromatic halides with acrylates. Most interestingly, the prepared Pd/PCMS heterogeneous palladium catalyst can also be employed in the environmentally-benign aqueous solution due to the highly hydrophilic hydroxyl and amino functional groups of chitosan. The large size of the microsphere structure can greatly facilitate separation and recycling of the expensive and toxic palladium catalysts from the reaction mixture and the recovered Pd/PCMS catalyst can preserve the catalytic activity and selectivity for the Heck reaction without any observable degradation over ten recycling times. The high activity and stability of the Pd/PCMS catalyst have been attributed to a combination of the high specific surface area of the porous structure as well as the strong chelation of palladium species with the abundant chitosan surface hydroxyl, amino and carbonyl functional groups. (C) 2012 Elsevier B.V. All rights reserved.