Pyridine Functionalized Polystyrene Supported Cobalt Superfine Fibers as an Efficient and Recyclable Catalyst for Heck Reactions

Abstract

Supported cobalt catalysts have attracted more and more attention for their easy separation and recyclability. Herein, cobalt-embedded pyridine functionalized polystyrene superfine fibers were readily fabricated by electrospinning. Then, the pyridine functionalized polystyrene and polystyrene molecules inside the fibers were cross-linked by paraldehyde to improve the fiber stability. The synthesis of pyridine functionalized polystyrene and cross-linking of polystyrene molecules inside the fibers were confirmed by FT-IR spectra. The fiber morphologies were characterized by SEM. The dispersion of cobalt species was analyzed by SEM–EDS, XRD and TEM. Finally, the Heck reactions were employed to evaluate the catalytic performance of this novel fibrous catalyst. The catalysis results show that this novel fiber catalyst exhibited excellent catalytic activity for the Heck reactions of aromatic iodides with alkenes to afford coupling products with yields over 80%. Moreover, due to the embedment of cobalt species and chelation of pyridine groups, this novel fiber catalyst can be reused five times with little loss of catalytic activity. In all, we have developed a highly active and stable supported cobalt catalyst, which holds great potential for green chemical processes.