• Abdol R. Hajipour & 
• Shaghayegh Sadeghi 

Journal of the Iranian Chemical Society volume 18, pages3219–3233 (2021)Cite this article

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Abstract

Design of hyperbranched polymers (HBPs) and crafting them in catalytic systems especially in organic chemistry are a relatively unexplored domain. This paper reports the utilization of triazine-hyperbranched polymer (THBP)-coated magnetic chitosan nanoparticles (MCs) as stabilizing matrix for cobalt nanoparticles. Cobalt nanoparticles were fabricated by coordination cobalt(II) ions with amine-terminated triazine polymer and then reduced into Co(0) using sodium borohydride in aqueous medium. The Co(0)-THBP@MCs were fully characterized by FT-IR, SEM–EDX, TEM, and TGA analyses. The presence of metallic cobalt was determined by ICP and XRD techniques. This novel hyperbranched polyaromatic polymer-encapsulated cobalt nanoparticles showed high catalytic activity in Mizoroki–Heck and Suzuki–Miyaura cross-coupling reactions. Heck and Suzuki reactions were carried out using 0.35 and 0.4 mol% of cobalt nanoparticles in which the turnover number (TON) values were calculated as 271 and 225, respectively. In addition, the produced heterogeneous catalyst could be recovered and reused without considerable loss of activity. Oxygen stability and high reusability over 7 runs with trace leaching of the cobalt into the reaction media as well as moisture stability of the immobilized cobalt nanoparticles are their considerable worthwhile advantages.