Pd nanoparticles immobilized on poly(NIPAM-co-4-VP) hydrogel: Highly active and reusable catalyst for carbon–carbon coupling reactions in water

Abstract

Poly(N-isopropylacrylamide-co-4-vinylpyridine) [poly(NIPAM-co-4-VP)] co-polymer exhibited inverse temperature solubility with a lower critical solution temperature (LCST) in water. Pd nanoparticles were immobilized on these poly(NIPAM-co-4-VP) hydrogels. The heterogeneous Pd catalyst showed high catalytic activities for carbon–carbon coupling reactions, such as Suzuki–Miyaura, Heck–Mizoroki, and Sonogashira coupling reactions in water. The Pd catalyst immobilized on poly(NIPAM-co-4-VP) hydrogel (NIPAM:4-VP = 1:1 M ratio) showed an excellent recyclability and excellent yield for carbon–carbon coupling reactions.