N-heterocyclic carbene bearing thermoresponsive poly(NIPAM) supported palladium (II) complex: Synthetic strategy and application

Publication date: Available online 20 February 2020Source: Journal of Organometallic ChemistryAuthor(s): Nagaraju Pentela, Varnakumar Gayathri, Debasis SamantaAbstractIn this article, We have reported the synthesis of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) bearing N-heterocyclic carbene (NHC) based palladium complex through carbene formation. The complex was synthesized from the polymer, which was obtained by SET-LRP (Single Electron Transfer - Living Radical Polymerization) technique using suitable N-heterocyclic carbene (NHC) based initiator. The single-crystal X-ray diffraction (XRD) confirms the structure of the initiator. Furthermore, NMR, FTIR and XPS studies confirmed the formation of the NHC–Pd (II) complex. Our complex possessed unique thermoresponsive characteristics in water i.e, water-soluble at below lower critical solution temperature (LCST) and water-insoluble at LCST. Hence, it can be used as a smart catalyst for Suzuki coupling reactions of various aryl halides in water medium at ambient temperature (30 °C). Due to its thermoresponsive behavior, it can be easily recovered from the reaction medium simply by the elevation of temperature and reused for several cycles.Graphical abstract

Source: Journal of Organometallic Chemistry - February 21, 2020 Category: Chemistry Source Type: research