Nanopalladium on polyethylenimine–grafted starch: An efficient and ecofriendly heterogeneous catalyst for Suzuki–Miyaura coupling and transfer hydrogenation reactions

Abstract

Functionalized natural polysaccharides are attractive supports for colloidal metal nanocatalysts due to their abundance, cheapness, biocompatibility and biodegradability. In this study, isocyanate-functionalized starch was prepared by treating with diisocyanate. Polyethylenimine grafted onto starch via the formation of urea linker. The palladium nanoparticles deposited starch PEIS@Pd(0) was obtained through a chelating-in situ reduction procedure. Characterization of these materials was done using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and inductive coupled plasma atomic emission spectrometry. The catalytic activity of PEIS@Pd(0) was then tested in two series of model reactions: Suzuki-Miyaura coupling and transfer hydrogenation. The catalyst could be recovered by simple filtration and was reused for five times without significant loss of catalytic activity, which confirmed the good stability of the catalyst.

Biodegradable Microporous Starch with Assembled Thrombin for Rapid Induction of Hemostasis

“…Microporous starch (MS) is a biocompatible material with high porosity and, consequently, a large surface area with exposed hydroxyl and aldehyde groups that increase its hydrophilicity and water absorption capacity. − Moreover, MS can be enzymatically degraded in vivo into the oligosaccharides maltose and glucose, which are readily absorbed by human tissue. , Owing to these properties, MS is an excellent carrier of adsorbents, , catalysts, − and other molecules for various biological applications, including temporary vascular occlusion and drug delivery . MS can also be used as a hemostatic agent, ,, such as Arista (Medafor, Minneapolis, MN, U.S.A.), a widely used hemostatic starch that is safe and effective for stopping conventional bleeding.…”

Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context

“…11,12 PEI is a hyperbranched polymer containing very high densities of primary, secondary and tertiary amines, in a 1 : 2 : 1 ratio, and are capable of coordination with transition metals to form nanostructures. 13,14 Recent reports on amine functionalized polymersupported heterogeneous catalysts for C-C coupling reactions (Table 1-SI †) prompted us to deploy PEI as a matrix for synthesizing surface-bound palladium nanoparticles for use as catalysts of C-C coupling reactions. For catalytic applications, a miniaturized microuidic setup, such as a lab-on-a-chip device, can signicantly reduce the consumption of chemicals, catalysts, process time and be benecial for on-site analysis.…”

Engineered mesoporous ionic‐modified γ‐Fe2O3@hydroxyapatite decorated with palladium nanoparticles and its catalytic properties in water

“…Palladium‐catalysed coupling reactions, especially the Heck reaction, are some of the most important, efficient and versatile methods for the formation of carbon–carbon bonds commonly used in intermediates of pharmaceuticals and fine chemicals. Cross‐coupling reactions in aqueous media with lower cost, decreased environmental pollution and higher safety are of paramount importance for organic synthesis …”