A novel and efficient heterogeneous CuSO 4 nanoparticles (CuSO 4 NPs) immobilized on carboxymethylcellulose/polyaniline (CuSO 4 NPs@CMC/PANI) composites were prepared via one-pot and one-step interfacial oxidative polymerization of aniline with sodium carboxymethylcellulose (CMC) as soft template and CuSO 4 as catalyst. The in situ formed CuSO 4 NPs were dispersed uniformly and firmly on the resultant composites and stabilized by complexation with hydroxyl groups (─OH), carboxylate groups (─COO À ), nitrogen atoms, and delocalized π-π conjugate benzenoid and quinoid moieties of CMC/PANI composites. The morphology, composition, and structure of the as-fabricated composites were systematically characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and derivative thermogravimetry (DTG) techniques. The CuSO 4 NPs@CMC/PANI composites were successfully applied as catalysts in aldehyde-alkyne-amine (A 3 ) coupling reactions, A 3cycloisomerization tandem reactions, and Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reactions. All reactions proceeded smoothly and afforded the desired products in excellent yields. Moreover, no significant decrease in catalytic ability was observed in A 3 model reaction after 15 recycles, indicating CuSO 4 NPs@CMC/PANI composites exhibited easy separability and high reusability. Tolerance of wide scope of substrate, excellent catalytic activity, easy operation, recycling of catalyst, and environmental benign are the salient features of these catalytic process.

Through the esteri cation of cellulose (Cell) with ethylenediaminetetraacetic dianhydride, ethylenediaminetetraacetic acid-functionalized cellulose (Cell-EDTA) was conveniently obtained. Furtherly a novel and e cient Cell-EDTA-supported palladium catalyst (Pd@Cell-EDTA) was easily prepared via coordination of Cell-EDTA with PdCl 2 . The as-prepared Pd@Cell-EDTA was fully characterized by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray photoelectron spectroscopy (XPS), Flourier transform infrared spectra (FTIR), energy-dispersive spectroscopy (EDS), scanning electron microscopy, transmission electron microscopy (SEM), thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTG) techniques. Then Pd@Cell-EDTA were successfully exerted as catalysts in Suzuki reactions and Sonogashira reactions. Due to the interactions of carboxylic groups, nitrogen atoms, and hydroxyl groups on cellulose, the Pd complex showed excellent activity towards these carbon-carbon cross-coupling reactions. The catalyst recycling experiment for Suzuki model reaction showed that the catalyst can be reused at least ve times without signi cant losing its catalytic performance. The present cellulose-based Pd@Cell-EDTA catalyst offers the salient features of wide application, excellent catalytic activity, good reusability, tolerance of broad scope of substrate, and environmental benign.

Using polymeric composite incorporated transition metal nanoparticles to promote various organic reactions has been found as one of the most powerful strategies in organic synthesis. In this paper, CuSO4 nanoparticles (CuSO4 NPs) anchored on the surface of polymeric composites comprising of water‐insoluble acidic poly (toluenesulfonic acid‐formaldehyde) (PTSAF) and water‐soluble basic polyethyleneimine (PEI) to form the desired PEI/PTSAF‐supported CuSO4 NPs catalyst (CuSO4NPs@PEI/PTSAF) have been fabricated. Characterization of the as‐synthesized catalyst by inductively coupled plasma (ICP), Fourier transform infrared (FTIR), X‐Ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive spectroscopy (EDX) and elemental mapping analysis, transmission electron microscopy (TEM), and thermogravity analysis (TGA) demonstrated successful immobilization of the CuSO4 NPs on the PEI/PTSAF composite. This novel catalyst was highly active in the one‐pot A3 and decarboxylative A3 coupling reactions toward generating corresponding propargylamines in good to excellent yields under solvent‐free reaction. The nature of the well distribution of CuSO4 NPs coordinated with PEI ligand in the CuSO4NPs@PEI/PTSAF composite leads to superior catalytic activity. The present methodology offers several advantages such as high catalytic activity, good to excellent yields, short reaction times, simple operations, compatibility of broad scope of substrates, and environmental friendliness. More importantly, the catalyst can be easily recovered from the reaction mixture by a simple filtration and still exhibits remarkable reusability with only marginal loss of its performance after five consecutive runs.

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