An efficient and recyclable waste oyster shell powders (OSPs)-supported CuBr catalyst (OSPs–CuBr) has been successfully prepared and well characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), atomic absorption spectroscopy (AAS), and powder X-ray diffraction (XRD). Then, OSPs–CuBr was used as a heterogeneous catalyst for the one-pot multicomponent synthesis of 1,4-disubstituted 1,2,3-triazole derivatives via a Cu(I)-catalyzed azide–alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. Compared with a CaCO3–CuBr catalyst, the OSPs–CuBr catalyst showed higher catalytic activity and stability characteristics. The chitin and protein molecules on the OSP particles surfaces play an important role in the chelation of the CuBr species, which leads to the better chemical stability of OSPs–CuBr. The 1,2,3-triazoles are readily obtained in good to excellent yields and on a multigram scale by the reaction of aryl/alkyl halides, alkynes, and NaN3 under microwave irradiation conditions. It also showed good reusability, could be easily recovered through filtration and washing, and was reused at least eight times with virtually no evident loss of catalytic performance.Keywords: 1,2,3-Triazoles; Click chemistry; CuAAC; Green chemistry; Heterogeneous catalyst; Oyster shell powders;

A superparamagnetic graphene oxide (GO)/Fe3O4–CuBr catalyst was prepared via a simple chemical method and characterized by Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The GO/Fe3O4–CuBr catalyst could be dispersed homogeneously in water and further used as an excellent semi-heterogeneous catalyst for the one-pot multi-component Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction. 1,4-Disubstituted mono/bis-1,2,3-triazoles are readily obtained on a multi-gram scale by the reaction of aryl/alkyl halides, alkynes and sodium azide under microwave irradiation conditions in good to excellent yields. Moreover, GO/Fe3O4–CuBr could be separated conveniently from the reaction mixtures by an external permanent magnet and reused in at least six consecutive runs without a noticeable drop in the product yield and its catalytic activity.

An efficient and practical approach was developed to synthesize 1,2,3-triazoles using recyclable Fe3O4 magnetic nanoparticle (MNP)-supported copper(I) catalysts via a one-pot multi-component copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction in water. Under microwave irradiation conditions, terminal alkynes reacted quickly with benzyl/alkyl azides, which were generated in situ from corresponding primary halides and sodium azide. The 1,2,3-triazoles can be exclusively generated in good to excellent yields and on a multi-gram scale.

A new class of shape-persistent dendronized copolymers 1[Gn]4–5(a–d) (n = 1, 2) with an alternating structure was synthesized via a combination of conventional radical copolymerization and Cu(I)-catalyzed click reaction (i.e. CuAAC). Firstly, azide-functionalized dendronized copolymers 1[Gn]4-N3 that could be used as “clickable” single molecular platforms were synthesized through two steps: (i) the preparation of methanesulfonate-modified copolymers by a radical copolymerization of styrene derivatives pendant with Percec-type polyether dendron and methanesulfonate-containing maleimide; (ii) the replacement reaction of methanesulfonate unit with sodium azide. Then a series of functional molecules bearing an alkyne group, respectively, such as anthracene and mini-dendritic wedges, were attached onto each maleimide unit of the copolymers through CuAAC. Moreover, a postmodification of the denpols bearing anthracene has been conducted using Diels–Alder cycloaddition between the attached anthracenes and the maleimide dendron, demonstrating that more complicated denpols can be fabricated. These novel dendronized copolymers have been characterized by nuclear magnetic resonance spectroscopy, atom force microscopy, Fourier transform infrared spectroscopy, UV–vis spectroscopy.Graphical abstractHighlights► Azide-modified dendronized copolymers were used as “clickable” single molecular platforms. ► Post-polymerization modification of dendronized copolymers via CuAAC and Diels–Alder reactions. ► Dendronized copolymers with heterogeneous composition were fabricated in a controlled way.

A class of well-defined dendritic star polymers with poly (ε-caprolactone) (PCLs) on the periphery has been prepared via one-pot double click reactions (Cu-catalyzed azide/alkyne click chemistry, i.e., CuAAC and Diels–Alder [4+2] cycloaddition reactions). The predecessors for Diels–Alder reaction, maleimide end-functionalized PCLs were produced by ring-opening polymerization (ROP). Obtained dendritic star polymers were characterized by 1H NMR, size exclusion chromatography (SEC), UV/vis, and fluorescence spectroscopy.

An efficient and practical approach was developed to synthesize 1,2,3-triazoles using recyclable Fe3O4 magnetic nanoparticle (MNP)-supported copper(I) catalysts via a one-pot multi-component copper-catalyzed azide–alkyne cycloaddition (CuAAC) reaction in water. Under microwave irradiation conditions, terminal alkynes reacted quickly with benzyl/alkyl azides, which were generated in situ from corresponding primary halides and sodium azide. The 1,2,3-triazoles can be exclusively generated in good to excellent yields and on a multi-gram scale.