Mesoporous epoxidized soybean oil-supported copper-based magnetic nanocatalyst and amberlite-supported azide as a green and efficient catalytic system for 1,2,3-triazole synthesis

Fe3O4@HA-Cu(OAc)2 nanocomposite as a nanomagnetic water-compatible catalyst for efficient synthesis of 1,2,3-triazoles in water

A new humic acid-based nanomagnetic copper(II) composite was prepared and used as an eco-friendly recoverable catalyst for synthesizing 1,4-disubstituted 1,2,3-triazoles. The synthesis was done via the three-component click reaction of alkyl halide, sodium azide, and terminal alkyne with good to excellent yield. A simple magnetic copper acetate composite, Fe3O4@HA-Cu(OAc)2, was prepared using humic acid and characterized by SEM, TEM, XRD, EDX, EDS-mapping, VSM, TGA, AAS, and FT-IR. The catalyst showed high catalytic potential in a one-pot three-component click reaction in the synthesis of 1,2,3-triazoles. The nanomagnetic Fe3O4@HA-Cu(OAc)2 catalyst demonstrated high efficiency, stability, compatibility with oxygen/water and recyclable copper(II), with cost-effectiveness. The catalyst was easily recovered with an external magnetic field, and therefore, time and energy were saved as no filtration or decantation technique was needed. Due to the high dispersibility in water, nanomagnetic Fe3O4@HA-Cu(OAc)2 was utilized as a highly efficient catalyst for the click synthesis of triazoles.

Cu/N-doped carbon spheres derived from soybean flour as an active green nanocomposite for the synthesis of 1,4-disubstituted 1H-1,2,3-triazole derivatives

Cu immobilized onto N-doped carbon spheres (Cu/N-doped CS) derived from soybean flour was synthesized via the hydrothermal method and certified as a green high-efficiency catalyst for the regioselective synthesis of 1,4-disubstituted 1H-1,2,3-triazoles. The obtained N-doped carbon spheres from a combination of glucose and soy flour have a larger size and suitable affinity for load copper species. The morphology and structure of the as-prepared catalyst have been confirmed based on FT-IR, XRD, FE-SEM, EDX, BET, and ICP-OES characterizations. The catalytic performance of the Cu/N-doped carbon spheroids was investigated experimentally. It was found that the Cu/N-doped CS nanocomposite has a high efficiency and recyclability for 5 cycles without any appreciable loss in its catalytic activity in the synthesis of 1,4-disubstituted 1H-1,2,3-triazoles via the three-component condensation reaction of various epoxide/alkyl or aryl halides, sodium azide, and phenylacetylene in a water medium. Furthermore, significant advantages such as stability, ease of preparation, low cost of the carbon resource, high regioselectivity, and good product yield have been achieved in the heterogeneous catalyst system attractive for large-scale in many industrial products.

A New Insight Into The Huisgen Reaction: Heterogeneous Copper Catalyzed Azide-Alkyne Cycloaddition for the Synthesis of 1,4-Disubstituted Triazole (From 2018-2023)

The Huisgen cycloaddition, often referred to as 1,3-Dipolar cycloaddition, is a well-established method for synthesizing 1,4-disubstituted triazoles. Originally conducted under thermal conditions [3+2] cycloaddition reactions were limited by temperature, prolonged reaction time, and regioselectivity. The introduction of copper catalyzed azide-alkyne cycloaddition (CuAAC) revitalized interest, giving rise to the concept of "click chemistry". The CuAAC has emerged as a prominent method for producing 1,2,3-triazole with excellent yields and exceptional regioselectivity even in unfavorable conditions. Copper catalysts conventionally facilitate azide-alkyne cycloadditions, but challenges include instability and recycling issues. In recent years, there has been a growing demand for heterogeneous and porous catalysts in various chemical reactions. Chemists have been more interested in heterogenous catalysts as a result of the difficulties in separating homogenous catalysts from reaction products. These catalysts are favored for their abundant active sites, extensive surface area, easy separation from reaction mixtures, and the ability to be reused. Heterogeneous catalysts have garnered significant attention due to their broad industrial utility, characterized by cost-effectiveness, stability, resistance to thermal degradation, and ease of removal compared to their homogeneous counterparts. The present review covers recent advancements from year 2018 to 2023 in the field of click reactions for obtaining 1,2,3-triazoles through Cu catalyzed 1,3-dipolar azide-alkyne cycloaddition and the properties of the catalyst, reaction conditions such as solvent, temperature, reaction time, and the impact of different heterogeneous copper catalysts on product yield.

Efficient Suzuki coupling over novel magnetic nanoparticle: Fe3O4/L-(+)-tartaric acid/Pd(0)

A new eco-friendly catalytic system is devised for C-C bond formation through Suzuki coupling, using an impressive nanocatalyst (Fe₃O₄/L-(+)-tartaric acid/Pd-NPs). It contains immobilized palladium (0) onto magnetite nanoparticles, stabilized by tartaric acid, and is characterized by FT-IR, XRD, EDS, SEM, TEM, TGA, and VSM. The catalyst is used in an efficient synthesis of biaryls in EtOH/H₂O (1:1), in the presence of K₂CO₃. Our Fe₃O₄/tartaric acid/Pd-NPs exhibit magnetic recoverability and reusability for five cycles without measurable loss of its activity.