Copper(II)‐Schiff Base Complex‐Functionalized Polyacrylonitrile Fiber as a Green Efficient Heterogeneous Catalyst for One‐Pot Multicomponent Syntheses of 1,2,3‐Triazoles and Propargylamines

Abstract

A series of copper(II)‐Schiff bases‐functionalized polyacrylonitrile fiber catalysts were successfully prepared using copper acetate as copper source and characterized by elemental analysis, fourier‐transfer infrared spectroscopy, ultraviolet‐visible spectroscopy, X‐ray photoelectron spectroscopy and inductively coupled plasma analysis. Excellent physical strength and thermal stability of the fiber catalysts were demonstrated by scanning electron microscopy, X‐ray diffraction, thermogravimetric/differential scanning calorimetry analysis and mechanical strength measurements. Furthermore, these catalysts were successfully applied to one‐pot multicomponent copper‐catalyzed azide‐alkyne cycloaddition (CuAAC) reaction and aldehyde, alkyne, amine (A3) coupling reaction in which the influences of different substituent groups on the catalytic activities of fiber catalysts were investigated in detail. Among them, the bis[N‐ethyl‐3,5‐di‐tert‐butyl‐salicylideneiminato]copper(II)‐functionalized polyacrylonitrile fiber (PANS2F−Cu) as a green, efficient catalyst exhibited the best catalytic activity for its high hydrophobic micro‐environment can aggregate the reactants to the catalytic sites and accelerate the reaction. In addition, the PANS2F−Cu has performed well in scaled‐up experiment and shown excellent recyclability (at least ten times), and these enable it to have great potential for further applications.magnified image

Amine Functionalized Metal–Organic Framework Coordinated with Transition Metal Ions: d–d Transition Enhanced Optical Absorption and Role of Transition Metal Sites on Solar Light Driven H2 Production

“…This indicates that the coordination of Co 2+ and Ni 2+ metal ions to –NH 2 group could not change the oxidation states due to less coordination tendency of –NH 2 group. However, the Cu‐MOF exhibits the peaks for both Cu 2+ (955.34 and 935.06 eV) and Cu + (952.82 and 933.01 eV) oxidation states . The existence of both +2 and +1 states can be ascribed to: i) the effective coordination of –NH 2 group through non‐bonded electrons of nitrogen and ii) the formation oxide layer on Ti‐MOF surface, which further confirms the existence of CuO x after the coordination as supported by XRD analysis.…”

1,2,3- Triazoles: general and key synthetic strategies

“…260 The potential of multicomponent reactions for the preparation of 1H-1,2,3-triazole derivatives has become extremely useful in recent years to produce complex macromolecular structures 261 and several studies have reported the use of this strategy in the preparation of 1,4-disubstituted 1H-1,2,3-triazoles. [262][263][264][265][266][267]…”

Polymer Beads Decorated with Dendritic Systems as Supports for A3 Coupling Catalysts

“…To perform the A 3 coupling effectively, the selective and active catalysts are required. Numerous catalytic systems have been explored in the A 3 coupling till now [30][31][32][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. Among them copper, silver and gold catalysts seem to play the most vital role in promoting these transformations [30,32,[44][45][46].…”

“…To perform the heterogenization of catalytically active species both synthetic (e.g. polyacrylonitrile fibers, polystyrene resins) [56][57][58] and natural organic polymers (e.g. chitosan) might be used [59,60].…”