Immobilized silver on surface-modified ZnO nanoparticles: As an efficient catalyst for synthesis of propargylamines in water

Nanosilver as a new generation of silver catalysts in organic transformations for efficient synthesis of fine chemicals

“…The authors suggested that it was possibly ascribed to the unfavorable effect of the SBA-15 channels on the addition of iminium ions to activated alkynes. Similarly, Movahedi and coworkers 94 have also reported a good example of catalytic synthesis of propargylamines through one-pot three-component A 3 condensation of aldehydes, amines, and alkynes, by immobilized silver on surface-modified ZnO nanoparticles. Although nanosilver-catalyzed A 3 -coupling of aldehydes, alkynes, and amines has been determined in 2010, the first example of 1,2addition of alkynes to aldehydes that catalyzed by silver nanoparticles was only reported in 2012.…”

Fe3O4/MIL‐101(Fe) nanocomposite as an efficient and recyclable catalyst for Strecker reaction

“…Thus, MOF crystals are uniformly enclosed by Fe 3 O 4 NPs to form a homogeneous magnetic product, defined as Fe 3 O 4 /MIL‐101(Fe). Continuously, as part of our previous studies to investigate catalytic performance of new heterogeneous nanocomposites, we have examined the catalytic efficiency of a kind of MOF structure, combined with amino‐modified core‐shell magnetic NPs, in order to extend merits of an environmentally‐friendly metal catalyst to accomplish bond‐forming processes. Indeed, we have shown that catalytic resources could comprise in a single architecture to intensify the catalytic function, in which is anticipated individually, for synthetic methodologies.…”

Fibroin‐functionalized magnetic carbon nanotube as a green support for anchoring silver nanoparticles as a biocatalyst for A3 coupling reaction

“…The probable reaction mechanism for the three‐component A 3 coupling preparation of propargylamines catalyzed by CNT–Fe 3 O 4 –fibroin–Ag is proposed in Scheme . Based on previous reports, the reaction was initiated by the activation of the terminal C–H bond of acetylene by silver NPs immobilized on CNT–Fe 3 O 4 –fibroin and production of π‐metal–alkyne intermediate A, which is a very important step in increasing terminal proton's acidity to simplify its abstraction and concurrently produce a silver alkylidene intermediate B on the surface of the nanocomposite. The catalyst can also promote the synthesis of iminium ion through the reaction of aldehyde and secondary amine.…”

“…in 2003, silver has gained considerable importance for its significant catalytic performance. Today, it is considered as a green and environmentally friendly metal and one of the best candidates for promoting A 3 coupling reaction; for example, previous studies have utilized ZnO–IL/Ag, Ag–CIN‐1, PANF–NHC@Ag, h‐Fe 2 O 3 @DA/Ag, Fe 3 O 4 @m–TiO 2 /Ag, Ag–Ni‐reduced graphene oxide, Ag–Co/hierarchical ZSM‐5, Ag‐based CPS, and AgNO 3 –IL . Although some of these approaches are promising protocols, many of these methods suffer from disadvantages such as the need for a toxic solvent, having harsh reaction conditions, high temperature requirement, tedious synthesis of complex ligands, long reaction time, and the difficulty to recycle the catalyst.…”