Synthesis of new 2-substituted pyrazolo[5,1- b ][1,3]oxazoles via Sonogashira coupling reactions in water

Palladium nanoparticles immobilized on sepiolite–cyclodextrin nanosponge hybrid: Efficient heterogeneous catalyst for ligand‐ and copper‐free C─C coupling reactions

“…Classically, these coupling reactions proceed in the presence of phosphine ligands and copper co‐catalysts . Development of copper‐ and ligand‐free protocols with the use of heterogeneous catalysts in aqueous media is considered as a turning point in this field and can facilitate the applications of such processes for industrials purposes . As an example, immobilization of Pd on cellulose–aluminium oxide composite and biopolymers can be mentioned.…”

“…[26,27] Development of copper-and ligand-free protocols [28] with the use of heterogeneous catalysts in aqueous media is considered as a turning point in this field and can facilitate the applications of such processes for industrials purposes. [26,[29][30][31][32][33][34][35][36][37][38][39][40] As an example, immobilization of Pd on cellulose-aluminium oxide composite [41] and biopolymers [42][43][44][45] can be mentioned. In this context, use of biopolymers such as wool, chitosan and cellulose as catalyst supports has attracted much attention due to their biodegradability, biocompatibility, chemical and physical versatility, availability and relatively low cost.…”

Synthesis of Thiazolo[3,2‐b] [1,2,4]triazoles through Pd‐Catalyzed Copper‐Free Sonogashira Coupling Reaction

“…investigated the Sonogashira reaction of alkyl chlorides using Nickel(II) complex. Recently, we reported the synthesis of pyrazolo[5,1‐b][1,3]oxazole derivatives using Sonogashira reaction of terminal alkynes with 2‐iodomethyl‐6‐methylpyrazolo[5,1‐b][1,3]oxazole . In continuation of our study on the synthesis of heterocyclic compounds through Sonogashira coupling reactions, herein, we report the synthesis of thiazolo[3,2‐b][1,2,4]triazoles via Sonogashira reaction of 6‐(iodomethyl)‐2‐methylthiazolo[3,2‐b][1,2,4]triazole with terminal alkynes.…”

Palladium nanoparticles immobilized on cyclodextrin‐decorated halloysite nanotubes: Efficient heterogeneous catalyst for promoting copper‐ and ligand‐free Sonogashira reaction in water–ethanol mixture

“…To circumvent these problems, the development of heterogeneous catalysts for Sonogashira reactions has been suggested . Moreover, the use of green procedures, especially use of aqueous media, for promoting C–C coupling reactions has been a focus …”

“…[4][5][6] Moreover, the use of green procedures, especially use of aqueous media, for promoting C-C coupling reactions has been a focus. [7][8][9][10][11][12][13][14][15] Halloysite nanotubes (HNTs) are a form of natural clay, mostly found in New Zealand, France, USA and China in large quantities, with tubular morphology and general formula Al 2 (OH) 4 Si 2 O 5 ⋅2H 2 O, in which the octahedral gibbsite Al(OH) 3 sheet forms the inner surface, while tetrahedral SiO 4 is in the outer surface. [16] Similar to kaolin, the ratio of Al to Si in HNTs is 1:1.…”