Biguanidine‐functionalized chitosan to immobilize palladium nanoparticles as a novel, efficient and recyclable heterogeneous nanocatalyst for Suzuki–Miyaura coupling reactions

Abstract

Biguanidine‐functionalized chitosan was synthesized and combined with palladium nanoparticles to yield a recyclable, environmentally benign, heterogeneous catalytic system for the Suzuki–Miyaura C–C coupling reaction. The catalyst was characterized using various techniques. The catalyst was used in Suzuki cross‐coupling reactions of various aryl halides, including less reactive chlorobenzenes, with phenylboronic acid to give biaryls without any additive or ligand. A reusability test demonstrated that the catalyst was highly efficient even after six runs. Solid‐phase poisoning and leaching tests indicated that the catalyst has a heterogeneous nature. Copyright © 2016 John Wiley & Sons, Ltd.

Palladium‐anchored multidentate SBA‐15/di‐urea nanoreactor: A highly active catalyst for Suzuki coupling reaction

“…Biaryls have broad applications in the synthesis of natural products, advanced materials and pharmaceuticals . Recently various types of Pd‐anchored ligand‐based SBA‐15 have been reported for the synthesis of biaryl compounds . Cao and co‐workers described the synthesis of a Pd‐diimine@SBA‐15 catalyst for Suzuki–Miyaura coupling through immobilizing Pd ions into the pore channels of diimine‐functionalized SBA‐15 mesoporous silica .…”

Valorization of Oceanic Waste Biomass: A Catalytic Perspective

“…Pd nanoparticles entrapped on biguanidine functionalized chitosan (Figure C) was used for Suzuki Miyaura coupling reaction. Excellent yields of the product were obtained (98 %) in EtOH−H 2 O with K 2 CO 3 as base at 40 °C for 2 h, without any leaching of Pd . In another approach, 2‐pyridine carboxaldehyde or 2‐(diphenylphosphino) benzaldehyde was condensed with amine groups of chitosan to give modified Schiff's base which was followed by Pd entrapment (Figure D and E).…”

“…Excellent yields of the product were obtained (98 %) in EtOHÀH 2 O with K 2 CO 3 as base at 40 8C for 2 h, without any leaching of Pd. [41] In another approach, 2-pyridine carboxaldehyde or 2-(diphenylphosphino) benzaldehyde was condensed with amine groups of chitosan to give modified Schiff 's base which was followed by Pd entrapment (Figure 2D and E). This catalyst also worked well for Suzuki-Miyaura and Heck cross coupling reactions.…”

Palladium nanoparticles‐decorated triethanolammonium chloride ionic liquid‐modified TiO2 nanoparticles (TiO2/IL‐Pd): A highly active and recoverable catalyst for Suzuki–Miyaura cross‐coupling reaction in aqueous medium

“…[13,14] This cross-coupling reaction was done commonly with valuable palladium in the presence of dangerous, expensive, poisonous, inflammable, and ligands includes hindered phosphines and carbenes in hazardous organic solvents such as DMF, dioxane, and toluene. Owing to several advantages of heterogeneous catalysts including simple isolation and recovering, Pd NPs were immobilized on numerous supports like Fe 3 O 4 NPs, [22] hydroxyapatite, [23] carbon, [24] metal-organic frameworks, [25] silica, [26] zeolites, [27] organic polymers, [28] and other synthetic adsorbents such as ion-exchange resins. These C-C bond-coupling reactions were often performed using the homogeneous palladium complexes, which generate problems in the product purification and the catalyst recovering.…”