Journal ArticleDOI
Chitosan as a support for heterogeneous Pd catalysts in liquid phase catalysis
Silke E. S. Leonhardt,Achim Stolle,Bernd Ondruschka,Giancarlo Cravotto,Cristina De Leo,Klaus D. Jandt,Thomas F. Keller +6 more
TLDR
In this paper, four different chitosan-supported palladium catalysts were prepared, whereby two of them were modified as Schiff base by reaction with salicylaldehyde and 2-pyridinecarboxaldehyde before complexation with palladium.Abstract:
Four different chitosan-supported palladium catalysts were prepared, whereby two of them were modified as Schiff base by reaction with salicylaldehyde and 2-pyridinecarboxaldehyde before complexation with palladium. The remaining differ in their preparation method: co-precipitation or adsorption. The properties of the catalysts were characterized by FTIR, XPS, ICP-MS, and TGA. Comparison of the catalysts activity was assessed in microwave-assisted Suzuki reactions in aqueous media, resulting in good yields and excellent selectivities concerning cross-coupling product. Additionally, the catalysts prove their activity under conductive heating conditions. The study was extended to microwave-assisted Heck and Sonogashira reactions in DMF, confirming the efficiency of chitosan-supported palladium derivatives as catalysts for C–C couplings. Experiments revealed that catalysts prepared by co-precipitation furnished inferior yields concerning the employed C–C coupling reactions. Modification of chitosan with 2-pyridinecarboxaldehyde and subsequent palladium deposition resulted in highly active catalysts affording high product selectivities and yields.read more
Citations
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Journal ArticleDOI
Recent advances in Sonogashira reactions
Rafael Chinchilla,Carmen Nájera +1 more
TL;DR: This critical review focuses on developments in the Sonogashira reaction achieved in recent years concerning catalysts, reaction conditions and substrates.
Journal ArticleDOI
A review on applications of chitosan-based Schiff bases.
TL;DR: The biological applications of CSBs including antimicrobial activity, anticancer activity, drug carrier ability, antioxidant activity and tissue engineering capacity are discussed and the applications in other fields such as catalysis, adsorption and sensors are demonstrated.
Journal ArticleDOI
In situ decorated Pd NPs on chitosan-encapsulated Fe3O4/SiO2-NH2 as magnetic catalyst in Suzuki-Miyaura coupling and 4-nitrophenol reduction.
TL;DR: A green protocol for in situ fabrication of ultrafine Pd nanoparticles on chitosan-encapsulated Fe3O4/SiO2-NH2- NH2 nanoparticles, without the use of any toxic reducing agents, is described.
Journal ArticleDOI
Waste materials – catalytic opportunities: an overview of the application of large scale waste materials as resources for catalytic applications
TL;DR: In this article, the authors present examples of the use of high volume waste materials in catalysis or for catalyst synthesis, including red mud, aluminium dross, fly ash, blast furnace slag, rice husk and various kinds of shell.
Journal ArticleDOI
Pd nanosized particles supported on chitosan and 6-deoxy-6-amino chitosan as recyclable catalysts for Suzuki-Miyaura and Heck cross-coupling reactions
TL;DR: Several chitosan and 6-deoxy-6-amino chitOSan-Schiff base ligands were prepared by condensation of either 2-pyridinecarboxaldehyde or 2-(diphenylphosphino)benzaldehyde with the amino group(s) on chitosa and its derivative (6-deox-6amino CHITosan).
References
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Journal ArticleDOI
Palladium(II)-catalyzed C-H activation/C-C cross-coupling reactions: versatility and practicality.
TL;DR: A review of palladium-catalyzed coupling of CH bonds with organometallic reagents through a PdII/Pd0 catalytic cycle can be found in this paper.
Journal ArticleDOI
Chitosan chemistry and pharmaceutical perspectives.
TL;DR: Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. S. Nagar, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of medicine, Jerusalem 91120, Israel.
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Carbon-Carbon Coupling Reactions Catalyzed by Heterogeneous Palladium Catalysts
Lunxiang Yin,Jürgen Liebscher +1 more
TL;DR: Pd on Modified Silica 159 4.5.1.
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Interactions of metal ions with chitosan-based sorbents: a review
TL;DR: In the case of metal anions, the metal cations can be adsorbed by chelation on amine groups of chitosan in near neutral solutions as discussed by the authors.
Journal ArticleDOI
Heterogeneous catalysis on chitosan-based materials: a review
TL;DR: Chitosan is an optically active biopolymer that is characterized by a strong affinity for transition metals and can be used as a support for the preparation of heterogeneous catalysts in the form of colloids, flakes, gel beads, fibers and other metal oxides as discussed by the authors.