Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation
Open Access
Abstract
Chitosan-grafted-poly(4-vinylpyridine) (Cs-PVP) copolymers could be synthesized under heterogeneous conditions in presence of a potassium persulfate and sodium sulfite redox system. The synthesized graft copolymer could be utilized effectively, in the form of beads, as an efficient catalyst for Michael additions of active methylenes to functionally substituted alkenes. Moreover, methyl moiety oxidation in methyl pyridazinyl carbonitriles by H2O2 in the presence of chitosan-g-polyvinyl pyridine–supported iron (III) complex, Cs-PVP/Fe, could be affected. A variety of pyrans, naphthopyrans, and thiopyrans could be synthesized efficiently in the presence of these graft copolymer beads by novel catalytic routes. These polymeric catalysts could be used instead of the old toxic commercial organic basic catalysts, piperidine or pyridine, and could be readily isolated from the reaction mixture and recycled several times without significant loss of catalytic activity.Keywords
This publication has 37 references indexed in Scilit:
- Chitosan: a highly efficient renewable and recoverable bio-polymer catalyst for the expeditious synthesis of α-amino nitriles and imines under mild conditionsGreen Chemistry, 2013
- Chitosan‐Based Heterogeneous Catalysts for Enantioselective Michael ReactionChirality, 2012
- Organocatalysis in Synthesis: L-Proline as an Enantioselective Catalyst in the Synthesis of Pyrans and ThiopyransMolecules, 2012
- Studies on 3-Oxoalkanenitriles: Novel Rearrangement Reactions Observed in Studies of the Chemistry of 3-Heteroaroyl-3-Oxoalkanenitriles as Novel Routes to 2-DialkylaminopyridinesMolecules, 2012
- Enaminones as Building Blocks in Heterocyclic Syntheses: Reinvestigating the Product Structures of Enaminones with Malononitrile. A Novel Route to 6-Substituted-3-Oxo-2,3-Dihydropyridazine-4-Carboxylic AcidsMolecules, 2008
- Preparation of Chitosan from Brine Shrimp (Artemia urmiana) Cyst Shells and Effects of Different Chemical Processing Sequences on the Physicochemical and Functional Properties of the ProductMolecules, 2008
- Homogeneous and heterogeneous grafting of 4‐vinylpyridine onto chitosanJournal of Applied Polymer Science, 2006
- Biotechnology—a sustainable alternative for chemical industryBiotechnology Advances, 2005
- Removal of copper(II) ions from aqueous solution onto chitosan and cross-linked chitosan beadsReactive and Functional Polymers, 2002
- Activated Nitriles in Heterocyclic Synthesis: A Novel Synthesis of Pyrano[2,3-c]pyrazolesHETEROCYCLES, 1981