Molecules 2013, 18(5), 5288-5305; doi:10.3390/molecules18055288
Article

Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation

1,2 and 1,*
Received: 10 April 2013; in revised form: 28 April 2013 / Accepted: 28 April 2013 / Published: 8 May 2013
(This article belongs to the Special Issue Organocatalysis)
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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: chitosan; chitosan-g-poly(4-vinylpyridine); graft copolymer; [chitosan-g-PVP]-supported iron (III) complex; Michael additions
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Khalil, K.D.; Al-Matar, H.M. Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation. Molecules 2013, 18, 5288-5305.

AMA Style

Khalil KD, Al-Matar HM. Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation. Molecules. 2013; 18(5):5288-5305.

Chicago/Turabian Style

Khalil, Khaled D.; Al-Matar, Hamad M. 2013. "Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation." Molecules 18, no. 5: 5288-5305.


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