Rajesh Krishnan, G; Dr. Sreekumar, K(Cochin University of Science and Technology, June , 2008)
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Abstract:
The present thesis has described the development of some heterogeneous
catalysts based on polymer supported dendrimers. Attachment of dendrimers to
crosslinked polymer produced new catalysts with combined benefits of both
dendrimers and heterogeneous catalysts. These were used as heterogeneous
catalysts in selected reactions. All possible attempts were taken to avoid
halogenated and aromatic solvents and toxic reagents. In short the present work
has dealt with development of environmental friendly catalysts based on
dendrimers.
Description:
Department of Applied Chemistry, Cochin University of Science and
Technology
Knoevenagel condensation between carbonyl compounds and active methylene compounds as well as three component Mannich reaction between aldehydes, ketones and amines proceeded smoothly in water with good to excellent yield and high selectivity in the presence of zero and first generation poly(amidoamine) (PAMAM) dendrimers. The products and the catalyst were separated by simple biphasic extraction. The catalyst was found to be reusable.
Sreekumar, K; Rajesh Krishnan, G(Taylor & Francis, February 22, 2010)
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Abstract:
Poly(amidoamine) dendrimers were synthesized on cross-linked aminomethyl polystyrene. Palladium
complexes of supported dendrimers prepared by ligand exchange method were reduced to dendrimernanoparticle
conjugates supported on polystyrene resin. The supported nanoparticles were used as
heterogeneous catalysts for the Suzuki coupling between aryl boronic acids and aryl halides. Various factors
affecting the catalysts performance were studied. Higher generation dendrimers gave well-defined
nanoparticles without agglomeration and these particles showed good catalytic performance