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Thesis Details
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Title
CERTIFICATE
DECLARATION
ACKNOWLEDGEMENT
DEDICATIONs
CONTENTS
ABBREVIATIONS
1 Introduction and Objetives
Objectives of the Work
Organisation of the Thesis
2 Polymer Bound Reagents - A Review
2.1 Introduction
2.2 Nature of Polymer Support
2.2.1 Physical form of the polymer
2.2.1a Linear polymers
2.2.1b Crosslinked polymer
i) Microporous or gel type resins
ii) Macroporous and Macroreticular resins
iii) Popcorn polymers
iv) Macrunet polymers
2.3 Methods of Functionalisation of Polymer
2.3.1 Copolymerisation of functional monomer
2.3.2 Chemical modification of preformed polymer
2.4 Effect of Solvent
2.5 Molecular Character and Extent of Cross linking
2.6 Diffusional and Molecular Sieving Effects
2.7 Steric Effects and Spacer Effects
2.8 Microenvironmental Effects
2.9 Site-Site Interactions and Site Isolation
2.10 Neighbouring Group Effect
2.11 Characterisation of Functionalised Polymers
2.12 Polymer Supported Reducing Agents
2.12.1 Polyvinylpyridine-borane reagent
2.12.2 Polymer bound borohydride
2.12.3 Polymer supported tin hydrides
2.12.4 Polypropylene sulfide-borane and haloborane reagents
2.12.5 Polymer supported amino alcohol-borane
2.13 Conclusion
3 Preparation of Ethylenediamene-borane Reagent on Cross linked Polystyrene Resins
3.1 Preparation of Cross linked Polystyrene Resins
3.2 Characterisation of HDODA-PS and BDDMA-PS resins
3.3 Chloromethylation of Cross linked Polystyrene Resins
3.4 Preparation of Ethylenediaminomethyl Resins (lc, 2c1, -2c6and 3c)
3.5 Conversion of Aminated Resins to Amine Hydrochloride Resins
3.6 Preparation of Polymer Bound EDA-borane
3.7 Characterisation of Polymer Bound EDA-borane
3.8 Swelling Studies
4 Reduction Stud Using the Polymer Bound EDA-borane Reagent
4.1 Reduction Studies
4.1.a Reduction of aldehydes
4.1.b Reduction of ketones
4.2 Mechanism of Reduction Using polymer Bound EDA-borane
4.3 Chemoselectivity of the Polymer Bound EDA-borane Reagent
4.4 Effect of Nature of Cross linking Agent on the Reduction Reaction
4.5 Extent of Conversion with Time
4.6 Effect of Degree of Cross linking on the Reactivity of the Polymer Bound EDA-borane Reagent
4.7 Effect of Solvent on the Reactivity of Polymer Bound EDA-Borane
4.8 Effect of Temperature
4.9 Effect of Catalyst
4.10 Effect of Concentration of Polymeric Reagent
4.11 Regeneration and Recyclability of the Polymer Supported EDA-borane Reagent
4.12 Effect of Mononofunctional Amines on the Reactivity of the Polymer Bound Amine-boran
4.12.1 Preparation of aminomethyl polystyrene (2c)
4.12.2 Preparation of ethylaminomethyl polystyrene
4.12.3 Preparation of diethylaminomethyl polystyrene
4.12.4 Preparation of Polymer bound 10: 20 and 30 amine-boranes from 2c, 2c and 2c
4.12.5 Reduction of aldehydes using 2e, 2en and Ze
5 Preparation of Polyacrylamide Supported Amine-borane Reagent and Investigation of its Reducing Properties
5.1 Introduction
5.2 Preparation of 5-mole Percentage NNMBA Cross linked Polyacrylamide.
5.3 Preparation of 5% HDODA. Cross linked Polyacrylamide
5.4 Amino Functionalisation of Polyacrylamide Resins
5.5 Preparation of Polyacrylamids Bound Amine-borane Reagent
5.6 Swelling Studies
5.7 Reduction of Aldehyde with the Polyacrylamide Supported Amine-Borane Reagent
6 Experimental
6.1 Materials
6.2 Instrumental
6.3 Preparation of Cross linked Polystyrene Resins
6.3.1 Preparation of 2% DVB crosslinked polystyrene (la)
6.3.2 Preparation of HDODA crosslinked polystyrene resins
6.3.3 Preparation of 2% BDDMA crosslinked polystyrene (3a)
6.4 Funtionalisation of the Cross linked Polymers (DVB-PS, BDDMA-PS, HDODA-PS)
6.4.3 Chloromethylation of crosslinked polystyrene resins: Preparation ofresins (lb, 2bl-2b6 and 3b)
6.5 Estimation of Chlorine Capacity
6.6 Conversion of Chloromethyl Resins to Ethylenediaminomethyl Resins (1c, 2c1-2c6 and 3c)
6.7 Estimation of Amino Group Capacity: Gisins Method
6.8 Conversion of Ethylenediaminomethyl Resins to the Corresponding Amine Hydrochloride Resins (lad, 2d, -2d6 and 3d)
6.9 Preparation of Polymer Supported EDA-borane Reagents (1 e, 2e, -2e6 and 3e)
6.10 Determination of the Borane Reagent Function Available for Reduction
6.11 Reduction of Aldehydes with the Polymer Supported EDA-Borane Reagent
6.12 Selective Reduction of Benzaldehyde in the Presence of Acetophenone
6.13 Quantitative Study of Reduction
6.14 Extent of Reduction of 2-nitrobenzaldehyde with Polymer Bound EDA-borane Reagents (l e and 2e1)
6.15 Effect of Various Parameters en the Reactivity of the Polymer Bound EDA-borane
6.15.1 Effect of degree of crosslinking
6.15.2 Effect of solvent
6.15.3 Effect of temperature
6.15.4 Effect of acid catalyst on the reactivity of polymer bound EDA- borane
6.15.5 Effect of concentration of polymeric reagent
6.16 Regeneration and Recycling of the Resin
6.17 Preparation of Polymer Bound Monofunctional Amines
6.17.1 Preparation of aminomethyl polystyrene
6.17.2 Preparation of polymer-bound ethylamine
6.17.3 Preparation of diethylaminomethyl polystyrene resin
6.18 Preparation of Polymer Bound Amine-borane Reagents Using Monofunctional Amines
6.18.1 Preparation of Polymer bound methylamine-borane (lo amine-boranereagent (2e) from aminomethyl polystyrene)
6.18.2 Preparation of polymer bound secondary amine-borane (2e) fromethylaminomethyl resin
6.18.3 Preparation of polymer bound diethylamine-borane (2e)
6.19 Reduction of Aldehydes Using. Polymer Bound Amine-borane Reagents (2e, 2e, 2e)
6.20 Swelling Studies
6.21 Preparation of Amine-borane Reagents on Cross linked Polyacrylamide Resins
6.21.1 Preparation of 5% NNMBA crosslinked polyacrylamide
6.21.2 Preparation of 5% HDODA crosslinked polyacrylamide
6.21.3 Incorporation of amino groups on crosslinked polyacrylamide resinby transamidation
6.21.4 Estimation of amino capacity
6.21.5 Conversion of the amino functionalised resins to the correspondingamine-hydrochloride
6.21.6 Preparation of amine-borane reagent on polyacrylamide resins
6.22 Reduction of Aldehydes
6.22.1 Reduction of aldehyde at high temperature
6.22.2 Reduction in the presence of acid catalyst
7 Summary and Outlook
References