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Preparation of Polymer Supported Cinchona Alkaloids and Their Catalytic Performance for Asymmetric Michael Reaction

Author: QinYanYan
Tutor: CuiYuanChen
School: Henan University
Course: Polymer Chemistry and Physics
Keywords: Sulfhydryl resin Chitosan Cinchona base Polymer -supported catalyst Asymmetric Michael addition reaction
CLC: O643.32
Type: Master's thesis
Year: 2011
Downloads: 47
Quote: 0
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Abstract

Polymer chiral catalyst has a simple separation reusable heterogeneous catalyst advantage to overcome a large amount of homogeneous catalysts, recycling difficult issues such as, in line with the current green chemistry and sustainable development needs. This article 10 new polymer supported chiral catalysts synthesized by different methods and their application in the asymmetric Michael reaction. This paper reads as follows: synthetic polymer load quinine catalyst synthesis and catalytic properties of the asymmetric Michael reaction the natural cinchona bases (quinine) synthetic polymer grafting reaction prepared six load type catalyst for the Michael addition reaction catalyzed 1,3 - two carbonyl compounds and N-benzylmaleimide maleimide. Substrate, solvent, amount of catalyst, the catalytic properties of a sulfhydryl resin load quinine catalyst and its reusability. The results showed that: Six catalyst could catalytically above reaction, wherein optimal mercapto resin load quinine catalyst V catalytic effect, catalyst V in a suitable solvent having a high stereoselectivity and activity, the yield was 83%, ee value up to 86%, and mild reaction conditions, easy to recycle, re-use and better performance (at least 6) reusable. Chitosan supported the cinchona alkali catalyst synthesis and its asymmetric Michael reaction with functional groups of natural macromolecules is Organocatalyst good carrier containing natural big rich amino and hydroxy molecular chitosan as the carrier got the two chitosan load cinchona alkali catalyst prepared by a simple method. Chitosan - cinchona base as a heterogeneous catalyst for the asymmetric Michael reaction catalyzed 1,3 - two carbonyl compounds and N-benzylmaleimide maleimide, good yield and stereoselectivity ( ee value of 94%, the DR value of 85: 15) generates a highly dense (adjacent to the tertiary carbon and quaternary carbon atoms) functional product. Simple experimental procedure, environmental friendliness, and highlight the advantages of natural macromolecules supported catalyst catalyst recyclability. Polymer load off A quinine catalyst synthesis and applications in asymmetric Michael reaction with sulfhydryl resin, chitosan, quinine as raw material, synthetic sulfhydryl resin - off A quinine catalyst and chitosan - off A quinine catalyst, used for the catalytic nitroolefin and dimethylmalonate the asymmetric Michael addition reaction solvent, amount of catalyst, temperature, substrate sulfhydryl resin - deformylase quinine catalyst the impact of the performance. The results showed that the two catalysts can be effective to catalyze the nitroolefin malonate asymmetric Michael addition reaction, wherein the mercapto resin load off A quinine catalyst having a high catalytic activity and preferably in tetrahydrofuran the stereoselectivity of the corresponding Michael addition reaction yield of more than 80%, the value reaches 88% ee, and easily recovered and reused better performance.

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CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalytic reaction
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