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Synthesis of PVC Supported L-proline Derivative and Its Catalytic Properties for Direct Asymmetric Aldol Reaction

Author: ZouJun
Tutor: CuiYuanChen
School: Henan University
Course: Polymer Chemistry and Physics
Keywords: PVC Tetraethylenepentamine Proline Asymmetric Aldol Reaction
CLC: O643.32
Type: Master's thesis
Year: 2008
Downloads: 98
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Abstract

The catalytic asymmetric reaction of small organic molecules is the recent development of a new field of research. Because it overcomes the enzyme catalyst harsh reaction conditions, the transition metal catalyst is expensive toxicity greater disadvantage become the focus of attention. Polymer supported catalyst can effectively overcome the large amount of catalyst of small organic molecules, difficult recovery drawbacks. This thesis is synthesized two novel polymer load of small organic molecules catalyst. A more in-depth study of the optimization of the reaction conditions, the scope of the exploration, catalyst recovery. The main tasks include the following three parts. (1) to tetraethylammonium stays pentamine PVC as raw material for industries amine modification, synthetic PVC tetraethylenepentamine - proline compound (PTP), through condensation reaction, and by infrared, thermal weight and other means to characterize this compound. The results prove that proline can be effectively supported on the PVC tetraethylenepentamine this polymer carrier. (2) the catalyst is the PTP applied to catalytic asymmetric Aldol reaction. By optimizing the reaction conditions, we found that, as compared with the organic solvent having a better catalytic performance of the catalyst in water. In a non-alkaline environment water for the medium under the conditions of catalyst the PTP has good selectivity; under the medium condition the both excellent catalytic activity of the catalyst has a good selectivity (yield up to 94% water in an alkaline environment, ee values ??up to 97%). Effects of substrate applicability of this catalyst under optimal conditions, the results show that an alkaline environment, water media under the conditions better substrate suitability PVC tetraethylenepentamine - proline compounds. Electron-aldehydes is superior with the electron donating group of the aldehyde substrate aldehyde with suction. By examining the performance of the repeated use of the catalyst, we found that the water in an alkaline environment for a medium under conditions that the catalyst has a better reusability and catalyst was reused 15 times the catalytic activity is not significantly reduced. (3) by the hydrolysis reaction to the industrial PVC modified synthesis of a hydrophilic polymer carrier, and then through the amine, condensation, etc., synthesized by the reaction of the hydrolysis of a hydrophilic PVC tetraethylenepentamine - proline compounds (HPTP). The catalyst used in catalytic asymmetric Aldol reaction. By optimizing the reaction conditions, we have found that hydrophilic hydrolysis of polyvinyl chloride tetraethylene pentamine - proline having good catalytic activity and selectivity of compounds in water as solvent conditions; while an organic solvent as the solvent, the catalyst The catalytic activity is not ideal but the selectivity is relatively good. Also investigated the substrate applicability of such catalysts, the results show that the catalyst has a certain substrate applicability. The substrate aldehyde, the reaction of the aldehyde with an electron withdrawing group with electron donor groups, aldehydes. The catalyst also has a certain re-use performance.

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