Dissertation > Excellent graduate degree dissertation topics show

Synthesis of 4-substituted Chiral Organocatalysts Derived from L-prolines and the Catalytic Effects on the Asymmetric Direct Aldol Reaction

Author: FuShaoDong
Tutor: FuXiangZuo
School: Southwestern University
Course: Organic Chemistry
Keywords: Prolinamide derivatives Organocatalysis Aldol reaction Water
CLC: O643.32
Type: Master's thesis
Year: 2010
Downloads: 94
Quote: 0
Read: Download Dissertation

Abstract


In the latest decade, asymmetric organocatalysis has become an important area of research in organic synthesis. Organocatalysts which are metal-free small organic molecules are able to function as efficient and selective catalysts making many organocatalytic reactions superior to those carried out using more conventional methods, and among these reactions, the aldol reaction which is recognized as one of the most powerful carbon-carbon bond-forming reactions in modern organic synthesis, creating the (3-hydroxy carbonyl structural unit found in many natural products and drugs, has received much attention in recent years.However, unlike enzymatic reactions in nature that occur in water, enantioselective organocatalytic processes have typically been carried out in organic solvents, such as DMSO, DMF, or in mixed aqueous organic solvent, under mild conditions. Therefore, highly efficient catalytic system, which gives high enantioselectivity for a broad range of substrates in water, is still limited and currently a sought-after goal in modern chemistry.In this dissertation, a new system of 4-tert-butyldimethylsiloxy substituted organocatalysts derived from N-prolylsulfonamide has been designed by our group and proved to be effective in catalyzing the direct aldol reactions of cyclic ketones with a series of aromatic aldehydes. The research showed that the best catalytic efficiency was observed with 1b. When 3 mol% of 1b was used to catalyze the reaction without using any additives in a large amount of water under mild conditions(at room temperature), the aldol products were obtained in very good yields (>99%) with excellent diastereoselectivities up to>99:1 and enantioselectivities up to>99%.

Related Dissertations

  1. Preparation and Performance of Molecular Imprinted Polymers for Rhodamine-B and Rhodamine-6G,O631.3
  2. Temporal and Spatial Variation of Methane Emission from Urban Lake and Its Relationship with the Hydrology-water Quality,X524
  3. The Research of Ecological Compensation on the Restoration of Water Quantity in the Man-Made Seasonal Rivers,X143
  4. Studies on the Drying Modle and Technology of Tilapia by Heat Pump,TS254.4
  5. Clinical study of Xu heart,such as academic thought and clinical experience and Yiqi Huoxue,Xiefei Diuresis treatment,congestive heart failure,R259
  6. Capsaicin / β - cyclodextrin system to dissolve and penetrate the,R943
  7. Effects of Intensitive Cycling of Papermaking Water on Sizing and Its Improvement,TS727.5
  8. Synthesis and Application of A Novel Series of Cation Hydrophobically Modified Polyacrylamide,TQ323.6
  9. Study on Mechanism of Seawater Pearl Dyeing and Optimization of Dyeing Technology,TS933.23
  10. The Study on R-M Instability of the Material Interface in Gas-water Compressible Flow,O359.1
  11. The Application of Eggshell Membrane for Solid-phase Extraction and the Determination of Trace Metal Elements in Environment Water,X832
  12. Hydrogeological Conditions and Mine Section Prediction of Wenshan Chief Cabinet Secretary Tungsten Mine Area,TD742
  13. Research on PSA/Cotton Blend Fabric of Coatinging of Water Resistance and Moisture Permeability,TS195.6
  14. Spatial Analysis and Pollution Evaluation about Water Environment Actuality of Rural Surface Water in Typical Regions of Jiangsu Province,S271
  15. Research on Evaluation System of Irrigation Area Drought,S423
  16. Drip Irrigation Control System Based on Pulse Width Modulation (PWM),S152.7
  17. Under Environment History Angle of View Traditiao Farmland Water Conservancy Constructino Research,S274
  18. The Effects of Water and Fertilizer Coupling on Growth and Yield in Semi-winterness Wheat,S512.1
  19. Influence of Controlled Partial Root Drying Irrigation on Water Use Efficiency of Potato,S532
  20. Physiological Response to Drought Stress of Different Drought Resistance Winter Wheat Varieties,S512.11
  21. Research of Relationship between Carbon Dioxide Net Exchange and Water Use Efficiency in Winter Wheat Field Ecosystem in Taiyuan Basin,S512.11

CLC: > Mathematical sciences and chemical > Chemistry > Physical Chemistry ( theoretical chemistry ),chemical physics > Chemical kinetics,catalysis > Catalytic > Catalytic reaction
© 2012 www.DissertationTopic.Net  Mobile