Dissertation > Excellent graduate degree dissertation topics show

Firedel-cratfs Reaction Catalyzed by Fluorinated Alcohols and Organo Bifunctional Catalysts

Author: LiGuoXing
Tutor: QuZuo
School: Nankai University
Course: Organic Chemistry
Keywords: fluorinated alcohol epoxide Friedel–Crafts reaction amino acid aldimine phenol asymmetric bifunctional catalyst
CLC: O643.32
Type: PhD thesis
Year: 2012
Downloads: 3
Quote: 0
Read: Download Dissertation

Abstract


This thesis contains two parts:Part I: The regio-and stereo-selective Friedel Crafts alkylation ofarenes with epoxides is important in organic synthesis. These reactionsare generally catalyzed by Lewis acids which activate epoxides towardselectrophilic substitution. However, degradation and polymerization ofepoxides sometimes occur before electrophilic substitution in thepresence of strong Lewis acids. Therefore, to make this reaction anefficient transformation, it is necessary to suppress degradation andpolymerization side reactions.Firstly, we tried the intramolecular Friedel Crafts reacton of(phenoxymethyl)o-xiranes in pure water. It was found that the cyclicalkylation product wasonly obtained in moderate yield due to the hydrolysis of epoxide to diol side product. Based on this finding, we reasoned that a more acidic andpolar, but less nucleophilic solvent than water can make as a catalyst topromote this transformation.1,1,1,3,3,3-Hexafluoroisopropanol waschosen as the best solvent to promote the intra-and intermolecularFriedel Crafts reacton between arenes and epoxides with high regio-andstereo-selectivity.It was found that fluorinated alcohols could also promote thereactions which were traditionaly catalyzed by Lewis acids, and eventransformations that only could be catalyzed by metal.Part Ⅱ: Asymmetric Friedel–Crafts reaction between an aromaticcompound and an aldimine is an important approach for the preparationof optically active benzylic amines. Up to date, most asymmetricFriedel–Crafts reactions of aldimines are completed with heteroaromatics.We developed The first enantioselective Friedel–Crafts reaction catalyzedby natural amino acid derived bifunctional catalyst between electron-rich phenols and N-tosylaldiminesA series of bifunctional (amine/thiourea) catalysts weresynthesized and used in the model asymmetric Friedel–Crafts reactionbetween3,5-dimethoxylphenol andN-benzylidene-4-methylbenzenesulfonamide. We found the catalystderived from Leucine gave the highest enantioselectivity. AsymmetricFriedel–Crafts reactions catalyzed by this catalyst between electron-richphenols and aldimines were carried out with high regioselectivity, and upto96%yield and95%ee.

Related Dissertations

  1. The Research and Realization on Asymmetric Sine Inverter with Adjustable Frequency and Amplitude,TM464
  2. Effects of Enzymes on Metabolism of Polycyclic Aromatic Hydrocarbons in Plant,X173
  3. Theeffect of Environmental Factor on Rooting Culture of Paeonia Suffruticosa in Vitro,S685.11
  4. The optimal scale of investment of private equity funds,O224
  5. Study on Effect of Nutritional Regulation on Pig Production Performance and Discharge of Nitrogen and Phosphorus,S828.5
  6. Research on Predicting Intrinsic Disorder Protein Structure Based on Supervision Manifold Learning Algorithm,Q51
  7. Synthesis and Application of New Halogen-free Flame Retardant Cotton with Expandable Anti-wrinkle Agent PNX,TQ314.248
  8. The Influence of Antibiotics on Yogurt During the Fermentation,TS252.54
  9. Study on Oxidation Treatment of Phenol Contaminted Soil Using Potassium Ferrate,X53
  10. Growth Response and Osmotic Adaptation of Rice Seedings to Nitrogen Forms and Water Stress,S511
  11. Effect of Pyruvate, Creatine and Creatine-Pyuvate on Profile of Amino-Acids and Relevant Enzyme Activity in Broiler Chickens,S831.5
  12. Effects of CrPyr on Protein Metabolism in Rats,S865.12
  13. Study on Synthetic of BINOL, Amino Acid and Derivatives Molecularly Imprinted Polymers and Their Application in the Chiral Resolution,O631.3
  14. Preparation of Electrode by Electrodeposition and Study on Performance of Degradation Phenol Wastewater,X703
  15. QTL Maping and Gnenetic Analysis of Amino Acids and Vitamin C Content in Soybean Sprouts,S649
  16. Research on Isolation and Polyphasic Taxonomy of a Phenol Tolerant Novel Species-Comamonas Zonglianii BF-3~T,X172
  17. Characterization of a New L-amino Acid Oxidase from Agkistrodon Blomhoffii Ussurensis Snake Venom,Q55
  18. The Study of Protection of Amino Acid and Peptide Bond Synthesis,O629.71
  19. Synthesis and Asymmetric Catalytic Behaviors of Chiral Imine and Dimines Schiff Bases,O621.3
  20. The Syntheses and Applications of Nanao Cadmium Sulfide Based on the Green Chemical Concept,O614.242
  21. Synthesis and Biological Activities of 3-(1’-Alkyloxycarbonylmethylimino) Ethyl-4-Hydroxypyrroline-2-One Derivatives,TQ463.5

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