Copper-Catalyzed Aminolysis of Beta，beta-Dialkylthio Carbonyls with Ammonia：Synthesis of Enaminones with a free beta-Amino Group

摘要

Enaminones are a class of 13-dicarbonyl enamines compounds and they synthesis havebeen actively developed in this recent years.They are still remaining a current subject inorganic chemistry due to their multiples utility and applications.They are useful intermediatesfor the preparation of various heterocyclic and biological active compounds such as dopamine auto-receptor agonists，and acetylcholinestersase inhibitors，oxytocin antagonists andanticonvulsants.Several papers have been published relating their synthesis and theirimportance in organic chemistry,medical and pharmaceutical chemistry.Recent studies haverevealed that some ofthe simple β-enaminones are biologically active and serve as leads for’antibacterial agent development.
　　 And as useful intermediaries，enarninones have considerable applications；these derivatives have been also extremely used for the preparation of variety of heterocyclicsystem including some natural products and analogues.Recently Kepe V and his coworkershave developed β-dimethyl amino-α，β-unsaturated ketones and nitriles into pyridine，isoquinoline，pyrazole，isoxazole，pyrimidine and Pyranone derivatives which are veryimportant and useful heterocyclic rings.Due to their wide range of activity and importance，avariety of methods for the synthesis of enaminones are published in the literature.Among theplethora of methods，the most attractive protocol is obviously the direct condensation of 1，3-dicarbonyl compounds with amines.
　　 A practical approach towards to the synthesis of 13-enaminones Was reported by Baraldiin 1983，in which the target compounds were made by refluxing 1，3-dicarbonyl compoundswith amine or ammonium acetate in the presence of acetic acid in benzene with azeotropicremoval of water.Since then several new protocols leading to 13-enaminonederivatives，in，which，AL2O3，SiO2，montmorillonite，K1 O，1，3-diketonatoboron，difluorides，NaAuCh,Zn(C1O4)2，Bi(OCOCF3)3 and CeC.H2O were used as catalysts or as reagents have beenpublished.Some new improvements as also been done；like the reaction of Dithioacetals withamines which afforded enaminones in good to excellent yields.Number of these methodspresents the disadvantage of including not readily available reagents，high temperature anddifficult accessible catalyst.It is noteworthy noticing that very few methods have beenpublished leading the enaminones starting from readily available Dithioacetals.And on theother hand it must be noticed that most of these methods afford enaminones with secondary and tertiary alnino group.Very little case has been reported for enaminones with flee amino group.
　　 As part of our ongoing research towards on the synthesis of enaminones we developed afacile method for the synthesis enaminones containing a free beta amino group.Therefore ithas been known that this kind of compounds is difficult to prepare，and there ale very few examples for the preparation of enaminones with free amino group which from a synthetic point of view are much more valuable functional group for manipulation.Not only that few efforts were made to synthesize enaminones with a flee amino group also it has been reportedinthe few case the preparation ofthese compound starting from Dithioacetals as a substrate.
　　 In summary，this work presents all easy way for the synthesis ofenaminones containing afree amino group using Beta,beta—Dialkylthio carbonyls as starting materials in the presence of Cu(II)salts as catalyst.

目录

英文文摘

Acknowledgements

Chapiter-1- Introduction

1 - Background studies on importance of enaminones

1 -1- Brief History of enaminones

1 -2- Enaminones in heterocyclic synthesis

1 -3- Enaminones: Reactivity and use as versatile intermediates in organic synthesis.

1 -4- Importance of enaminones in pharmaceutical chemistry

1 -5- Importance of enaminones containing free amino group

2 - Background studies on the synthesis of enaminones

2 -1- Related work on the synthesis of enaminones

2 -2-Related work on the synthesis of enaminones with free amino group

2 - 2mportance of this research

2 -3 - Statement of the problem

4 - Beta, beta-Dialkylthio Carbonyls

4 -1- Literature review on the synthesis of beta, beta-Dialkylthio Carbonyls

4 -2 -Beta, beta-Dialkylthio Carbonyls as intermediates in organic chemistry

4 -3 -Reactivity of beta, beta-Dialkylthio Carbonyls

5 - Concluding remarks

Chapter- 2 -Experimental part

2 -1 Synthesis of Beta, beta-Dialkylthio Carbonyls

2 -1-1-General procedure for the synthesis of Beta, beta-Dialkylthio Carbonyls

2 -2-Synthesis of enaminones

2 -2-1-Optimization of the reaction condition

2 -2-2-General procedure for the synthesis of enaminones

2 -4-Concluding remarks

Chapter- 3- Data analysis

3 -1H NMR and 13CNMR Spectrum data of starting materiel

3 -2 H NMR and 13CNMR Spectrum data of enaminones

General conclusions and further works

Publications

References