dc.description.abstract | The carbon–carbon bond plays an important role in organic chemstry, and its stereospecificity has been one of the issues that chemists have to challenge in the process of organic synthesis. Most important of all, the stereospecificity of the carbon-carbon bond in the biochemistry is the key to affect the activity of the biomolecules. Hence, there is a must to develop a new method to synthesize the carbon-carbon bond. Our laboratory has been published a new method to synthesize the the carbon-carbon bond in 2011. In our new method, we use β-amino alcohols as starting materials to react with carbon disulfide under the base conditions, and five-membered ring compound is produced. Then, the five-membered ring compound reacts with benzyne throught a [3+2] cycloaddition and a retro [3+2] cycloaddition to produce the olefin. In order to investigate the feasibility of the method, the thesis will continue the new method and do further research.
The thesis changes the environment of the β-carbon on the β-amino alcohols to examine whether the olefin synthesis will be influenced. The experiment contains three parts. In the first part, we changed the number of substituents of the β-carbon on the β-amino alcohols, di, tri, and tetra-substitutents respectively. In the second part, we changed the substituent size of the β-carbon on the β-amino alcohols. In the third part, we examined the electronic effect of indole substituents of the β-carbon on the β-amino alcohols.
In conclusion, the electronic effect of indole substituents and the number of substitute of the β-carbon on the β-amino alcohols were not influenced to get the thiazolidine-2-thiones which were five-membered ring compounds directly. The steric effect of methyl and phenyl substituents of the β-carbon on the β-amino alcohols influenced to get the thiazolidine-2-thiones directly. All the five-membered ring compounds react with benzyne to give olefins. Finally, I confirmed the influences of steric effects of various substituents on the olefin synthesis by use of Molecular simulations.
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