探討電子效應和立體障礙對於「胺基醇」轉換成烯類化合物之影響

Electronic and Steric Effects around the β-Carbon of the β-Amino Alcohols in Their Conversion to Alkenes

陳麗君(Li-jyun Chen)

指導教授 ： 胡紀如

國立中央大學/理學院/化學系/碩士(2012年)

摘要

碳與碳雙鍵不僅是有機化學上重要的一環，其立體特性也是化學家們在有機合成上所需要挑戰的課題之一，更重要的是在生化方面雙鍵的立體結構常常是影響生物活性的關鍵，因此發展一新形態之雙鍵合成方法有其必要性。本實驗室於2011年發表一項合成碳與碳雙鍵的新方法，其合成方法是利用β胺基醇作為反應之起始物與二硫化碳於鹼性環境下進行環化反應，得到一五圓環化合物再和苯炔進行[3 + 2]環化反應，緊接著進行反向[3 + 2]環化反應即可得到烯類化合物，而為了要探討此方法應用性之廣度，此篇論文將延續此新方法做更進一步的探討。
本篇論文是改變起始物胺基醇之β碳上的環境以探討是否會影響烯類化合物形成，其中實驗分成三個主要部分，第一部分是探討改變起始物胺基醇中β碳的取代基數目，分別為二取代基、三取代基與四取代基，第二部分是改變起始物胺基醇中β碳之取代基大小和第三部分探討電子效應是否會影響β碳的環境，使合成烯類化合物之五圓環中間產物受到阻礙，導致無法形成雙鍵。
由實驗結果我們得知兩項重點，第一項是起始物胺基醇中β碳的取代基數目和電子效應並不會影響五圓環的形成，然而當β碳上的立體障礙太大則會導致無法得到以thiazolidine-2-thione為核心的五圓環中間產物，第二項是只要合成出以thiazolidine-2-thione為核心的中間產物皆可以與苯炔反應得到烯類化合物。最後本人藉由實驗結果推測並配合分子模擬輔助加以印證立體障礙對合成烯類化合物所造成的影響。

關鍵字

雙鍵 ； 胺基醇

並列摘要

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.

並列關鍵字

amino alcohol ； double bond

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