選擇性sp3碳氫鍵自由基烯基化

Site-Selective Radical Alkenylation of C(sp3)-H Bonds

王亦廷(Yi-Ting Wang)

指導教授 ： 柳日馨 ； 吳彥谷

國立交通大學/理學院/應用化學系所/碩士(2020年)

摘要

儘管sp3碳氫鍵活化在有機合成中非常重要，透過自由基的選擇性碳氫鍵官能基化卻鮮少被研究。這篇論文包含了兩個部分，皆是著重以氧自由基做位置選擇性的sp3碳氫鍵活化，再進行加成、脫去反應，而得到烯基化產物。主要題目用的是較為龐大的四正丁基銨十聚鎢酸鹽作為光催化劑進行烯基化反應。透過照射特定波長的激發光源，十聚鎢酸根離子會激發至激發態，並形成龐大的氧自由基團。接著透過雙分子自由基取代反應，能夠選擇性地活化sp3碳氫鍵，並進行加成、脫去反應，得到烯基化產物。這也是十聚鎢酸銨鹽第一次被研究於烯基化反應。而次要題目也使用加成、脫去反應的策略，欲達成烯基化反應，因此使用了過硫酸鹽。過當量的過硫酸鹽透過加熱反應，過硫酸根離子會進行均裂反應，而形成體積較小的硫酸根自由基(-OSO3·)。我們發現兩者十分相似，都能夠選擇性地進行sp3碳氫鍵活化，再透過加成、脫去反應得到烯基化產物。另外，這也是第一篇有關於過硫酸根用於烯基化反應的研究。本篇論文探討四正丁基十聚鎢酸銨鹽以及過硫酸鹽之烯基化反應，探討位置選擇性以及反應性的不同，並推測不同的反應機制與原因。

關鍵字

位置選擇性 ； 自由基 ； 烯基化 ； 四正丁基銨十聚鎢酸 ； 過硫酸鉀

並列摘要

Despite that C(sp3)-H bonds activated reaction is very crucial in organic chemistry, site-selective C(sp3)-H bonds functionalization through radical reactions are less studied. The thesis includes two parts, in which we both focus on the use of oxygen-centered radical for site-selective functionalization reaction. Afterwards, it undergoes radical addition/elimination sequence to form our desired alkenylated products. In the main topic, we used the enormous TBADT, as known as tetrakis(tetra-n-butylammonium) decatungstate, as photo-catalyst for alkenylation reaction. After a certain wavelength of photo-irradiation, the excited state TBADT formed an enormous oxygen-centered radical. The radical then underwent SH2 reaction to activate C(sp3)-H bonds site-selectively, and underwent addition/elimination sequence to afford the alkenylated product. It is the first time that alkenylation reaction by TBADT is reported. In the sub-chapter, we used addition/elimination strategy for alkenylation reaction using persulfate salt. When stoichiometric amount of potassium persulfate is heated up, homolysis reaction takes place and generate sulfonyl radical (-OSO3·) as oxygen-centered radical, which is compact in size. The two radical sources acted similar that can activate C(sp3)-H bonds site-selectively, and gave alkenylated product after addition/elimination reaction. Besides, it is also the first time that persulfate is used for alkenylation reaction. In the thesis, we reported TBADT and persulfate for alkenylation reaction, discussed about site-selective and reactive manner, and purposed each mechanisms.

並列關鍵字

site-selective ； radical ； alkenylation ； tetrabutylammonium decatungstate ； potassium persulfate

參考文獻

1. S. Kim, C. J. Lim, Angew. Chem. Int. Ed. 2002, 41, 3265-3267.

2. S. Lee, C. J. Lim, S. Kim, Bull. Korean. Chem. Soc. 2004, 25, 1611.

3. A.-P. Schaffner, V. Darmency, P. Renaud, Angew. Chem. Int. Ed. 2006, 45, 5847-5849.

4. M. Lüthy, V. Darmency, P. Renaud, Eur. J. Org. Chem. 2011, 547-552.

5. V. Liautard, F. Robert, Y. Landais, Org. Lett. 2011, 13, 2658.