催化劑控制亞胺葉立德進行 (3+2) 環加成反應之位向選擇性並合成高鏡像選擇性之 Chromanopyrrolidines 藉由有機膦試劑及鹼催化下進行 Wittig 反應並控制其化學選擇性高效率合成多取代呋喃分子。

Catalysts controlled regioselective (3+2) cycloaddition between azomethine ylide and indandionebenzylidines to prepare highly enantioselective chromanopyrrolidines Synthesis of functionalized furans via chemoselective reduction/Wittig reaction using catalytic trimethylamine and phosphine

余鎮奎(Yu Jhen-Kuei)

指導教授 ： 林文偉

國立臺灣師範大學/理學院/化學系/碩士(2017年)

https://doi.org/10.6345/NTNU202202854

摘要

I. 催化劑控制亞胺葉立德進行 (3+2) 環加成反應之位向選擇性並合成高鏡像選擇性之 Chromanopyrrolidines。
II. 藉由有機膦試劑及鹼催化下進行 Wittig 反應並控制其化學選擇性高效率合成多取代呋喃分子。
第一章：透過亞胺葉立德前趨物進行 (3+2) 環加成反應，建立高光學選擇性的 Chromanopyrrolidines。過去對於 Chromanopyrrolidines 不同異構物合成中，較為困難地 Chromano[3,4-b]pyrrolidines 以高效率高立體選擇性的方式建構。於合成過程中克服了過去對於加成位向選擇性的限制並且加以控制。此外，對其選擇性來源及 (3+2) 環加成部分進行機構的探討。
第二章：以本實驗室早期開發高官能性呋喃化合物之方法，進一步改良為催化途徑，以提高反應之效率。透過一連串反應優化，成功地得以控制反應的選擇性以及排除副反應之影響，建立一高效的還原反應、Michael 反應、氧醯化反應、分子內 Wittig 反應的循環。

關鍵字

有機催化 ； 有機膦試劑 ； 不對稱合成

並列摘要

I. Catalyst-controlled regioselective (3+2) cycloaddition of azomethine ylide and indandionebenzylidines for synthesis of highly enantioselective chromanopyrrolidines.

II. Synthesis of functionalized furans via chemoselective reduction/Wittig reaction using catalytic triethylamine and phosphine

Part I. A novel and highly enantioselective (3+2) cycloaddition/esterification cascade for the synthesis of chromano[3,4-b]pyrrolidine derivatives is reported. Quinine-derived base, hydroquinine squaramide, affects this cascade reaction efficiently providing the products in good yields and stereoselectivities. Furthermore we found out the interesting phenomenon while the basicity change the reioselectivity of (3+2) cycloaddition could be controlled. The mechanism of how the regioselectivity could be controlled is also revealed in this work.

Part II. An efficient protocol for the synthesis of highly functionalized furans via intramolecular Wittig reaction has been developed using catalytic amounts of phosphine and triethylamine. Silyl chloride served as the initial promoter to activate the phosphine oxide. Reduction of the activated phosphine oxide by hydrosilane resulted in the generation of phosphine, while the decomposition of triethylamonium chloride resulted in the regeneration of base, both of which mediated the formation of phosphorus ylide. Remarkably, the in situ generated by-product, triethylammonium chloride, is also found to catalyze the reduction of phosphine oxide.

並列關鍵字

none

參考文獻

第一章參考資料

1. Gothelf, K. V.; Jørgensen, K. A. Chem. Rev. 1998, 98, 863.

2. Adrio, J.; Carretero, J. C. Chem. Commun. 2014, 50, 12434.

3. Allway, P ; Grigg, R. Tetrahedron Lett., 1991, 32, 5817.

4. Grigg, R, Tetrahedron: Asymmetry 1995, 6, 2475-2486