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  • 學位論文

一、硝基乙酸烯丙酯之Feist-Bénary加成脫去反應的探討 二、苯炔與烯類化合物之[2+2]環化加成反應

指導教授 : 陳焜銘
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摘要


本論文主要分為兩部分,第一部分為多取代呋喃化合物之合成反應,第二部分為利用苯炔高活性中間體,進行[2+2]環化加成反應。   第一部分:多取代呋喃的衍生物,常是天然物分子具有的結構,並於藥物分子開發占有重要的角色。利用本實驗室製備的硝基乙酸烯丙酯48a為起始物,和1,3-雙羧基化合物或α位有拉電子基的酮化合物,在乙腈作為反應溶劑,碳酸銫為鹼試劑。在溫和條件下,進行Feist-Bénary加成-脫去反應,經過分子內SN2'反應,合成多取代呋喃化合物,得到良好的產率(32-99%)。並探討不同官能基的起始物對產率的影響及反應機構的研究。   第二部分:苯炔為高活性反應中間體,常用於有機合成、反應機構探討,功能性材料的合成。以鄰位三甲基矽基-芳香族羥基三氟甲磺酸11為苯炔前驅物,使用不同雙鍵官能基化合物,氟化銫提供氟離子,乙腈作為反應溶劑,在室溫下進行[2+2]環化反應,成功得到[2+2]環化產物,並獲得良好的產率(29-76%)。

並列摘要


This dissertation is divided into two parts, Part 1 is efficient synthesis of tetrasubstituted furans. In part 2, [2+2]cyclization been activated by benzyne as a reactive intermediate.   Part 1:tetrasubstitutited furans represent an important role that have been used for the synthesis of many pharmaceutical molecules and natural products. We present herein an efficient synthetic strategy for accessing tetrasubstituted furans that exploits a Feist–Bénary type reaction between electron-deficient nitroallylic acetate 48a and 1,3-dicarbonyl/α-activating ketones in CH3CN, Cs2CO3 was employed as a base. The corresponding multifunctional tetrasubstituted furans were typically obtained in respectable to excellent yield (52–99%) via an interesting SN2’ addition–elimination sequence that proceeds under very mild reaction conditions. Next, studied the feasibility and scope of our new reaction with various startingmaterials and substituted nitroallylic acetates.   Part 2:Benzyne is a highly reactive intermediate and its substituted variants in the total synthesis of natural products. The [2+2] cycloaddition of alkenes and benzyne, apply o-(trimethylsilyl)aryl triflate as benzyne precussor, CsF provided the fluoride ion. generated the corresponding [2+2] cycloadducts in CH3CN, with moderate to good yield (29-76%). keywords : nitroallylic acetate, Feist–Bénary addition–elimination, tetrasubstituted furan, Benzyne, [2+2]cyclization

參考文獻


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