研究生: |
楊承曦 |
---|---|
論文名稱: |
β-硝基苯乙烯系列物與穩定的親核性試劑反應之探討 |
指導教授: | 姚清發 |
學位類別: |
碩士 Master |
系所名稱: |
化學系 Department of Chemistry |
畢業學年度: | 86 |
語文別: | 中文 |
論文頁數: | 52 |
中文關鍵詞: | 硝基苯乙烯 、親核性試劑 |
論文種類: | 學術論文 |
相關次數: | 點閱:137 下載:0 |
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β-nitrostyrene系列與穩定的親核試劑反應後經稀酸水溶液水解後 可得到1,4-加成的產物,如硝基烷類。如果將反應所形成之中間體 nitronates加入冰浴的濃鹽酸水溶液中,預期會進行 Nef or Meyer 反應而得到羰基或敖酸的化合物。但分析實驗結果卻意外地發現氯 離子可以捕捉住活潑的中間體而形成hydroximoyl chlorides。 hydroximoyl chlorides在鹼性條件下可脫去HCl而形成 nitrile oxides。 nitrile oxides可以和烯或炔類進行1,3-dipolar cycloaddition反應而生成具有立體專一性或高度立體選擇性的產物 2-isoxazolines或isoxazoles。β-nitrostyrene系列可與具有不 飽和鍵的穩定性親核試劑經由1,4-加成反應(Michael addition)後 用35% HCI(aq)及Et3N處理後得到經由分子內反應而產生5,5-環之環 狀化合物或環醚類。
β-nitrostyrenes can react with stabilized nucleophiles to form 1,4-addition products such as primary nitroalkanes after workup with dilute aqueous acid solution. It is expected to undergo Nef or Meyer reaction to generate carbonyl compounds or carboxylic acids if the intermediate-nitronates are slowly added to the ice cold concentrated hydrochloric acid. Surprisingly, chloride ion can trap the reactive intermediates to generate hydroximoyl chlorides. Hydroximoyl chlorides can be converted into nitrile oxides by treating with base such as triethylamine. It is known that nitrile oxides undergo 1,3-dipolar cycloaddition with alkenes or alkynes to generate stereospecific or stereoselective product such as 2-isoxazolines or isoxazoles. One-pot synthesis of five-membered carbocycles or cyclic ether from the Michael addition of the stabilized nucleophiles with the β- nitrostyrenes is reported.