研究生: |
陳崇弘 |
---|---|
論文名稱: |
二茂鐵穩定之三苯甲基氯化物在烯丙基化和醛醇加成催化反應之研究 α-ferrocenyl Stabilized Trityl-type Chloride as Catalyst in Allylation and Mukaiyama Aldol Reaction |
指導教授: | 陳建添 |
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: | 229 |
中文關鍵詞: | 二茂鐵 、三苯甲基氯化物 |
論文種類: | 學術論文 |
相關次數: | 點閱:149 下載:0 |
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我們以二茂鐵為骨架,合成一系列官能化三芳香基甲基醇並與
乙醯氯作用可得到三芳香基甲基氯化物。此氯化物具有路易士酸的
性質,可應用在催化Mukalyama醛醇加成反應上。我們以各種官能
化醛類和丁酸內酯所衍生的矽烷基半縮醛進行Mukaiyama醛醇加成
反應,並且比較各種官能化醛類進行Mukaiyama醛醇加成反應的相
對速率。在多種不同的溶劑系統下,產物的選擇性亦會受到影響。
其中以四氫口夫喃溶劑所得產物選擇性最佳產物以反式為主(73/27)。
此外,此官能化三芳香基甲基氯化物,配合三甲基矽烷之使用,
可應用於催化烯丙基化反應。我們改變反應的溶劑系統,發現二氯
甲烷是最適當的溶劑,並以各種官能化醛類進行烯丙基化反應以瞭
解其適用的範圍和可能的反應機構。
以甲苯基磺醯化之天然氨基酸為手性骨架,與二茂鐵基二溴化
硼消去兩分子的溴化氫形成以硼為路易士酸中心的硼酸口咢口坐口林。
此催化劑可應用在以苯甲醛和丁酸內酯所衍生的矽烷基半縮醛進行非
對稱醛醇加成反應上,所得之醛醇產物以反式為主(67/33)其鏡像超
越值為76%。
We have prepared functional, ferrocene-based trityl alcohols. By chloration with acetyl chloride, the trityl alcohols can be readily transformed to the corresponding trityl chlorides. It was found that they can act as Lewis acids in catalyzing Mukaiyama aldol addition between silyl ketene acetal derived from γ-butyrolactone and various functional aldehydes. Competition experiments between these aldehydes allow us to assess their relative rates of aldol addition. The selectivity of the aldol products highly depends on the solvent employed. THF was found to be the solvent leading to the best yield and selectivity of the product. The major product was predominated in the anti (73/27) isomer.
These functional trityl chlorides are also capable of catalyzing the allylation reaction between allyltributyltin and aldehydes in the presence of TMSC1 promoter. Out of 5 different solvents investigated, dichloromethane was found to be the best solvent. The scope, limit, and possible mechanism of the reaction were evaluated with a variety of functional aldehydes.
We have developed a new type of chiral oxazaborolidinone-based Lewis acid stabilized by ferrocene. By condensing chiral N-tosylated valine with dibromoferrocenylborane, we were able to assemble the boron-center Lewis acid. They were found to catalyze the aldol addition between silyl ketene acetal derived from γ-butyrolactone and benzaldehyde with significant intervention of silyl catalysis. The free aldol adducts were obtained with anti preference (67/33) and in 76%ee.