Friedel–Crafts 反應是指在利用在路易士酸(Lewis acid)或布忍司特酸(Brønsted acid)的催化下，使鹵 化烴、醇、醯、醯鹵或酸酐等化合物與芳香烴(arenes)反應，在芳香環上引入烷基或醯基。為工業與 學術研究上合成藥品或特用化學品的重要反應之一。在Friedel–Crafts 反應中，常用的催化劑有AlCl3、 FeCl3、BF3、H2SO4、HCl 或HF 等路易士酸或布忍司特酸。然而些催化劑存在產物選擇率低、催化劑 無法收再利用、或是易造成設備腐蝕與環境污染的問題。 離子液體結構為有機陽離子與有機或無機陰離子所組成之離子化合物，其在寬廣的溫度範圍內處 於液體狀態，並具有高熱穩定、無發揮性、不易燃等特性，可降低使用揮發性有機溶劑對環境的汙染， 因此離子液體被稱為是一種綠色溶劑。由於離子液體中陰、陽離子的改變都可能對其物、化性質產生 重大的影響，因此本研究計畫以實驗室已建立的離子液體研究為基礎，合成同時具有布忍司特酸與路 易士酸特性的離子液體，並探討其在進行催化Friedel–Crafts反應的研究。 Friedel-Crafts reaction is defined as the use of arenes react with alkyl halides, alcohols, alkenes, acyl halides and acid anhydrides under acidic catalyst (such as Lewis acids or Brønsted acids) to introduce an alkyl group or an acyl group on an aromatic ring. It is an important reaction both on laboratory and industry that has been used in the production of pharmaceuticals and fine chemicals. Traditional catalysts used for Friedel-Crafts chemistry include Lewis acids (AlCl3, FeCl3 and BF3) or Brønsted acids (H2SO4, HCl and HF). The inherent problems of these acid catalysts include low stereoselectivity, non-reusability, corrosion of equipment, and large amount of acidic liquid waste. Ionic liquids are molten salts that are composed of organic cations and inorganic anions or organic anions. They have excellent properties such as wide temperature operation range, high thermal stability, and non-flammability. Moreover, ionic liquids have been termed as "green solvents" as they are non-volatility that can avoid the solvent losses. Changing the cation or anion of ionic liquids could notable influence the physical properties or chemical properties of the materials. This research is based on the characteristics of ionic liquids and synthesis technology in our previous work. We will synthesize novel Brønsted-Lewis acidic ionic liquids and study their catalytic activity for Friedel–Crafts reaction.
