探討（Metal-salen）錯合物在有機鹼催化二氧化碳與環氧化物環加成反應中的影響

Abstract

在我們之前研究中發現單獨有機鹼DMAP、Et3N、DBU的存在便具有催化性，且產物全為五員環的環狀碳酸酯，所以本篇論文我們以有機鹼作為催化劑，探討加入不同Metal-salen時，對於二氧化碳與環氧化物環化加成反應中的影響。且針對壓力、Metal-salen濃度、環氧化物種類及反應時間，討論改變各變數後對於其催化過程的影響。 由於Metal-salen為一個可以活化環氧化物的金屬錯合物，於是我們加入不同的Metal-salen比較其結果，發現並非所有的Metal-salen都可活化環氧化物，進而提高產率，如Cu-salen、Ni-salen在以環氧丙烷作為起始物的反應中，有抑制產率的上升，反之Cr-salen卻可以提高產率而且與DMAP有機鹼結合時的催化系統產率為最高。 另外根據Metal-salen可以活化環氧化物，有機鹼可以作為一親核試劑攻擊被活化的環氧化物，合成一具有長鏈有機鹼Metal-salen，並探討其對於環化加成反應的影響。It has been reported that Organic bases of DMAP、Et3N and DBU can catalyze the reaction of epoxides with carbon dioxide to produce the five-membered cyclic carbonate. Employing different metal-salens in the reaction of epoxides with carbon dioxide, in the presence of organic bases were undertaken. It was found that not all metal-salens could enhance the yield of the reaction. Both Cu-salen and Ni-salen can stunt the raising yield in the reaction as the propylene oxide is an initiator. On the contrary, Cr-salen can increase the yield effectively and was the best catalytic system when use DMAP as the catalyst. In addition, we also discussed the effects of changing the reaction pressure, the equivalents of promoter, and the reaction time in the reaction of epoxides with carbon dioxide. Finally, based on the organic bases could be treated as nucleophiles to attack eopxides and metal-salen could activate epoxides, we synthesis metal-salens with long chain organic base, and discuss the effect in the ring addition reactions. It was found that metal-salens with long chain organic base could enhance the yield more than other catalysts like organic base or metal-salens.