含氮雜環碳烯銥金屬錯合物用於催化N-烷基化胺類化合物

本論文探討新型咪唑氮上修飾腈官能基之含氮雜環碳烯金屬錯合物的合成、結構解析、催化的應用以及其配位基效應。以新發展出的腈官能基-含氮雜環碳烯作為金屬配位基，藉由金屬碳烯轉移反應，成功將配位基從銀金屬轉移至目標銥金屬上，得到相對應之銥金屬錯合物4，藉由X光單晶繞射分析其晶體結構，揭示其金屬中心有環辛二烯及碳烯的配位，且金屬中心呈平面四邊形的結構，而碳烯上修飾之腈官能基並未配位至銥金屬中心。銥金屬錯合物4可與四氟硼酸銀反應脫去氯離子，使腈官能基配位至金屬中心，生成腈-含氮雜環碳烯的雙芽配位銥金屬錯合物5，並以核磁共振光譜及紅外線光譜確認其結構。將銥金屬錯合物4與一氧化碳反應來取代弱配位性的環辛二烯配位基可生成兩順式一氧化碳配位的錯合物6。碳烯銥金屬錯合物可以應用於氫轉移反應作為催化劑，在醇類與胺類的N-烷基化催化反應上展現優良的催化活性，成功得到二級胺產物。於是利用胺類的N-烷基化反應進一步探討不同銥金屬錯合物間的催化活性及碳烯-腈官能基的半穩定配位基效應。另一方面，試著從氫轉移反應的原理來延伸出其他催化反應的可能性，成功地將銥金屬錯合物4分別應用於醇類與吲哚之C-烷基化反應以及乙基苯基酮在α位置之甲基化反應得到C3位置烷基化之吲哚產物與甲基化產物。

關鍵字

含氮雜環碳烯；腈官能化；銥金屬錯合物； N-烷基化；胺類

並列摘要

NHC (N-heterocyclic carbene) complexes are versatile in transition metal catalysis due to the stronger NHC-metal bond and the stability of the complex. In this work, we have prepared the NHC-iridium complexes (4-6) processing nitrile functional group on imidazolium ligand and investigated the ligand effect on the catalytic reactions. Herein, we used 1-aryl-3-cyanomethylimidazolium salts as the carbene ligands. The iridium complexes 4 were prepared via transmetalation from the corresponding silver carbene complexes 3. The cationic complexes 5 were prepared by abstraction of the chloride in the corresponding neutral complexes 4 by AgBF4. The coordinated COD (COD = 1,5-cyclooctadiene) of complexes 4 were replaced by carbon monoxide to yield the corresponding carbonyl complexes 6. The catalytic activities on N-alkylation of amines with alcohols of all complexes via hydrogen transfer reduction were examined. We also investigated the weak coordination effect of nitrile on the ligand of a series of iridium complexes in N-alkylation of amines. Furthermore, we studied the C-alkylation of indole with alcohol catalyzed by 4.

並列關鍵字

N-heterocyclic carbene ； nitrile functionalized ； iridium complex ； N-alkylation ； amine

參考文獻

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含氮雜環碳烯銥金屬錯合物用於催化N-烷基化胺類化合物

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