Synthesis of the Novel Multidentate Ligand and Its Mono- and Di-nuclear Ruthenium Complex for Cyanation of Tertiary Amines

本篇論文的主要內容為合成2,8-di(2-pyridyl)-5-phenyl-l,9,10-anthyridine (4a)多牙氮配位基以及其單核和雙核釕金屬錯合物，並將其作為三級胺氫化反應的催化劑，進而比較單核與雙核釕金屬錯合物之性質與催化活性。 將2,6-diamino-4-phenylpyridine-3,5-dicarboxaldehyde (3)與2-acetylpyridine進行Friedlander synthesis，可合成擁有五個N配位基團的化合物4a，擁有比bpNP更多的配位環境以及立體空間。使用兩種釕金屬前趨物RuCl2(CO)3(THF)以及[(η6-p-cymene)RuCl2]2與4a進行配位可分別得到單核釕金屬錯合物Ru1 ([(4a)Ru(CO)3Cl)(Ru(Cl)3(CO)3])以及雙核釕金屬錯合物Ru2 ([(4a)Ru2(p-cymene)2(Cl)2][(PF6)(Cl)])；藉由X光單晶繞射分析儀器鑑定，顯示此系列釕金屬錯合物均為六配位的形態存在，同時利用NMR以及ESI-MASS質譜分析兩錯合物的結構，其數據皆與晶體資料相符合。多種數據顯示Ru2上其中一個p-cymene擁有fluxion的現象，可能是p-cymene以垂直其C2軸垂直並通過苯環某一組對稱的碳做為軸，進行振動的現象。利用變溫1H NMR實驗觀察p-cymene隨溫度降低之氫譜變化並計算出此旋轉的轉動速率以及自由能。 在催化應用探討上，測試單釕金屬錯合物Ru1以及雙釕金屬錯合物Ru2對於三級胺氰化反應的活性。發現酸性條件下，錯合物Ru2在雙氧水做氧化劑下，可有效將氰化鈉與三級胺反應，得到產率不錯的α-胺基腈產物。相較於單金屬錯合物Ru1，雙金屬錯合物Ru2為較佳的催化濟。We have successfully prepared 2,8-di(2-pyridyl)-5-phenyl-l,9,10-anthyridine (4a), which is a multidentate ligand. For the ligand synthesis, the double Friedlander condensations of 2,6-diamino-4-phenylpyridine-3,5-dicarboxaldehyde (3) with 2-acetylpyridine yielded 4a. Coordination of 4a with two kinds of ruthenium precursor, RuCl2(CO)3(THF) and [(η6-p-cymene)RuCl2]2 , resulted in the formatioon of a mono-nuclearspecies ([(4a)Ru(CO)3Cl)(Ru(Cl)3(CO)3]) (Ru1) and a dinuclear ruthenium complex ([(4a)Ru2(p-cymene)2(Cl)2][(PF6)(Cl)]) (Ru2), respectively. Two complexes were characterized by X-ray crystals, NMR, ESI-MASS. We had found that one of the p-cymene of Ru2 is fluxional, and we proposed that the p-cymene might vibrate when Ru2 is dissolved in solvent. The vibrate frequency and free energy was determined by the low-temperature 1H NMR experiment. In the catalytic application, mono- and di-nuclear ruthenium complexes were active for the cyanation of tertiary amines with sodium cyanide. Complex Ru2 afforded the corresponding a-aminonitriles with good yields with hydrogen peroxide as the oxidant under acidic condition