中文摘要 延續了實驗室的系統,我們合成了 3,5-雙取代 N-亞柳胺基酸所衍生的掌性希夫鹼,進一步和硫酸氧釩化合物於氧氣飽合之甲醇溶劑中合成掌性的五價氧釩錯合物,進一步去進行不對稱 1,4-共軛加成反應及不對稱 N-H 嵌合反應。 在不對稱 1,4-共軛加成方面,以 2-酮基環戊烷甲酸苄酯為 Michael donor,而甲基乙烯基酮為 Michael acceptor,以進行碳-碳鍵的生成。我們設計了在 N-亞柳胺基酸的 C-3 位置是立體障礙較高的芳香環取代基,C-5 位置則引入拉電子性較強的硝基取代基,當使用 1d 為掌性催化劑時效果最佳,可得 81 % 的加成產物,其鏡像選擇性為 82 % ee。 由於先前並沒有文獻研究有關於利用氧釩錯合物進行不對稱嵌合反應,所以本實驗室利用氧釩錯合物去進行此類型的反應。其中以最容易製備的 3,5-雙溴取代之錯合物作為催化劑,去將 2-重氮-2-苯基乙酸苄酯及苯胺化合物進行不對稱 N-H 嵌合反應,在 40 ˚C 的條件下,以乙腈為溶劑的效果最好,雖然僅得到 20 % 的嵌合產物,但是其鏡像選擇性可達 74 % ee。 Abstract A series of chiral oxidovanadium(V) methoxides were prepared from 3,5-disubstituted-N-salicylidene L-tert-butylglycinates and vanadyl sulfate in oxygen-saturated methanol. These complexes serve as highly enantioselective catalysts for asymmetric 1,4-conjugate addition and asymmetric N-H insertion reactions. In part 1, we used benzyl 2-oxocyclopentanecarboxylate as a Michael donor and methyl vinyl ketone as a Michael acceptor for C-C bond forming 1,4-conjugate addition reaction. We also prepared some catalysts bearing bulky aryl group at C-3 position and strong electron withdrawing, nitro group at C-5 position. The best results were obtained (81 % yield, 82 % ee) by using 1d as a chiral catalyst for 1,4-conjugate addition reaction. In part 2, we explored chiral oxidovanadium complexes as catalysts for asymmetric N-H insertion for the first time. The best scenarios involve the use of tridentate chiral vanadyl complex derived from 3,5-dibromo-salicyaldehyde and tert-leucine. This catalyst promoted asymmetric N-H insertion reaction of benzyl 2-diazo-2-phenylacetate and aniline in acetonitrile at slightly elevated temperatures (40 ˚C) affording the insertion product in 20 % yield and up to 74 % ee.