本論文利用重氮化合物與銠金屬催化劑──乙酸亞銠 (Rh2(OAc)4) 進行分子內N-H卡賓插入反應得到2-膦酸酯吲哚。
以往合成2-膦酸酯吲哚的方式多為以現有的吲哚化合物和過量磷試劑在金屬的催化下進行反應，這些方法多半需要高溫、耗時、過量的化學藥劑且產物多為3-膦酸酯吲哚，因此我們希望可以設計出一種較溫和、原子使用效率高且只會得到2-膦酸酯吲哚的方法。我們利用一系列N-Boc-2-(溴甲基)苯胺的化合物與Seyferth-Gilbert試劑 (重氮甲基膦酸二甲酯) 進行反應，得到相對應的重氮烷基膦酸酯後，再利用重氮基與銠金屬形成金屬卡賓進行分子內N-H插入反應，順利得到N-Boc-2-膦酸酯吲哚。此反應只需要在室溫、一般大氣環境下即可反應，改善了以往嚴苛的條件以及解決位置選擇性的問題。
此反應雖然順利得到2-膦酸酯吲哚且反應總產率中等甚至偏高，但有獲得意料之外的副產物──吲哚酮，雖然目前沒有完全阻斷它的產生，不過我們推測其機制可能是-氫消除反應時的氫位置不同導致有兩種產物，其中副產物是因為後續水攻擊並脫去亞磷酸二甲酯而生成，經由NMR光譜確實有看到亞磷酸二甲酯的訊號。

In this study, we reported the synthesis of 2-phosphoindoles by intramolecular N-H carbene insertion with rhodium(II) acetate from the -diazoalkylphosphonate compounds.
Phosphoindoles are commonly carried out from the indole systems under the treatment of catalytic amount of metals and excess phosphonates or phosphines at high temperature. However, the process regio-selectively prefers 3-phosphoindole over 2-phosphoindole due to the most reactive carbon at C3 position of indole system. In order to develop an exclusive and milder reaction for the synthesis of 2-phosphoindole, we used a series of N-Boc-2-(bromomethyl)anilines to react with Seyferth-Gilbert reagent and obtained the corresponding tert-butyl (2-(2-diazo-2-(dimethoxyphosphoryl)ethyl)-phenyl)carbamates. These well-arranged -diazophosphonates then participated into the rhodium-carbenoid N-H intramolecular insertion.
Although the process could give 2-phosphoindole derivatives in moderate to high yield at room temperature, the 2-oxindoles always accompanied as side products which might be formed from the two molecular of coordinating water on the undried Rh2(OAc)4. We observed the signal of dimethyl phosphite by NMR and speculated the mechanism might be through a series of -hydride elimination, H2O attacking, and dimethyl phosphite cleavage for the oxindole.

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