School of Chemistry, Bharathidasan University, Tiruchirappalli-620 024, India.
Org Biomol Chem. 2022 Jan 19;20(3):558-564. doi: 10.1039/d1ob02002a.
A BF·OEt catalyzed highly chemoselective formal CC double bond cleavage reaction of α,β-enones with diazoamides for the synthesis of 3-alkylated oxindoles is developed. Boron trifluoride etherate is found to be an effective catalyst for the chemoselective C-C cleavage of enones to obtain 3-alkylated oxindoles. The product formation indicates a selective β-carbon elimination pathway of α,β-enones using the inexpensive BF·OEt as a catalyst, transition metal-free conditions, an open-air environment, good functional tolerance and broad substrate scope. The synthetic utility of this protocol is highlighted by synthesizing spiro-indolooxiranes.
BF·OEt 催化的 α,β-烯酮与重氮甲酰胺的高化学选择性 CC 双键断裂反应，用于合成 3-烷基化氧吲哚。三氟化硼乙醚被发现是一种有效的催化剂，用于烯酮的化学选择性 C-C 断裂，以获得 3-烷基化氧吲哚。产物的形成表明，使用廉价的 BF·OEt 作为催化剂，在无过渡金属条件下，在开放的空气环境中，具有良好的官能团耐受性和广泛的底物范围，可以选择性地进行α,β-烯酮的β-碳消除途径。该反应条件温和，通过合成螺吲哚恶嗪进一步证明了该方法的实用性。
