Dipartimento di Scienze Farmaceutiche, Sezione di Chimica Generale e Organica "A. Marchesini", Università degli Studi di Milano, Via G. Venezian 21, 20133, Milano, Italy.
Dipartimento di Chimica, Università degli Studi di Milano, Via C. Golgi 19, 20133, Milano, Italy.
Org Biomol Chem. 2021 May 5;19(17):3925-3931. doi: 10.1039/d1ob00076d.
A simple and efficient approach for the synthesis of 2-spirocyclopropyl-indolin-3-ones is herein described. The method involves a diasteroselective cyclopropanation of aza-aurones with tosylhydrazones, selected as versatile carbene sources, and represents a remarkable synthetic alternative to get access to this class of C2-spiropseudoindoxyl scaffolds. The reactions proceed in the presence of a base and catalytic amounts of benzyl triethylammonium chloride and well-tolerate a broad range of substituents on both aza-aurones and tosylhydrazones to afford a series of C2-spirocyclopropanated derivatives in high yields. In addition, selected functional group transformations of the final products were explored demonstrating the synthetic potential of these indole-based derivatives.
本文描述了一种简单高效的合成 2-螺环丙基-3-吲哚啉酮的方法。该方法涉及氮杂薁酮与对甲苯磺酰腙的非对映选择性环丙烷化反应，对甲苯磺酰腙作为多功能卡宾源，是获得此类 C2-螺环伪吲哚骨架的一种显著的替代合成方法。反应在碱和催化量的苄基三乙基氯化铵存在下进行，对氮杂薁酮和对甲苯磺酰腙上的各种取代基具有良好的耐受性，以高产率得到一系列 C2-螺环丙基化衍生物。此外，还探索了最终产物的一些功能团转化，展示了这些基于吲哚的衍生物的合成潜力。
