Facile Synthesis of Spirooxindole-Cyclohexenes via Phosphine-Catalyzed [4 + 2] Annulation of <i>α</i>
-Substituted Allenoates
作者:Rongshun Chen、Xia Fan、Zhaozhong Xu、Zhengjie He
DOI:10.1002/cjoc.201700112
日期:2017.9
phosphine‐catalyzed [4 + 2] annulation of α‐substituted allenoate with exocyclic alkene moiety of oxindoles or indan‐1,3‐diones has been developed. Thus, under the catalysis of PPh3 (20 mol%), a series of spirooxindole‐ or spiroindan‐1,3‐dione‐cyclohexenes have been obtained in moderate to excellent yields and regioselectivity from the annulations of α‐methyl allenoates with 3‐methyleneoxindoles or 2‐methyleneindan‐1
已经开发出了膦催化的[4 + 2] α-取代的烯酸酯与羟吲哚或茚满-1,3-二酮的环外烯烃部分的环化反应。因此,在PPh 3(20 mol%)的催化下,从α-甲基烯丙基酸酯与3-甲基环戊酸酯的环化反应中获得了中等至极好的产率和区域选择性的一系列螺环吲哚或spiroindan-1,3-二酮-环己烯。亚甲基吲哚或2-亚甲基茚满-1,3-二酮。这种方法提供了结构上新颖的螺环己烯的简便途径。