Ugi Four-Component Reaction Based on thein situCapture of Amines and Subsequent Modification Tandem Cyclization Reaction: "One-Pot" Synthesis of Six- and Seven-Membered Heterocycles

The tandem reaction strategy of Ugi four-component reaction and its subsequent modification reaction based on in situ capture of amines to prepare three types of six-and seven-membered nitrogen-heterocycles are reported.According to this strategy, amines were synthesized in situ and immediately worked as the substrate for the Ugi four-component reaction reaction and subsequent modification tandem reaction.Starting from cheap and easily available nitro compounds, the application scope of substrates has been expanded and the problems of amines of easy oxidation, poor stability and versatility have been solved.Furthermore, due to the atom economy and versatility, the tandem reaction strategy has become a new approach for the synthesis of nitrogen-hete-rocycles.In addition, based on a series of conditional control experiments, a plausible mechanism for the reaction is proposed.Keywords in situ capture of amines; Ugi four-component reaction /Wittig reaction; Ugi four-component reaction/Staudinger/aza-Wittig reaction; tandem reaction; one-pot synthesis; heterocycles 多组分反应(MCR)因其具有较高的原子经济性、较 广泛的底物普适性、较高的产物选择性和一锅法所具备 的操作简便性等优点, 在新药研发以及新荧光材料的设 计 等 方 面 都 有 广 泛 的 应 用 [1] .近 年 来 , 发 展 较 快 的 Mannich 反应、Passerini 反应、Petasis 反应和 Ugi 反应 等多组分反应被用于构建天然产物和各种杂环化合