Synthesis of Functionalized Quinolines from 4-(<i>o</i>
-Nitroaryl)-Substituted 3-Acyl-4,5-Dihydrofurans: Reductive Cyclization and C=C Bond Cleavage
作者:Sergey V. Zaytsev、Elena V. Villemson、Konstantin L. Ivanov、Ekaterina M. Budynina、Mikhail Ya. Melnikov
DOI:10.1002/ejoc.201700256
日期:2017.5.18
5-dihydrofurans. Reduction of 3-carbonyl-substituted dihydrofurans is accomplished by C=C double-bond cleavage in the dihydrofuran ring and 1,6-cyclization, which leads to 3,4-dihydroquinolines. The latter can be easily oxidized to quinolines or reduced to tetrahydroquinolines. For dihydrofuran-3-carboxylates, reduction proceeds with retention of the dihydrofuran ring and affords a tricyclic dihydrofuroquinoline
基于 Zn-AcOH 系统作为 4-(邻硝基芳基)-3-酰基取代的 4,5-二氢呋喃的简单有效还原剂的应用,开发了一种功能化喹啉的新合成方法。3-羰基取代的二氢呋喃的还原是通过二氢呋喃环中的 C=C 双键断裂和 1,6-环化来完成的,这导致 3,4-二氢喹啉。后者很容易被氧化成喹啉或还原成四氢喹啉。对于二氢呋喃-3-羧酸盐,还原过程会保留二氢呋喃环,并在更苛刻的条件下提供三环二氢呋喃喹啉核。所提出的一般反应模式得到了 DFT 计算结果的支持。此外,类似的还原系统可以成功应用于二氢呋喃无环前体的转化,