l -Proline catalyzed condensation of salicylaldehydes with ethyl nitroacetate: an efficient access to 3-nitrocoumarins
摘要:
Abstractl-Proline catalyzed condensation of salicylaldehydes and ethyl nitroacetate afforded 3-nitrocoumarins in good to high yields under mild conditions. This organocatalyzed process offers a much improved yield of 3-nitrocoumarins and well tolerates both electron-donating and electron-withdrawing substituents on the phenyl ring. Graphical abstract
Intensified synthesis of [3,4-d]triazole-fused chromenes, coumarins, and quinolones
作者:Georg Schwendt、Toma Glasnov
DOI:10.1007/s00706-016-1885-5
日期:2017.1
AbstractEfficient and metal-free synthesis of [3,4-d]triazole-fused chromenes, coumarins, and quinolones has been achieved in an intensified regime using microwave heating. The smooth 1,3-dipolarcycloaddition reaction of heterocyclic nitroalkenes with sodium azide provides a rapid entry into valuable heterocyclic scaffolds with potential biological properties. Graphical abstract
摘要使用微波加热在强化过程中已经实现了[3,4- d ]三唑稠合的色烯,香豆素和喹诺酮的高效无金属合成。杂环硝基烯烃与叠氮化钠的平滑1,3-偶极环加成反应可快速进入有价值的具有潜在生物学特性的杂环支架。 图形概要
Lewis acid-controlled divergent condensation of 1,1-bis(methylthio)-2‑nitroethylene and salicylaldehydes for the synthesis of 3-nitrocoumarins and 4H-chromenes
作者:Li Han、Xiaocao Quan、Xusheng Shao、Xiaoyong Xu、Zhong Li
DOI:10.1016/j.tetlet.2022.154080
日期:2023.3
An efficient Lewis acid-controlled divergent synthesis of 3-nitrocoumarins and 4H-chromenes under mild conditions has been developed. The corresponding 3-nitrocoumarin products were obtained in moderate to excellent yields through FeCl3-catalyzed annulation of 1,1-bis (methylthio)-2‑nitroethylene with various salicylaldehydes, while 4H-chromene products were afforded by using BF3·OEt2 as catalyst with