A Flexible Synthetic Approach to Fluorescent Chromeno[4,3‐
<i>b</i>
]pyridines and Pyrano[3,2‐
<i>c</i>
]chromenes from Electron‐Deficient 3‐Vinylchromones
作者:Nikita M. Chernov、Roman V. Shutov、Nadezhda Yu. Sipkina、Maxim N. Krivchun、Igor P. Yakovlev
DOI:10.1002/cplu.202100296
日期:2021.9
We report a flexible approach to the synthesis of phenanthrene-like heterocycles through organocatalytic ANRORC (Addition of the Nucleophile, Ring Opening, and Ring Closure) reaction of electron-deficient 3-vinylchromones with cyanoacetamide. Addition of highly basic DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or tetramethylguanidine (TMG) at 80 °C leads to chromeno[4,3-b]pyridines in good yields, whereas
我们报告了一种通过缺电子 3-乙烯基色酮与氰基乙酰胺的有机催化 ANRORC(亲核试剂加成、开环和闭环)反应合成菲类杂环的灵活方法。在 80 °C 下添加高碱性 DBU(1,8-二氮杂双环[5.4.0]十一碳-7-烯)或四甲基胍 (TMG) 会以良好的产率生成色并[4,3- b ]吡啶,而 Et 3 N在 20 °C 下,可以获得不易获得的吡喃并[3,2- c ]色烯及其 2-亚胺。该合成在温和条件(EtOH,20–80 °C)下进行,用途广泛,适用于多种反应物。所得化合物在各种溶剂(MeCN、DMSO、EtOH、H 2 O)中显示出460-595 nm范围内的明亮荧光,并具有高量子产率(高达0.84)。