A Convenient Modification of the Fischer Indole Synthesis with a Solid Acid
作者:Sosale Chandrasekhar、Somnath Mukherjee
DOI:10.1080/00397911.2014.984854
日期:2015.4.18
the cation exchange resin Amberlite IR 120 in refluxing ethanol. A variety of enolizable aldehydes, and ketones and several substituted phenylhydrazines could thus be converted to the corresponding indoles in excellent yields (70–88%). Reaction times were typically 6–10 h, with the resin being then filtered off and the product isolated after minimal workup. GRAPHICAL ABSTRACT
摘要 标题反应的新一锅版本包括在回流乙醇中加热羰基化合物、苯肼和阳离子交换树脂 Amberlite IR 120 的混合物。因此,各种可烯醇化的醛、酮和几种取代的苯肼可以以极好的收率(70-88%)转化为相应的吲哚。反应时间通常为 6-10 小时,然后将树脂过滤掉,并在最少的后处理后分离产物。图形概要
Carbon Atom Insertion into Pyrroles and Indoles Promoted by Chlorodiazirines
作者:Balu D. Dherange、Patrick Q. Kelly、Jordan P. Liles、Matthew S. Sigman、Mark D. Levin
DOI:10.1021/jacs.1c06287
日期:2021.8.4
calculations supporting a selectivity-determining cyclopropanation step. Computations surprisingly indicate that the stereochemistry of cyclopropanation is of little consequence to the subsequent electrocyclicringopening that forges the pyridine core, due to a compensatory homoaromatic stabilization that counterbalances orbital-controlled torquoselectivity effects. The utility of this skeletal transform is
One‐Carbon Ring Expansion of Indoles and Pyrroles: A Straightforward Access to 3‐Fluorinated Quinolines and Pyridines
作者:Huaixuan Guo、Shiqin Qiu、Peng Xu
DOI:10.1002/anie.202317104
日期:2024.1.25
1,1-Dibromoalkanes as bromocarbene sources make one-carbonringexpansion of indoles and pyrroles facile, allowing for direct access to structurally diverse azines, especially the pharmaceutically important 3-fluorinated quinolines and pyridines. This straightforward protocol features bench-stable reagents, a broad range of substrates, and good compatibility with various functional groups.