Cu-Catalyzed carbamoylation<i>versus</i>amination of quinoline<i>N</i>-oxide with formamides
作者:Yan Zhang、Shiwei Zhang、Guangxing Xu、Min Li、Chunlei Tang、Weizheng Fan
DOI:10.1039/c8ob02844c
日期:——
An efficient, direct carbamoylation and amination of quinoline N-oxides with formamides to access 2-carbamoyl and 2-amino quinolines has been developed throughcopper-catalyzed C–C and C–N bond formations via cross-dehydrogenative coupling reactions. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. Mechanistic studies suggest
Visible-Light Photocatalyzed Deoxygenation of N-Heterocyclic <i>N</i>-Oxides
作者:Kyu Dong Kim、Jun Hee Lee
DOI:10.1021/acs.orglett.8b03446
日期:2018.12.7
operationally simple method is described that allows for the chemoselective deoxygenation of a wide range of N-heterocyclic N-oxides (a total of 36 examples). This visible-light-induced protocol features the use of only commercially available reagents, room-temperature conditions, and unprecedented chemoselective removal of the oxygen atom in a quinoline N-oxide in the presence of a pyridine N-oxide in the
Fast sulfonylation of pyridine/quinoline N-oxides induced by iodine is demonstrated herein. The regioselective protocol occurs under metal-free conditions in a short reaction time (10 min), exhibiting high efficiency (up to 92% yield) and good compatibility (up to 33 examples). A gram-scale reaction was conducted with only a slight loss of production.
Regioselective Metal-Free Cross-Coupling of Quinoline <i>N</i>-Oxides with Boronic Acids
作者:Luis Bering、Andrey P. Antonchick
DOI:10.1021/acs.orglett.5b01456
日期:2015.6.19
A novel and operationally simple one-step C-H bond functionalization of quinoline N-oxides to 2-substituted quinolines was developed. This approach enables the regioselective functionalization under external oxidant- and metal-free conditions. The developed transformation represents the first application of the Petasis reaction in functionalization of heterocycles.
Highly Chemoselective Deoxygenation of N-Heterocyclic <i>N</i>-Oxides Using Hantzsch Esters as Mild Reducing Agents
作者:Ju Hyeon An、Kyu Dong Kim、Jun Hee Lee
DOI:10.1021/acs.joc.0c02805
日期:2021.2.5
Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount