A practical, efficient, and rapid method for the oxidation of electron deficient pyridines using trifluoroacetic anhydride and hydrogen peroxide–urea complex
作者:Stéphane Caron、Nga M Do、Janice E Sieser
DOI:10.1016/s0040-4039(00)00165-9
日期:2000.4
A general method for the oxidation of electron-poor pyridines to their N-oxides using UHP and TFAA in either CH2Cl2 or CH3CN was developed. The methodology proved to tolerate a number of functional groups and substitution patterns and proceeded on notoriously difficult to oxidize substrates.
Factors Influencing the Course of the Macrocyclization ofα,ω-Diamines with Esters ofα,ω-Dicarboxylic Acids
作者:Dorota Gryko、Daniel T. Gryko、Hanna Sierzputowska-Gracz、Piotr Pi??tek、Janusz Jurczak
DOI:10.1002/hlca.200490004
日期:2004.1
The efficient synthesis of eight newmacrocyclicamides (lactams) via reaction of diesters with diamines under normal dilution conditions is described. The role of intermolecular H-bond formation and steric hindrance is discussed based on 1H- and 15N-NMR studies of appropriate model compounds. Principles for the optimal choice of esters that can be efficiently transformed into diamides have been developed
Photocatalyzed difluoroalkylation of pyridine <i>N</i>-oxides
作者:Haiying Gong、Juan Wang、Yi Peng、Hua Chen、Hongmei Deng、Jian Hao、Wen Wan
DOI:10.1080/00397911.2022.2112057
日期:2022.9.2
A photoredox catalytic strategy has been developed for the regioselective C2-, or C4-difluoroalkylation of pyridineN-oxides under mild conditions. This method provides an efficient protocol for th...