26257-21-6Relevant academic research and scientific papers
Rapid Protium-Deuterium Exchange of 4-Aminopyridines in Neutral D2O under Microwave Irradiation
Bagley, Mark C.,Alnomsy, Ayed,Sharhan, Hussein I.
, p. 2467 - 2472 (2016)
4-Aminopyridines undergo surprisingly rapid and highly selective H/D exchange at C-2 and C-6 in neutral D2O upon microwave irradiation at only 190 °C for two hours in a sealed vessel. This method contrasts and complements acid-mediated H/D exchange, requires no catalyst, and is appropriate for the synthesis of deuterium isotopologues of N- and C-substituted 4-aminopyridines and a benzofused (quinoline) analogue.
Mechanism of 2,6-dichloro-4,4'-bipyridine-catalyzed diboration of pyrazines involving a bipyridine-stabilized boryl radical
Ichino, Tomoya,Maeda, Satoshi,Miyake, Yusuke,Morimasa, Yohei,Murata, Yasujiro,Ohmura, Toshimichi,Suginome, Michinori,Tajima, Kunihiko,Taketsugu, Tetsuya
, p. 1894 - 1902 (2021/08/16)
The mechanism of 4,4'-bipyridine-catalyzed diboration of pyrazines was studied by experimental observation of the intermediates and by theoretical calculations. Intermediary radical species were detected by ESR measurement of the reactions of 2,6-dichloro-4,4'-bipyridines with bis(pinacolato)diboron and identified by simulation. Based on these observations, radical processes involving 4,4'-bipyridine-stabilized boryl radicals were evaluated by DFT calculations combined with singlecomponent artificial force induced reaction (SC-AFIR). The results of calculations indicate that a radical transfer process from 4,4'-bipyridine-stabilized boryl radical to pyrazine is a major pathway in the catalytic reaction. The origin of the high catalytic efficiency of 2,6-dichloro-4,4'-bipyridine is ascribed to the effect of the chlorine atom on the stability of the corresponding N,N'-diboryl-4,4'-bipyridinylidene.
