From Pyridine-<i>N</i>-oxides to 2-Functionalized Pyridines through Pyridyl Phosphonium Salts: An Umpolung Strategy
作者:Dmitry I. Bugaenko、Marina A. Yurovskaya、Alexander V. Karchava
DOI:10.1021/acs.orglett.1c02165
日期:2021.8.6
The reactions of pyridine-N-oxides with Ph3P under the developed conditions provide an unprecedented route to (pyridine-2-yl)phosphonium salts. Upon activation with DABCO, these salts readily serve as functionalized 2-pyridyl nucleophile equivalents. This umpolung strategy allows for the selective C2 functionalization of the pyridine ring with electrophiles, avoiding the generation and use of unstable
A novel ring transformation of mesoionic 1,3-oxazolium-5-olates into 5-trifluoroacetylated and 5-perfluoroacylated imidazoles by reaction with amidines
作者:Masami Kawase
DOI:10.1039/c39940002101
日期:——
Treatment of mesoionic 1,3-oxazolium-5-olates with amidines causes a novel ring transformation affording 5-trifluoroacetyl- and 5-perfluoroacyl-imidazoles in moderate yields.