From Pyridine-<i>N</i>-oxides to 2-Functionalized Pyridines through Pyridyl Phosphonium Salts: An Umpolung Strategy
Dmitry I. Bugaenko, M. A. Yurovskaya, Alexander V. Karchava
Abstract
P 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 organometallic reagents. The protocol operates at ambient temperature and tolerates sensitive functional groups, enabling the synthesis of otherwise challenging compounds.
Topics & Concepts
UmpolungChemistryPhosphoniumPyridineElectrophileNucleophileReagentDABCOCombinatorial chemistryPhosphonium saltSurface modificationOrganic chemistrySalt (chemistry)CatalysisPhysical chemistryCatalytic C–H Functionalization MethodsSynthesis and Reactivity of HeterocyclesChemical Synthesis and Analysis