Pyridine Activation

Some articles on pyridine, pyridine activation:

Zincke Aldehyde
... reaction takes on a different shape forming Zincke aldehydes in which the pyridine ring is ring-opened with the terminal iminium group hydrolyzed to an aldehyde ... The use of the dinitrophenyl group for pyridine activation was first reported by Theodor Zincke ... The use of cyanogen bromide for pyridine activation was independently reported by W ...