“…Accordingly, at mercury in aqueous media, monohalogenated pyridines, in either their unprotonated or protonated forms, undergo a two-electron cleavage of the carbon-halogen bond, followed by protonation to yield pyridine [106]. Redox catalysis has been used to probe the reduction of 2-bromo-, 3-bromo-, 2-chloro-, and 3-chloropyridine at mercury [58].…”