Atom-Economical Route to Substituted Pyridines via a Scandium Imide

Taking advantage of a tautomerization process between (PNP)ScN(DIPP)(NC5H5) (PNP = N[2-P(CHMe2)2-4-methylphenyl]2−, DIPP = 2,6-iPr2C6H3) and (PNP)Sc(NH(DIPP))(η2-NC5H4) (1), we demonstrate in this work that pyridine can be both activated and functionalized with isonitriles (in one case catalytically) to ultimately afford mono- and bis-imino-substituted pyridines. Several intermediates in the cycle have been isolated and characterized.