162191-95-9Relevant articles and documents
REACTIONS OF AZAPYRYLIUM IONS WITH NUCLEOPHILES: FROM CRAZY PRODUCTS TO A NOVEL PYRIDINE SYNTHESIS
Homann, Kai,Zimmer, Reinhold,Reissig, Hans-Ulrich
, p. 531 - 538 (2007/10/02)
Reaction of an azapyrylium ion as generated from a 6H-1,2-oxazine provided a β-azidoaldehyde by subsequent substitution, sigmatropic rearrangement, and retro-Diels-Alder reaction.With moderately electron-rich alkynes azapyrylium ions react in a Diels-Alder reaction with inverse electron demand, and after fragmentation of a formyl cation pyridine derivatives are formed.Mechanism, scope and limitations of this novel pyridine synthesis are discussed.