Electronically Mediated Selectivity in Ring Opening of 1-Azirines. The 3-Z Mode: Convenient Route to 2-Aza-1,3-dienes.
Reaction of 1-azirine-3-methylacrylates 1a,b with imidazoles and pyrazoles under mild conditions results in the formation of 2-aza-1,3-dienes 2a-g containing a potential leaving group at the 1-position. Simple alcohols (methanol and ethanol) react similarly with 1a,b in the presence of sodium carbonate to afford 2h-j. Utilization of 2 in the hetero Diels-Alder reaction with electron-deficient dienophiles is described.
Barroso
Marcia T.
MT
Instituto de Química, Universidade Estadual de Campinas, C.P. 6154, Campinas, São Paulo 13.083-970, Brazil.
Kascheres
Albert
A