Diels-Alder Reaction of 2-Cyano-1-aza Dienes. The Effect of Nitrogen Substituents

Article abstract of DOI:10.1021/jo00060a023

The Diels-Alder reactions of 2-cyano-1-aza dienes with three nitrogen substituents possessing different electronic requirements (phenyl, CO2C2H5, and OCH3) were studied with three dienophiles with different electronic requirements (styrene, methyl acrylate, and ethyl vinyl ether).The N-phenyl substituent aza diene was equally reactive with all three dienophiles.The N-CO2C2H5-substituted aza diene behaved as an electrophilic diene being more reactive with the electron-rich ethyl vinyl ether than styrene or methyl acrylate.The N-CO2C2H5-substituted aza diene is more reactive with all three dienophiles, including methyl acrylate, than the N-phenyl substituent azadiene.The N-OCH3-substituent aza diene was unreactive with all three dienophiles under the conditions investigated.