Functionalisation in position 3 of 3,5-dichloro-2H-1,4-oxazin-2-ones
摘要:
Electrophilic catalysis is shown to give selective substitution of the imidoyl chloride group in 3,5-dichloro-2H-1,4-oxazin-2-ones, avoiding competitive reactions of the nucleophile with the lactone function. With other nucleophiles (SCN-, CH2N2) cyclisations involving the azadiene- or the imine function take place. Cycloaddition of the obtained oxazinones to acetylenic compounds provides polyfunctionalized pyridines.