Catalyzed Addition of Phenylisocyanate to β-Dicarbonyls: Steric and Electronic Effects of the β-Dicarbonyl

摘要

β-dicarbonyls bearing electron donating substituents react at the active methylene carbon with phenylisocyanate in the presence of catalytic amounts of bis-(2,4-pentanedionato)nickel(II) to produce amidodicarbonylmethanes in high yield. These amidodiketones undergo solvolyses with proton donors to produce acetoacetanilides in high yield. The rates of both reactions are a function of the nucleophilicity of the β-dicarbonyl and are relatively insensitive to steric effects. These reactions represent excellent syntheses for β-ketoamides.