Silver-Catalyzed Nucleophilic Addition of β-Dicarbonyls to Isocyano Group: Facile Access to Indolin-3-ol Derivatives.

A domino silver-catalyzed intermolecularly nucleophilic addition of β-dicarbonyls to the isocyano group and cyclization of the imidoyl silver sequence was developed for the direct and efficient synthesis of indolin-3-ol derivatives. This domino transformation tolerates a range of readily available o-acyl arylisocyanides and 1,3-dicarbonyls under an operationally simple procedure. Triple roles of silver carbonate are demonstrated in this reaction: (1) activation of isocyano group, (2) formation of enolate, and (3) promotion the nucleophilic reactivity of imidoyl intermediate.