title: Novel alternative for the N-N bond formation through a PIFA-mediated oxidative cyclization and its application to the synthesis of indazol-3-ones.
abstract: The synthesis of a series of N,N'-disubstituted indazolone derivatives starting from methyl anthranilates is presented. This general approach features a novel and easy way for access to the target N-heterocycles by formation of a new N-N single bond. The key cyclization step embraces the formation of an N-acylnitrenium intermediate, mediated by the hypervalent iodine reagent PIFA, and its succeeding intramolecular trapping by the amine moiety under rather mild experimental conditions.
authors.affiliation: Departamento de Química Organica II, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Euskal Herriko Unibertsitatea, P.O. Box 644, 48080 Bilbao, Spain.
authors.forename: Arkaitz
authors.initials: A
authors.lastname: Correa
authors.forename: Imanol
authors.initials: I
authors.lastname: Tellitu
authors.forename: Esther
authors.initials: E
authors.lastname: Domínguez
authors.forename: Raul
authors.initials: R
authors.lastname: Sanmartin