jo060070+_si_001.pdf (1.96 MB)
Novel Alternative for the N−N Bond Formation through a PIFA-Mediated Oxidative Cyclization and Its Application to the Synthesis of Indazol-3-ones†
journal contribution
posted on 2006-04-28, 00:00 authored by Arkaitz Correa, Imanol Tellitu, Esther Domínguez, Raul SanMartinThe 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.