10.1021/jo060070+.s002 Arkaitz Correa Arkaitz Correa Imanol Tellitu Imanol Tellitu Esther Domínguez Esther Domínguez Raul SanMartin Raul SanMartin Novel Alternative for the N<i>−</i>N Bond Formation through a PIFA-Mediated Oxidative Cyclization and Its Application to the Synthesis of Indazol-3-ones<sup>†</sup> American Chemical Society 2006 approach features series Cyclization Application intramolecular cyclization step methyl anthranilates access Formation Oxidative synthesis amine moiety heterocycle hypervalent iodine reagent PIFA formation acylnitrenium target N Bond disubstituted indazolone derivatives Indazol Synthesi bond 2006-04-28 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Novel_Alternative_for_the_N_i_i_N_Bond_Formation_through_a_PIFA_Mediated_Oxidative_Cyclization_and_Its_Application_to_the_Synthesis_of_Indazol_3_ones_sup_sup_/3372289 The synthesis of a series of N,N<i>‘</i>-disubstituted indazolone derivatives starting from methyl anthranilates is presented. This general approach features a novel and easy way for access to the target <i>N</i>-heterocycles by formation of a new N<i>−</i>N single bond. The key cyclization step embraces the formation of an <i>N</i>-acylnitrenium intermediate, mediated by the hypervalent iodine reagent PIFA, and its succeeding intramolecular trapping by the amine moiety under rather mild experimental conditions.