Herein we report dearomatization of pyrrole ring followed by rearomatization of cyclohexyl ring to obtain isoindolinone scaffold by a Pd/Cu dual catalysis approach in an atom economic way with moderate to high yield. The expected Pd/Cu catalyzed dual C(sp2)‐H activation via normal catalytic cycle can be override by unusual oxidative dearomatization reaction which has been established by DFT calculation. The biological importance of isoindolinone scaffold insists us to successfully investigate in vitro antileishmanial activity of L.Donovani.