“…Therefore, we speculated that conducting the dearomative (3 + 2) cycloaddition reaction between para-quinamines and 2-nitrobenzofurans would lead to the fusion of hydroindoline-5-one and 2,3-dihydrobenzofuran. As part of our ongoing research on the dearomatization of electron-deficient heteroarenes [54][55][56][57], herein, we will report the first nitrogen nucleophile-triggered dearomative (3 + 2) cycloaddition reaction of 2-nitrobenzofurans by using para-quinamines to construct benzofuro [3,2-b]indol-3-one skeletons (Scheme 1c). In recent years, extensive research on the dearomative cyclization reaction benzofuran has revealed the significant potential of this strategy in the con polycyclic compounds containing a 2,3-dihydrobenzofuran core (Scheme 1, t Among the numerous transformations with respect to the dearomative cycliz tion of 2-nitrobenzofurans, the carbon nucleophile-triggered dearomative (3 and (5 + 2) cyclization reactions have been extensively studied [29][30][31][32][33][34][35][36].…”