Cascade Annulation of <i>N</i> ‐Hydroxybenzamides with CF ₃ ‐Ynones Leading to CF ₃ ‐Isoxazolidine‐Fused Isoindolin‐1‐Ones

Both isoindolin‐1‐one and isoxazolidine are privileged scaffolds in developing new pharmaceuticals and functional materials. Presented herein is a novel synthesis of CF 3 ‐ isoxazolidine‐fused isoindolin‐1‐ones through the cascade reaction of N ‐hydroxybenzamides with CF 3 ‐ynones. The formation of product is initiated by aryl CH bond metalation and insertion of the triple bond, followed by protodemetalation, intramolecular aza ‐Michael addition, and oxo ‐nucleophilic addition. In this cascade process, the N ‐hydroxyamide group plays a triple role by acting as: 1) directing group for CH bond metalation; 2) N ‐nucleophilic site for isoindolin‐1‐one ring formation; and 3) O ‐nucleophilic site for isoxazolidine ring formation. To the authors' knowledge, this is the first report on the concurrent construction of these two privileged cyclic scaffolds in one pot. In addition, the products thus formed can be transformed into several valuable compounds through easy‐to‐run derivations by taking advantage of the rich chemistry of the functional groups embedded therein.