Substrate Controlled [3+3] Relay Catalytic Cyclization of α‐(3‐Isoindolinonyl) Propargylic Alcohols with 5‐Aminoisoxazoles

Two different skeletons have been constructed by cyclization of α‐(3‐isoindolinonyl) propargylic alcohols with 5‐aminoisoxazoles bearing different N ‐substituents under the relay catalysis of Brønsted acid and Lewis acid. This method provided spiro‐isoindolinone‐dihydropyridines with moderate to high yields (up to 99 %) as well as isoxazolo[4,5‐b]pyridines in moderate to good yields (up to 86 %). The structures of two products were determined by X‐ray crystal structural analyses. Moreover, fluorescence testing proved that one of the isoxazolo[4,5‐b]pyridines exhibited aggregation induced emission (AIE) effect. Finally, the control experiments revealed the possible reaction mechanism.