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

Abstract

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.