Gold-catalyzed bicyclic annulations between 4-hydroxy-1,5-diynamides and nitrones for the synthesis of cyclopentene-fused isoxazole carboxamides

This work reports gold-catalyzed reactions between 4-hydroxy-1,5-diynamides and nitrones, demonstrating the success of using 1,<i>n</i>-diynes to achieve bicyclic annulations. Mechanistic studies show the importance of the hydroxyl group to form reactive intermediates, followed by a [3+2]-nitrone cycloaddition with alkenylgold intermediates. This mechanism is supported by DFT-calculations.