One-Pot Regio-\nand Diastereoselective Gold-Catalyzed\nPropargylation of in Situ Activated Chromones and Consecutive Cyclization

Herein, we report a gold-catalyzed propargylation of\nchromone derivatives\nby propargylsilanes. Chromones are synergistically activated by the\nsilylium cation resulting from the gold activation of the propargylsilane.\nThe reaction exclusively occurs at the C2-position of the chromone,\nand a single diastereoisomer is formed. Computational studies performed\non the reaction mechanism rationalize the formation of the preferred\ndiastereoisomer. Finally, a dual consecutive cascade reaction based\non different gold catalysts enables the formation of complex tricyclic\ncompounds.