Regioselective and Diastereodivergent Gold-Catalyzed Propargylation of Synergistically Activated Chromones

In this work, we report the use of propargylsilanes in a gold-catalyzed regio and distereoselective propargylation of chromones synergistically activated by in situ generated TMS+, using a picolinate gold complex as catalyst. A diastereodivergence is observed compared with the analogous reaction using a phosphite ligand for the gold catalyst. Formation of the major diastereoisomer is supported by a density functional theory (DFT) computational analysis of the mechanistic pathway, indicating kinetic control of the reaction selectivity.