Enantioselective Gold(I)-Catalyzed Heterocyclization-Intermolecular Exo [4+3]-Cycloaddition Reactions for the Synthesis of Chiral Oxa-Bridged Benzocycloheptanes

The highly exo- and enantioselective gold-catalyzed tandem heterocyclization/[4 + 3] cycloaddition of 2-(1-alkynyl)-2-alken-1-ones and 1,3-diphenylisobenzofuran was implemented by utilizing Ming-Phos, which provides a facile access to chiral seven-membered oxa-bridged rings in 80-98% yield with high exo selectivity (exo/endo up to 50:1) and up to 97% ee.