Gold/HNTf<sub>2</sub>‑Cocatalyzed Asymmetric\nAnnulation of Diazo-Alkynes: Divergent Construction of Atropisomeric\nBiaryls and Arylquinones

Due to the inherent challenges posed by the linear coordination\nof gold(I) complexes, asymmetric gold-catalyzed processes remain challenging,\nparticularly in the atroposelective synthesis of axially chiral skeletons.\nExcept for extremely few examples of intramolecular annulations, the\nconstruction of axial chirality via asymmetric gold-catalyzed intermolecular\nalkyne transformation is still undeveloped. Herein, a gold/HNTf<sub>2</sub>-cocatalyzed asymmetric diazo-alkyne annulation is developed,\nallowing the atroposelective and divergent synthesis of chiral non-<i>C</i><sub>2</sub>-symmetric biaryls and arylquinones in generally\ngood to excellent yield (up to 93% yield) and enantioselectivity (up\nto 99% ee), with broad substrate scope. Notably, this work represents\nthe first gold-catalyzed atroposelective construction in an intermolecular\nmanner. More interestingly, this strategy is successfully extended\nto the first asymmetric construction of seven-membered-ring atropisomers\nbearing one carbon-centered chirality in excellent diastereoselectivity\nand high enantioselectivity (up to 93% ee and 50:1 dr). Remarkably,\nthe utility of this methodology is further illustrated by the successful\napplication of a representative axially chiral ligand in a series\nof enantioselective reactions. Importantly, the Brønsted acid\nas a proton-shuttle cocatalyst significantly promotes this asymmetric\nannulation. Additionally, the origin of enantioselectivity of this\nannulation and the role of HNTf<sub>2</sub> are disclosed by density\nfunctional calculations and control experiments.