Atroposelective Construction of Naphthylpyrazoles by Chiral Phosphoric Acid Catalyzed Enantioselective Cross‐Coupling of Pyrazoles with Naphthoquinone Esters

The catalytic asymmetric reaction of 5‐aminopyrazoles with naphthoquinone esters has been established. A wide range of unprecedented axially chiral naphthylpyrazole derivatives (29 examples) have been synthesized in moderate to excellent yields (up to 99 % yield) with excellent enantioselectivities (up to 99 % ee) by utilizing chiral phosphoric acid as a catalyst. This protocol features mild reaction conditions, a broad substrate scope, good scalability and facile derivatization. Moreover, preliminary mechanistic investigation was conducted to elucidate the mechanism.