A Catalytic Asymmetric Electrocyclization‐Protonation Reaction

Abstract The first enantioselective Brønsted acid‐catalyzed electrocyclization‐protonation reaction has been developed which provides a number of different cyclopentenones in good yields and with high enantioselectivities. The stereodetermining step of this asymmetric Nazarov cyclization reaction is an asymmetric Brønsted acid‐catalyzed kinetic protonation.