A condition-controlled regiodivergent 2π + 2σ cycloaddition/Alder-ene reaction of vinylbicyclo1.1.0butanes with cyclic N -sulfonylimines enabled by palladium catalysis is described. This protocol provides a wide range of azabicyclo2.1.1hexanes (aza-BCHs) in 30–71% yields with good to excellent selectivities. Additionally, cyclobutenes bearing two quaternary stereocenters are conveniently generated in good yields with excellent selectivities via a palladium-catalyzed Alder-ene reaction. This strategy features mild reaction conditions, a broad substrate scope, and excellent selectivities. Furthermore, scale-up reaction and derivatizations of the resulting aza-BCHs further demonstrate the practical utility of this protocol.
Zheng et al. (Wed,) studied this question.