Catalytic Asymmetric Conjugate Addition and Allylic Substitution of Cyclobutenones with Arylzinc Halides

Conjugate addition and allylic substitution are two essential chemical transformations, and they could be competitive for substrates with multiple reactive sites. Herein, we report the diversified enantioselective synthesis of cyclobutenes via the functionalization of cyclobutenones. The conjugate addition of cyclobutenones with arylzinc halides provided enantioenriched cyclobutenes with all-carbon quaternary centers. On the other hand, when cyclobutenones with gem-dichloro groups were employed, a chemo- and enantioselective allylic substitution occurred. Further synthetic utility was demonstrated for synthesizing versatile cyclobutane derivatives, together with ring-opening and expansion products.