Catalytic [5 + 1]-Cycloadditions of Vinylcyclopropanes and Vinylidenes
Conner M. Farley, Kohei Sasakura, You‐Yun Zhou, Vibha V. Kanale, Christopher Uyeda
Abstract
Polysubstituted cyclohexenes bearing 1,3 (meta) substitution patterns are challenging to access using the Diels–Alder reaction (the ortho–para rule). Here, we report a cobalt-catalyzed reductive [5 + 1]-cycloaddition between a vinylcyclopropane and a vinylidene to provide methylenecyclohexenes bearing all-meta relationships. Vinylidene equivalents are generated from 1,1-dichloroalkenes using Zn as a stoichiometric reductant. Experimental observations are consistent with a mechanism involving a cobaltacyclobutane formed from a [2 + 2]-cycloaddition between a cobalt vinylidene and a vinylcyclopropane.
Topics & Concepts
CycloadditionChemistryCobaltCatalysisStoichiometryMedicinal chemistryCombinatorial chemistryOrganic chemistryCyclopropane Reaction MechanismsCatalytic Alkyne ReactionsCatalytic C–H Functionalization Methods