Exploitation of the New Reactivity of Vinylcyclopropanes for Palladium‐Catalyzed, Asymmetric [5+2] Dipolar Cycloadditions

Vinylcyclopropanes (VCPs) are commonly used in transition metal-catalyzed cycloadditions, and the exploitation of their recently realized reactivities to construct new cyclic architectures is of great significance in modern synthetic chemistry. Herein, a palladium-catalyzed, visible light-driven, asymmetric [5+2] cycloaddition of VCPs with α-diazoketones was first accomplished by switching the reactivity of the Pd-containing dipolar intermediates from all-carbon 1,3-dipoles to oxo-1,5-dipoles. Enantioenriched 7-membered lactones were produced with good reaction efficiency and selectivity (23 examples, 52-92% yields with up to 99:1 er and 12.5:1 dr). In addition, computational investigations were performed to rationalize the observed high chemo- and periselectivities.