Stereoselective Access to Conjugated and Cross-Conjugated Dienoates by Rh- and Ru-Catalyzed Isomerizations of Vinylcyclopropanes

Org Lett. 2022 Jan 21;24(2):752-756. doi: 10.1021/acs.orglett.1c04223. Epub 2022 Jan 3.

Abstract

Two complementary catalytic protocols for the isomerization of stereoisomeric mixtures of vinylcyclopropanes are described. A commercially available cationic rhodium complex provides access to conjugated dienoates in high yield with excellent stereocontrol. The combination of a bisphosphine ligand and a ruthenium precatalyst affords cross-conjugated dienoates via a formal 1,3-ring opening. The products are obtained with moderate to high stereoselectivity. The ability of each type of dienoate to engage in [4 + 2] cycloaddition reactions has been demonstrated.