Rhodium(I)/Chiral Diene Complexes Catalyzed Asymmetric Desymmetrization of Alkynyl-Tethered 2,5-Cyclohexadienones Through an Arylative Cyclization Cascade.

Cis -hydrobenzofurans, cis -hydroindoles, and cis -hydrindanes, privileged structural motifs found in numerous biologically active natural and synthetic compounds, are efficiently prepared by a Rh(I)-catalyzed cascade syn -arylation/1,4-addition protocol. This approach starts with the regioselective syn -arylation of the alkyne tethered to 2,5-hexadienone moieties, using a chiral Rh(I) catalyst generated in situ from a chiral bicyclo[2.2.1]hepatadiene ligand L4f . By forging two new carbon-carbon bonds and introducing two chiral centers, the resulting alkenylrhodium species undergoes desymmetrization via an intramolecular 1,4-addition reaction, delivering annulated products with high yields and enantioselectivities.