Chiral Tetrafluorobenzobarrelene Ligands for the Rhodium‐Catalyzed Asymmetric Cycloisomerization of Oxygen‐ and Nitrogen‐Bridged 1,6‐Enynes

Abstract

The long and winding Rhoad: The asymmetric cycloisomerization of nitrogen- and oxygen-bridged 1,6-enynes proceeded in the presence of a cationic rhodium complex that was coordinated by PPh3 and a chiral diene ligand to afford high yields of chiral 3-aza- and 3-oxabicyclo[4.1.0]heptenes and high enantioselectivities. TS=4-toluenesulfonyl, Tf=trifluoromethanesulfonyl.