A spirosilane ligand induced highly enantioselective Rh-catalyzed cycloisomerization of 1,6-enynes

Transition metal-catalyzed cycloisomerization of 1,6-enynes is a highly effective approach to generating five-membered rings. Among the various catalytic systems developed, the use of chiral ligands in Rh-catalyzed cycloisomerization induced exceptional reactivity and enantioselectivity. In this study, we describe a novel approach to obtained kinds of five-membered rings via Rh-catalyzed cycloisomerization of N -aryl 1,6-enynes, employing a novel spirosilane diphosphine ligand with a significantly enhanced enantioselectivities. Mechanistic experiments and DFT calculations have provided insights into the reaction mechanism. We demonstrated a large-bite-angle spirosilane diphosphine ligand induced Rh-catalyzed cycloisomerization of 1,6-enynes with good reactivity and high level of enantioselectivities. A various of functionalized five-membered heterocycles compounds were prepared by this atom-economy process with high yields and excellent enantioselectivities.