Highly Diastereo- and Enantioselective Palladium-Catalyzed [3 + 2] Cycloaddition of Vinyl Epoxides and α,β-Unsaturated Ketones.

An asymmetric [3 + 2] cycloaddition reaction of vinyl epoxides with α,β-unsaturated ketones, the single activated electron-deficient alkenes, has been achieved under Pd-catalysis in excellent diastereo- and enantioselectivity. The utilities of the protocol are demonstrated by transformation of the products into other useful chiral molecules. Density functional theory calculations rationalize the stereocontrol of the reaction.