Divergent Coupling of β,γ-Unsaturated α-Ketoesters with Simple Olefins: Vinylation and [2 + 2] Cycloaddition.

Catalytic direct conjugate addition and [2 + 2] cycloaddition reactions of β,γ-unsaturated α-ketoesters with simple olefins have been developed, affording vinylation products and functionalized cyclobutanes, respectively, in good yields with high regioselectivity.