DABCO-catalyzed mono- and bisallylation of β,γ-unsaturated ketones with Morita–Baylis–Hillman carbonates

Abstract

Allylation of β,γ-unsaturated ketones with Morita–Baylis–Hillman carbonates in the presence of 5 mol% DABCO in dioxane at room temperature gave 2-alkoxycarbonylallyl β,γ-unsaturated ketones in moderate to high yields (44–96%) with excellent diastereoselectivities (>20 : 1 dr) in 5 min to 24 h. Meanwhile, bisallylation of β,γ-unsaturated ketones with Morita–Baylis–Hillman carbonates in the presence of 20 mol% DABCO in DCM at room temperature, offered α,α- and α,γ-di(2-alkoxycarbonyl)allyl ones in similar yields (33–91%) in 2–24 h. The reaction features mild reaction conditions (no strict water-free or oxygen-free conditions), easy practical operation and short reaction times in most cases.