Regioselective Rhodium‐Catalyzed Addition of β‐Keto Esters, β‐Keto Amides, and 1,3‐Diketones to Internal Alkynes

Abstract

The first rhodium‐catalyzed regioselective addition of 1,3‐dicarbonyl compounds, including β‐keto esters, β‐keto amides, and 1,3‐diketones, to internal alkynes furnishes branched allylic compounds. By applying Rh I /DPEphos/TFA as the catalytic system, aliphatic as well as aromatic internal methyl‐substituted alkynes act as suitable substrates to yield valuable branched α‐allylated 1,3‐dicarbonyl compounds regioselectively in good to excellent yields. A simple basic saponification–decarboxylation procedure provides access to valuable γ,δ‐unsaturated ketones. The reaction shows a broad functional‐group tolerance, and numerous structural variations on both reaction partners highlight the synthetic potential and flexibility of this method.