Phosphine-Catalyzed β,γ-Umpolung Domino Reaction of Allenic Esters: Facile Synthesis of Tetrahydrobenzofuranones Bearing a Chiral Tetrasubstituted Stereogenic Carbon Center

An enantio‐, diastereo‐, regio‐, and chemoselective phosphine‐catalyzed β,γ‐umpolung domino reaction of allenic esters with dienones has been developed for the first time. The designed sequence, involving oxy‐Michael and Rauhut–Currier reactions, produced highly functionalized tetrahydrobenzofuranones, bearing a chiral tetrasubstituted stereogenic center, in up to 96 % ee. Domino effect: An enantio‐, diastereo‐, regio‐, and chemoselective phosphine‐catalyzed β,γ‐umpolung domino reaction of allenic esters with dienones has been developed for the first time. The designed sequence involving oxy‐Michael and Rauhut–Currier reactions produced highly functionalized tetrahydrobenzofuranones bearing a chiral tetrasubstituted stereogenic center in up to 96 % ee.