ETD

• Rh-catalizzata, addizione coniugata
• Rh-catalyzed, conjugated addition

Conjugated addition of organometallic reagents to electron-poor alkenes is one of the most reliable carbon-carbon bond formation processes to afford beta-substituted carbonyl compounds. Although monodentate biaryl phosphites derived from deoxycolic acid have already been used extensively as chiral ligands in the Rh-catalyzed enantioselective conjugate addition of arylboronic acids to different substrates, no example concerning unsaturated lactones has been reported. In this work, we screened deoxycholic acid derived atropos and tropos ligands and a variety of arylboronic acids in the addition to 5,6-dihydro-2H-pyran-2-one, obtaining good conversions and high enantioselectivities. The promising results prompted us to apply these reaction conditions to the kinetic resolution of a racemic mixture of a 6-phenyl substituted lactone. Herein, we also reported unsatisfying results of the conjugated addition to prochiral dienones.