A Chiral Ruthenium-Monophosphine Catalyst for Asymmetric Addition of Arylboronic Acids to Aryl Aldehydes

A novel ruthenium catalyst on the basis of a chiral monophosphorus ligand is efficient for the asymmetric addition of arylboronic acids to aryl aldehydes, providing a series of chiral diarylmethanols in excellent yields and enantioselectivities (up to 92% ee). Preliminary study has shown that this process is catalyzed by a Ru complex with a single monophosphorus ligand.