Highly Efficient Synthesis of Quaternary α‐Hydroxy Phosphonates via Lewis Acid‐Catalyzed Hydrophosphonylation of Ketones

A Lewis acid catalyst has been first applied to the hydrophosphonylation of ketones, giving the corresponding quaternary α-hydroxy phosphonates in high yields (up to 98%). The present method was highly tolerable for functionalized ketones. Moreover, the first catalytic enantioselective hydrophosphonylation of an unactivated ketone was also realized by using a tridentate Schiff base-titanium complex.