Efficient synthesis of chiral β-hydroxy sulfones via iridium-catalyzed hydrogenation

A highly efficient Ir/f-Amphol-catalyzed asymmetric hydrogenation of prochiral β-keto sulfones was successfully developed to prepare a series of chiral β-hydroxy sulfones with good to excellent results (62%->99% conversions, 35%-99% yields and 86%->99% ee). Our Ir/f-Amphol L4 catalytic system exhibited very high activity; the gram-scale asymmetric hydrogenation was performed well with just 0.005 mol% catalyst loading (S/C = 20 000) to afford the desired product 2a with >99% conversion, 99% yield and 93% ee.