Highly enantioselective synthesis of β-hydroxysulfonamides by asymmetric transfer hydrogenation

Asymmetric transfer hydrogenation of β-oxosulfonamides using the Ru–TsDPEN–HCOOH–Et 3N catalytic system gives the corresponding optically active β-hydroxysulfonamides in excellent yields (up to 95%) with excellent diastereoselectivity (up to >99:1 dr) and enantioselectivity (up to >99% ee). A series of optically active β-hydroxy sulfonamides were synthesized for the first time by asymmetric transfer hydrogenation of the corresponding β-ketosulfonamides using the Ru–TsDPEN–HCOOH–Et 3N catalytic system, in excellent yields (up to 95%) with excellent diastereo- (up to > 99:1 dr) and enantioselectivities (up to >99% ee).