Rh‐Catalyzed Asymmetric Hydrogenation of α,β‐ and β,β‐Disubstituted Unsaturated Boronate Esters

Abstract A highly enantioselective hydrogenation of α,β‐unsaturated boronate esters catalyzed by Rh‐( S )‐DTBM‐Segphos complex has been developed. Both ( Z )‐α,β‐ and β,β‐disubstituted substrates can be successfully hydrogenated to afford chiral boronates with excellent enantioselectivities, up to 98 % ee . Furthermore, the obtained chiral boronate esters, as important versatile synthetic intermediates are successfully transformed to the corresponding chiral alcohols, amines and other important derivatives with maintained enantioselectivities.