Diastereoselective Reduction of Alkenylboronic Esters as a New Method for Controlling the Stereochemistry of up to Three Adjacent Centers in Cyclic and Acyclic Molecules

cis-Boronates are readily available via a diastereoselective Pd-catalyzed reduction of tetrasubstituted alkenylboronic esters using H2. Applying the reaction conditions presented to unsaturated open-chain boronic esters allows the stereochemistry of up to three adjacent centers to be controlled.