Kinetic Resolution of Acyclic 1,3-Diols by Copper-Catalyzed Regioselective Dehydrogenative Si–O-Coupling

A nonenzymatic kinetic resolution of acyclic 1,3-diols by regioselective Si–O coupling with a hydrosilane is reported. The in situ-formed Cu–H catalyst with (R,R)-Ph-BPE as the chiral ligand facilitates the enantioselective silylation of one of the two hydroxy groups. The differentiation between both the enantiomers and the regioisomers strongly depends on the choice of the hydrosilane with a bis(4-anisyl)-substituted tertiary hydrosilane giving the best results. A broad range of anti-1,3-diols is resolved with good to high selectivity factors, especially derivatives bearing a cycloprop-1,1-diyl group at the methylene moiety.