Kinetic Resolution of BINOLs and Biphenols by Atroposelective, Cu–H-Catalyzed Si–O Coupling with Hydrosilanes

A nonenzymatic kinetic resolution of monoprotected BINOL and biphenol derivatives by atroposelective Si–O coupling with hydrosilanes is described. The reaction relies on a previously unprecedented Cu–H-catalyzed silylation of phenols. The catalyst system consisting of CuCl, ( R , R )-Ph-BPE, and NaO t Bu enables the enantioselective coupling of the phenolic hydroxy group with a hydrosilane with moderate to good selectivity factors.