Uniform Organolanthanide Sites Catalyze C–O Bond Cleavage in Epoxides

Scientific Achievement:

Combination of ligand design and solid-state (SS) NMR establishes highly reactive, uniform surface dialkyl lanthanide species. Reactions with pinacolborane give catalytically active species for C–O bond cleavage organolanthanide by hydroboration, identified by 11B, 13C and 29Si SS NMR.

Significance and Impact:

A new class of highly active and recyclable catalysts leverage lanthanide oxophilicity and robust silica-lanthanide bonding to enable facile C–O bond cleavage reactions in transformations of oxygenated organic species for applications in hydroboration of epoxides.

Research Details:

–NMR spectroscopic properties of bridging Ln↼H-Si moieties reveal surface conformations of organolanthanide sites, used to establish uniform molecular lanthanide sites on the silica surface.

–Equivalent or improved catalytic rates and improved selectivities are obtained with surface-supported sites, compared to homogeneous precursors.

–1D and 2D 11B SSNMR spectroscopy have identified seven boron-containing species present during catalysis, and we have distinguished catalytically relevant, deactived species, and side products.

Wang, Z.; Patnaik, S.; Eedugurala, N.; Manzano, J. S.; Slowing, I. I.; Kobayashi, T.; Sadow, A. D.; Pruski, M., Silica-Supported Organolanthanum Catalysts for C–O Bond Cleavage in Epoxides. J. Am. Chem. Soc. 2020, 142, 2935-2947. doi:10.1021/jacs.9b11606