Phenyl@Rh(I)-Bridged Periodic Mesoporous Organometalsilica with High Catalytic Efficiency in Water-Medium Organic Reactions

A facile approach to prepare phenyl and, Rh(I) organometal bridged periodic-mesoporous organometalsilica was developed based on surfactant-directed co-condensation of RhCl[PPh2-(CH2)(2)Si(OEt3)(3)](3) and (OEt)(3)SiPhSi(OEt)(3). The as-prepared Rh(I)-Pfh(2)-PMO(Ph) exhibited matchable catalytic efficiency with the corresponding Rh(PPh3)(3)Cl homogeneous catalyst in water-medium reaction between phenylboronic acid and butyl acrylate or the 1,4-conjugate addition reaction between phenylboronic acid and N,N-dimehytlacyrlmaide, which could be attributed to the high dispersion of Rh(I) active sites, the ordered mesoporous channels and the strong surface hydrophobicity resulting from phenyl fragments embedded in silica walls, leading to the facilitated the diffusion and the adsorption of organic molecules onto the catalyst in aqueous solution. The Rh(I)-PPh2-PMO(Ph) could be used repetitively, showing the excellent durability that could be attributed to the effective inhibition of Rh(I) leaching and the high hydrothermal stability of the mesoporous structure.