59908-88-2Relevant academic research and scientific papers
Hydroformylation of Alkenes in a Planetary Ball Mill: From Additive-Controlled Reactivity to Supramolecular Control of Regioselectivity
Cousin, Kévin,Menuel, Stéphane,Monflier, Eric,Hapiot, Frédéric
, p. 10564 - 10568 (2017)
The Rh-catalyzed hydroformylation of aromatic-substituted alkenes is performed in a planetary ball mill under CO/H2 pressure. The dispersion of the substrate molecules and the Rh-catalyst into the grinding jar is ensured by saccharides: methyl-α-d-glucopyranoside, acyclic dextrins, or cyclodextrins (CDs, cyclic oligosaccharides). The reaction affords the exclusive formation of aldehydes whatever the saccharide. Acyclic saccharides disperse the components within the solid mixture leading to high conversions of alkenes. However, they showed typical selectivity for α-aldehyde products. If CDs are the dispersing additive, the steric hindrance exerted by the CDs on the primary coordination sphere of the metal modifies the selectivity so that the β-aldehydes were also formed in non-negligible proportions. Such through-space control via hydrophobic effects over reactivity and regioselectivity reveals the potential of such solventless process for catalysis in solid state.
Metal supported on dendronized magnetic nanoparticles: Highly selective hydroformylation catalysts
Abu-Reziq, Raed,Alper, Howard,Wang, Dashan,Post, Michael L.
, p. 5279 - 5282 (2007/10/03)
A method for homogenizing heterogeneous catalyst is described. The method is based on growing polyaminoamido (PAMAM) dendrons on silica-coated magnetic nanoparticles. After the dendronizing process, the silica-coated magnetic nanoparticles are more stable and more soluble in organic solvents. The dendronized particles are phosphonated, complexed with [Rh(COD)Cl]2, and applied in catalytic hydroformylation reactions. These new catalysts are proven to be highly selective and reactive.
