Ruthenium catalysis sulfonation

Interesting chiral water-soluble aminosulfonamide ligands containing a phenyl-sulfonic acid substituent have been synthesized and engaged directly with a ruthenium precursor to reduce enantioselectively aromatic ketones to the corresponding alcohols [84]. As concluded by the authors, these ligands should be evaluated in bi-phasic catalysis. 

Ruthenium(II) complexes containing a phosphine-sulfonate chelate catalyse hydrogenation of aryl ketones in fair to good ee, with significant co-catalysis by tertiary amines. " Key species have been characterized by X-ray crystallography and H- and P-NMR, including a ruthenium-hydride resting state and a -dihydride intermediate. 

The catalytic properties of the sulfonated diphosphine-stabilized RuNPs and sulfonated diphosphine/cyclodextrin-stabilized RuNPs were compared in the hydrogenation of unsaturated model substrates (styrene, acetophenone, and w-methylanisole) in biphasic liquid-hquid conditions (i.e., ruthenium aqueous colloidal solution and organic substrate no added solvent). Whilst all of these RuNPs displayed suitable performances in catalysis, different activities and selec-tivities were observed. This highhghted that supramolecular interactions on the metallic surface in the presence of a cyclodextrin control the catalytic reactivity of the nanocatalysts. Interestingly the CD acts as a phase-transfer promotor, which... 

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