Chiral diphosphine/1,2-diamine-Ru(II) complexes catalyse the rapid, productive and enantioselective hydrogenation of simple ketones. The carbonyl-selective hydrogenation takes place via a non-classical metal-ligand bifunctional mechanism. The reduction of the C=O function occurs in the outer coordination sphere of an 18e trans-RuH2(diphosphine)(diamine) complex without interaction between the unsaturated moiety and the metallic centre. The Ru atom donates a hydride and the NH2 ligand delivers a proton through a pericyclic six-membered transition state, directly giving an alcoholic product without metal alkoxide formation. The enantiofaces of prochiral ketones are differentiated on the chiral molecular surface of the saturated RuH2 species. This asymmetric catalysis manifests the significance of 'kinetic' supramolecular chemistry.
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http://dx.doi.org/10.1098/rsta.2004.1536 | DOI Listing |
Chem Sci
December 2024
School of Materials Science and Engineering, PCFM Lab, the Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University Guangzhou 510006 P. R. China
Metal-ligand cooperation (MLC) is an essential strategy in transition metal catalysis. Traditional NH-based and OH-based MLC catalysts, as well as the later developed (de)aromatization strategy, have been widely applied in atom-economic borrowing hydrogen/hydrogen auto-transfer (BH/HA) reactions. However, these conventional MLC approaches are challenging for low-coordination and low-activity coinage metal complexes, arising from the instability during (de)protonation on the coordination atom, the constraint in linear coordination, and possible poisoning due to extra functional sites.
View Article and Find Full Text PDFJ Org Chem
September 2024
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
The development of efficient methods for the direct introduction of a methyl group into molecules is becoming increasingly important. Herein, the β-methylation of primary alcohols with methanol has been accomplished under environmentally benign conditions using [Cp*Ir(2,2'-bpyO)(HO)] as a catalyst. It was found that functional groups in the ligand are crucially important for the activity of the iridium complex.
View Article and Find Full Text PDFInorg Chem
July 2024
School of Chemistry and Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, P. R. China.
An efficient method for the selective conversion of glycerol, the major byproduct of the biodiesel manufacturing process, to lactic acid in water via acceptorless dehydrogenation has been developed. In the presence of a water-soluble [Cp*Ir(6,6'-(OH)-2,2'-bpy)(HO)][OTf] (0.1 mol %) and KOH (1.
View Article and Find Full Text PDFJ Am Chem Soc
June 2024
Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Complex interactions between noncoordinating residues are significant yet commonly overlooked components of macromolecular catalyst function. While these interactions have been demonstrated to impact binding affinities and catalytic rates in metalloenzymes, the roles of similar structural elements in synthetic polymeric catalysts remain underexplored. Using a model Suzuki-Miyuara cross-coupling reaction, we performed a series of systematic studies to probe the interconnected effects of metal-ligand cross-links, electrostatic interactions, and local rigidity in polymer catalysts.
View Article and Find Full Text PDFJ Org Chem
June 2024
School of Chemical Engineering, Nanjing University of Science & Technology, Nanjing 210094, P. R. China.
[(-Cymene)Ru(2,2'-bpyO)(HO)] was proven to be an efficient catalyst for the synthesis of amino-(-alkyl)benzenesulfonamides via selective N-alkylation of aminobenzenesulfonamides with alcohols. It was confirmed that functional groups in the bpy ligand are crucial for the activity of catalysts. Furthermore, the utilization of this catalytic system for the preparation of a biologically active compound was presented.
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