- A study on the deoxygenation of trialkyl-, dialkyl-phenyl- and alkyl-diphenyl phosphine oxides by hydrosilanes
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The deoxygenation of 1-alkyl-3-methyl-3-phospholene 1-oxides, which may be regarded as trialkyl phosphine oxides (R3PO), and the reduction of dialkyl-phenylphosphine oxides (R2PhPO) and methyl-diphenylphosphine oxide (MePh2PO) have been elaborated by applying user-friendly silanes, such as tetramethyldisiloxane (>SiH–O–HSin) under solvent-free, catalyst-free, and microwave (MW)-assisted conditions. New silanes of type Ar2SiH2, alkyl2SiH2, and Ar3SiH were also applied in a few cases. The reactivity of the phosphine oxides and the silanes could be mapped on the basis of our experimental data.
- Kovács, Tamara,Urbanics, Anita,Csatlós, Flóra,Keglevich, Gy?rgy
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- Efficient catalytic hydrogenation of levulinic acid: A key step in biomass conversion
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γ-Valerolactone (GVL) has been proposed as a sustainable liquid, and could be used for the production of hydrocarbons by using both homogeneous and heterogeneous catalytic systems. The selective reduction of levulinic acid (LA) to GVL is a key transformation for biorefinery concepts based on platform molecules. We report a detailed investigation of the conversion of LA to GVL using molecular hydrogen in the presence of a catalyst in situ generated from Ru(acac)3, and electronically and sterically characterized alkyl-bis(m-sulfonated-phenyl)- and dialkyl-(m-sulfonated-phenyl)phosphine (RnP(C6H4-m-SO3Na)3-n (n = 1 or 2; R = Me, Pr, iPr, Bu, Cp) ligands. The hydrogenation experiments were performed in the range of 5-100 bar H2 at 140 °C using 0.016 mol% catalyst and 5-20 eqv. of ligand. The effects of hydrogen pressure and Ru/ligand ratio on the LA conversion were determined. The nBuP(C 6H4-m-SO3Na)2 (χ = 12.5, Tol = 153°) showed the highest activity achieving turnover numbers up to 6200 with a yield and selectivity higher than 99% in a solvent, chlorine and promoter free reaction mixture. The catalyst was successfully recycled for six consecutive runs without loss of activity. The characterization of sulfonated and non-sulfonated phosphines indicated that the sulfonation had no significant effect on the steric and electronic properties of the ligands. The Royal Society of Chemistry 2012.
- Tukacs, Jozsef M.,Kiraly, David,Stradi, Andrea,Novodarszki, Gyula,Eke, Zsuzsanna,Dibo, Gabor,Kegl, Tamas,Mika, Laszlo T.
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supporting information; experimental part
p. 2057 - 2065
(2012/08/14)
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- Phosphinegold (I) salts having antiarthritic activity
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The compounds are (pyridine) (trisubstituted phosphine) gold(I) salts which have antiarthritic activity.
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- Tri-substituted phosphinegold(I) 1-thio-β-D-glucopyranosides
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The compounds are tri-substituted phosphinegold(I) 1-thio-β-D-glucopyranosides which have antiarthritic activity and, in particular, are of use in the treatment of rheumatoid arthritis. Of the three substituents on the phosphine one is optionally substituted phenyl and the others are lower alkyl or lower alkoxy.
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