890085-08-2Relevant academic research and scientific papers
Chemo- and Enantioselective Addition and β-Hydrogen Transfer Reduction of Carbonyl Compounds with Diethylzinc Reagent in One Pot Catalyzed by a Single Chiral Organometallic Catalyst
Huang, Huayin,Zong, Hua,Bian, Guangling,Song, Ling
, p. 12614 - 12619 (2016/01/09)
Using a single chiral phosphoramide-Zn(II) complex as the catalyst, the asymmetric β-H transfer reduction of aromatic α-trifluoromethyl ketones and enantioselective addition of aromatic aldehydes with Et2Zn in one pot were successfully realized, affording the corresponding additive products of secondary alcohols in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee) and the reduction products of α-trifluoromethyl alcohols in good to excellent yields with up to 77% ee.
Catalytic asymmetric β-hydrogen transfer reduction of α-trifluoromethyl aromatic ketones with diethylzinc
Huang, Huayin,Zong, Hua,Bian, Guangling,Song, Ling
, p. 835 - 839 (2015/08/18)
Abstract The catalytic asymmetric β-hydrogen transfer reduction of α-trifluoromethyl ketones using diethylzinc as the β-hydrogen donor was developed with the use of phosphinamide chiral ligand. The corresponding alcohol products were afforded in good yields with up to 73% ee. This method was successfully applied to the chemo- and enantioselective reduction of α-methyl/trifluoromethyl diketone, affording 88% yield and 70% ee of the fluorinated hydroxylketone product.
The enantioselective trifluoromethylation of aromatic aldehydes by quaternary ammonium bromide and (IPr)CuF at low catalyst loading
Wu, Shaoxiang,Guo, Jiyi,Sohail, Muhammad,Cao, Chengyao,Chen, Fu-Xue
, p. 19 - 29 (2013/04/23)
A general catalytic enantioselective trifluoromethylation of aromatic aldehydes using (IPr)CuF and quinidine-derived quaternary ammonium salt as catalysts has been developed. A wide range of aromatic aldehydes are converted to the corresponding products in up to 92% yield and 81% ee at 2 mol% of catalyst loading.
Asymmetric hydrosilylation of ketones catalyzed by complexes formed from trans-diaminocyclohexane-based diamines and diethylzinc
Gajewy, Jadwiga,Gawronski, Jacek,Kwit, Marcin
experimental part, p. 1045 - 1054 (2012/09/22)
Chiral acyclic and macrocyclic amines derived from trans-1,2- diaminocyclohexane in complexes with diethylzinc efficiently catalyze asymmetric hydrosilylation of aryl-alkyl and aryl-aryl ketones with enantiomeric excess of the product up to 86 %. A trianglamine ligand with a cyclic structure or the presence of an additional coordinating group increases the enantioselectivity of the reaction, in comparison with catalysis by a simple acyclic N,N′-dibenzyl-1,2-diaminocyclohexane ligand. In addition, the effect of the asymmetric activation of the catalyst by a variety of alcohols and diols is studied.
PYRROLO [3, 2 -E] [1,2,4] TRIAZOLO [1,5 -A] PYRIMIDINES DERIVATIVES AS INHIBITORS OF MICROGLIA ACTIVATION
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Page/Page column 11, (2011/04/26)
The invention relates to novel compounds useful in the treatment and prophylaxis of disease. Compounds of the formula (I) wherein X is halogen, independently selected form chlorine and fluorine and n is 0, 1 or 2. and their pharmaceutically acceptable salts are useful in the treatment and prophylaxis of diseases caused by activation of microglia, particularly Alzheimer's disease.
Investigation into the enantioselection mechanism of ruthenium-arene- diamine transfer hydrogenation catalysts using fluorinated substrates
Slungrd, Sigrid Volden,Krakeli, Tor-Arne,Thvedt, Thor Hkon Krane,Fuglseth, Erik,Sundby, Eirik,Hoff, Brd Helge
experimental part, p. 5642 - 5650 (2011/08/22)
The effects of both steric and electronic properties of ketones on the selectivity in asymmetric transfer hydrogenation have been studied with aryl alkyl/fluoroalkyl ketones using four ruthenium based catalysts and two different media. The 1-arylethanones, 1-aryl-2-fluoroethanones and 2,2- difluoroacetophenones could be reduced with medium to high ee (86-99%), while the 1-aryl-2,2,2-trifluoroethanones were reduced with low selectivity in most systems. The change in enantioselectivity upon structural variation has been rationalised aided by regression analysis with substituent constants and the partial charge of the carbonyl carbon as predictors. The steric bulk of the alkyl/fluoroalkyl chain was found to be the major factor in determining selectivity in formic acid/triethylamine, while for reduction of a series of substituted 1-arylethanones and 1-aryl-2-fluoroethanones, the selectivity was found to depend on the electronic properties of the aromatic ring, supporting previous evidence that π-π interaction between the substrate and catalyst is important in determining the selectivity. For reductions in water using sodium formate as the hydrogen donor, altered and more complex selectivity mechanisms were observed. Experiments and regression focused on the variation of the alkyl/fluoroalkyl group of phenyl and 1-naphthyl ketones, showed that the selectivity correlated with the size of the substituent, but also the partial charge of the carbonyl carbon.
Rational electronic tuning of CBS catalyst for highly enantioselective borane reduction of trifluoroacetophenone
Korenaga, Toshinobu,Nomura, Kenji,Onoue, Kazutaka,Sakai, Takashi
supporting information; experimental part, p. 8624 - 8626 (2011/01/03)
α,α,α-Trifluoroacetophenone (2), which is susceptible to noncatalytic reduction by BH3, could be reduced to chiral alcohol up to 90% ee by using electronically tuned-CBS catalyst (1) with BH3. The enantioselectivities highly correlated with the differential orbital energies between 1-BH3 adduct and 2, which were calculated by DFT method.
Nonenzymatic kinetic resolution of racemic 2,2,2-trifluoro-1-aryl ethanol via enantioselective acylation
Xu, Qing,Zhou, Hui,Geng, Xiaohong,Chen, Peiran
supporting information; experimental part, p. 2232 - 2238 (2009/07/11)
Kinetic resolution of a series of 2,2,2-trifluoro-1-aryl ethanol with (R)-benzotetramisole as the catalyst has been investigated. The result showed that when the aryl group in the substrate was a phenyl (or a phenyl substituted by an electron-donating group) or a naphthyl (an extended phenyl) group, the system could give an s value higher than 20. Preparative KR examples demonstrated the applicability of this method in the preparation of some of enantiomerically pure 2,2,2-trifluoro-1-aryl ethanol or 2,2,2-trifluoro-1-aryl-ethyl iso-butyrate.
SULFONAMIDE COMPOUNDS AS CYSTEINE PROTEASE INHIBITORS
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Page/Page column 72, (2008/06/13)
The present invention is directed to compounds of formula ( I ) that are inhibitors of cysteine proteases, in particular, cathepsins B, K, L, F, and S and are therefore useful in treating diseases mediated by these proteases. The present invention is directed to pharmaceutical compositions comprising these compounds and processes for preparing them. Wherein R3 is-alkylene-SO2NR5R6.
ALPHA KETOAMIDE COMPOUNDS AS CYSTEINE PROTEASE INHIBITORS
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Page/Page column 58, (2008/06/13)
The present invention is directed to compounds that are inhibitors of cysteine proteases, in particular, cathepsins B, K, L, F, and S and are therefore useful in treating diseases mediated by these proteases. The present invention is directed to pharmaceutical compositions comprising these compounds and processes for preparing them.
