37617-33-7Relevant articles and documents
An OPAA enzyme mutant with increased catalytic efficiency on the nerve agents sarin, soman, and GP
Bae, Sue Y.,Myslinski, James M.,McMahon, Leslie R.,Height, Jude J.,Bigley, Andrew N.,Raushel, Frank M.,Harvey, Steven P.
, p. 65 - 71 (2018)
The wild-type OPAA enzyme has relatively high levels of catalytic activity against several organophosphate G-type nerve agents. A series of mutants containing replacement amino acids at the OPAA Y212, V342, and I215 sites showed several fold enhanced catalytic efficiency on sarin, soman, and GP. One mutant, Y212F/V342L, showed enhanced stereospecificity on sarin and that enzyme along with a phosphotriesterase mutant, GWT, which had the opposite stereospecificity, were used to generate enriched preparations of each sarin enantiomer. Inhibition of acetylcholinesterase by the respective enantioenriched sarin solutions subsequently provided identification of the sarin enantiomers as separated by normal phase enantioselective liquid chromatography coupled with atmospheric pressure chemical ionization–mass spectrometry.
GEMINALLY SUBSTITUTED CYANOETHYLPYRAZOLO PYRIDONES AS JANUS KINASE INHIBITORS
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Page/Page column 112, (2014/10/03)
The instant invention provides compounds of Formula (I) which are JAK inhibitors, and as such are useful for the treatment of JAK-mediated diseases such as rheumatoid arthritis, asthma, COPD and cancer.
Asymmetric hydrogenation of tert-alkyl ketones: DMSO effect in unification of stereoisomeric ruthenium complexes
Yamamura, Tomoya,Nakatsuka, Hiroshi,Tanaka, Shinji,Kitamura, Masato
supporting information, p. 9313 - 9315 (2013/09/12)
Face off: The ruthenium complexes of a new axially chiral PNNligand (L) are highly efficient in the presence of dimethylsulfoxide (DMSO) for hydrogenation of both functionalized and unfunctionalized tert-alkyl ketones. DMSO is thought to narrow down the many possible complex stereoisomers into a single facial L/Ru complex, thus enhancing the reactivity, selectivity, and productivity. Copyright
Screening method for the evaluation of asymmetric catalysts for the reduction of aliphatic ketones
Boukachabia, Mourad,Zeror, Saoussen,Collin, Jacqueline,Fiaud, Jean-Claude,Zouioueche, Louisa Aribi
supporting information; experimental part, p. 1485 - 1489 (2011/05/16)
ATH reductions of aliphatic ketones in water catalyzed by ruthenium coordinated by prolinamide ligands produce alcohols with moderate enantiomeric excesses in most cases. A set of seven aliphatic ketones is proposed for a rapid evaluation of the enantioselectivity of catalysts by one-pot multi-substrates reduction. The screening of a library of prolinamides shows that according to the structure of the ketones different ligands give the best asymmetric inductions.
The 3-(3-pyridine)propionyl anchor group for protease-catalyzed resolutions: p-toluenesulfinamide and sterically hindered secondary alcohols
Savile, Christopher K.,Kazlauskas, Romas J.
, p. 1183 - 1192 (2007/10/03)
Compared to an acetyl acyl group, the 3-(3-pyridine)propionyl group increases substrate binding to many proteases and substrate solubility in water, thereby increasing the rates of protease-catalyzed reactions. For example, proteases reacted up to six hundred-fold faster with the 3-(3-pyridine)propionyl ester of 1-phenylethanol than with the corresponding acetate ester. In addition, the 3-(3-pyridine)propionyl group enables a simple, mild acid extraction to separate the remaining starting material and product. To demonstrate the synthetic usefulness of this strategy, we resolved multi-gram quantities of (R)- and (S)-p-toluenesulfinamide with α-chymotrypsin and gram quantities of (R)- and (S)-2,2-dimethylcyclopentanol with subtilisin Carlsberg. The 3-(3-pyridyl)propionyl group was better for these resolutions than the corresponding acetate or dihydrocinnamate because it decreased the reaction time due to increased reactivity, decreased the reaction volume due to increased substrate solubility and enabled purification without chromatography. Molecular modeling suggests the enantioselectivity of α-chymotrypsin toward (R)-p-toluenesulfinamide is high (E = 52) because of a favorable hydrophobic interaction between the p-tolyl group of the fast-reacting (R)-enantiomer and leaving group pocket. The enantioselectivity of subtilisin Carlsberg toward (S)-2,2-dimethylcyclopentanol is high (E = 43) because the large substituent (the 2,2-dimethyl quaternary carbon) of the slow-reacting (R)-enantiomer cannot fit in the S1′ leaving group pocket.
The scope and limitations of 1,3-stannyl shift-promoted intramolecular cyclizations of α-stannyl radicals with a formyl group
Ueng, Shau-Hua,Chen, Ming-Jen,Chu, Shu-Fang,Shao, Yar-Fang,Fan, Gang-Ting,Chang, Sheng-Yueh,Tsai, Yeun-Min
, p. 1502 - 1512 (2007/10/03)
α-Tributylstannyl radicals can be generated from the corresponding bromides or xanthates. These radicals undergo efficient intramolecular 1,5-cyclizations with a formyl group. The resulting β-stannyl alkoxy radicals proceed through a 1,3-stannyl shift fro
Amino acid mediated borane reduction of ketones
Teodorovi?, Aleksandar V.,Joksovi?, Milan D.,Konstantinovi?, Stanimir K.,Mojsilovi?, Biljana M.,Mihailovi?, Mihailo L.
, p. 91 - 95 (2007/10/03)
Acetophenone, 2,2-dimethylcyclopentanone, 3,3-dimethyl-2-butanone, 3-methyl-2-butanone, and 2-pentanone were reduced with (S)-proline-and (S)-phenylalanine-mediated borane in good to very good yields giving predominantly (32-86% ee) alcohols of (R)-configuration.
2-TOSYLOXYMETHYLCYCLANONES: RING SIZE DEPENDENCE OF FRAGMENTATION VERSUS INTRAMOLECULAR ALKYLATION
Heinz, Uwe,Adams, Elisabeth,Klintz, Ralf,Welzel, Peter
, p. 4217 - 4230 (2007/10/02)
The results reported seem to indicate, that in the presence of a nucleophilic base intramolecular alkylation is the normal reaction mode of tosyloxymethylcyclanones of type 14 and that the fragmentation reaction of five-membered compounds is the exception, probably because of the high steric energy of the alkylation transition states, e.g. of type E.
REGIOCHEMISTRY OF THE METAL-HALOGEN EXCHANGE INDUCED CYCLIZATION OF ω-IODOEPOXIDES
Cooke, Manning P.,Houpis, Ioannis N.
, p. 3643 - 3646 (2007/10/02)
The regiochemistry of the cyclization reactions of some ω-lithioepoxides as a function of chain length and substitution pattern has been examined.Striking changes in regiochemistry have been observed in the presence of certain Lewis acids and metal halides.
Nucleophilic substitution of 5,5-dimethyl-2-cyclopentenyl derivatives. Lack of SN2' reaction
Kopecky, Karl R.,Levine, Cyril
, p. 3273 - 3279 (2007/10/02)
Treatment of tetramethyl-1,3-cyclobutadienone with two equivalents of allyl oxide anion at 140 deg C yields 2,2-dimethyl-4-pentenoic acid which is cyclized via the acid chloride whith aluminium chloride to 5,5-dimethyl-2-cyclopentenone 4.Reduction of 4 with aluminium hydride provides 5,5-dimethyl-2-cyclopentenol 1-OH which is pyrolyzed to 5,5-dimethyl-1,3-cyclopentadiene in dimethylsulfoxide.Reduction of 4 with tri-t-butoxyaluminium hydride at -70 deg C gives 2,2-dimethylcyclopentanone.The 2,6-dichlorobenzoate ester of 1-OH failed to yield SN2' products under a variety of conditions.The rate constants for solvolysis of the p-nitrobenzoate esters of 1-OH, 2-cyclopentenol and Z-2-methyl-4-hexene-3-ol in 80 percent ethanol at 80 deg C are 20.2, 523, and 0.63 x 1E-6s-1, respectively, and the main products of solvolysis are 5-ethoxy-3,3-dimethylcyclopentene, 3-ethoxycyclopentene, and E-2-ethoxy-5-methyl-3-hexene, respectively.There is steric hindrance to solvatation during ionization of the p-nitrobenzoate of 1-OH.