857521-44-9Relevant academic research and scientific papers
A Hammett Study of Clostridium acetobutylicum Alcohol Dehydrogenase (CaADH): An Enzyme with Remarkable Substrate Promiscuity and Utility for Organic Synthesis
Berkowitz, David B.,Kudalkar, Gaurav P.,Lee, Joshua D.,Tiwari, Virendra K.
, p. 237 - 247 (2020)
Described is a physical organic study of the reduction of three sets of carbonyl compounds by the NADPH-dependent enzyme Clostridium acetobutylicum alcohol dehydrogenase (CaADH). Previous studies in our group have shown this enzyme to display broad substrate promiscuity, yet remarkable stereochemical fidelity, in the reduction of carbonyl compounds, including α-, β- and γ-keto esters (d -stereochemistry), as well as α,α-difluorinated-β-keto phosphonate esters (l -stereochemistry). To better mechanistically characterize this promising dehydrogenase enzyme, we report here the results of a Hammett linear free-energy relationship (LFER) study across three distinct classes of carbonyl substrates; namely aryl aldehydes, aryl β-keto esters and aryl trifluoromethyl ketones. Rates are measured by monitoring the decrease in NADPH fluorescence at 460 nm with time across a range of substrate concentrations for each member of each carbonyl compound class. The resulting v 0 versus [S] data are subjected to least-squares hyperbolic fitting to the Michaelis-Menton equation. Hammett plots of log(V max) versus σ X yield the following Hammett parameters: (i) for p -substituted aldehydes, ρ = 0.99 ± 0.10, ρ = 0.40 ± 0.09; two domains observed, (ii) for p -substituted β-keto esters ρ = 1.02 ± 0.31, and (iii) for p -substituted aryl trifluoromethyl ketones ρ = -0.97 ± 0.12. The positive sign of ρ indicated for the first two compound classes suggests that the hydride transfer from the nicotinamide cofactor is at least partially rate-limiting, whereas the negative sign of ρ for the aryl trifluoromethyl ketone class suggests that dehydration of the ketone hydrate may be rate-limiting for this compound class. Consistent with this notion, examination of the 13 C NMR spectra for the set of p -substituted aryl trifluo romethyl ketones in 2percent aqueous DMSO reveals significant formation of the hydrate (gem -diol) for this compound family, with compounds bearing the more electron-withdrawing groups showing greater degrees of hydration. This work also presents the first examples of the CaADH-mediated reduction of aryl trifluoromethyl ketones, and chiral HPLC analysis indicates that the parent compound α,α,α-trifluoroacetophenone is enzymatically reduced in 99percent ee and 95percent yield, providing the (S)-stereoisomer, suggesting yet another compound class for which this enzyme displays high enantioselectivity.
Visible light-promoted umpolung coupling of aryl tri-/difluoroethanones with 2-alkenylpyridines
Xu, Xiao,Min, Qing-Qiang,Li, Na,Liu, Feng
supporting information, p. 11017 - 11020 (2018/10/08)
Tertiary alcohols bearing a trifluoromethyl group are of considerable medicinal interest. Using an umpolung strategy, we herein report the first intermolecular reductive cross-coupling of aryl tri-/difluoroethanones with 2-alkenylpyridines with the aid of a Br?nsted acid catalyst upon visible-light irradiation. This metal-free reaction is operationally simple and performed at ambient temperature, allowing access to desired tertiary alcohols with tri-/difluoromethyl groups in moderate to excellent yields. The commercially available and easily handled Hantzsch ester effectively serves as an electron donor, as well as a hydrogen atom source.
4-AMINO-5-OXO-7, 8-DIHYDROPYRIMIDO [5,4-F] [1,4] OXAZEPIN-6 (5H) -YL) PHENYL DERIVATIVES, PHARMACEUTICAL COMPOSITIONS AND USES THEREOF
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Page/Page column 44, (2010/08/09)
The invention provides compounds of Formula (I), wherein R1, R2a, R2b, R3, m and A are as defined herein, as well as compositions thereof and methods for treating a disease, condition or disorder that is modulated by the inhibition of the diacylglycerol O-acyltransferase 1 (DGAT-1) enzyme by administering the compounds of the present invention and/or compositions thereof.
4-AMINO-7,8-DIHYDROPYRIDO[4,3-d]PYRIMIDIN-5(6H)-ONE DERIVATIVES
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Page/Page column 21, (2010/08/08)
The invention provides compounds of the general Formula (I) where R1, R2, and A are defined herein, as well as the preparation, compositions and uses thereof.
AZACYCLIC SPIRODERIVATIVES AS HSL INHIBITORS
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, (2010/12/17)
Compounds of formula (I) as well as pharmaceutically acceptable salts thereof can be used in the form of pharmaceutical compositions, wherein n, m, A, R1 and R2 have the significance given in claim 1. The compounds are useful as HSL inhibitors for the treatment of diabetes dyslipidemia, atherosclerosis and obesity.
PYRIDO[2,3-D]PYRIMIDINE-2,4-DIAMINES AS PDE 2 INHIBITORS
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Page/Page column 22, (2010/02/12)
The invention provides compounds of formula (I) prodrugs thereof, and the pharmaceutically acceptable salts of the compounds or prodrugs, wherein n, X, and Y are as defined herein; pharmaceutical compositions thereof; combinations thereof; and uses thereo
