3246-80-8Relevant articles and documents
Kinetics of the hydride reduction of an NAD+ analogue by isopropyl alcohol in aqueous and acetonitrile solutions: Solvent effects, deuterium isotope effects, and mechanism
Lu, Yun,Qu, Fengrui,Zhao, Yu,Small, Ashia M. J.,Bradshaw, Joshua,Moore, Brian
, p. 6503 - 6510 (2009)
(Chemical Equation Presented) The rate constants of the hydride-transfer reactions from isopropyl alcohol (i-PrOH) to an NAD+ model, 9-phenylxanthyliumion (PhXn+), in acetonitrile (AN) and inwater containing AN (80% H2O/20% AN) were determined over a temperature range from 36 to 67°C. The reactions follow second-order rate laws. In the latter solution, formation of the water adduct of PhXn+ was observed as a side-equilibrium (K). The observed inverse solvent kinetic isotope effect (kH2Oobs/kD2Oobs = 0.54), the larger than unity equilibrium isotope effect (K(H2O)/K(D2O) = 2.69), and the results of acid effect on the observed rate constants of the reactions are consistent with the "side-equilibriummechanism". Kinetic isotope effects at all three H/D positions of i-PrOH for the net hydride-transfer process were determined in both solutions at 60°C: KIE α-DH = 3.2(AN), 3.2(H2O); KIE β-D6H = 1.05(AN), 1.16(H2O); KIE ODH = 1.08(AN), 1.04(H2O). These KIE values are consistent with the presence of the positively charged alcohol moiety in the transition state (TS) for cleavage of the α-C-H bond, the delocalization of the positive charge over the α-C-OH group, and the stepwise hydride and proton transfer processes. Comparison of the activation parameters for the reactions in the two solvent systems as well as those in the i-PrOH/AN (1:1 v/v) reported earlier suggests that the AN medium promotes the reaction by activating the ground-state alcohol reactant through weak interactions with the electron pairs on alcohol O, while water and parent alcohol media facilitate the reaction by H-bonding stabilization of the alcohol moiety of the TS. Results suggest that in the alcohol dehydrogenases without a Zn(II) cofactor in the active sites alcohols would be oxidized via hydride transfer to NAD+ coenzyme followed by the rapid deprotonation to the nearby basic species in the active site of the enzymes.
NaHSO4/SiO2catalyzed generation of: o -quinone/ o -thioquinone methides: synthesis of arylxanthenes/ arylthioxanthenes via oxa-6π-electrocyclization
Anthony, Savarimuthu Philip,Karthick, Muthupandi,Konikkara Abi, Edwin,Ramanathan, Chinnasamy Ramaraj,Someshwar, Nagamalla
, p. 8653 - 8667 (2020/11/17)
ortho-Quinone methides, very reactive transient intermediates, are utilized successfully in synthesizing complex organic molecules of natural and biological significance. Among several synthetic protocols, the acid catalyzed generation of ortho-quinone me
Method for constructing carbon-hydrogen bond by catalyzing alcohol dehydroxylation with palladium/platinum
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Paragraph 0104-0110; 0112, (2019/12/25)
The invention discloses a method for constructing a carbon-hydrogen (deuterium) bond. The method comprises the following step: in the presence of a palladium/platinum catalyst and aryl halide, an alcohol hydroxyl group of an alcohol and hydrogen (deuterium) gas is replaced by hydrogen (deuterium) to construct the carbon-hydrogen (deuterium) bond. According to the method, the palladium/platinum catalyst is used as a catalyst, the green hydrogen (deuterium) gas is used as a hydrogen (deuterium) source, efficient alcohol dehydroxylation is performed at room temperature to construct the carbon-hydrogen (deuterium) bond, and the method is particularly suitable for constructing the carbon-deuterium bond and can be widely applied to synthesis of deuterated drugs.