17537-31-4Relevant articles and documents
Infrared studies of acetophenone and its deuterated derivatives
Gambi, A.,Giorgianni, S.,Passerini, A.,Visinoni, R.,Ghersetti, S.
, p. 871 - 878 (1980)
The i.r. spectra of acetophenone and their deuterated analogues (-d3, -d5, -d8) in the liquid-phase have been recorded and analyzed in the range 4000-130 cm-1.Additional data on band contours in the gas-phase, in conjuction with the deuteration effects, allowed us to assign all the fundamentals for the four isotopic varieties.A valence force field calculation was also used to support the proposed assignment.
Rearrangements Accompanying the Fragmentation of Ionized 1-Phenylalkan-1-ols
Budzikiewicz, H.,Drabner, G.,Hammes, Ch.
, p. 1326 - 1328 (1993)
Some aspects of the fragmentation sequence of 1-phenylalkan-1-ols(C6H5CH(OH)R), which consists of the loss of R(.) followed by the elimination of CO and subsequently of H2, are discussed.Labelling studies and collision activation data of reference compounds allow a mechanism to be proposed for this rearrangement.
Intermolecular hydrogen bonds in water@IL supramolecular complexes
Zanatta, Marcileia,Dupont, Jairton,Wentz, Gabriela Negruni,Dos Santos, Francisco P.
, p. 11608 - 11614 (2018)
The role of small amounts of water in ionic liquids (ILs), namely, 1-n-butyl-2,3-dimethylimidazolium imidazolate (BMMI·Im), 2-methylimidazolate (BMMI·MeIm), and pyrazolate (BMMI·Pyr), is examined using NMR spectroscopy and density functional theory (DFT) calculations. The nuclear Overhauser effect (NOE) indicates that a water molecule is trapped inside the ionic network, keeping the ion pair in contact through strong H-bonds involving the hydrogen atoms of water and the nitrogen atoms of the IL anions to give a guest@host supramolecular structure. The formation of the H2O@IL pair complex with different ILs combined with the strong hydrogen bond strength within the complex is responsible for the selective H/D exchange reactions at the imidazolium C2-Me and ketone Cα positions.
The structure of ethylbenzene as a solute in liquid crystalline solvents via analysis of proton NMR spectra
Algieri,Castiglione,Celebre,De Luca,Longeri,Emsley
, p. 3405 - 3413 (2000)
Previous attempts to analyze the proton spectrum of ethylbenzene as a solute in nematic liquid crystalline solvents failed, but a successful strategy has now been devised and is described here. The proton spectra of samples of ethylbenzene dissolved in four different liquid crystals have been analyzed to yield sets of the partially-averaged dipolar couplings, D(ij). The couplings are then used to test models for the structure and conformation of this molecule.
The oxidation of secondary alcohols by dimethyldioxirane: Re-examination of kinetic isotope effects
Baumstark, Alfons L.,Vasquez, Pedro C.,Cunningham, Mark,Leggett-Robinson, Pamela M.
, p. 217 - 220 (2010)
The kinetic isotope effects for the oxidation of a series of deuterated isopropanols and a -trideuteromethyl benzyl alcohol by dimethyldioxirane ( 1 ) to the corresponding ketones were determined in dried acetone at 23 ° C. A primary kinetic isotope effect (PKIE) of 5.2 for the oxidation of isopropyl-2-d alcohol by 1 was obtained. The SKIEs for oxidation of a -trideuteromethyl benzyl alcohol and isopropyl-1,1,1,3,3,3-d6 alcohol were found to be 1.07 and 0.98, respectively. Oxidation of isopropanol-d by 1 yielded a k OH /k OD value of 1.12, which is similar to that previously reported for α -methylbenzyl alcohol-d. Both normal and inverse secondary kinetic isotope effect (SKIEs) are observed. Mechanistically, the results indicate that the process is more complex than the previously proposed models.
Secondary deuterium isotope effects for enolization reactions
Alston II, William C.,Haley, Kari,Kanski, Ryszard,Murray, Christopher J.,Pranata, Julianto
, p. 6562 - 6569 (1996)
Secondary α- and β-deuterium isotope effects for enolization reactions and equilibria have been determined by ab initio calculations, 1H NMR spectroscopy, and triton exchange kinetics. Kinetic and equilibrium α-deuterium isotope effects for hydroxide ion-catalyzed enolization of acetaldehyde calculated by ab initio methods are normal and depend on the orientation of the secondary hydrogen with respect to the carbonyl group. The computed transition state structure indicates a small degree of bond rehybridization at the transition state. Experimentally measured secondary isotope effects on the deuteroxide ion-catalyzed proton exchange of acetophenone are k(H)/k(D) = 1.08 ± 0.07 for α-CH3 exchange and k(H)/k(D) = 0.96 ± 0.08 for α-CH2D exchange. For α-CH2T exchange in water, the corresponding secondary isotope effect is k(H)/k(D) = 1.06 ± 0.02, assuming the rule of the geometric mean is valid. These effects are smaller than the calculated equilibrium isotope effect for formation of the enolate ion-water complex: K(H)/K(D) = 1.11-1.22 at the MP2 level. The normal kinetic isotope effects are smaller than might be expected due to a loss in hyperconjugation of the out-of-plane C-H bond and a lag in structural reorganization that contributes to the intrinsic barrier for proton transfer from carbon. Ionization of protonated acetone gives rise to an inverse secondary isotope effect of 0.97/D for the C-L bond adjacent to the carbonyl group and is consistent with a loss in hyperconjugation upon formation of the neutral ketone.
Organocatalytic Deuteration Induced by the Dynamic Covalent Interaction of Imidazolium Cations with Ketones
Ananikov, Valentine P.,Galkin, Konstantin I.,Gordeev, Evgeniy G.
, p. 1368 - 1378 (2021/01/18)
In this article, we suggest a new organocatalytic approach based on the dynamic covalent interaction of imidazolium cations with ketones. A reaction of N-alkyl imidazolium salts with acetone-d6 in the presence of oxygenated bases generates a dynamic organocatalytic system with a mixture of protonated carbene/ketone adducts acting as H/D exchange catalysts. The developed methodology of the pH-dependent deuteration showed high selectivity of labeling and good chiral functional group tolerance. Here we report a unique methodology for efficient metal-free deuteration, which enables labeling of various types of α-acidic compounds without trace metal contamination. (Figure presented.).
Ruthenium-Catalyzed Deuteration of Aromatic Carbonyl Compounds with a Catalytic Transient Directing Group
Kopf, Sara,Ye, Fei,Neumann, Helfried,Beller, Matthias
, p. 9768 - 9773 (2021/06/17)
A novel ruthenium-catalyzed C?H activation methodology for hydrogen isotope exchange of aromatic carbonyl compounds is presented. In the presence of catalytic amounts of specific amine additives, a transient directing group is formed in situ, which directs selective deuteration. A high degree of deuteration is achieved for α-carbonyl and aromatic ortho-positions. In addition, appropriate choice of conditions allows for exclusive labeling of the α-carbonyl position while a procedure for the preparation of merely ortho-deuterated compounds is also reported. This methodology proceeds with good functional group tolerance and can be also applied for deuteration of pharmaceutical drugs. Mechanistic studies reveal a kinetic isotope effect of 2.2, showing that the C?H activation is likely the rate-determining step of the catalytic cycle. Using deuterium oxide as a cheap and convenient source of deuterium, the methodology presents a cost-efficient alternative to state-of-the-art iridium-catalyzed procedures.
