Topic
Hydrogen atom abstraction
About: Hydrogen atom abstraction is a research topic. Over the lifetime, 7059 publications have been published within this topic receiving 151781 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the synergistic control of the SH2 transition states of hydrogen abstraction by polar and steric effects provides a promising strategy in achieving site-selective C(sp3)-H functionalization under decatungstate anion photocatalysis.
Abstract: The synergistic control of the SH2 transition states of hydrogen abstraction by polar and steric effects provides a promising strategy in achieving site-selective C(sp3)–H functionalization under decatungstate anion photocatalysis. By using this photocatalytic approach, the C–H bonds of alkanes, alcohols, ethers, ketones, amides, esters, nitriles, and pyridylalkanes were functionalized site-selectively. In the remarkable case of a 2,4-disubstituted cyclohexanone bearing five methyl, five methylene, and three methine C–H bonds, one methine C–H bond in the isoamyl tether was selectively functionalized.
247 citations
Book•
01 Jan 1987
TL;DR: Theoretically, the most related work to ours is as mentioned in this paper, which proposes a combination of Solid State Chemistry and X-Ray Crystallography for the prediction of chemical reactivity within organic solids.
Abstract: Organic Solid State Reactions: Topochemistry and Mechanism. Geometric Requirements for Intramolecular Photochemical Hydrogen Atom Abstraction: Studies Based on a Combination of Solid State Chemistry and X-Ray Crystallography (J.R. Scheffer). Topotactic and Topochemical Photodimerisation of Benzylidenecyclopentanones (C.R. Theocharis, W. Jones). The Prediction of Chemical Reactivity Within Organic Crystals Using Geometric Criteria (S.K. Kearsley). Phonon Spectroscopy of Organic Solid State Reactions (P.N. Prasad). Four-Center Type Photopolymerization of Diolefin Crystals (M. Hasegawa). Some Stereochemical Questions: Pure and Applied Chemistry. Organic Molecules in Constrained Environments (J.M. Thomas, K.D.M. Harris). Clathrates (G. Tsoucaris). Solid State Chemistry of Phenols and Possible Industrial Applications (R. Perrin et al.). Gas-Solid Reactions and Polar Crystals (I.C. Paul, D.Y. Curtin). Intermolecular Interactions: From Crystallography to Chemical Physics. Phase Transitions in Organic Solids (C.N.R. Rao). Molecular Motions in Organic Crystals: The Structural Point of View (A. Gavezzotti, M. Simonetta). Interatomic Potentials and Computer Simulations of Organic Molecules in the Solid State (S. Ramdas, N.W. Thomas,). Conformational Polymorphism (J. Bernstein). Crystal Engineering A 4 A - Short Axis Structure for Planar Chloro Aromatics (G.R. Desiraju).
241 citations
TL;DR: In this work, the OH + formaldehyde and OH + acetaldehyde reactions have been characterized using accurate ab initio methods with large basis sets and consideration of the prereactive complex is shown to be essential for the determination of the height of the energy barrier and thus for the correct calculation of the tunneling factor.
Abstract: In this work, the OH + formaldehyde and OH + acetaldehyde reactions have been characterized using accurate ab initio methods with large basis sets. The results clearly indicate that the reaction occurs by hydrogen abstraction, and that the OH addition channel is unfavorable. Close to zero (for formaldehyde) and negative (for acetaldehyde) activation energy values are obtained, which are in excellent agreement with the experimentally observed values. The reaction rate constants, calculated using the classical transition-state theory as applied to a complex mechanism involving the formation of a prereactive complex, reproduce very well the reported experimental results. Consideration of the prereactive complex is shown to be essential for the determination of the height of the energy barrier and thus for the correct calculation of the tunneling factor.
239 citations
238 citations
TL;DR: The flash vacuum pyrolysis (FVP) of methoxy-substituted beta-O-4 lignin model compounds has been studied at 500 degrees C to provide mechanistic insight into the primary reaction pathways that occur under conditions of fast pyroblysis.
Abstract: The flash vacuum pyrolysis (FVP) of methoxy-substituted β-O-4 lignin model compounds has been studied at 500 °C to provide mechanistic insight into the primary reaction pathways that occur under conditions of fast pyrolysis. FVP of PhCH2CH2OPh (PPE), a model of the dominant β-O-4 linkage in lignin, proceeds by C−O and C−C cleavage, in a 37:1 ratio, to produce styrene plus phenol as the dominant products and minor amounts of toluene, bibenzyl, and benzaldehyde. From the deuterium isotope effect in the FVP of PhCD2CH2OPh, it was shown that C−O cleavage occurs by homolysis and by 1,2-elimination in a ratio of 1.4:1, respectively. Methoxy substituents enhance the homolysis of the β-O-4 linkage, relative to PPE, in o-CH3O-C6H4OCH2CH2Ph (o-CH3O-PPE) and (o-CH3O)2-C6H3OCH2CH2Ph ((o-CH3O)2-PPE) by a factor of 7.4 and 21, respectively. The methoxy-substituted phenoxy radicals undergo a complex series of reactions, which are dominated by 1,5-, 1,6-, and 1,4-intramolecular hydrogen abstraction, rearrangement, and β−...
236 citations