Mechanistic Borderline of One-Step Hydrogen Atom Transfer versus Stepwise Sc3+-Coupled Electron Transfer from Benzyl Alcohol Derivatives to a Non-Heme Iron(IV)-Oxo Complex

2012 ◽  
Vol 51 (18) ◽  
pp. 10025-10036 ◽  
Author(s):  
Yuma Morimoto ◽  
Jiyun Park ◽  
Tomoyoshi Suenobu ◽  
Yong-Min Lee ◽  
Wonwoo Nam ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Benzyl Alcohol ◽  
Hydrogen Atom Transfer ◽  
Heme Iron ◽  
Atom Transfer ◽  
Non Heme Iron ◽  
One Step

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

Atmospheric formation of the NO3 radical from gas-phase reaction of HNO3 acid with the NH2 radical: proton-coupled electron-transfer versus hydrogen atom transfer mechanisms

2014 ◽  
Vol 16 (36) ◽  
pp. 19437-19445 ◽  
Author(s):  
Josep M. Anglada ◽  
Santiago Olivella ◽  
Albert Solé
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Phase Reaction ◽  
Electron Transfer Mechanism ◽  
Proton Coupled Electron Transfer ◽  
No3 Radical ◽  
Transfer Mechanisms ◽  
Atmospheric Formation

The amidogen radical abstracts the hydrogen from nitric acid through a proton coupled electron transfer mechanism rather than by an hydrogen atom transfer process.

Kinetics and Mechanism of the Oxidation of Substituted Benzyl Alcohols by oxo(salen)manganese(V) complexes

2001 ◽  
Vol 2001 (5) ◽  
pp. 179-181 ◽  
Author(s):  
Vinita Kumbhat ◽  
Pradeep K. Sharma ◽  
Kalyan K. Banerji
Keyword(s):  
Hydrogen Atom ◽  
Benzyl Alcohol ◽  
Hydrogen Atom Transfer ◽  
Kinetics And Mechanism ◽  
Atom Transfer ◽  
Benzyl Alcohols ◽  
Hydride Ion ◽  
Oxidation Of Benzyl Alcohol

The oxidation of benzyl alcohol by oxo(salen)manganese (V) complexes proceeds via either a hydride-ion or a hydrogen-atom transfer from the alcohol to the manganese (V) complexes.

The water–boryl radical as a proton-coupled electron transfer reagent for carbon dioxide, formic acid, and formaldehyde — Theoretical approach

2013 ◽  
Vol 91 (2) ◽  
pp. 155-168
Author(s):  
Waled Tantawy ◽  
Ahmed Hashem ◽  
Nabil Yousif ◽  
Eman Flefel
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Bond ◽  
Electron Transfer ◽  
Hydrogen Atom ◽  
Transfer Process ◽  
Carbonyl Compounds ◽  
Hydrogen Atom Transfer ◽  
Transfer Reactions ◽  
Atom Transfer ◽  
Proton Coupled Electron Transfer

The thermochemistry of the hydrogen atom transfer reactions from the H2O–BX2 radical system (X = H, CH3, NH2, OH, F) to carbon dioxide, formic acid, and (or) formaldehyde, which produce hydroxyformyl, dihydroxymethyl, and hydroxymethyl radicals, respectively, were investigated theoretically at ROMP2/6–311+G(3DF,2P)//UB3LYP/6–31G(D) and UG3(MP2)-RAD levels of theory. Surprisingly, in the cases of a strong Lewis acid (X = H, CH3, F), the spin transfer process from the water–boryl radical to the carbonyl compounds was barrier-free and associated with a dramatic reduction in the B–H bond dissociation energy (BDE) relative to that of isolated water–borane complexes. Examining the coordinates of these reactions revealed that the entire hydrogen atom transfer process is governed by the proton-coupled electron transfer (PCET) mechanism. Hence, the elucidated mechanism has been applied in the cases of weak Lewis acids (X = NH2, OH), and the variation in the accompanied activation energy was attributed to the stereoelectronic effect interplaying in CO2 and HCOOH compared with HCHO. We ascribed the overall mechanism as a SA-induced five-center cyclic PCET, in which the proton transfers across the so-called complexation-induced hydrogen bond (CIHB) channel, while the SOMOB–LUMOC=O′ interaction is responsible for the electron migration process. Owing to previous reports that interrelate the hydrogen-bonding and the rate of proton-coupled electron-transfer reactions, we postulated that “the rate of the PCET reaction is expected to be promoted by the covalency of the hydrogen bond, and any factor that enhances this covalency could be considered an activator of the PCET process.” This postulate could be considered a good rationale for the lack of a barrier associated with the hydrogen atom transfer from the water-boryl radical system to the carbonyl compounds. Light has been shed on the water–boryl radical reagent from the thermodynamic perspective.

scholarly journals Regio- and chemoselective Csp3–H arylation of benzylamines by single electron transfer/hydrogen atom transfer synergistic catalysis

2018 ◽  
Vol 9 (44) ◽  
pp. 8453-8460 ◽  
Author(s):  
Takafumi Ide ◽  
Joshua P. Barham ◽  
Masashi Fujita ◽  
Yuji Kawato ◽  
Hiromichi Egami ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Hydrogen Atom ◽  
Hydrogen Atom Transfer ◽  
Single Electron ◽  
Atom Transfer ◽  
Single Electron Transfer ◽  
Synergistic Catalysis

Catalyst controlled regio-, and chemo-selective C-H arylation of benzylamines.

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