447-53-0Relevant articles and documents
Valkovich,P.B.,Weber,W.P.
, p. 229 - 230 (1975)
Transfer of Hydrogen by Hydroaromatics. 2. The Temperature Dependence of the Rate Constants and Catalytic Site Populations in the Tetralin/Iron Catalyst Systems
Gangwer, T.E.
, p. 575 - 579 (1981)
The heterogeneous mechanism of dehydrogenation for the tetralin/iron catalyst system previously reported is further documented.The temperature dependences of the rate constants are reported.The effective activation energies on these heterogeneous surface were found to be in the -20 to +30 kcal/mol range.The catalytic site populations and temperature dependences were used to determine the binding energy, Rb, of the organic reactants at the catalytic sites.The Eb values were found to be in the 20-40 kcal/mol range.
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Baddeley,Chadwick
, p. 368,372 (1951)
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Stoichiometry of protonation of aromatic hydrocarbon radical anions by weak proton donors. A marked discrepancy between the number of protons used and those incorporated into the aromatic structure
Screttas, Constantinos G.,Ioannou, Georgios I.,Micha-Screttas, Maria
, p. 217 - 225 (1996)
The stoichiometries of the reaction between alkali metal radical anions of biphenyl, naphthalene, phenanthrene and anthracene, and methanol and/or other proton donors have been determined by the magnetic titration technique. In the case of naphthalene radical anion and, for example, methanol as the proton source, the stoichiometry was found to be cation-dependent: Li, 2: 1; Na, 1.75: 1; K, 1.33: 1. The reaction products using the experimentally determined stoichiometric conditions were ca. 95% naphthalene and 5% dihydronaphthalene(s). Thus, a marked discrepancy is observed between the protons used and those incorporated into the naphthalene molecule. Radical anions, at concentrations comparable with those of preparative reactions, react with carbon acids or amines according to the first-order kinetic law, although the initial concentrations of the two reactants were of the same order of magnitude or even equal. Lithium anthacene radical anion reacts with phenylacetylene and diethylamine at comparable rates, although the two "acids" differ in their acidities by ca. 10 orders of magnitude. A deuterium isotope effect of 2.49 ± 0.05 was observed in the reaction between lithium anthracene radical anion and diethylamine. A general reaction scheme is proposed that involves electron transfer to the proton donor and hydrogen-atom attack on the neutral hydrocarbon as the key reaction steps.
Intramolecular electrophilic aromatic substitution reactions with methyl vinyl ethers for the synthesis of dihydronaphthalenes
Harrowven, David C,Tyte, Melloney J
, p. 5971 - 5972 (2002)
A simple and inexpensive method to effect the conversion of 4-arylalk-1-en-1-yl methyl ethers to dihydronaphthalenes has been developed. Cyclisation is accomplished by warming a toluene solution of the substrate with 1,2-ethanediol and para-toluenesulfonic acid and proceeds via in situ formation of a 1,3-dioxolane. Reactions generally give good yields and have been successful with electron rich, unsubstituted and halogenated arenes. They display excellent regioselectivity; appearing to follow the course of lowest steric demand.
Misono et al.
, p. 2921 (1968)
Banwell,M.G. et al.
, p. 2165 - 2168 (1977)
Broadening the scope of photostimulated SmI2 reductions
Amiel-Levy, Mazal,Hoz, Shmaryahu
, p. 805 - 809 (2010)
A study was conducted to demonstrate that the exploitation of the biomolecular process significantly broadened the scope of photostimulated SmI2 reduction. Two UV cells containing naphthalene, SmI2, and MeOH were set up under a preliminary test and one of them was exposed to a simple UV lamp, while the other was placed on the bench as a control under ordinary laboratory fluorescent lighting. It was observed that the reaction in the cell under the UV lamp progressed slowly, while significant reaction took place in the cell on the bench. Significant reaction was also observed when the same reaction was carried out with a mercury lamp and a filter that cut off wavelengths below 600 nm. Two methods were employed for the assessment of the photostimulated reactions. One of the methods was based on the fact that stopped flow irradiated the sample continuously in the diode array mode.
Olefination via Cu-Mediated Dehydroacylation of Unstrained Ketones
Dong, Guangbin,Xu, Yan,Zhou, Xukai
supporting information, p. 20042 - 20048 (2021/12/03)
The dehydroacylation of ketones to olefins is realized under mild conditions, which exhibits a unique reaction pathway involving aromatization-driven C-C cleavage to remove the acyl moiety, followed by Cu-mediated oxidative elimination to form an alkene between the α and β carbons. The newly adopted N′-methylpicolinohydrazonamide (MPHA) reagent is key to enable efficient cleavage of ketone C-C bonds at room temperature. Diverse alkyl- and aryl-substituted olefins, dienes, and special alkenes are generated with broad functional group tolerance. Strategic applications of this method are also demonstrated.
A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
, p. 6684 - 6690 (2021/05/31)
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
Vanadium Pyridonate Catalysts: Isolation of Intermediates in the Reductive Coupling of Alcohols
Griffin, Samuel E.,Schafer, Laurel L.
supporting information, (2020/04/15)
The reductive coupling of alcohols using vanadium pyridonate catalysts is reported. This attractive approach for C(sp3)-C(sp3) bond formation uses an oxophilic, earth-abundant metal for a catalytic deoxygenation reaction. Several pyridonate complexes of vanadium were synthesized, giving insight into the coordination chemistry of this understudied class of compounds. Isolated intermediates provide experimental mechanistic evidence that complements reported computational mechanistic proposals for the reductive coupling of alcohols. In contrast to previous mononuclear vanadium(V)/vanadium(III)/vanadium(IV) cycles, this pyridonate catalyst system is proposed to proceed by a vanadium(III)/vanadium(IV) cycle involving bimetallic intermediates.
