- The effect of pressure on hydrogen transfer reactions with quinones
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The effect of pressure on the oxidation of hydroarenes 3-9 with 2,3-dichloro-5,6-dicyano-1,4-quinone (DDQ; 1a) or o-chloranil (10), leading to the corresponding arenes, has been investigated. The activation volumes were determined from the pressure dependence of the rate constants of these reactions monitored by on-line UV/Vis spectroscopic measurements in an optical high-pressure cell (up to 3500 bar). The finding that they are highly negative and only moderately dependent on the solvent polarity (ΔV ?=-13 to -25 in MTBE and -15 to -29 cm3mol -1 in MeCN/AcOEt, 1:1) rules out the formation of ionic species in the rate-determining step and is good evidence for a hydrogen atom transfer mechanism leading to a pair of radicals in the rate-determining step, as was also suggested by kinetic measurements, studies of kinetic isotope effects, and spin-trapping experiments. The strong pressure dependence of the kinetic deuterium isotope effect for the reaction of 9,10-dihydroanthracene 5/5-9,9,10,10-D4 with DDQ (1a) can be attributed to a tunneling component in the hydrogen transfer. In the case of formal 1,3-dienes and enes possessing two vicinal C-H bonds, which have to be cleaved during the dehydrogenation, a pericyclic hydrogen transfer has to considered as one mechanistic alternative. The comparison of the kinetic deuterium isotope effects determined for the oxidation of tetralin 9/9-1,1,4,4-D4/9-2,2,3,3-D4/9-D 12 either with DDQ (1a) or with thymoquinone 1c indicates that the reaction with DDQ (1a) proceeds in a stepwise manner through hydrogen atom transfer, analogously to the oxidations of 1,4-dihydroarenes, whereas the reaction with thymoquinone 1c is concerted, following the course of a pericyclic hydrogen transfer. The difference in the mechanistic courses of these two reactions may be explained by the effect of the CN and Cl substituents in 1a, which stabilize a radical intermediate better than the alkyl groups in 1c. The mechanistic conclusions are substantiated by DFT calculations.
- Wurche, Frank,Sicking, Wilhelm,Sustmann, Reiner,Klaerner, Frank-Gerrit,Ruechard, Christoph
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- Transfer of Hydrogen by Hydroaromatics. 2. The Temperature Dependence of the Rate Constants and Catalytic Site Populations in the Tetralin/Iron Catalyst Systems
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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.
- Gangwer, T.E.
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- Oxidation of cyanobenzocycloheptatrienes: Synthesis, photooxygenation reaction and carbonic anhydrase isoenzymes inhibition properties of some new benzotropone derivatives
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The oxidation of some cyanocycloheptatrienes with CrO3 and pyridine was investigated and a few new nitrile functionalised benzotropone derivatives were obtained. Photooxygenation reaction of these products was also studied. The structures of the formed products were determined on the basis of NMR spectroscopy and the formation mechanism of unusual products was discussed. Human carbonic anhydrase isoenzymes I, and II (hCA I and hCA II) inhibition properties of nitrile functionalized new benzotropone derivatives were also studied. Both CA isozymes were inhibited in the low micromolar range by these nitrile functionalized benzotropone analogues. The newly synthesized benzotropone derivatives showed inhibition constants in the sub-micromolar range (2.51-4.06 μM). The best hCA I inhibition was observed in 5H-benzocycloheptene-7-carbonitrile (Ki: 2.88 ± 0.86 μM). On the other hand, 5-oxo-5H-benzocycloheptatriene-7-carbonitrile showed the powerful inhibitory effect against hCA II (Ki: 2.51 ± 0.34 μM).
- Gueney, Murat,Coskun, Ahmet,Topal, Fevzi,Dastan, Arif,Guelcin, Ilhami,Supuran, Claudiu T.
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- Cycloallenes. Part 15:1 3δ2-1H-naphthalene (2,3-didehydro-1,2- dihydronaphthalene) from 3-bromo-1,2-dihydronaphthalene
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As a test as to whether the title intermediate 13 can be liberated from 3-bromo-1,2-dihydronaphthalene (19), the latter was treated with potassium tert-butoxide (KOtBu). Being the major products, naphthalene (20) and 3-tert- butoxy-1,2-dihydronaphthalene (21) provide unambiguous evidence for the intermediacy of 13. When the reaction was carried out in the presence of furan, 2,5-dimethylfuran and spiro[2,4]hepta-4,6-diene, expected (31, 32, 33, 34) and unexpected compounds (30, 35-37) were formed, which either directly resulted from the cycloaddition of 13 or were consecutive products of cycloadducts. Performed in the presence of benzophenone, the generation of 13 gave, inter alia, naphth-2-yldiphenylmethanol (27). This product testifies the intermediacy of the naphth-2-yl anion (24), which emerged from the deprotonation of 13 and was trapped by benzophenone. (C) 2000 Elsevier Science Ltd.
- Groetsch, Stefan,Spuziak, Joanna,Christl, Manfred
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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
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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.
- Screttas, Constantinos G.,Ioannou, Georgios I.,Micha-Screttas, Maria
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- Hybrid Class Phenylthiazole and 1,2,3,4-Tetrahydronaphthalene Target Sertraline Transporter for Antidepressant Action Revealed by Molecular Docking Studies
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Phenylthiazolyl-substituted 1,2,3,4-tetrahydronaphthalene derivatives were synthesized, and their chemical structures were elucidated by Fourier transform infrared, 1H-NMR, 13C-NMR spectral data and elemental analyses. Antidepressant-like activities of these compounds were screened using both Porsolt's behavioural despair on albino mice and tail suspension tests. Open field test was also performed for the examination of probable neurological deficits, which may interfere with the test results. The test compounds exhibited different levels of antidepressant activities. Additionally, the key ligand was further substantiated by docking experiment to explore plausible mode of binding in molecular dynamics overflow. The studies elucidates role of a hydrophilic H-bonding region and pi-cation binding as a major driving force for biological activity.
- Uppal, Archana,Kothiyal, Preeti,Singh, Anita
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- Intramolecular electrophilic aromatic substitution reactions with methyl vinyl ethers for the synthesis of dihydronaphthalenes
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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.
- Harrowven, David C,Tyte, Melloney J
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- 1-H-Cyclobuta[a]naphthalen-2-one
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1-H-Cyclobuta[a]naphthalen-2-one (2) was synthesized in eight steps starting from α-tetralone. With 2 the last missing compound of the three possible cyclobutanaphthalenones has been prepared.
- Neudeck, Horst,Brinker, Udo H.
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- Transfer of Hydrogen by Hydroaromatics. 1. Mechanism of Dehydrogenation/Hydrogenation in Tetralin/Iron Catalyst Systems
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At 400 deg C, the gas-phase dehydrogenation of teralin over iron catalysts is found to result in formation of naphthalene via the reaction of intermediate 1,2-dihydronaphthalene.The kinetic data for these systems were found to follow heterogeneous, first-order rate laws.A mechanism is presented which quatitatively describes the measured teralin and naphthalene kinetic behavior and successfully predicts the kinetic data observed for the 1,2-dihyronaphthalene intermediate.The rate-limiting reactions inthese systems are proposed as involving dehydrogenation/hydrogenation reactions on the surfaces of the catalysts.Based on data analysis, the rate constants for the surface reactions have values in the 1E-4-1E-5 s-1 range.The catalytic surface site populations were found to be in the range 1E13-1E14 molecules cm-2.
- Gangwer, T.
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- Broadening the scope of photostimulated SmI2 reductions
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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.
- Amiel-Levy, Mazal,Hoz, Shmaryahu
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- Selective conversion of α-tetralones to dihydronaphthalenes
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A simple procedure for selective conversion of α-tetralones to dihydronaphthalenes is described. A novel protic acid catalyzed hydride migration mechanism is proposed.
- Vuligonda, Vidyasagar,Lin, Yuan,Chandraratna, Roshantha A.S.
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- Olefination via Cu-Mediated Dehydroacylation of Unstrained Ketones
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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.
- Dong, Guangbin,Xu, Yan,Zhou, Xukai
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supporting information
p. 20042 - 20048
(2021/12/03)
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- Electro-mediated PhotoRedox Catalysis for Selective C(sp3)–O Cleavages of Phosphinated Alcohols to Carbanions
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We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)?O bonds of phosphinated alcohols to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation, and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for an intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)?O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions tolerate aryl chlorides/bromides and do not give rise to Birch-type reductions.
- Barham, Joshua P.,K?nig, Burkhard,Karl, Tobias A.,Reiter, Sebastian,Tian, Xianhai,Yakubov, Shahboz,de Vivie-Riedle, Regina
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p. 20817 - 20825
(2021/08/18)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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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.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Method for synthesizing E-methyl styrene compound
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The method for preparing E-pyridyl or alkyl-substituted,bipyridine, in a solvent, in the presence of nitrogen protection, in, reaction 0 °C -50 °C in the presence of a metal nickel salt 24 - 36h, ligand and an additive is E, and the preparation method disclosed by the invention has the advantages, cheap 2,2 ’ - raw materials, easiness in obtaining 2,2 ’ - and the like. The ligand is,bipyridine or an alkyl-substituted bipyridyl compound, in the. presence of a nitrogen, protection agent, in a solvent.
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Page/Page column 12
(2020/03/25)
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- Highly selective electrocatalytic oxidation of benzyl C-H using water as safe and sustainable oxygen source
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The selective oxidation of C-H bond is critical for feedstock manufacturing in chemical industry. Current strategies typically involve the use of oxygen or peroxide as the oxidation reagent under high temperature, which sets severe challenges in production sustainability and industrial safety. Herein, we demonstrate an environmental-friendly and safe electrocatalytic strategy for the selective oxidation of benzyl group to ketones at ambient conditions, while using water as the sole oxygen source. Water addition reduces the onset potential of anodic C-H oxidation, and produces 1-tetralone with satisfying conversion and excellent ketone to alcohol ratio. Layered MnO2 catalysts (with rich oxygen vacancies) further adjust the water affinity and facilitate the oxidation, leading to a significantly improved faradaic efficiency. This journal is
- Ding, Mengning,Li, Xiaoshan,Sun, Yuxia,Xie, Jin,Xu, Wentao,Yang, Miao
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supporting information
p. 7543 - 7551
(2020/11/18)
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- Vanadium Pyridonate Catalysts: Isolation of Intermediates in the Reductive Coupling of Alcohols
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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.
- Griffin, Samuel E.,Schafer, Laurel L.
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supporting information
(2020/04/15)
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- AuCl3-Catalyzed Ring-Closing Carbonyl–Olefin Metathesis
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Compared with the ripeness of olefin metathesis, exploration of the construction of carbon–carbon double bonds through the catalytic carbonyl–olefin metathesis reaction remains stagnant and has received scant attention. Herein, a highly efficient AuCl3-catalyzed intramolecular ring-closing carbonyl–olefin metathesis reaction is described. This method features easily accessible starting materials, simple operation, good functional-group tolerance and short reaction times, and provides the target cyclopentenes, polycycles, benzocarbocycles, and N-heterocycle derivatives in good to excellent yields.
- Wang, Rui,Chen, Yi,Shu, Mao,Zhao, Wenwen,Tao, Maoling,Du, Chao,Fu, Xiaoya,Li, Ao,Lin, Zhihua
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supporting information
p. 1941 - 1946
(2020/02/11)
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- Thiourea-Mediated Halogenation of Alcohols
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The halogenation of alcohols under mild conditions expedited by the presence of substoichiometric amounts of thiourea additives is presented. The amount of thiourea added dictates the pathway of the reaction, which may diverge from the desired halogenation reaction toward oxidation of the alcohol, in the absence of thiourea, or toward starting material recovery when excess thiourea is used. Both bromination and chlorination were highly efficient for primary, secondary, tertiary, and benzyl alcohols and tolerate a broad range of functional groups. Detailed electron paramagnetic resonance (EPR) studies, isotopic labeling, and other control experiments suggest a radical-based mechanism. The fact that the reaction is carried out at ambient conditions, uses ubiquitous and inexpensive reagents, boasts a wide scope, and can be made highly atom economic, makes this new methodology a very appealing option for this archetypical organic reaction.
- Mohite, Amar R.,Phatake, Ravindra S.,Dubey, Pooja,Agbaria, Mohamed,Shames, Alexander I.,Lemcoff, N. Gabriel,Reany, Ofer
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supporting information
p. 12901 - 12911
(2020/11/26)
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- Diastereoselective Synthesis of Cyclic sp 3 -Enriched cis -β-Alkoxysulfonyl Chlorides
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A three-step synthesis of β-alkoxy-substituted alicyclic sulfonyl chlorides from cyclic alkenes and alcohols is reported. The scope of the method was studied for a range of the substrates with various steric and electronic properties. The title compounds were obtained on a hundred-gram scale in up to 52% overall yield scale as single cis -diastereomers.
- Sokolov, Andriy,Golovach, Sergey,Kozlinsky, Ihor,Dolia, Krystyna,Tolmachev, Andrey A.,Kuchkovska, Yuliya,Grygorenko, Oleksandr O.
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p. 848 - 858
(2019/02/10)
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- Double Functionalization of Styrenes by Cu-Mediated Assisted Tandem Catalysis
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The double functionalization of styrenes through Cu-mediated assisted tandem catalysis was developed. The reaction was initiated by Cu-catalyzed aziridination and the subsequent nucleophilic ring-opening, which was triggered by the addition of (NH4)2S2O8 as an oxidant of Cu-catalyst to form a variety of C–C and C–X bonds. The expansion to three contiguous catalytic cycles led to the synthesis of functionalized indolines by one-pot operation.
- Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
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p. 2056 - 2060
(2019/03/13)
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- A Conformationally Restricted Aza-BODIPY Platform for Stimulus-Responsive Probes with Enhanced Photoacoustic Properties
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Photoacoustic (PA) dyes, which absorb near-infrared (NIR) light to generate an ultrasonic signal, can be detected at centimeter depths in tissues with significantly higher resolution than dyes imaged with fluorescence-based methods. As such, PA agents show great promise as research tools for the study of live-animal disease models. However, the development of activatable PA probes has been hampered by the relative scarcity of appropriate PA-active molecular platforms with properties that can be manipulated in a rational manner. Herein we synthesized and evaluated six modifications to the aza-BODIPY dye platform with respect to their absorbance, fluorescence, and PA properties. We identified a promising conformationally restricted aza-BODIPY (CRaB) scaffold that prioritizes three criteria necessary for the design of stimulus-responsive dyes with optimal ratiometric PA response: absorbance at NIR wavelengths, strong PA intensity, and large Δλ upon interaction with the desired stimulus. Using this scaffold, we synthesized three chemically diverse stimulus-responsive PA probes and demonstrated between 2- and 8-fold improvements in theoretical ratiometric response in vitro. This suggests that improvements in PA parameters are generalizable. Finally, we validated the in vitro turnover of each CRaB PA probe and demonstrated the in vivo potential of the CRaB scaffold by direct comparison to an established hypoxia-responsive probe for the detection of tumor hypoxia.
- Zhou, Effie Y.,Knox, Hailey J.,Liu, Chang,Zhao, Weili,Chan, Jefferson
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supporting information
p. 17601 - 17609
(2019/11/11)
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- Chemoenzymatic Synthesis of a Chiral Ozanimod Key Intermediate Starting from Naphthalene as Cheap Petrochemical Feedstock
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Ozanimod represents a recently developed, promising active pharmaceutical ingredient (API) molecule in combating multiple sclerosis. Addressing the goal of a scalable, economically attractive, and technically feasible process for the manufacture of this drug, a novel alternative synthetic approach toward (S)-4-cyano-1-aminoindane as a chiral key intermediate for ozanimod has been developed. The total synthesis of this intermediate is based on the utilization of naphthalene as a readily accessible, economically attractive, and thus favorable petrochemical starting material. At first, naphthalene is transformed into 4-carboxy-indanone within a four-step process by means of an initial Birch reduction, followed by an isomerization of the C=C double bond, oxidative C=C cleavage, and intramolecular Friedel-Crafts acylation. The transformation of the 4-carboxy-indanone into (S)-4-cyano-1-aminoindane then represents the key step for introducing the chirality and the desired absolute S configuration. When evaluating complementary biocatalytic approaches based on the use of a lipase and transaminase, respectively, the combination of a chemical reductive amination of the 4-carboxyindanone followed by a subsequent lipase-catalyzed resolution turned out to be the most efficient route, leading to the desired key intermediate (S)-4-cyano-1-aminoindane in satisfactory yield and with excellent enantiomeric excess of 99%.
- Uthoff, Florian,L?we, Jana,Harms, Christina,Donsbach, Kai,Gr?ger, Harald
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p. 4856 - 4866
(2019/05/02)
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- A Cu-Doped ZIF-8 metal organic framework as a heterogeneous solid catalyst for aerobic oxidation of benzylic hydrocarbons
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Mixed-metal metal organic frameworks have received considerable attention in recent years and it has been shown that the activity of the parent metal organic framework (MOF) is often enhanced upon doping with external metal ions within the framework. In this context, Cu2+ ions with different loadings were incorporated within the ZIF-8 framework to obtain a series of Cu-doped ZIF-8 materials and their activity was examined in the aerobic oxidation of hydrocarbons. The as-synthesized Cu-doped solids were characterized by powder X-ray diffraction (XRD), ultraviolet diffuse reflectance spectroscopy (UV-DRS), scanning electron microscopy (SEM), Fourier Transform infrared (FT-IR), electron paramagnetic resonance (EPR) and inductively coupled plasma (ICP) analysis. The experimental results revealed that the activity of Cu-doped ZIF-8 is much higher than that of the parent ZIF-8 in all the tested substrates at 120 °C. Furthermore, the activity of the Cu-doped ZIF-8 with the highest Cu loading was eight fold higher than that of the parent ZIF-8 in the aerobic oxidation of cyclooctane (1) at 120 °C with more than 80% selectivity to the corresponding cyclooctanol/cyclooctanone (ol/one) mixture. Cu-doped ZIF-8 was reused two times with no significant drop in its activity under identical conditions. Furthermore, comparison of the two times reused solid with that of the fresh solid by powder XRD and SEM analysis revealed identical structural integrity and morphology, respectively during the oxidation reactions.
- Nagarjun, Nagarathinam,Dhakshinamoorthy, Amarajothi
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p. 18702 - 18712
(2019/12/09)
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- Efficient and selective hydrogenation of C-O bonds with a simple sodium formate catalyzed by nickel
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A Ni-catalyzed hydrogenation of C-O compounds with sodium formate is developed. Various esters, i.e. aryl, alkenyl, benzyl pivalates, and even the aryl ethers, were efficiently reduced with a loading of nickel catalysts down to 0.5 mol%. Reactive functional groups such as C-C double bonds, carbonyl, CN, MeS and halogen groups are tolerable. This reaction can be used for the modification of complex molecules and carried out at a large scale.
- Xi, Xiaoxiang,Chen, Tieqiao,Zhang, Ji-Shu,Han, Li-Biao
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p. 1521 - 1524
(2018/02/19)
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- Stable Carbocation Generated via 2,5-Cyclohexadien-1-one Protonation
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Protonation of a substituted cyclohexadien-1-one (1) leads to the generation of carbocation [3]+, capable of effecting hydride abstraction and oxidation reactions. The molecular structure of [3]+ shows it to be structurally similar to [(p-MeO-C6H4)Ph2C]+. The ability to easily access [3]+ from stable and available precursors, such as 1 and commercially available acids, may allow a wider application of the growing number of trityl-based reactions in organic syntheses.
- Fraser, Craig,Young, Rowan D.
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p. 505 - 509
(2018/02/19)
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- A process for the preparation and synthetic ChondriamideA and ChondriamideC method (by machine translation)
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The invention provides a process for the preparation of synthetic Chondriamide A and Chondriamide C and method, wherein the invention provides a process for the preparation, including: formula (I) compounds of structure, palladium catalyst, phosphorus ligand, alkali and organic solvent at room temperature the illumination reaction, formula (II) structure obtained olefin; wherein through the selection of a particular phosphorus ligand; make the method of the invention can be under the photocatalysis, room temperature to realize high-efficient catalytic conversion, and the mild reaction conditions, simple operation, in line with the development of green environment-friendly chemical requirements, and the range of choice of substrate and functional group compatibility has more universal, and has outstanding chemical selectivity; and the method can be successfully applied to complex molecular introducing carbon-carbon double bond to the programme, to optimize a part of the drug molecular synthesis strategy, improve the synthesis efficiency, reduce the cost, with industrial synthetic value and prospects. (by machine translation)
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Paragraph 0078-0082; 0108-0111
(2018/09/13)
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- Multimetallic Ni- and Pd-Catalyzed Cross-Electrophile Coupling to Form Highly Substituted 1,3-Dienes
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The synthesis of highly substituted 1,3-dienes from the coupling of vinyl bromides with vinyl triflates is reported for the first time. The coupling is catalyzed by a combination of (5,5′-bis(trifluoromethyl)-2,2′-bipyridine)NiBr2 and (1,3-bis(diphenylphosphino)propane)PdCl2 in the presence of a zinc reductant. This method affords tetra- and penta-substituted 1,3-dienes that would otherwise be difficult to access and tolerates electron-rich and -poor substituents, heterocycles, an aryl bromide, and a pinacol boronate ester. Mechanistically, the reaction appears to proceed by an unusual zinc-mediated transfer of a vinyl group between the nickel and palladium centers.
- Olivares, Astrid M.,Weix, Daniel J.
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supporting information
p. 2446 - 2449
(2018/02/28)
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- Catalyst-free synthesis of amines from cyclic ketones and formamides in superheated water
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A novel and environmentally benign protocol for the synthesis of amines from cyclic ketones and formamides is demonstrated. The reaction proceeds under catalyst-free and superheated water conditions and yields range from poor to excellent.
- Kumar, Macharla Arun,Srujana, Kodumuri,Swamy, Peraka,Naresh, Mameda,Durgaiah, Chevella,Rammurthy, Banothu,Narender, Nama
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supporting information
p. 516 - 522
(2016/05/02)
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- Deoxygenation of carbonyl compounds using an alcohol as an efficient reducing agent catalyzed by oxo-rhenium complexes
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This work describes the first methodology for the deoxygenation of carbonyl compounds using an alcohol as a green solvent/reducing agent catalyzed by oxo-rhenium complexes. The system 3-pentanol/ReOCl3(SMe2)(OPPh3) was successfully employed in the deoxygenation of several aryl ketones to the corresponding alkenes and also in the deoxygenation of aryl aldehydes to alkanes with moderate to excellent yields. The catalyst ReOCl3(SMe2)(OPPh3) can also be used in several catalytic cycles with good activity.
- Bernardo, Joana R.,Fernandes, Ana C.
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supporting information
p. 2675 - 2681
(2016/05/24)
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- Lewis base-assisted Lewis acid-catalyzed selective alkene formation via alcohol dehydration and synthesis of 2-cinnamyl-1,3-dicarbonyl compounds from 2-aryl-3,4-dihydropyrans
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Acid-catalyzed dehydration of alcohols has been widely employed for the synthesis of alkenes. However, activated alcohols when employed as substrates in dehydration reactions are often plagued by the lack of alkene selectivity. In this work, the reaction system can be significantly improved through enhancing the performance of Lewis acid catalysts in the dehydration of activated alcohols by combining with a Lewis base. Observations of the reaction mechanism revealed that the Lewis base component might have changed the reaction rate order. Although both the principal and side reaction rates decreased, the effect was markedly more observed on the latter reaction. Therefore, the selectivity of the dehydration reaction was improved. On the basis of this observation, a new route to synthesize 2-cinnamyl-1,3-dicarbonyl compounds was developed by using 2-aryl-3,4-dihydropyran as a starting substrate in the presence of a Lewis acid/Lewis base combined catalyst system.
- Liu, Changhui,Pan, Bin,Gu, Yanlong
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p. 979 - 986
(2016/07/06)
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- A Switchable Gold Catalyst by Encapsulation in a Self-Assembled Cage
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Dinuclear gold complexes have the ability to interact with one or more substrates in a dual-activation mode, leading to different reactivity and selectivity than their mononuclear relatives. In this contribution, this difference was used to control the catalytic properties of a gold-based catalytic system by site-isolation of mononuclear gold complexes by selective encapsulation. The typical dual-activation mode is prohibited by this catalyst encapsulation, leading to typical behavior as a result of mononuclear activation. This strategy can be used as a switch (on/off) for a catalytic reaction and also permits reversible control over the product distribution during the course of a reaction.
- Jans, Anne C. H.,Gómez-Suárez, Adrián,Nolan, Steven P.,Reek, Joost N. H.
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supporting information
p. 14836 - 14839
(2016/10/11)
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- Exploring substrate scope and stereoselectivity of P450 peroxygenase OleTJE in olefin-forming oxidative decarboxylation
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As recently reported, the olefin-forming oxidative decarboxylation of straight-chain C4-C22 carboxylic acids catalyzed by P450 peroxygenase OleTJE constitutes a mild alkene synthesis. The present study shows that structurally different carboxylic acids are also accepted, including those that generate di-substituted olefins. Exploratory mutational experiments lead to increased trans-selectivity.
- Wang, Jian-Bo,Lonsdale, Richard,Reetz, Manfred T.
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supporting information
p. 8131 - 8133
(2016/07/06)
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- Facile Protocol for Catalytic Frustrated Lewis Pair Hydrogenation and Reductive Deoxygenation of Ketones and Aldehydes
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A series of ketones and aldehydes are reduced in toluene under H2 in the presence of 5 mol % B(C6F5)3 and either cyclodextrin or molecular sieves affording a facile metal-free protocol for reduction to alcohols. Similar treatment of aryl ketones resulted in metal-free deoxygenation yielding aromatic hydrocarbons.
- Mahdi, Tayseer,Stephan, Douglas W.
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p. 8511 - 8514
(2015/11/27)
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- Dioxomolybdenum Complexes as Excellent Catalysts for the Deoxygenation of Aryl Ketones to Aryl Alkenes
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This work describes a new methodology for the selective deoxygenation of aryl ketones to the corresponding aryl alkenes catalyzed by dioxomolybdenum complexes using silanes as reducing agents. The best results were obtained with the system PhSiH3/MoO2Cl2(H2O)2 (5-10 mol %), which was very efficient for the deoxygenation of a large variety of aryl ketones to alkenes in excellent yields. This new methodology has the advantages of using an inexpensive, environmentally friendly, easily prepared, and air-stable catalyst in ether solution.
- Fernandes, Tiago A.,Fernandes, Ana C.
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p. 3503 - 3507
(2015/11/10)
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- Verification of the Major Metabolic Oxidation Path for the Naphthoyl Group in Chemoattractant Receptor-Homologous Molecule Expressed on Th2 Cells (CRTh2) Antagonist 2-(2-(1-Naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic Acid (Setipiprant/ACT-129968)
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Various racemic and enantioenriched (trans)-X,Y-dihydroxy-X,Y-dihydronaphthoyl analogues as well as X-hydroxy-naphthoyl analogues of CRTh2 antagonist 2-(2-(1-naphthoyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid (1, Setipiprant/ACT-129968) were synthesized in order to gain insight into regio- and enantioselectivity of the metabolic oxidation of 1 and to verify the structures of four metabolites that were proposed earlier in a clinical ADME study. Analytical data of the synthetic standards were compared with data from samples of biological origin. The two major metabolites M7 and M9 were unambiguously verified as 2-(2-((trans)-3,4-dihydroxy-3,4-dihydronaphthalene-1-carbonyl)- and 2-(2-((trans)-5,6-dihydroxy-5,6-dihydronaphthalene-1-carbonyl)-8-fluoro-3,4-dihydro-1H-pyrido[4,3-b]indol-5(2H)-yl)acetic acid, respectively, each composed of two enantiomers with 68% and 44% ee in favor of (+)-(3S,4S)-M7 and (+)-(5S,6S)-M9, respectively. Likewise, minor metabolites M3 and M13 were identified as 2-(8-fluoro-2-(5-hydroxy-1-naphthoyl)- and 2-(8-fluoro-2-(4-hydroxy-1-naphthoyl)-1,2,3,4-tetrahydro-5H-pyrido[4,3-b]indol-5-yl)acetic acid, respectively.
- Risch, Philippe,Pfeifer, Thomas,Segrestaa, Jerome,Fretz, Heinz,Pothier, Julien
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p. 8011 - 8035
(2015/11/09)
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- Carbon Dioxide Copolymerization Study with a Sterically Encumbering Naphthalene-Derived Oxide
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Poly(1,4-dihydronaphthalene carbonate) has been prepared via the catalytic coupling of carbon dioxide and 1,4-dihydronaphthalene oxide using chromium(III) catalysts. The copolymer formation is found to be greatly dependent on the steric environment around the metal center. Traditional (salen)CrIIIX/cocatalyst systems bearing bulky t-butyl groups hinder the approach of the large monomer, significantly diminishing polymer chain growth and providing the entropically favored cyclic byproduct in excess. In contrast, employing the sterically unencumbered azaannulene-derived catalyst, (tmtaa)CrIIIX/cocatalyst system (tmtaa = tetramethyltetraazaannulene) shows polymer selectivity close to 90% with three times the activity (TOF = 20-30 h-1). With the use of a bifunctional (salen)CrIII catalyst, even higher polymer selectivity (>90%) can be observed. The complete synthesis of a new bifunctional tetraazaannulene ligand for a more effective catalyst is also described herein.
- Darensbourg, Donald J.,Kyran, Samuel J.
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p. 5421 - 5430
(2015/09/15)
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- HETEROCYCLIC COMPOUNDS AND METHODS OF USE THEREOF
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Provided herein are heterocyclyl compounds, methods of their synthesis, pharmaceutical compositions comprising the compounds, and methods of their use. The compounds provided herein are useful for the treatment, prevention, and/or management of various neurological disorders, including but not limited to, psychosis and schizophrenia.
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- A mild and efficient method for bromination of alcohols using α,α-dibromo-β-dicarbonyl compounds as halogen sources
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Exploration of α,α-dibromo-β-dicarbonyl compounds as novel bromine agents for the conversion of alcohols to alkyl bromides under neutral conditions has been achieved. This method can be used for acid-sensitive substrates and allows the bromination of various primary and secondary alcohols to proceed at room temperature within a very short period of time.
- Cui, Xiao-Meng,Guan, Yong-Hong,Li, Na,Lv, Hao,Fu, Lin-An,Guo, Kun,Fan, Xiaohui
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supporting information
p. 90 - 93
(2014/01/06)
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- Endo-selective pd-catalyzed silyl methyl heck reaction
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A palladium (Pd)-catalyzed endo-selective Heck reaction of iodomethylsilyl ethers of phenols and aliphatic alkenols has been developed. Mechanistic studies reveal that this silyl methyl Heck reaction operates via a hybrid Pd-radical process and that the silicon atom is crucial for the observed endo selectivity. The obtained allylic silyloxycycles were further oxidized into (Z)-alkenyldiols.
- Parasram, Marvin,Iaroshenko, Viktor O.,Gevorgyan, Vladimir
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supporting information
p. 17926 - 17929
(2015/03/04)
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- Towards a practical development of light-driven acceptorless alkane dehydrogenation
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The efficient catalytic dehydrogenation of alkanes to olefins is one of the most investigated reactions in organic synthesis. In the coming years, an increased supply of shorter-chain alkanes from natural and shale gas will offer new opportunities for inexpensive carbon feedstock through such dehydrogenation processes. Existing methods for alkane dehydrogenation using heterogeneous catalysts require harsh reaction conditions and have a lack of selectivity, whereas homogeneous catalysis methods result in significant waste generation. A strong need exists for atom-efficient alkane dehydrogenations on a useful scale. Herein, we have developed improved acceptorless catalytic systems under optimal light transmittance conditions using trans-[Rh(PMe3) 2(CO)Cl] as the catalyst with different additives. Unprecedented catalyst turnover numbers are obtained for the dehydrogenation of cyclic and linear (from C4) alkanes and liquid organic hydrogen carriers. These reactions proceed with unique conversion, thereby providing a basis for practical alkane dehydrogenations.
- Chowdhury, Abhishek Dutta,Weding, Nico,Julis, Jennifer,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 6477 - 6481
(2014/06/24)
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- Homogeneous catalysis and selectivity in electrochemistry
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The relationship between homogeneous catalysis and electrochemistry is examined in light of two examples based on our work concerning (a) catalyst activation, regarding selective electrochemical C-H oxidation with RuIII/RuIV mediation, and (b) catalyst suppression, regarding controlling selectivity in electrochemical aromatic chlorination. The first example (a) deals with the role of catalysis at the working electrode. The electrochemical (EC) oxidation of specific hydrocarbons such as tetralin and indane is performed using tris(acetonitrile)ruthenium trichloride (Ru(CH3CN)3Cl3) as a mediator. The role of this mediator in the oxidation of tetralin has been reported. This homogeneous C-H activation by electron transfer (ET) is accompanied by the redox transitions of the mediator in the course of the catalytic oxidation, and these are the main points of interest here. Additional studies with a rotating ring disk electrode (RRDE) provided a follow-up of creation and recovery of RuIII/RuII and RuIII/RuIV species in the process. Using electrochemistry linked with electrospray ionization mass spectrometry (EC/ESI-MS) gave additional information on the structure of the reduced and oxidized forms of Ru(CH3CN)3Cl3 and the effect of water in the solvent on their lifetimes. The second example (b) of electrochlorination has been reported elsewhere and is brought up as complementary remarks. Aromatic electrophilic chlorination of 1,4-dimethoxy-2-tertbutylbenzene is autocatalyzed and unselective. The EC procedure provides a simple means to inhibit the catalytic runaway reaction. This example shows how the counter electrode affects catalysis and selectivity. (Figure Presented)
- Michman, Michael,Appelbaum, Lina,Gun, Jenny,Modestov, Alexander D.,Lev, Ovadia
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p. 4729 - 4737
(2015/04/27)
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- Iron-catalyzed C-C bond cleavage and C-N bond formation
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A novel approach for C-N bond formation was developed by iron-catalyzed C-C bond cleavage. Anilines and sulfonamides reacted smoothly with 2-substituted 1,3-diphenylpropane-1,3-diones to afford N-alkylation products, in which the 1,3-dicarbonyl group acts as a leaving group in the presence of an iron catalyst. The reversible C-C bond cleavage plays a driving force to give the thermodynamically stable products. The method is complementary to the previous methods for C-N bond formation. Copyright
- Li, Wenjuan,Zheng, Xiaojian,Li, Zhiping
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p. 181 - 190
(2013/03/13)
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- Organic reactivity of alcohols in superheated aqueous salt solutions: An overview
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The low dielectric constant and high self-dissociation constant of water in a temperature range between 150 and 250 °C make it a very appealing solvent for synthesis. Surprisingly, while organic chemistry in water at low temperature or around its critical point has been investigated in detail, very little seems to be known about the behaviour of organic molecules under hydrothermal conditions. The present work thus aims at shading some light on this field. As a start, we decided to investigate the reactions in which alcohols can undergo in water in the above-mentioned temperature range. Knowing that very strong salt effects on organic reactions have already been observed in super critical water, the impact of salt on the outcome of our tests was also investigated in detail.
- Avola, Sabine,Goettmann, Frederic,Antonietti, Markus,Kunz, Werner
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scheme or table
p. 1568 - 1573
(2012/10/07)
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- Enzymatic allylic oxidations with a lyophilisate of the edible fungus Pleurotus sapidus
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Allylic oxidations belong to the most attractive synthetic transformations because they convert readily available and cheap starting materials into value-added products. In this study, we describe oxidative conversions of terpenoids and a number of related cycloalkenes with a lyophilisate of the edible fungus Pleurotus sapidus. The biocatalytic protocol is simple and the biocatalyst is readily available. The conversions of various cycloalkenes proceed cleanly in most cases to the corresponding enones. The substrate scope is remarkable and includes a number of mono- and sequiterpenes, functionalized terpenoids as well as simple cyclohexenes and benzylic substrates. Enzymatic allylic oxidations by Pleurotus sapidus are thus an excellent non-toxic alternative to metal-mediated oxidation procedures in academic labs and for industrial application in food technology, cosmetics or pharmaceutical research. The Royal Society of Chemistry 2012.
- Rickert, Aljona,Krombach, Verena,Hamers, Oliver,Zorn, Holger,Maison, Wolfgang
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experimental part
p. 639 - 644
(2012/04/23)
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- Direct alkylation of aromatics using alcohols in the presence of NaHSO 4/SiO2
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Simple and efficient procedure for alkylation of aromatics from alcohols in the presence of NaHSO4/SiO2 was developed. Various triaryl methanes were obtained in good yields in short reaction time. For instance the reaction of mesitylene with benzhydrol in the presence of NaHSO4/SiO2 gave the corresponding triaryl methane in a quantitative yield. NaHSO4/SiO2 was regenerated by simple treatment and could be recycled eight times without activity loss.
- Sato, Yuta,Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
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scheme or table
p. 7077 - 7081
(2012/08/28)
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- Supramolecular control on chemo- and regioselectivity via encapsulation of (NHC)-Au catalyst within a hexameric self-assembled host
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The encapsulation of a Au(I) catalyst within a self-assembled, hydrogen bonded, hexameric capsule dramatically changes its catalytic activity, leading to unusual products due to the steric requirements of the host's cavity.
- Cavarzan, Alessandra,Scarso, Alessandro,Sgarbossa, Paolo,Strukul, Giorgio,Reek, Joost N. H.
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supporting information; experimental part
p. 2848 - 2851
(2011/04/25)
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- Acid catalysed reaction of indanones, tetralones and benzosuberone with neopentyl glycol and other alkanediols under forced conditions
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Upon reaction with an excess of 2,2-dimethylpropane-1,3-diol (neopentyl glycol, NPG) under acid catalysis, indanones and tetralones yield indenes and dihydronaphthalenes, respectively. The reaction can also be carried out with butane-1,3-diol.
- Imai, Masao,Morais, Goreti Ribeiro,Al-Hindawi, Bassam,Al-Sulaibi, Mazen A.M.,Meetani, Mohammad,Thiemann, Thies
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experimental part
p. 325 - 329
(2010/10/19)
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- Design of thermally stable versions of the burgess reagent: Stability and reactivity study (1)
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Three new versions of the Burgess reagent were synthesized and their thermal stability investigated by NMR. The new reagents exhibited improved reactivity toward epoxides, diols, and vinyl oxiranes as compared with the original version.
- Metcalf, Thomas A.,Simionescu, Razvan,Hudlicky, Tomas
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supporting information; experimental part
p. 3447 - 3450
(2010/07/07)
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- The first total synthesis of racemic 3,4-dihydroxy-2-(3-methylbut-2-enyl)- 3,4-dihydronaphthalen-1(2 H)-one
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Racemic 3,4-dihydroxy-2-(3-methylbut-2-enyl)-3,4-dihydronaphthalen-1(2H)- one is synthesized for the first time, in seven steps, starting from commercially available -tetralone. The key steps in this process are dihydroxylation using osmium tetroxide, benzylic oxidation mediated by sodium chlorite-tert-butyl hydroperoxide, and prenylation. Georg Thieme Verlag Stuttgart New York.
- Suresh, Vangaru,Selvam, Jondass Jon Paul,Rajesh, Karuturi,Shekhar, Vanam,Babu, Dokuburra Chanti,Venkateswarlu, Yenamandra
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experimental part
p. 1763 - 1765
(2010/08/03)
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- Catalytic dehydration of benzylic alcohols to styrenes by rhenium complexes
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The oxygen content of biomass-based materials can be reduced by selective dehydration of hydroxyl groups. As a first step towards biomass-based chemicals, rhenium-based catalysts are shown to be active in the dehydration of various benzylic alcohols to styrene moieties. The turnover frequencies are superior to the benchmark catalyst sulfuric acid, without sacrificing any selectivity.
- Korstanje, Ties J.,Jastrzebski, Johann T. B. H.,Gebbink, Robertus J. M. Klein
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experimental part
p. 695 - 697
(2011/12/15)
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- Gas-phase pyrolytic reaction of 4-Aryl-3-buten-2-ols and allyl benzyl ethers: Kinetic and mechanistic study
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Flash vacuum pyrolysis (FVP) of 4-aryl-3-buten-2-ols [ArCH=CHCH(CHs)OH, where Ar is phenyl, p-MeO, p-Me, p-Cl, p-NO2] gave the corresponding buta-1,3-dien-1-ylbenzene (ArCH=CH-CH=CH2, where Ar is Ph, p-MeO, p-Me, p-Cl, pNO2) and 7-×-1,2-dihydronaphthalene derivatives (where X is H, MeO); FVP of 1-aryl-3benzyloxyl-1-butenes and benzyl cinnamyl ethers [ArCH=CHCH(X)OCH2Ph, where Ar is phenyl, p-MeO, p-Me, p-Cl, X is H, Me, Ph] gave the corresponding but-2-en-l-ylbenzene derivatives (ArCH 2CH=CH-X, where X is H, Me, Ph) together with benzaldehyde. The proposed mechanism of these pyrolytic transformations was supported by kinetic and product analysis.
- Al-Etaibi, Alya M.,Al-Awadi, Nouria A.,Ibrahim, Maher R.,Ibrahim, Yehia A.
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experimental part
p. 407 - 419
(2010/05/02)
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- Methods for Treating Dependence
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Provided are methods of treating patients suffering from or susceptible to at least one symptom of abuse of, dependence on, or withdrawal from at least one substance with Compound A. Also provided are methods of treating at least one phase of substance dependence on at least one substance in patients and certain methods of treating at least one phase of cocaine dependence in patients.
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- Mild and efficient debromination of vic-dibromides to alkenes with fecl36h2o/indium system
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The FeCl36H2O/indium system efficiently causes debromination of various dibromides to the corresponding alkenes in good to excellent yields under mild conditions.
- Woo Yoo, Byung,Woo Choi, Jin,Hye Yang, Min
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experimental part
p. 1488 - 1493
(2009/09/27)
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- Synthesis of aryl-containing terpenoids based on 1,4-dihydronaphthalene
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Successive transformations including oxidation of 1,4-dihydronaphthalene into 1,2,3,4-tetrahydronaphthalen-2-one, Reformatskii reaction of the latter with methyl bromoacetate, ozonolysis of the Reformatsky reaction product, and Emmons olefination of the aldehyde group in methyl 3-oxo-5-(2-formylphenyl) pentanate thus formed gave analogs of highly active dienoate juvenoids having an aromatic ring in their molecules.
- Kukovinets,Kislitsyn,Zainullin,Mukhamedzyanova,Galin,Abdullin
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p. 362 - 368
(2008/12/22)
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- Simple and efficient synthesis of 4,7-dimethoxy-1(H)-indene
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Stirring 4,7-dimethoxy-1-indanol in chloroform at room temperature in the presence of a catalytic amount of p-toluenesulfonic acid gave 4,7-dimethoxy-1(H)-indene in quantitative yield. Other solvents, including benzene, which was the most frequently used one for this reaction, gave mostly polymeric materials. The new method was also effective for dehydration of other electron-rich benzylic alcohols. Copyright Taylor & Francis Group, LLC.
- Zhang, Xiang,Thimmaiah, Muralidhara,Fang, Shiyue
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p. 1873 - 1877
(2008/02/03)
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- Secondary benzylation with benzyl alcohols catalyzed by a high-valent heterobimetallic Ir-Sn complex
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(Chemical Equation Presented) A highly efficient secondary benzylation procedure has been demonstrated using a high-valent heterobimetallic complex [Ir2(COD)2(SnCls)2(Cl)2(μ-Cl) 2] 1 as the catalyst in 1,2-dichloroethane to afford the corresponding benzylated products in moderate to excellent yields. The reaction was performed not only with carbon nucleophiles (arenes and heteroarenes) but also with oxygen (alcohol), nitrogen (amide and sulfonamide), and sulfur (thiol) nucleophiles. Mechanistic investigation showed the intermediacy of the ether in this reaction. An electrophilic mechanism is proposed from Hammett correlation.
- Podder, Susmita,Choudhury, Joyanta,Roy, Sujit
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p. 3129 - 3132
(2008/02/07)
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