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Trapping Pd(0) in nanoparticle-assembled microcapsules: An efficient and reusable catalyst
Pd nanoparticles dually encased by soft (polyamine) and hard (silica) materials in a microcapsule structure, obtained via a nanoparticle self-assembly method, exhibit excellent catalytic activity, with efficient catalyst recovery and reusability. The Royal Society of Chemistry.
Amali, Arlin Jose,Rana, Rohit Kumar
p. 4165 - 4167
(2008)
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Preparation method of pazopanib intermediate
The invention provides a preparation method of a pazopanib key intermediate 2,3-dimethyl-N-(2-chloropyrimidin-4-yl)-N-methyl-2H-indazole-6-amine. The method comprises the following steps: by taking 6-halogenated-2,3-dimethyl-2H-indazole as a raw material, conducting reacting to obtain N,2,3-trimethyl-2H-indazole-6-amine; and further carrying out a reaction to obtain the 2,3-dimethyl-N-(2-chloropyrimidin-4-yl)-N-methyl-2H-indazole-6-amine. The method has the advantages of short synthesis route, accessible raw materials, low cost, mild reaction conditions, high safety and high yield, and is suitable for industrial mass production.
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(2021/03/24)

Hydroboration reduction reaction of aromatic nitro compounds without transition metal catalysis
The invention relates to a hydroboration reduction reaction of aromatic nitro compounds without transition metal catalysis. According to the method, triethyl boron and potassium tert-butoxide are used as catalysts for the first time, and an aromatic nitro compound and pinacol borane which is low in price and easy to obtain can be conveniently catalyzed to be subjected to a hydroboration reduction reaction under mild conditions to prepare aromatic amine products. Compared with a traditional method, the method generally has the advantages that the catalyst is cheap and easy to obtain, operation is convenient, and reaction is safe. The selective hydroboration reduction reaction of the non-transition metal reagent catalyzed aromatic nitro compound and pinacol borane is realized for the first time, and a practical new reaction strategy is provided for laboratory preparation or industrial production of aromatic amine products.
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(2021/07/31)

Chemoselective Hydrogenation of Nitroarenes Using an Air-Stable Base-Metal Catalyst
The reduction of nitroarenes to anilines as well as azobenzenes to hydrazobenzenes using a single base-metal catalyst is reported. The hydrogenation reactions are performed with an air-and moisture-stable manganese catalyst and proceed under relatively mild reaction conditions. The transformation tolerates a broad range of functional groups, affording aniline derivatives and hydrazobenzenes in high yields. Mechanistic studies suggest that the reaction proceeds via a bifunctional activation involving metal-ligand cooperative catalysis.
Zubar, Viktoriia,Dewanji, Abhishek,Rueping, Magnus
supporting information
p. 2742 - 2747
(2021/05/05)

Cobalt nanoclusters coated with N-doped carbon for chemoselective nitroarene hydrogenation and tandem reactions in water
The development of active and selective non-noble metal-based catalysts for the chemoselective reduction of nitro compounds in aquo media under mild conditions is an attractive research area. Herein, the synthesis of subnanometric and stable cobalt nanoclusters, covered by N-doped carbon layers as core-shell (Co@NC-800), for the chemoselective reduction of nitroarenes is reported. TheCo@NC-800catalyst was prepared by the pyrolysis of the Co(tpy)2complex impregnated on Vulcan carbon. In fact, the use of a molecular complex based on six N-Co bonds drives the formation of a well-defined and distributed cobalt core-shell nanocluster covered by N-doped carbon layers. In order to elucidate its nature, it has been fully characterized by using several advanced techniques. In addition, this as-prepared catalyst showed high activity, chemoselectivity and stability toward the reduction of nitro compounds with H2and under mild reaction conditions; water was used as a green solvent, improving the previous results based on cobalt catalysts. Moreover, theCo@NC-800catalyst is also active and selective for the one-pot synthesis of secondary aryl amines and isoindolinones through the reductive amination of nitroarenes. Finally, based on diffraction and spectroscopic studies, metallic cobalt nanoclusters with surface CoNxpatches have been proposed as the active phase in theCo@NC-800material.
Agostini, Giovanni,Calvino, Jose. J.,Corma, Avelino,Gutiérrez-Tarri?o, Silvia,Lopes, Christian W.,O?a-Burgos, Pascual,Rojas-Buzo, Sergio
supporting information
p. 4490 - 4501
(2021/06/28)

Cu-Catalyzed Cross-Coupling of Nitroarenes with Aryl Boronic Acids to Construct Diarylamines
The development and study of a simple copper-catalyzed reaction of nitroarenes with aryl boronic acids to form diarylamines that uses phenyl silane as the stoichiometric terminal reductant is described. This cross-coupling reaction requires as little as 2 mol % of CuX and 4 mol % of diphosphine for success and tolerates a broad range of functional groups on either the nitroarene or the aryl boronic acid to afford the amine in good yield. Mechanistic investigations established that the cross-coupling reaction proceeds via a nitrosoarene intermediate and that copper is required to catalyze both the deoxygenation of the nitroarene to afford the nitrosoarene and C-NAr bond formation of the nitrosoarene with the aryl boronic acid.
Guan, Xinyu,Zhu, Haoran,Driver, Tom G.
p. 12417 - 12422
(2021/10/12)

Effect of solvent in the hydrogenation of acetophenone catalyzed by Pd/S-DVB
A solvent effect was found in the hydrogenation of acetophenone catalyzed by a new Pd/S-DVB catalyst, immobilized on a styrene (S)/divinylbenzene (DVB) copolymer containing phosphinic groups. The porous structure of the catalyst was characterized by a specific surface area of 94.7 m2g?1. The presence of Pd(ii) and Pd(0) in Pd/S-DVB was evidenced by XPS and TEM. Pd/S-DVB catalyzes the hydrogenation of acetophenone (APh) to 1-phenylethanol (PhE) and ethylbenzene (EtB). The highest conversion of APh was obtained in methanol (MeOH) and in 2-propanol (2-PrOH), while in water it was lower. The conversion of APh correlates well with the hydrogen-bond-acceptance (HBA) capacity of the solvent. However, in all binary mixtures of alcohol and water the APh conversion and the yield of products significantly decreased. The observed inhibiting effect can be explained by the microheterogeneity of these mixtures and the blocking of the catalyst surface restricting access of the substrates to the Pd centers.
Bereta, Tomasz,Mieczyńska, Ewa,Ronka, Sylwia,Tylus, W?odzimierz,Trzeciak, Anna M.
p. 5023 - 5028
(2021/03/26)

Minimization of Back-Electron Transfer Enables the Elusive sp3 C?H Functionalization of Secondary Anilines
Anilines are some of the most used class of substrates for application in photoinduced electron transfer. N,N-Dialkyl-derivatives enable radical generation α to the N-atom by oxidation followed by deprotonation. This approach is however elusive to monosubstituted anilines owing to fast back-electron transfer (BET). Here we demonstrate that BET can be minimised by using photoredox catalysis in the presence of an exogenous alkylamine. This approach synergistically aids aniline SET oxidation and then accelerates the following deprotonation. In this way, the generation of α-anilinoalkyl radicals is now possible and these species can be used in a general sense to achieve divergent sp3 C?H functionalization.
Zhao, Huaibo,Leonori, Daniele
supporting information
p. 7669 - 7674
(2021/03/08)

Superhydrophobic nickel/carbon core-shell nanocomposites for the hydrogen transfer reactions of nitrobenzene and N-heterocycles
In this work, catalytic hydrogen transfer as an effective, green, convenient and economical strategy is for the first time used to synthesize anilines and N-heterocyclic aromatic compounds from nitrobenzene and N-heterocycles in one step. Nevertheless, how to effectively reduce the possible effects of water on the catalyst by removal of the by-product water, and to further introduce water as the solvent based on green chemistry are still challenges. Since the structures and properties of carbon nanocomposites are easily modified by controllable construction, a one step pyrolysis process is used for controllable construction of micro/nano hierarchical carbon nanocomposites with core-shell structures and magnetic separation performance. Using various characterization methods and model reactions the relationship between the structure of Ni?NCFs (nickel-nitrogen-doped carbon frameworks) and catalytic performance was investigated, and the results show that there is a positive correlation between the catalytic performance and hydrophobicity of catalysts. Besides, the possible catalytically active sites, which are formed by the interaction of pyridinic N and graphitic N in the structure of nitrogen-doped graphene with the surfaces of Ni nanoparticles, should be pivotal to achieving the relatively high catalytic performance of materials. Due to its unique structure, the obtained Ni?NCF-700 catalyst with superhydrophobicity shows extraordinary performances toward the hydrogen transfer reaction of nitrobenzene and N-heterocycles in the aqueous state; meanwhile, it was also found that Ni?NCF-700 still retained its excellent catalytic activity and structural integrity after three cycles. Compared with traditional catalytic systems, our catalytic systems offer a highly effective, green and economical alternative for nitrobenzene and N-heterocycle transformation, and may open up a new avenue for simple construction of structure and activity defined carbon nanocomposite heterogeneous catalysts with superhydrophobicity.
Duan, Zhiying,Liu, Fangfang,Pang, Shaofeng,Su, Qiong,Wang, Yanbin,Xie, Xin,Zhang, Ping,Zhang, Yujing,Zhou, Feng
p. 1996 - 2010
(2020/04/07)

Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
supporting information
p. 4119 - 4129
(2020/08/10)

Short time synthesis of titania modified-CMK-3 carbon mesostructure as support for Ir-catalyst applied in catalytic hydrotreating
Ti-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The method developed here, allows to reduce time, energy consumptionand cost. Structural and textural characterization of the titanium modified-mesoporous carbonwas performed by N2 adsorption, XRD, UV–vis-DRS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was used as support of the iridium nanoparticles, in order to prepare a catalyst to be tested in model hydrotreating reactions. The catalyst obtained by wet impregnation with iridium acetylacetonate were characterized by ICP-AES, H2 chemisorption, TEM, XPS and FTIR of adsorbed pyridine. The high Ir dispersion and small particle size, along with the moderate Lewis acidity generated by the presence of titanium in the support, were responsible for the good performance and stability of the catalyst in the hydrogenation of tetralin in presence of nitrogen compounds. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for HDT reactions.
Beltramone, Andrea R.,Juárez, Juliana M.,Ledesma, Brenda C.
p. 210 - 216
(2018/04/17)

Room Temperature Iron-Catalyzed Transfer Hydrogenation and Regioselective Deuteration of Carbon-Carbon Double Bonds
An iron catalyst has been developed for the transfer hydrogenation of carbon-carbon multiple bonds. Using a well-defined β-diketiminate iron(II) precatalyst, a sacrificial amine and a borane, even simple, unactivated alkenes such as 1-hexene undergo hydrogenation within 1 h at room temperature. Tuning the reagent stoichiometry allows for semi- and complete hydrogenation of terminal alkynes. It is also possible to hydrogenate aminoalkenes and aminoalkynes without poisoning the catalyst through competitive amine ligation. Furthermore, by exploiting the separate protic and hydridic nature of the reagents, it is possible to regioselectively prepare monoisotopically labeled products. DFT calculations define a mechanism for the transfer hydrogenation of propene with nBuNH2 and HBpin that involves the initial formation of an iron(II)-hydride active species, 1,2-insertion of propene, and rate-limiting protonolysis of the resultant alkyl by the amine N-H bond. This mechanism is fully consistent with the selective deuteration studies, although the calculations also highlight alkene hydroboration and amine-borane dehydrocoupling as competitive processes. This was resolved by reassessing the nature of the active transfer hydrogenation agent: experimentally, a gel is observed in catalysis, and calculations suggest this can be formulated as an oligomeric species comprising H-bonded amine-borane adducts. Gel formation serves to reduce the effective concentrations of free HBpin and nBuNH2 and so disfavors both hydroboration and dehydrocoupling while allowing alkene migratory insertion (and hence transfer hydrogenation) to dominate.
Espinal-Viguri, Maialen,Neale, Samuel E.,Coles, Nathan T.,MacGregor, Stuart A.,Webster, Ruth L.
supporting information
p. 572 - 582
(2019/01/08)

Highly chemoselective reduction of azides to amines by Fe(0) nanoparticles in water at room temperature
A highly chemoselective reduction of aryl, heteroaryl, acyl and sulfonyl azides to the corresponding amines has been achieved by Fe(0) nanoparticles in water at room temperature in the absence of external hydride source. Several readily reducible functionalities including alkene, alkyne, S-S linkage, OTBDMS remain unaffected during reduction.
Panja, Subir,kundu, Debasish,Ahammed, Sabir,Ranu, Brindaban C.
supporting information
p. 3457 - 3460
(2017/08/10)

Novel Preparation of Titania-Modified CMK-3 Nanostructured Material as Support for Ir Catalyst Applied in Hydrodenitrogenation of Indole
Abstract: Iridium catalyst was prepared using a novel titanium oxide-CMK-3 support synthesized as a replica of Ti-SBA-15. The catalyst was applied in the hydrodenitrogenation of indole. The activity was compared with an iridium catalyst supported over a grafted titanium-CMK-3. Structural and textural characterization of the catalysts was performed by means of N2 adsorption, XRD, UV–Vis–DRS, Raman spectroscopy, XPS, TEM and H2 Chemisorption. Ir-Ti-CMK-3 was the most active catalyst for the hydrodenitrogenation reaction at mild conditions. Titanium oxide contained in carbon ordered mesoporous CMK-3 promotes a very good anchorage of iridium metallic clusters in the carbon framework reaching high active site distribution and more stable nanoclusters. Graphical Abstract: [Figure not available: see fulltext.]
Ledesma, Brenda C.,Juárez, Juliana M.,Valles, Verónica A.,Anunziata, Oscar A.,Beltramone, Andrea R.
p. 1029 - 1039
(2017/03/24)

Conformations, equilibrium thermodynamics and rotational barriers of secondary thiobenzanilides
The article deals with conformational behaviour of 2-methoxy-2′-hydroxythiobenzanilides. The CS-NH group of these compounds preferentially adopts the Z-conformation. Entropy favours the Z-conformer over the E-conformer, whereas enthalpy slightly favours the E-conformer over the Z-conformer. The rotational barrier about the CS-NH bond was determined to be (81.5±0.4) kJ/mol. No significant rotational barrier was found on the Ar-CS and Ar-NH bonds. All experimental outcomes are compared with the results of quantum-chemical calculations.
Kozic, Ján,Novák, Zdeněk,?ímal, Václav,Profant, Václav,Kune?, Ji?í,Vin?ová, Jarmila
p. 2072 - 2083
(2016/04/09)

A triazine-phosphite polymeric ligand bearing cage-like P,N-ligation sites: An efficient ligand in the nickel-catalyzed amination of aryl chlorides and phenols
A novel P,N-ligand was introduced for efficient Ni-catalyzed amination of aryl chlorides. Reaction of cyanuric acid (1,3,5-triazine-2,4,6-triol) and trichlorophosphine (PCl3) resulted in the production of a new porous material (TPPM) containing triazine rings with phosphite moieties in a sheet morphology. Cavities in the prepared compound create sites on the surface of the material with appropriate ligation character to coordinate with metals for catalytic purposes. The nickel-catalyzed amination of aryl chlorides and of phenols in their 2,4,6-triaryloxy-1,3,5-triazine (TAT) protected form were efficiently accomplished in the presence of this easily prepared and reusable P,N-ligand under mild reaction conditions. More importantly, TPPM was reusable for 5 iterations following this protocol without significantly decreasing in its activity.
Panahi, Farhad,Roozbin, Fatemeh,Rahimi, Sajjad,Moayyed, Mohammadesmaeil,Valaei, Aria,Iranpoor, Nasser
supporting information
p. 80670 - 80678
(2016/10/12)

Electrophilic amination of aromatics with sodium azide in BF3-H2O
Boron trifluoride monohydrate is an excellent Br?nsted acid catalyst system for a wide range of reactions. It is a non-oxidizing acid catalyst prepared easily by bubbling BF3 into water. We have found boron trifluoride monohydrate/sodium azide combination to be an efficient reagent system for aromatic electrophilic amination. The present method avoids the use of expensive superacids such as trifluoromethanesulfonic acid and provides a facile access to aromatic amines directly from aromatics.
Prakash, G.K. Surya,Gurung, Laxman,Marinez, Eric R.,Mathew, Thomas,Olah, George A.
supporting information
p. 288 - 291
(2016/01/12)

The ortho effect on the acidic and alkaline hydrolysis of substituted formanilides
The kinetics of formanilides hydrolysis were determined under first-order conditions in hydrochloric acid (0.01-8 M, 20-60°C) and in hydroxide solutions (0.01-3 M, 25 and 40°C). Under acidic conditions, second-order specific acid catalytic constants were used to construct Hammett plots. The ortho effect was analyzed using the Fujita-Nishioka method. In alkaline solutions, hydrolysis displayed both first- and second-order dependence in the hydroxide concentration. The specific base catalytic constants were used to construct Hammett plots. Ortho effects were evaluated for the first-order dependence on the hydroxide concentration. Formanilide hydrolyzes in acidic solutions by specific acid catalysis, and the kinetic study results were consistent with the AAC2 mechanism. Ortho substitution led to a decrease in the rates of reaction due to steric inhibition of resonance, retardation due to steric bulk, and through space interactions. The primary hydrolytic pathway in alkaline solutions was consistent with a modified BAC2 mechanism. The Hammett plots for hydrolysis of meta- and para-substituted formanilides in 0.10 M sodium hydroxide solutions did not show substituent effects; however, ortho substitution led to a decrease in rate constants proportional to the steric bulk of the substituent.
Desai, Salil Dileep,Kirsch, Lee E.
p. 471 - 488
(2015/06/30)

Assembly of multiple components in a hybrid microcapsule: Designing a magnetically separable pd catalyst for selective hydrogenation
In analogy to the role of long-chain polyamines in biosilicification, poly-L-lysine facilitates the assembly of nanocomponents to design multifunctional microcapsule structures. The method is demonstrated by the fabrication of a magnetically separable catalyst that accommodates Pd nanoparticles (NPs) as active catalyst, Fe3O4 NPs as magnetic component for easy recovery of the catalyst, and silica NPs to impart stability and selectivity to the catalyst. In addition, polyamines embedded inside the microcapsule prevent the agglomeration of Pd NPs and thus result in efficient catalytic activity in hydrogenation reactions, and the hydrophilic silica surface results in selectivity in reactions depending on the polarity of substrates.
Amali, Arlin Jose,Sharma, Bikash,Rana, Rohit Kumar
p. 12239 - 12244
(2015/03/31)

One step C-N bond formation from alkylbenzene and ammonia over Cu-modified TS-1 zeolite catalyst
A Cu doped TS-1 zeolite sample was applied to catalyze the formation of C-N bonds on both the ring and the side chain of toluene, as well as other alkylbenzenes. A yield of 3.4% of toluidine was obtained for the amination of toluene, with a 1.0% yield of nitrobenzene. Cyanobenzene was also obtained as the C-N bond product on the side chain with a yield of 1.0%. The selectivity for C-N bond formation was 52.4%. The catalyst promoted the formation of a hydroxylamine intermediate from ammonia and hydrogen peroxide, and then the instantaneously generated amino cation reacted with the substrate to form C-N bonds on both the ring and side chain. Cyanobenzene was produced from the dehydration of benzylamine, formed via the reaction of ammonia and toluene. The formation of C-N bonds on the ring had an ortho-orientation advantage for mono-substituted-benzenes. With the increase in the number of methyl substituents, the yield of the ring products decreased, which might be caused by steric hindrance. the Partner Organisations 2014.
Xia, Sheng,Yu, Tianhua,Liu, Huihui,Li, Guiying,Hu, Changwei
p. 3108 - 3119
(2014/08/18)

Palladium-catalyzed amination of aryl chlorides and bromides with ammonium salts
We report the palladium-catalyzed coupling of aryl halides with ammonia and gaseous amines as their ammonium salts. The coupling of aryl chlorides and ortho-substituted aryl bromides with ammonium sulfate forms anilines with higher selectivity for the primary arylamine over the diarylamine than couplings with ammonia in dioxane. The resting state for the reactions of aryl chlorides is different from the resting state for the reactions of aryl bromides, and this change in resting states is proposed to account for a difference in selectivities for reactions of the two haloarenes.
Green, Rebecca A.,Hartwig, John F.
supporting information
p. 4388 - 4391
(2015/01/08)

POLYMER SUPPORTED REAGENTS AND METHODS OR REDUCING AROMATIC NITRO COMPOUNDS BY USING THE SAME
The present invention relates to a polymer supported reagent comprising a novel crosslinked mesoporous polymer, enabling a simple and easy production of an azoxy compound or an azo compound from an aromatic nitro compound, and a method of selectively reducing an aromatic nitro compound by using the same. The polymer supported reagent comprises a certain acrylamide mesoporous crosslinked polymer.
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(2013/10/07)

Platinum-catalyzed assembly of quinaldine from aniline and ethylene
The selectivity of the catalytic reaction between aniline and ethylene in the presence of the Brunet catalyst (PtBr2/Br-) shifts from the hydroamination product N-ethylaniline to the heterocyclization product 2-methylquinoline (quinaldine) when conducted in the presence of PPh3 (1 equiv per Pt atom). Condition optimization revealed that this process works best in the absence of any halide salt additive, that it is essentially insensitive to the nature of the halide in PtX2, that the best promoter in the PMexPh3-x series is PPh3 when used in strictly stoichiometric amounts, and that the 4-RC6H 5NH2 (R = nBu, Cl, OMe, NMe2) substrates are equally converted albeit less efficiently. Slight dilution of the system with THF or toluene slightly improves the activity, and a kinetic profile shows the presence of an induction phase and a deactivating step, which however does not involve reduction to metallic platinum contrary to the PPh3-free Brunet catalyst. Mechanistic considerations are presented.
Bethegnies, Aurelien,Dub, Pavel A.,Poli, Rinaldo
p. 1882 - 1891
(2013/05/21)

An examination of the palladium/Mor-DalPhos catalyst system in the context of selective ammonia monoarylation at room temperature
An examination of the [{Pd(cinnamyl)Cl}2]/Mor-DalPhos (Mor-DalPhos=di(1-adamantyl)-2-morpholinophenylphosphine) catalyst system in Buchwald-Hartwig aminations employing ammonia was conducted to better understand the catalyst formation process and to guide the development of precatalysts for otherwise challenging room-temperature ammonia monoarylations. The combination of [{Pd(cinnamyl)Cl}2] and Mor-DalPhos afforded [(κ 2-P,N-Mor-DalPhos)Pd(η1-cinnamyl)Cl] (2), which, in the presence of a base and chlorobenzene, generated [(κ2-P,N- Mor-DalPhos)Pd(Ph)Cl] (1 a). Halide abstraction from 1 a afforded [(κ3-P,N,O-Mor-DalPhos)Pd(Ph)]OTf (5), bringing to light a potential stabilizing interaction that is offered by Mor-DalPhos. An examination of [(κ2-P,N-Mor-DalPhos)Pd(aryl)Cl] (1 b-f) and related precatalysts for the coupling of ammonia and chlorobenzene at room temperature established the suitability of 1 a in such challenging applications. The scope of reactivity for the use of 1 a (5 mol %) encompassed a range of (hetero)aryl (pseudo)halides (X=Cl, Br, I, OTs) with diverse substituents (alkyl, aryl, ether, thioether, ketone, amine, fluoro, trifluoromethyl, and nitrile), including chemoselective arylations. Copyright
Alsabeh, Pamela G.,Lundgren, Rylan J.,McDonald, Robert,Johansson Seechurn, Carin C. C.,Colacot, Thomas J.,Stradiotto, Mark
supporting information
p. 2131 - 2141
(2013/03/14)

One-step double reduction of aryl nitro and carbonyl groups using hydrazine
Single-step reduction of aryl nitro and carbonyl groups to the corresponding synthetically useful alkyl-anilines occurs with excellent yields by treatment with hydrazine and a base in a solvent-free reaction. The method has been applied to a broad range of compounds with different properties. Investigations into the mechanism of the reduction reveal that each group is reduced independently. A mechanism is proposed for this novel reduction of aromatic nitro groups.
Diez-Cecilia, Elena,Kelly, Brendan,Rozas, Isabel
supporting information; experimental part
p. 6702 - 6704
(2012/01/05)

A new class of heterogeneous platinum catalysts for the chemoselective hydrogenation of nitroarenes
A new series of nanostructured platinum catalysts able to catalyze the selective reduction of nitroarenes has been developed. The materials, made of organosilica physically doped with nanostructured platinum(0), are stable and efficient. Reactions in general proceed with high yield and often go to completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry named SiliaCat Platinum-Hydrogel.
Pandarus, Valerica,Ciriminna, Rosaria,Beland, Francois,Pagliaro, Mario
scheme or table
p. 1306 - 1316
(2011/06/25)

The effect of temperature, catalyst and sterics on the rate of N-heterocycle dehydrogenation for hydrogen storage
Efficient hydrogen storage is one of the critical requirements for the use of hydrogen fuel cells in light-duty vehicles. Our investigation of reversible chemical hydrogen storage systems has led to the development of a mixed endothermic-exothermic carrier system. Herein we further investigate the factors affecting the dehydrogenation rate of these carriers. A range of heterogeneous catalysts was synthesized via sol-gel methodology and their activity for indoline dehydrogenation was assessed. Metals used included Fe, Co, Ni, Cu, Ru, Rh, Pd, Ir and Pt. SiO2, Al2O3, TiO2 and ZrO2 were used as supports and Pd/SiO2 gave the highest conversion over a fixed time. A marked increase in the rate of indoline dehydrogenation was observed when the temperature was increased between 100 and 180 °C, with measured first order rate constants of 1.8 × 10 -4 s-1 at 100 °C and 5.9 × 10-4 at 120 °C. Although piperidines dehydrogenate more slowly than indolines, steric hindrance around the nitrogen atom in piperidine increases its dehydrogenation rate significantly.
Dean, Darrell,Davis, Boyd,Jessop, Philip G.
body text
p. 417 - 422
(2011/04/21)

One-pot aryl-1,4-thiomorpholine 1,1-dioxide synthesis via double 1,4-addition of in situ reduced nitroarenes to divinyl sulfones
One-pot reduction-triggered double aza-Michael type 1,4-addition reactions of various nitroarenes to divinyl sulfones were investigated. In the presence of indium/AcOH in MeOH or in sat. aq NH4Cl/MeOH, nitroarenes and divinyl sulfones were cycl
Han, Joon Hee,Choi, Jaehwan,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
experimental part
p. 317 - 327
(2010/08/20)

N-butyllithium-mediated reactions of 1-(2-azidoarylmethyl)-1H- benzotriazoles with alkyl halides
(Chemical Equation Presented) Treatment of 1-(2-azidoarylmethyl)-1H- benzotriazoles (6) with n-BuLi (2.5 equiv.) in THF at -78°C, followed by an addition of alkyl halides such as allyl, benzyl, and ethyl bromides with stirring for 2 h at room temperature afforded 2-(dialkylamino)-3-(benzotriazol- 1-yl)-2H-indazoles (8), 3-(benzotriazol-1-yl)-2H-indazoles (9), 2-[(benzotriazol-1-yl)methyl]arylamine (10), and 2-[(benzotriazol-1-yl)(alkyl) methyl]arylamine (11).
Kim, Taehoon,Kim, Kyongtae
experimental part
p. 98 - 111
(2010/04/23)

Halide-free ethylation of phenol by multifunctional catalysis using phosphinite ligands
The ortho-alkylation of phenols or aniline by catalytic C-H activation and multifunctional catalysis is described. The Royal Society of Chemistry 2006.
Carrion, M. Carmen,Cole-Hamilton, David J.
p. 4527 - 4529
(2008/09/18)

Suggested improved method for the Ing-Manske and related reactions for the second step of gabriel synthesis of primary amines
This work demonstrates an improvement in the Ing-Manske and related procedures by the increase of pH of the reaction mixture after the complete disappearance of N-substituted phthalimide. Hydrazinolysis of N-phenylphthalimide (1a) gave 80% of the desired primary amines after 5.3 h in the absence of added NaOH. The reaction time was reduced to 1.6 h and 1.2 h when 1 eq. and 5eq. of NaOH were added to the reaction mixture after the complete disappearance of 1a. Hydroxyaminolysis of N-(4-ethylphenyl)phthalimide (1b) gave 80% of the desired primary amines after 7.5 h of reaction time (at added [NaOH] = 0). When 10 eq. and 20 eq. of NaOH were added to the reaction mixture after the disappearance of Ib, the reaction time was reduced to 4 h and 2 h, respectively. Methylaminolysis of N-(2-ethylphenyl)phthalimide (1c) gave 80% of the desired primary amines after 1.7 h (at added [NaOH] = 0). The reaction time was reduced to 1 h and 0.7 h when 1 eq. and 25 eq. of NaOH were added to the reaction mixture after the complete disappearance of 1c.
Ariffin, Azhar,Khan, Mohammad Niyaz,Lan, Lai Chwee,May, Fan Yen,Yun, Chien Siew
p. 4439 - 4445
(2007/10/03)

Hydrogenation of ortho-substituted nitrobenzenes over palladium catalysts
Hydrogenation of o-nitrobenzenes, under mild conditions (1 atm of hydrogen, 20-40°C, organic solvents) over a Pd/C catalyst and the palladium-containing anion exchangers AN-1 and AV-17-8 proceeds without the formation of intermediate products. The yield of primary amines varies from 25 to 100%. It was shown that the palladium-containing anion exchangers are superior to Pd/C in selectivity and stability in the hydrogenation of o-nitrobenzenes. Based on quantum-chemical calculations of substrate molecules, a two-parameter correlation was proposed to describe the electronic and steric effects of the substituent on the hydrogenation rate.
Klyuev,Volkova,Abdullaev
p. 30 - 33
(2007/10/03)

Hydrodenitrogenation activities of methyl-substituted indoles
The HDN reactivities of indole and several methyl-substituted indoles were obtained over a NiMo/Al2O3 catalyst and a CoMo/Al2O3 catalyst using a fixed-bed reactor at 340°C and 31 atm hydrogen pressure. A methyl
Massoth,Kim
p. 70 - 78
(2007/10/03)

Method for inhibiting neoplastic lesions by administering 4-(arylmethylene)- 2, 3- dihydro-pyrazol-3-ones
A method for treating neoplasia involving the administration of certain pyrazolinone derivatives.
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(2008/06/13)

Bifunctional behavior of bulk MoOxNy and nitrided supported NiMo catalyst in hydrodenitrogenation of indole
Oxynitrides of early transition metals are bifunctional catalysts (metallic and addic sites) active in hydrodenitrogenation (HDN). TheHDN of indole was used as a molecular probe reaction to study the metallic and acidic properties of the dual sites on oxy
Miga,Stanczyk,Sayag,Brodzki,Djega-Mariadassou
p. 63 - 68
(2007/10/03)

Chemically induced dynamic nuclei polarization and free radicals in the reaction of triethylaluminum with nitrobenzene
The reaction of triethylaluminum with nitrobenzene in hydrocarbon solvents was studied by GC-MS and CIDNP techniques. Radical intermediates participating in a complex process of reduction and alkylation of nitrobenzene were observed in the reaction products (nitrobenzene radical anion, ethyl radical, and nitroxyl radical), and routes of their formation and decay were discussed.
Sadykov
p. 1924 - 1927
(2007/10/03)

Hydrogenation of ortho-Substituted Nitrobenzenes over AV-17-8 Palladium-Containing Anion Exchanger
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Abdullaev,Nasibulin,Klyuev
p. 1676 - 1677
(2007/10/03)

A general, regioselective synthesis of 2-alkylanilines
Reduction of selected 2,1-benzothiazines with sodium amalgam leads to the formation of 2-alkylanilines in high yield. Since the benzothiazines are ultimately derived from aniline, the process constitutes a general, regioselective functionalization of aniline not readily achieved by other means.
Harmata,Kahraman
p. 142 - 144
(2007/10/02)

Direct Aromatic Amination by Azides: Reactions of Hydrazoic Acid and Butyl Azides with Aromatic Compounds in the Presence of Both Trifluoromethanesulfonic Acid and Trifluoroacetic Acid
Reactions of hydrazoic acid with aromatic compounds in the presence of both trifluoromethanesulfonic acid (TFSA) and trifluoroacetic acid (TFA) efficiently gave primary arylamines without diamine contaminants.The reactions provide mainly the ortho- and para-monoamines wven for readily oxidised aromatic compounds such as cumene, mesitylene, durene, isodurene and anisole.The mechanistic investigation demonstrates that the reactions proceed via a concerted process involving both arene attack on a conjugate acid of the azide and elimination of N2 from the conjugate acid.The reaction of butyl azide with benzene and mesitylene in the presence of both TFSA and TFA produced N-butylarylamines in low yields together with high yields of butanal via a butylnitrenium ion intermediate; a similar reaction with tert-butyl azide gave no tert-butylarylamines.
Takeuchi, Hiroshi,Adachi, Taki,Nishiguchi, Hideaki,Itou, Katsutaka,Koyama, Kikuhiko
p. 867 - 870
(2007/10/02)

Efficient Direct Aromatic Amination by Parent Nitrenium Ion. Photolyses of 1-Aminopyridinium and 1-Aminoquinolinium Salts and Effect of Crown Ethers
Photolyses of 1-aminopyridinium salts 1a-f, 2-aminoisoquinolinium salt 2 and 1-aminoquinolinium salts 3a-f gave aniline 4 or a mixture of 2-, 3- and 4-toluidines 5a-7a in benzene-trifluoroacetic acid (TFA) or in toluene-TFA, respectively.The use of 1-aminoquinolinium perchlorate 3a showed the highest yield in these photolyses.Irradiation of 3a in the presence of ethylbenzene, p-xylene, mesitylene, anisole and chlorobenzene similarly yielded arylamines.The yields of arylamines were generally increased in the presence of a small amount of crown ether.The aromatic amination is discussed in terms of the intermediacy of a parent nitrenium ion.
Takeuchi, Hiroshi,Higuchi, Dai,Adachi, Taki
p. 1525 - 1529
(2007/10/02)

Carbon Dioxide: A Reagent for the Simultaneous Protection of Nucleophilic Centers and the Activation of Alternative Locations to Electrophilic Attack. 17. Substitution of N-Methyl-1- and N-Methyl-2-naphthylamine and Side-Chain Functionalization of o-Toluidine
N-Methyl-1-naphthylamine is readily converted into a range of 2-substituted derivatives in one-pot sequences, using carbon dioxide for NH protection.Similarly, N-methyl-2-naphthylamine yields 3-substituted derivatives in the first direct preparation of 2,3-disubstituted naphthalenes.The intermediate lithium carbamates are further lithiated by tert-butyllithium at the 2-position for N-methyl-1-naphthylamine and at the 3-position for N-methyl-2-naphthylamine and then reacted with an electrophile; the products undergo acid-catalyzed decarboxylation during workup. o-Toluidine is converted into its methyl-functionalized derivatives in a similar way, except that 2 equiv of tert-butyllithium are used for the further lithiation of the intermediate lithium carbamate.
Katritzky, Alan R.,Black, Michael,Fan, Wei-Qiang
p. 5045 - 5048
(2007/10/02)

Para-bromination of ortho-alkyl anilines
A process of selectively preparing p-bromo-o-alkylanilines (e.g. 4-bromo-2-methylaniline) by reacting o-alkylanilines (e.g., 2-methylaniline) with unadsorbed bromine in a solvent selected from the group consisting of an inert di- tri- or tetrahaloaliphatic hydrocarbon (e.g., dichloromethane and dibromomethane), an alkyl nitrile (e.g., acetonitrile) and mixtures thereof.
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(2008/06/13)

A kinetic study of alkaline hydrolysis of β-Arylaminoacrolein
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Ono,Todoriki,Mitake,Yukawa,Goto,Tamura
p. 2902 - 2908
(2007/10/02)

Poly(hydrocarbylthio)anilines
Novel poly(hydrocarbylthio)anilines are 2,4,6-trisubstituted anilines wherein the substituents in at least two of the ortho and para positions are hydrocarbylthio substituents, any other p-substituent is hydrocarbyl or hydrocarbyloxy, any other ar-substituents are chloro, fluoro, hydrocarbyl, hydrocarbyloxy, and/or hydrocarbylthio, and any N-substituents are hydrocarbyl.
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(2008/06/13)

Hydrodesazotation de l'indole sur catalyseur fer supporte sur amiante
The aim of this study is to examine hydrodenitrogenation (HDN) of indole on asbestos catalysts (chrysotile and crocidolite) under hydrogen pressure.HDN is carried out according to two competitive pathways, either via ortho-ethylaniline or via ortho-toluid
Zalma, Roger,Bonneau, Lionel,Fournier, Jeanine,Guignard, Joelle,Borg, Francoise,Pezerat, Henri
p. 523 - 527
(2007/10/02)

KINETICS FOR SIMULTANEOUS HDS, HDN AND HYDROGENATION MODEL REACTIONS ON A Co-Mo/Al2O3 CATALYST
A kinetic analysis of simultaneous hydrodesulfurization (HDS) of dibenzothiophene (DBT), hydrodenitrogenation (HDN) of indole (IN) and hydrogenation (HYD) of naphthalene (NAP) is carried out.These compounds represent the major functional groups in heavy petroleum feeds.The goal of these experiments is to simulate the performance of a commercial catalyst with more complex feedstocks.The purposes are to determine the competitive inhibition effects of the various reactants as well as to investigate a microscopic model which can be generalized to more realistic feedstocks.Kinetic data are generated over a CoMo/Al2O3 catalyst in a temperature range of 260-350 deg C and total pressure of 25-81 105 Pa.The partial pressures of hydrogen and the other reactants are varied individually.From the data, a kinetic model is developed based on the competitive chemisorption of reactants, intermediates and products on identical surface sites.The kinetic model developed accounts for rates of appearance of the products and rates of disappearance of DBT, NAP and IN.The results suggest that compounds containing sulfur, nitrogen, aromatics or aliphatics are adsorbed with very different strength.
Zeuthen, Per,Stolze, Per,Pedersen, Ulla B.
p. 985 - 996
(2007/10/02)

Regiospecific Hydrogenation of Quinolines and Indoles in the Heterocyclic Ring
Quinolines, indoles, acridine and carbazole were hydrogenated using a large variety of heterogeneous catalysts in hydrocarbon solvents in an effort to achieve selective hydrogenation of the heterocyclic ring.When quinolines were hydrogenated using supported platinum, palladium, rhodium, ruthenium, or nickel metal catalysts in the presence of hydrogen sulfide, carbon disulfide, or carbon monoxide, there was exclusive hydrogenation of the heterocyclic ring to give only 1,2,3,4-tetrahydroquinolines.Use of iridium, rhenium, molybdenum(VI) oxide, tungsten(VI) oxide, chromium(III) oxide, iron(III) oxide, cobalt(II) oxide-molybdenum(VI) oxide, or copper chromite catalysts also caused exclusive hydrogenation of the heterocyclic ring even without addition of sulfur compounds or carbon monoxide.Hydrogenation of indoles using platinum, rhenium, or, in some cases, nickel catalysts (with or without sulfur compounds) occurred exclusively in the heterocyclic ring to give indolines, but conversions were affected by indole-indoline equilibria.
Shaw, J.E.,Stapp, P.R.
p. 1477 - 1483
(2007/10/02)

New diamines and a process for their production
New aminoalkyl anilines having the formula: STR1 wherein k is 0 or 1; QNH2 is a residue of formula STR2 which is situated in one of the positions of the benzene ring ortho or para to the amino group and wherein n is an integer from 1 to 15, R1 is C1 -C8 alkyl, R2 is C1 -C4 alkyl or R1 and R2, together with the carbon atom to which they are attached, form a C5 -C8 cycloalkylene residue, R3 is H or C1 -C6 alkyl, C3 -C8 cycloalkyl, or C6 -C10 aryl; and R4 and R5 are H or C1 -C4 alkyl; as well as the corresponding salts of compounds of formula I with organic or inorganic acids and metal salt complexes; process for their production; and their use as intermediates for polyamides.
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(2008/06/13)

Intramolecular Selectivity of the Alkylation of Substituted Anilines by Gaseous Cations
The intramolecular selectivity of the electrophilic reactions of Et(1+), i-Pr(1+), and Me2F(1+) cations with substituted anilines, including m-toluidine, m-anisidine, and m- and p-fluoroaniline, has been investigated in the dilute gas state at pressures ranging from 100 to 720 torr by a radiolytic technique, complemented by chemical ionization mass spectrometry.The results indicate an appreciable kinetic bias for the nitrogen atom, leading to predominant N-methylation by Me2F(1+).The reactivity of the carbenium ions is complicated by the simultaneous occurrence of proton transfer, in particular to the NH2 group, which increases the relative extent of ring alkylation.The positional selectivity is characterized, aside from the usual orienting effects of the substituents, by the enchanced reactivity of the ring positions ortho to an n-type substituent, irrespective of its activating or deactivating properties.The effect is traced to the preliminary formation of an electrostatic adduct between the aniline and the gaseous electrophile.
Attina, Marina,Cacace, Fulvio,de Petris, Giulia
p. 1556 - 1561
(2007/10/02)

CATALYTIC FUNCTIONALITIES OF SUPPORTED SULFIDES III. CORRELATION OF ACTIVITIES AT ELEVATED PRESSURE WITH OXYGEN CHEMISORPTION
A number of different supported CoMo catalysts, that had been characterized by O2 chemisorption measurements, were evaluated for hydrodesulfurization of dibenzothiophene, hydrogenation of naphthalene, and C-N-bond hydrogenolysis of indole at elevated pressure.Only rough correlations between the different catalyst functionalities, and between the functionalities and O2 chemisorption, were obtained.It is concluded that different active sites are involved for the different reactions, and that O2 chemisorption is generally related to the dispersion of the active MoS2 phase rather than to any specific reaction site.
Liu, Y.,Massoth, F.E.,Shabtai, Joseph
p. 627 - 634
(2007/10/02)