cas 2237-30-1, 3-Aminobenzonitrile | Articles data

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Room-temperature chemoselective reduction of nitro groups using non-noble metal nanocatalysts in water
Purely aqueous-phase chemoselective reduction of a wide range of aromatic and aliphatic nitro substrates has been performed in the presence of inexpensive Ni- and Co-based nanoparticle catalysts using hydrazine hydrate as a reducing agent at room temperature. Along with the observed high conversions and selectivities, the studied nanoparticle catalysts also exhibit a high tolerance to other highly reducible groups present in the nitro substrates. The development of these potential chemoselective reduction catalysts also provides a facile route for the synthesis of other industrially important fine chemicals or biologically important compounds, where other highly reducible groups are present in close proximity to the targeted nitro groups.
Rai, Rohit K.,Mahata, Arup,Mukhopadhyay, Sushobhan,Gupta, Sampa,Li, Pei-Zhou,Nguyen, Kim T.,Zhao, Yanli,Pathak, Biswarup,Singh, Sanjay K.
p. 2904 - 2909
(2014)
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Hydrogenation of nitro-compounds over rhodium catalysts supported on poly[acrylic acid]/Al2O3 composites
In this report, poly[acrylic acid] gels containing Al2O3 were prepared by simultaneous free-radical polymerization and sol-gel chemistry using different amounts of 3-(trimethoxysilyl)propyl methacrylate (TMPM) as a compatibilizer. The hybrid materials were used as supports for a rhodium catalyst in the chemoselective hydrogenation of 3-substituted aromatic nitro-compounds. The supported rhodium catalyst was prepared by an ion-exchange process. In situ H2 flux was used to produce active species of the catalysts. The resulting materials were characterized by infrared spectroscopy, thermogravimetric analysis, solid-state 29Si and13 C NMR, X-ray diffraction, transmission/scanning electron microscopy, and X-ray photoelectron spectroscopy. All materials exhibited simultaneous interpenetrating hybrid network structures (SIHNs). The morphologies and physicochemical properties depended on the amount of TMPM used. The catalysts were found to be effective for the reduction of nitrobenzene in ethanol at room temperature and a hydrogen pressure of 20atm. The most active and selective catalyst was used in the hydrogenation of different 3-substituted aromatic nitro-compounds. The hydrogenation reactions displayed high conversion levels and promoted exclusive-NO2 group reduction, resulting in the sole formation of the corresponding amino-compound, with the exception of 1,3-dinitrobenzene, in which over-hydrogenation was detected. The presence of electron-donating/electron-withdrawing substituents at the 3-position resulted in different rates of-NO2group hydrogenation. This effect was quantified in terms of the Hammett relationship, in which the catalyst displayed a linear correlation between the substituent constant (σi) and the hydrogenation rate, with the exception of-OH, -NH2, and-OCH3 groups. One explanation for this behavior is a proposed support-substrate hydrogen bond interaction during the catalytic reaction.
Campos, Cristian H.,Rosenberg, Edward,Fierro, José L.G.,Urbano, Bruno F.,Rivas, Bernabé L.,Torres, Cecilia C.,Reyes, Patricio
p. 280 - 291
(2015)
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Cohen,Deets
p. 55
(1972)
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METHOD OF REDUCING AROMATIC NITRO COMPOUNDS
A method for reducing a substrate selected from 2-methyl-5-nitropyridine and methyl 4-(2-fluoro-3-nitrobenzyl)piperazine-1-carboxylate is provided catalysed by a nitroreductase and a disproportionation agent.
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Paragraph 0332; 0344

(2022/02/26)

Facile dehydration of primary amides to nitriles catalyzed by lead salts: The anionic ligand matters
The synthesis of nitrile under mild conditions was achieved via dehydration of primary amide using lead salts as catalyst. The reaction processes were intensified by not only adding surfactant but also continuously removing the only by-product, water from the system. Both aliphatic and aromatic nitriles can be prepared in this manner with moderate to excellent yields. The reaction mechanisms were obtained with high-level quantum chemical calculations, and the crucial role the anionic ligand plays in the transformations were revealed.
Ruan, Shixiang,Ruan, Jiancheng,Chen, Xinzhi,Zhou, Shaodong
(2020/12/09)

One pot synthesis of aryl nitriles from aromatic aldehydes in a water environment
In this study, we found a green method to obtain aryl nitriles from aromatic aldehyde in water. This simple process was modified from a conventional method. Compared with those approaches, we used water as the solvent instead of harmful chemical reagents. In this one-pot conversion, we got twenty-five aryl nitriles conveniently with pollution to the environment being minimized. Furthermore, we confirmed the reaction mechanism by capturing the intermediates, aldoximes.
Chen, Qingqing,Han, Hongwei,Lin, Hongyan,Ma, Xiaopeng,Qi, Jinliang,Wang, Xiaoming,Yang, Yonghua,Zhou, Ziling
p. 24232 - 24237
(2021/07/29)

Yeast supported gold nanoparticles: an efficient catalyst for the synthesis of commercially important aryl amines
Candida parapsilosisATCC 7330 supported gold nanoparticles (CpGNP), prepared by a simple and green method can selectively reduce nitroarenes and substituted nitroarenes with different functional groups like halides (-F, -Cl, -Br), olefins, esters and nitriles using sodium borohydride. The product aryl amines which are useful for the preparation of pharmaceuticals, polymers and agrochemicals were obtained in good yields (up to >95%) using CpGNP catalyst under mild conditions. The catalyst showed high recyclability (≥10 cycles) and is a robust free flowing powder, stored and used after eight months without any loss in catalytic activity.
Krishnan, Saravanan,Patel, Paresh N.,Balasubramanian, Kalpattu K.,Chadha, Anju
supporting information
p. 1915 - 1923
(2021/02/06)

Magnetically‐recoverable Schiff base complex of Pd(II) immobilized on Fe3O4@SiO2 nanoparticles: an efficient catalyst for the reduction of aromatic nitro compounds to aniline derivatives
Fe3O4@SiO2/Schiff base/Pd(II) is reported as a magnetically recoverable heterogeneous catalyst for the chemoselective reduction of aromatic nitro compounds to the corresponding amines through catalytic transfer hydrogenation (CTH). In this regard, a small amount of the nanocatalyst (0.52?mol% Pd) and hydrazine hydrate, showing safe characteristics and perfect ability as the hydrogen donor, were added to the nitro substrates. The experiments described the successful reduction of aromatic nitro compounds with good to excellent yields and short reaction times. The catalyst, due to its magnetic property, could be simply separated from the reaction mixture by a permanent magnet and reused in seven consecutive reactions without considerable loss in its activity. Moreover, the leaching of Pd was only 3.6% after the seventh run. Thus, the most striking feature of this method is to use a small amount of the magnetic nanocatalyst along with a cheap and safe hydrogen source to produce the important amine substances selectively, which makes the method economical, cheap, environmentally friendly, and simple. Graphic abstract: [Figure not available: see fulltext.]
Azadi, Sedigheh,Esmaeilpour, Mohsen,Sardarian, Ali Reza
p. 809 - 821
(2021/07/20)

Selective Reduction of Nitroarenes to Arylamines by the Cooperative Action of Methylhydrazine and a Tris(N-heterocyclic thioamidate) Cobalt(III) Complex
We report an efficient catalytic protocol that chemoselectively reduces nitroarenes to arylamines, by using methylhydrazine as a reducing agent in combination with the easily synthesized and robust catalyst tris(N-heterocyclic thioamidate) Co(III) complex [Co(κS,N-tfmp2S)3], tfmp2S = 4-(trifluoromethyl)-pyrimidine-2-thiolate. A series of arylamines and heterocyclic amines were formed in excellent yields and chemoselectivity. High conversion yields of nitroarenes into the corresponding amines were observed by using polar protic solvents, such as MeOH and iPrOH. Among several hydrogen donors that were examined, methylhydrazine demonstrated the best performance. Preliminary mechanistic investigations, supported by UV-vis and NMR spectroscopy, cyclic voltammetry, and high-resolution mass spectrometry, suggest a cooperative action of methylhydrazine and [Co(κS,N-tfmp2S)3] via a coordination activation pathway that leads to the formation of a reduced cobalt species, responsible for the catalytic transformation. In general, the corresponding N-arylhydroxylamines were identified as the sole intermediates. Nevertheless, the corresponding nitrosoarenes can also be formed as intermediates, which, however, are rapidly transformed into the desired arylamines in the presence of methylhydrazine through a noncatalytic path. On the basis of the observed high chemoselectivity and yields, and the fast and clean reaction processes, the present catalytic system [Co(κS,N-tfmp2S)3]/MeNHNH2 shows promise for the efficient synthesis of aromatic amines that could find various industrial applications.
Ioannou, Dimitris I.,Gioftsidou, Dimitra K.,Tsina, Vasiliki E.,Kallitsakis, Michael G.,Hatzidimitriou, Antonios G.,Terzidis, Michael A.,Angaridis, Panagiotis A.,Lykakis, Ioannis N.
p. 2895 - 2906
(2021/02/27)

NaI/PPh3-Mediated Photochemical Reduction and Amination of Nitroarenes
A mild transition-metal- and photosensitizer-free photoredox system based on the combination of NaI and PPh3 was found to enable highly selective reduction of nitroarenes. This protocol tolerates a broad range of reducible functional groups such as halogen (Cl, Br, and even I), aldehyde, ketone, carboxyl, and cyano. Moreover, the photoredox catalysis with NaI and stoichiometric PPh3 provides also an alternative entry to Cadogan-type reductive amination when o-nitrobiarenes were used.
Qu, Zhonghua,Chen, Xing,Zhong, Shuai,Deng, Guo-Jun,Huang, Huawen
supporting information
p. 5349 - 5353
(2021/07/21)

Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information
p. 3723 - 3728
(2021/04/07)

Revisiting the synthesis of aryl nitriles: a pivotal role of CAN
Facilitated by the dual role of Ceric Ammonium Nitrate (CAN), herein we report a cost-effective approach for the cyanation of aryl iodides/bromides with CAN-DMF as an addition to the existing pool of combined cyanation sources. In addition to being an oxidant, CAN acts as a source of nitrogen in our protocol. The reaction is catalyzed by a readily available Cu(ii) salt and the ability of CAN to generate ammonia in the reaction medium is utilized to eliminate the additional requirement of a nitrogen source, ligand, additive or toxic reagents. The mechanistic study suggests an evolution of CN?leading to the synthesis of a variety of aryl nitriles in moderate to good yields. The proposed mechanism is supported by a series of control reactions and labeling experiments.
Saikia, Rakhee,Park, Kwihwan,Masuda, Hayato,Itoh, Miki,Yamada, Tsuyoshi,Sajiki, Hironao,Mahanta, Sanjeev P.,Thakur, Ashim J.
p. 1344 - 1351
(2021/02/27)

Preparation method of aminobenzonitrile
The invention relates to the technical field of fine chemical synthesis, and discloses a preparation method of aminobenzonitrile. Aminobenzamide is taken as a raw material, and aminobenzonitrile is obtained through a three-step reaction of amino protection, dehydration and hydrolysis by taking thionyl chloride as an amino protective agent and a dehydrating agent, The preparation method comprises the following steps: amino protection and dehydration are carried out on aminobenzamide by thionyl chloride in sequence to obtain an amino-protected nitrile organic matter, then water is added to carryout a hydrolysis reaction, and the protective agent on the amino group is removed to obtain the aminobenzonitrile product. The thionyl chloride is used, so the dehydration effect can be achieved, anda new group formed by a reaction of the thionyl chloride with the amino group can play a role in protecting the amino group in the reaction process, thereby the product yield and quality are obviously improved, the reaction temperature is greatly lower than that of a traditional process, the reaction time is obviously shortened, the safety is obviously improved, the operation is simple, the conditions are mild, the method is green and clean, aminobenzonitrile can be efficiently prepared at low cost, and the method is suitable for industrial production.
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Paragraph 0024-0026; 0033-0038

(2020/07/02)

NHC-catalyzed silylative dehydration of primary amides to nitriles at room temperature
Herein we report an abnormal N-heterocyclic carbene catalyzed dehydration of primary amides in the presence of a silane. This process bypasses the energy demanding 1,2-siloxane elimination step usually required for metal/silane catalyzed reactions. A detailed mechanistic cycle of this process has been proposed based on experimental evidence along with computational study.
Ahmed, Jasimuddin,Hota, Pradip Kumar,Maji, Subir,Mandal, Swadhin K.,Rajendran, N. M.
supporting information
p. 575 - 578
(2020/01/29)

Method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by Ru coordination compound
The invention discloses a method for catalyzing receptor-free dehydrogenation of primary amine to generate nitrile by a Ru coordination compound. The method comprises: adding a Ru coordination compound, an alkali, a primary amine and an organic solvent into a reaction test tube according to a mol ratio of 1:100:(100-500):1000-3000, and carrying out a stirring reaction under the condition of 80 to120 DEG C; and when gas chromatography monitors that the raw materials completely disappear, stopping the reaction, collecting the reaction solution, centrifuging the reaction solution, taking the supernatant, extracting with dichloromethane, merging the organic phases, drying, filtering, evaporating the organic solvent under reduced pressure to obtain a filtrate, and carrying out column chromatography purification on the filtrate to obtain the target product nitrile. According to the invention, the catalyst is good in activity, single in catalytic system, good in product selectivity, simple in subsequent treatment and good in system universality after the reaction is finished, has a good catalytic effect on various aryl, alkyl and heteroaryl substituted primary amines, and also has a gooddehydrogenation performance on secondary amines.
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Paragraph 0034-0039; 0112-0117

(2020/09/16)

Method for reducing aromatic nitro into arylamine
The invention relates to a method for reducing aromatic nitro to arylamine. The method comprises the following steps: (1) taking an aromatic nitro compound as a raw material, water as a hydrogen source, a palladium compound, cheap and easy to obtain, as a catalyst and tetrahydroxydiboron as an additive to reduce nitro to obtain a product; (2) taking the aromatic nitro compound as the raw material, a copper salt, cheap and easy to obtain, as the catalyst, the tetrahydroxydiboron as the additive to reduce the nitro to obtain a product; and (3) taking the aromatic nitro compound as the raw material, water as the hydrogen source, and the tetrahydroxydiboron as the additive, without needing a metal catalyst, to reduce the nitro to obtain a product. A preparation method for the arylamine, which is provided by the invention, is mild in reaction condition, low in costs, environment-friendly, high in yield, and suitable for industrial production.
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Paragraph 0129-0132; 0229-0232; 0273-0276

(2020/07/15)

Dibenzonitrile derivative of o-carborane, modified compound thereof, and synthetic methods thereof
The invention provides a dibenzonitrile derivative of o-carborane. Besides, in order to further improve the affinity with tumor cells and the high-boron aggregation effect in the tumor cells so as toenable the derivative to have a potential anti-tumor application performance, structural modification is performed on the derivative, and a modified compound of the derivative is provided. Meanwhile,the invention also provides a synthesis method of the compounds. An in-vitro experiment is adopted to screen the structure of the dibenzonitrile derivative of the novel o-carborane; an m-amino benzonitrile structure is introduced through chemical synthesis; the purpose of increasing the lipophilicity of the compound and the affinity of tumor cells is achieved, the technical effect of targeted ultra-high concentration enrichment of boron ions in the tumor cells is achieved through the novel structure, and then the bottleneck problem that the concentration of p-borane phenylalanine (BPA) in thetumor cells cannot reach a high level is solved.
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Paragraph 0021-0022

(2020/06/16)

Cobalt oxide NPs immobilized on environmentally benign biological macromolecule-derived N-doped mesoporous carbon as an efficient catalyst for hydrogenation of nitroarenes
Highly nitrogen-doped mesoporous carbon (N-mC) material incorporated cobalt oxide nanoparticles was synthesized through simple pyrolysis of environmentally friendly chitosan-polyaniline-Co(OAc)2 precursor in one-step. The as-prepared catalyst named CoO&at;N-mC with 14.65 ?wtpercent nitrogen content was characterized by different analysis techniques. The heterogeneous catalyst exhibits outstanding catalytic activity for the reduction of a variety of nitroaromatic compounds in the presence of NaBH4 as a reducing agent in water as a green solvent at 75 ?°C. Utilization of natural biological macromolecules such as chitosan as green and cheap starting material with harmless aniline and earth-abundant cobalt salt, facile synthesis, excellent product yield, short reaction time, high chemoselectivity, sustainable and mild reaction condition, and reusability of catalyst for at least five cycles without any significant decline in the catalytic efficiency are some prominent merits of this new nanocatalyst.
Elhampour, Ali,Nanadegani, Zahra Soleimani,Nemati, Firouzeh,Rangraz, Yalda
(2020/09/15)

Commercially Available CuO Catalyzed Hydrogenation of Nitroarenes Using Ammonia Borane as a Hydrogen Source
Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high-cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support-free, excellent chemoselectivity, low-cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction.
Du, Jialei,Chen, Jie,Xia, Hehuan,Zhao, Yiwei,Wang, Fang,Liu, Hong,Zhou, Weijia,Wang, Bin
p. 2426 - 2430
(2020/03/30)

Palladium-Catalyzed Cyanation under Mild Conditions: A Case Study to Discover Appropriate Substrates among Halides and Pseudohalides
A case study has been effectively carried out to identify a suitable substrate among halides and pseudohalides for the palladium-catalyzed cyanation reactions under mild conditions. Among the various substrates considered for evaluation, aryl pentafluorobenzenesulfonates and nonaflates were identified to be the best substrates when compared to corresponding halides and pseudohalides. The substoichiometric use of nontoxic, environmentally benign potassium hexacyanoferrate as a cyanide source and exceptionally milder conditions further highlights the significance of the protocol developed. A wide range of electronically biased and sterically challenging substrates provided the corresponding the nitriles in good to excellent yields.
Rajendra, Merla Arjuna,Sunil,Sajith, Ayyiliath Meleveetil,Joy, Muthipeedika Nibin,Bakulev, Vasiliy A.,Haridas, Karickal Raman
supporting information
p. 1629 - 1633
(2020/09/15)

Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species
Cyano-containing compounds constitute important pharmaceuticals, agrochemicals and organic materials. Traditional cyanation methods often rely on the use of toxic metal cyanides which have serious disposal, storage and transportation issues. Therefore, there is an increasing need to develop general and efficient catalytic methods for cyanide-free production of nitriles. Here we report the reductive cyanation of organic chlorides using CO2/NH3 as the electrophilic CN source. The use of tridentate phosphine ligand Triphos allows for the nickel-catalyzed cyanation of a broad array of aryl and aliphatic chlorides to produce the desired nitrile products in good yields, and with excellent functional group tolerance. Cheap and bench-stable urea was also shown as suitable CN source, suggesting promising application potential. Mechanistic studies imply that Triphos-Ni(I) species are responsible for the reductive C-C coupling approach involving isocyanate intermediates. This method expands the application potential of reductive cyanation in the synthesis of functionalized nitrile compounds under cyanide-free conditions, which is valuable for safe synthesis of (isotope-labeled) drugs.
Dong, Yanan,Li, Yuehui,Yang, Peiju,Zhao, Shizhen
(2020/08/19)

Palladium-Catalyzed Cyanation of Aryl Halides Using Formamide and Cyanuric Chloride as a New “CN” Source
A new source of “CN” employing formamide and cyanuric chloride is introduced for the cyanation reactions. The treatment of formamide and 2,4,6-trichloro-1,3,5-triazine (TCT; cyanuric chloride) afforded an efficient cyanating agent which it can be used as a nontoxic, readily available, and non-expensive reagent in the cyanation transformations. In this study, palladium-catalyzed cyanation of aryl halides was successfully accomplished using this new “CN” source in high yields.
Niknam, Esmaeil,Panahi, Farhad,Khalafi-Nezhad, Ali
p. 2699 - 2707
(2020/04/08)

Acceptorless dehydrogenation of amines to nitriles catalyzed by N-heterocyclic carbene-nitrogen-phosphine chelated bimetallic ruthenium (II) complex
We have developed a clean, atom-economical and environmentally friendly route for acceptorless dehydrogenation of amines to nitriles by combining a new dual N-heterocyclic carbene-nitrogen-phosphine ligand R(CNP)2 (R = o-xylyl) with a ruthenium precursor [RuCl2(η6-C6H6)]2. In this system, the electronic and steric factors of amines had a negligible influence on the reaction and a broad range of functional groups were well tolerated. All of the investigated amines could be converted to nitriles in good yield of up to 99% with excellent selectivity. The unprecedented catalytic performance of this system is attributed to the synergistic effect of two ruthenium centers chelated by R(CNP)2 and a plausible reaction mechanism is proposed according to the active species found via in situ NMR and HRMS.
Chen, Hua,Fu, Haiyan,Ji, Li,Li, Ruixiang,Nie, Xufeng,Zheng, Yanling
p. 378 - 385
(2020/10/02)

One-Pot Generation of Benzynes from Phenols: Formation of Primary Anilines by the Deoxyamination of Phenols
Benzynes were selectively generated in situ from phenols and trapped regioselectively with potassium hexamethyldisilazide to form primary anilines following acidic workup. The direct conversion of a phenolic hydroxyl group into a free amino group is a useful method for the preparation of primary aryl amines that are hard to synthesize by using coupling reactions involving phenol derivatives with ammonia. Whereas reactions of ortho- and meta-substituted phenols produced meta-substituted anilines exclusively, those of para-substituted phenols provided ortho-silylanilines.
Akai, Shuji,Ikawa, Takashi,Masuda, Shigeaki
(2020/03/23)

Aromatic C-H amination in hexafluoroisopropanol
We report a direct radical aromatic amination reaction that provides unprotected anilines with an improvement in the substrate scope compared to prior art. Hydrogen bonding by the solvent hexafluoroisopropanol to anions of cationic species is responsible for increased reactivity and can rationalize the enhancement in substrate scope. Our findings may have bearings on radical additions to arenes for direct C-H functionalization in general.
D'Amato, Erica M.,B?rgel, Jonas,Ritter, Tobias
p. 2424 - 2428
(2019/02/28)

Method for preparing aromatic amine compounds from aromatic nitro compounds by catalytic reduction of nano porous gold catalyst
The invention discloses a method for preparing aromatic amine compounds from aromatic nitro compounds by catalytic reduction of a nano porous gold catalyst. The nano porous gold catalyst and the aromatic nitro compounds are taken as substrates and subjected to a reaction in methanol with ammonia borane as a hydrogen source at the room temperature, and a product is obtained. The high probability ofagglomeration of conventional granular catalysts is prevented, the nano porous gold catalyst shows excellent structural stability and good recycling efficiency, has excellent universality, especiallyfor the aromatic nitro compounds, and has green and mild catalytic conditions, high yield and good selectivity. The yield of m-nitroaniline from m-nitrotoluene can reach 98%. Moreover, the catalyst can be centrifugally recovered and can be recycled without other treatment, the yield of preparing m-nitroaniline from m-nitrotoluene by catalyzing can still reach 88% after being recycled five times,and thus, waste is effectively avoided. The catalyst shows high activity during the reaction and excellent stability under the reaction conditions.
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Paragraph 0024; 0025

(2019/07/04)

Ruthenium(II)-cored supramolecular organic framework-mediated recyclable visible light photoreduction of azides to amines and cascade formation of lactams
Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reduction of phenyl, benzyl, 2-phenylethyl and 3-phenylpropyl azides in acetonitrile to produce the corresponding amines in good to high yields. For the last two kinds of azides that bear a CO2Me group at the para-position of the benzene ring, cascade reactions take place to generate the corresponding lactams in high yields. Compared with homogeneous control [Ru(bpy)3]Cl2, SMOF-1 exhibits remarkably increased photocatalysis activity as a result of synergistic effect of the [Ru(bpy)3]2+ units that form cubic cages to host the azide molecules and related intermediates. Moreover, SMOF-1 displays high recyclability and considerable photocatalysis activity after 3 to 12 runs.
Wu, Yi-Peng,Yan, Meng,Gao, Zhong-Zheng,Hou, Jun-Li,Wang, Hui,Zhang, Dan-Wei,Zhang, Junliang,Li, Zhan-Ting
p. 1383 - 1386
(2019/05/06)

Metal-free chemoselective reduction of nitroaromatics to anilines via hydrogen transfer strategy
A novel protocol for chemoselective reduction of aromatic nitro compounds to aromatic amines has been established. The metal-free reduction goes through a hydrogen transfer process. Various easily reducible functional groups can be well tolerated under the optimized reaction conditions.
Shuai, Qi,Li, Jun,Zhao, Feng,Su, Weike,Deng, Guojun
p. 965 - 975
(2019/04/13)

One-Pot Synthesis of Heterobimetallic Metal–Organic Frameworks (MOFs) for Multifunctional Catalysis
A one-pot synthesis of bimetallic metal–organic frameworks (Co/Fe-MOFs) was achieved by treating stoichiometric amounts of Fe and Co salts with 2-aminoterephthalic acid (NH2-BDC). Monometallic Fe (catalyst A) and Co (catalyst F) were also prepared along with mixed-metal Fe/Co catalysts (B–E) by changing the Fe/Co ratio. For mixed-metal catalysts (B–E) SEM energy-dispersive X-ray (EDX) analysis confirmed the incorporation of both Fe and Co in the catalysts. However, a spindle-shaped morphology, typically known for the Fe-MIL-88B structure and confirmed by PXRD analysis, was only observed for catalysts A–D. To test the catalytic potential of mixed-metal MOFs, reduction of nitroarenes was selected as a benchmark reaction. Incorporation of Co enhanced the activity of the catalysts compared with the parent NH2-BDC-Fe catalyst. These MOFs were also tested as electrocatalysts for the oxygen evolution reaction (OER) and the best activity was exhibited by mixed-metal Fe/Co-MOF (Fe/Co batch ratio=1). The catalyst provided a current density of 10 mA cm?2 at 410 mV overpotential, which is comparable to the benchmark OER catalyst (i.e., RuO2). Moreover, it showed long-term stability in 1 m KOH. In a third catalytic test, dehydrogenation of sodium borohydride showed high activity (turnover frequency=87 min?1) and hydrogen generation rate (67 L min?1 g?1 catalyst). This is the first example of the synthesis of bimetallic MOFs as multifunctional catalysts particularly for catalytic reduction of nitroarenes and dehydrogenation reactions.
Iqbal, Bushra,Saleem, Murtaza,Arshad, Salman Noshear,Rashid, Jamshaid,Hussain, Naveed,Zaheer, Muhammad
p. 10490 - 10498
(2019/07/15)

Ultra-low-loading palladium nanoparticles stabilized on nanocrystalline Polyaniline (Pd@PANI): A efficient, green, and recyclable catalyst for the reduction of nitroarenes
Ultra-low-loading Pd@PANI nanocomposites (0.048 w.t% Pd) were synthesized via a method that combined interfacial polymerization and in situ composite with camphor sulfonic acid ((+)-CSA) as a dopant. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, and X-ray photoelectron spectroscopy (XPS) were performed to characterize the structures. It can be used as an efficient catalyst for the reduction of nitroarenes in aqueous solution by using a smaller amount of NaBH4 (2.5 equiv.) at room temperature with high activity (TON?=?3.4?×?103), good stability (cycled eight times), as well as wide applicability (27 substrates). The catalyst also showed a marvelous activity in the gram-level reaction (yield?=?92%). UV–Visible spectrophotometry was used to investigate the reaction kinetics for the reduction of 4-nitrophenol to 4-aminophenol, and the results reconfirmed the excellent performance of the catalyst. The unique properties and superior performance of the prepared ultra-low-loading Pd@PANI nanocomposites lead it be an attractive alternative catalyst for conventional organic catalytic applications.
Wang, Gang,Yuan, Shuo,Wu, Zhiqiang,Liu, Wanyi,Zhan, Haijuan,Liang, Yanping,Chen, Xiaoyan,Ma, Baojun,Bi, Shuxian
(2019/08/30)

Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS): An efficient catalyst for cyanation reaction in aqueous media
Immobilized palladium nanoparticles on a cyclodextrin-polyurethane nanosponge (Pd-CD-PU-NS) were found to be an efficient heterogeneous catalyst in the cyanation reaction of aryl halides in aqueous media. This catalyst system is containing palladium nanoparticles with a size of ～7 nm. Moreover, the CD-PU-NS support formed microsphere-shaped structures with a size of ～100–200 nm. The TEM images show that Pd nanoparticles were formed in near spherical shape morphology and were immobilized in the structure of the CD-PU-NS support. Under our optimized reaction conditions, aryl cyanides were obtained in high yields in the presence of the Pd-CD-PU-NS catalyst. Our results demonstrated that the Pd-CD-PU-NS catalyst is highly effective in the cyanation reaction in aqueous media. Furthermore, the catalyst could be simply extracted from the reaction mixture, providing an efficient methodology for the synthesis of aryl cyanides. The Pd-CD-PU-NS catalyst could be recycled four times with almost consistent catalytic efficiency.
Khajeh Dangolani, Soheila,Sharifat, Sara,Panahi, Farhad,Khalafi-Nezhad, Ali
supporting information
p. 256 - 265
(2019/06/07)

Mechanochemical catalytic transfer hydrogenation of aromatic nitro derivatives
Mechanochemical ball milling catalytic transfer hydrogenation (CTH) of aromatic nitro compounds using readily available and cheap ammonium formate as the hydrogen source is demonstrated as a simple, facile and clean approach for the synthesis of substituted anilines and selected pharmaceutically relevant compounds. The scope of mechanochemical CTH is broad, as the reduction conditions tolerate various functionalities, for example nitro, amino, hydroxy, carbonyl, amide, urea, amino acid and heterocyclic. The presented methodology was also successfully integrated with other types of chemical reactions previously carried out mechanochemically, such as amide bond formation by coupling amines with acyl chlorides or anhydrides and click-type coupling reactions between amines and iso(thio)cyanates. In this way, we showed that active pharmaceutical ingredients Procainamide and Paracetamol could be synthesized from the respective nitro-precursors on milligram and gram scale in excellent isolated yields.
Portada, Tomislav,Margeti?, Davor,?trukil, Vjekoslav
supporting information

(2018/12/11)

The Direct Synthesis of Imines, Benzimidazoles and Quinoxalines from Nitroarenes and Carbonyl Compounds by Selective Nitroarene Hydrogenation Employing a Reusable Iron Catalyst
The “replacement” of noble metals by earth abundant metals is a desirable aim in catalysis and a possible way of conserving rare elements. The “replacement” is especially attractive if novel selectivity patterns are observed permitting the development of novel coupling reactions. Herein, we report on a novel, robust and reusable iron catalyst, which permits the selective hydrogenation of nitroarenes in the presence of hydrogenation-sensitive functional groups. Based on the selectivity pattern observed, the direct iron-catalyzed synthesis of imines and benzimidazoles from nitroarenes and aldehydes becomes feasible. In addition, we introduce the direct synthesis of quinoxalines from nitroarenes and diketones applying our catalyst.
B?umler, Christoph,Kempe, Rhett
supporting information
p. 8989 - 8993
(2018/05/30)

Metal-free Reduction of Nitro Aromatics to Amines with B 2 (OH) 4 /H 2 O
A metal-free reduction of nitro aromatics mediated by diboronic acid with water as both the hydrogen donor and solvent under mild conditions has been developed. A series of aromatic amines were obtained with good functional group tolerance and in good yields.
Chen, Danyi,Zhou, Yanmei,Zhou, Haifeng,Liu, Sensheng,Liu, Qixing,Zhang, Kaili,Uozumi, Yasuhiro
supporting information
p. 1765 - 1768
(2018/06/26)

Unravelling 2-aminoquinazolin-4(3: H)-one as an organocatalyst for the chemoselective reduction of nitroarenes
A novel, mild and transition metal-free, 2-aminoquinazolin-4(3H)-one-assisted reduction of nitroarenes employing hydrazine hydrate as reducing agent and potassium carbonate as a base is reported. For the first time, the activation of hydrazine hydrate with an organocatalyst has been explored for reduction reactions. Also for the first time, 2-aminoquinazolin-4(3H)-one and its derivatives have been investigated as hydrogen bonding organocatalysts for the reduction of nitroarenes to anilines. Sensitive functional groups such as sulfonamide, carboxyl, amide and halides were well tolerated in this green methodology with scalability and high chemoselectivity.
Thakur, Maheshwar S.,Nayal, Onkar S.,Rana, Rohit,Kumar, Manoranjan,Sharma, Sushila,Kumar, Neeraj,Maurya, Sushil K.
supporting information
p. 1373 - 1378
(2018/02/06)

Cu-catalyzed reduction of azaarenes and nitroaromatics with diboronic acid as reductant
A ligand-free copper-catalyzed reduction of azaarenes with diboronic acid as reductant in an aprotic solvent under mild conditions has been developed. Most interestingly, the nitroazaarenes could be reduced exclusively to give the corresponding amines without touching the azaarene moieties. Furthermore, the reductive amination of aromatic nitro compounds and aromatic aldehydes has also been realized. A series of hydrogenated azaarenes and secondary amines were obtained with good functional group tolerance.
Pi, Danwei,Zhou, Haifeng,Zhou, Yanmei,Liu, Qixing,He, Renke,Shen, Guanshuo,Uozumi, Yasuhiro
p. 2121 - 2129
(2018/03/23)

The synergic effects at the molecular level in CoS2 for selective hydrogenation of nitroarenes
Catalytic functionalized aniline formation from nitroarenes is a core technology in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals. However, control of chemoselectivity still poses particular challenges with aromatic nitro substrates bearing one or more reducible groups. Here, we report the low-cost synthesis of a porous carbon supported CoS2 catalyst (CoS2/PC) and successfully apply the catalyst in the chemoselective hydrogenation of nitroarenes. For hydrogenation of 3-nitrostyrene, the catalyst furnishes a superior selectivity of 99% towards 3-aminostyrene at a conversion of >99%. Density functional theory calculations together with X-ray absorption fine structure spectroscopy reveal that terdentate and tetrahedral coordinated Co atoms in CoS2 (labeled as Co3 and Co4) are possible active sites. The face to face located Co3 and Co4 sites make the reaction rather local, and Co3 and Co4 sites are occupied by substrates and H2, respectively, which is beneficial to the superior activity and selectivity. The Co3-Co4 "synergic active site pair" in CoS2 makes the investigation of the synergic effects at the molecular level a reality on heterogeneous catalysts.
Wei, Zhongzhe,Mao, Shanjun,Sun, Fanfei,Wang, Jing,Mei, Bingbao,Chen, Yiqing,Li, Haoran,Wang, Yong
p. 671 - 679
(2018/02/14)

Visible-Light-Driven Chemoselective Hydrogenation of Nitroarenes to Anilines in Water through Graphitic Carbon Nitride Metal-Free Photocatalysis
Green and efficient procedures are essential for the chemoselective hydrogenation of functionalized nitroarenes to form industrially important anilines. Herein, it is shown that visible-light-driven, chemoselective hydrogenation of functionalized nitroarenes with groups sensitive to forming anilines can be achieved in good to excellent yields (82–100 %) in water under relatively mild conditions and catalyzed by low-cost and recyclable graphitic carbon nitride. The process is also applicable to gram-scale reaction, with a yield of aniline of 86 %. A study of the mechanism reveals that visible-light-induced electrons are responsible for the hydrogenation reactions, and thermal energy can also promote the photocatalytic activity. A study of the kinetics shows that this reaction possibly occurs through one-step hydrogenation or stepwise condensation routes. A wide range of applications can be expected for this green, efficient, and highly selective photocatalysis system in reduction reactions for the synthesis of fine chemicals.
Xiao, Gang,Li, Peifeng,Zhao, Yilin,Xu, Shengnan,Su, Haijia
supporting information
p. 1950 - 1955
(2018/07/31)

Controlled Transformations of Aryl Halides in a Flow System: Selective Synthesis of Aryl Azides and Aniline Derivatives
Copper-mediated nitrogenation of aryl halides with sodium azide can result in either aryl azides or aniline derivatives. The selectivity of the transformation is highly dependent on reaction time and temperature, which led to contradictory literature results with respect to product selectivity and the conditions applied. The advantages of a strictly controlled flow reactor environment were exploited in order to facilitate selective haloarene transformations. Reaction conditions were carefully investigated to understand their role on product selectivity. Aryl azides and aryl amines were successfully prepared from the same starting materials using the same auxiliaries by means of precise control over residence time and reaction temperature, thereby ensuring time-, cost- and atom-efficient syntheses. (Figure presented.).
Georgiádes, ádám,?tv?s, Sándor B.,Fül?p, Ferenc
p. 1841 - 1849
(2018/04/09)

Catalytic application of 1,3,5-triazine-pentaethylenehexamine polymer-supported palladium nanoparticles in the convenient reduction of nitroarenes with sodium borohydride or hydrazine
The catalytic activity of 1,3,5-triazine-pentaethylenehexamine (TAPEHA) polymer-supported Pd nanoparticles was investigated in the reduction of nitro arenes to the corresponding amines by NaBH4 or N2H4 .H2 O. Optimized reaction conditions for both systems were successfully tested on 20 nitroarenes with different characteristics. Considerably high yields (80%-98% in NaBH4 and 85%-98% in N2H4) were obtained in a short time and at ambient temperature. In addition to these methods being selective against other reducible functionalities such as -CN, -Br, -Cl, and -I, the catalyst can be recovered easily and reused more than ten times.
Gen?, Hayriye,Zengin, Mustafa,Kü?ükislamo?lu, Mustafa,Imamoglu, Mustafa,Toplan, Hüseyin ?zkan,Arslan, Mustafa
p. 784 - 792
(2017/11/20)

Water as a hydrogen source in palladium-catalyzed reduction and reductive amination of nitroarenes mediated by diboronic acid
An unprecedented palladium-catalyzed chemoselective reduction and reductive amination of nitroarenes with water as a hydrogen source mediated by diboronic acid have been discovered. A series of aryl amines containing various reducible functional groups were obtained in good to excellent yields.
Zhou, Yanmei,Zhou, Haifeng,Liu, Sensheng,Pi, Danwei,Shen, Guanshuo
p. 3898 - 3904
(2017/06/13)

Photoinduced Reduction of Nitrobenzenes to Primary Aromatic Amines
Primary aromatic amines were synthesized from the corresponding nitrobenzenes via photoinduced reduction. The reaction was found to be effective when nitrobenzenes with electron-withdrawing substituents were irradiated with a broad band of UV light centered at 306 nm. When reactions are completed, products could be isolated by acid-base extraction or by column chromatography. This presenting photoreaction procedure for the synthesis of primary aromatic amines from the corresponding nitrobenzenes proceeds without the need of a sensitizer in isopropanol or THF. Without the usage of catalysts, or stoichiometric reducing reagent containing heavy metals, this photoinduced reduction of nitrobenzenes fulfils the concept of green chemistry.
Huang, Hua-Hsuan,Chen, Yu-Feng,Niu, Guang-Hao,Chuang, Gary J.
supporting information
p. 1191 - 1194
(2017/06/13)

AgPd Nanoparticles Deposited on WO2.72 Nanorods as an Efficient Catalyst for One-Pot Conversion of Nitrophenol/Nitroacetophenone into Benzoxazole/Quinazoline
We report a seed-mediated growth of 2.3 nm AgPd nanoparticles (NPs) in the presence of 40 × 5 nm WO2.72 nanorods (NRs) for the synthesis of AgPd/WO2.72 composites. The strong interactions between AgPd NPs and WO2.72 NRs make the composites, especially the Ag48Pd52/WO2.72, catalytically active for dehydrogenation of formic acid (TOF = 1718 h-1 and Ea = 31 kJ/mol) and one-pot reactions of formic acid, 2-nitrophenol, and aldehydes into benzoxazoles in near quantitative yields under mild conditions. The catalysis can also be extended to the one-pot reactions of ammonium formate, 2-nitroacetophenone, and aldehyde for high yield syntheses of quinazolines. Our studies demonstrate a new catalyst design to achieve a green chemistry approach to one-pot reactions for the syntheses of benzoxazoles and quinazolines.
Yu, Chao,Guo, Xuefeng,Xi, Zheng,Muzzio, Michelle,Yin, Zhouyang,Shen, Bo,Li, Junrui,Seto, Christopher T.,Sun, Shouheng
supporting information
p. 5712 - 5715
(2017/05/04)

Ex situ generation of stoichiometric HCN and its application in the Pd-catalysed cyanation of aryl bromides: Evidence for a transmetallation step between two oxidative addition Pd-complexes
A protocol for the Pd-catalysed cyanation of aryl bromides using near stoichiometric and gaseous hydrogen cyanide is reported for the first time. A two-chamber reactor was adopted for the safe liberation of ex situ generated HCN in a closed environment, which proved highly efficient in the Ni-catalysed hydrocyanation as the test reaction. Subsequently, this setup was exploited for converting a range of aryl and heteroaryl bromides (28 examples) directly into the corresponding benzonitriles in high yields, without the need for cyanide salts. Cyanation was achieved employing the Pd(0) precatalyst, P(tBu)3-Pd-G3 and a weak base, potassium acetate, in a dioxane-water solvent mixture. The methodology was also suitable for the synthesis of 13C-labelled benzonitriles with ex situ generated 13C-hydrogen cyanide. Stoichiometric studies with the metal complexes were undertaken to delineate the mechanism for this catalytic transformation. Treatment of Pd(P(tBu)3)2 with H13CN in THF provided two Pd-hydride complexes, (P(tBu)3)2Pd(H)(13CN), and [(P(tBu)3)Pd(H)]2Pd(13CN)4, both of which were isolated and characterised by NMR spectroscopy and X-ray crystal structure analysis. When the same reaction was performed in a THF : water mixture in the presence of KOAc, only (P(tBu)3)2Pd(H)(13CN) was formed. Subjection of this cyano hydride metal complex with the oxidative addition complex (P(tBu)3)Pd(Ph)(Br) in a 1 : 1 ratio in THF led to a transmetallation step with the formation of (P(tBu)3)2Pd(H)(Br) and 13C-benzonitrile from a reductive elimination step. These experiments suggest the possibility of a catalytic cycle involving initially the formation of two Pd(ii)-species from the oxidative addition of LnPd(0) into HCN and an aryl bromide followed by a transmetallation step to LnPd(Ar)(CN) and LnPd(H)(Br), which both reductively eliminate, the latter in the presence of KOAc, to generate the benzonitrile and LnPd(0).
Kristensen, Steffan K.,Eikeland, Espen Z.,Taarning, Esben,Lindhardt, Anders T.,Skrydstrup, Troels
p. 8094 - 8105
(2017/11/27)

Photoinduced Copper(I)-Catalyzed Cyanation of Aromatic Halides at Room Temperature
The first photoinduced copper(I)-catalyzed cyanation of aromatic halides at room temperature has been developed. The sp2 cyanation reaction exhibits outstanding tolerance to functional groups including primary amines and carboxylic acids, and chemoselectivity to SN2-reactive alkyl chlorides. Mechanistic investigations indicate that the reaction occurs via a single-electron transfer (SET) between the aryl halide and an excited copper(I) cyanide catalytic intermediate. (Figure presented.).
Kim, Kicheol,Hong, Soon Hyeok
supporting information
p. 2345 - 2351
(2017/07/22)

Selective Cross-Coupling of (Hetero)aryl Halides with Ammonia to Produce Primary Arylamines using Pd-NHC Complexes
Herein we report the first example of (hetero)arylation of ammonia using a monoligated palladium-NHC complex. The new, rationally designed, precatalyst (DiMeIHeptCl)Pd(allyl)Cl featuring highly branched alkyl chains has been shown to be effective in selective aminations across a range of challenging substrates, including nitrogen-containing heterocycles and those featuring base-sensitive functionality. The less bulky Pd-PEPPSI-IPentCl precatalyst performs well for ortho-substituted aryl halides, giving monoarylated products in high yield with good selectivity.
Lombardi, Christopher,Day, Jonathan,Chandrasoma, Nalin,Mitchell, David,Rodriguez, Michael J.,Farmer, Jennifer L.,Organ, Michael G.
supporting information
p. 251 - 254
(2017/04/26)

Controllable Synthesis of Mesoporous Iron Oxide Nanoparticle Assemblies for Chemoselective Catalytic Reduction of Nitroarenes
Iron(III) oxide is a low-cost material with applications ranging from electronics to magnetism, and catalysis. Recent efforts have targeted new nanostructured forms of Fe2O3 with high surface area-to-volume ratio and large pore volume. Herein, the synthesis of 3D mesoporous networks consisting of 4-5 nm γ-Fe2O3 nanoparticles by a polymer-assisted aggregating self-assembly method is reported. Iron oxide assemblies obtained from the hybrid networks after heat treatment have an open-pore structure with high surface area (up to 167 m2 g-1) and uniform pores (ca. 6.3 nm). The constituent iron oxide nanocrystals can undergo controllable phase transition from γ-Fe2O3 to α-Fe2O3 and to Fe3O4 under different annealing conditions while maintaining the 3D structure and open porosity. These new ensemble structures exhibit high catalytic activity and stability for the selective reduction of aryl and alkyl nitro compounds to the corresponding aryl amines and oximes, even in large-scale synthesis.
Papadas, Ioannis T.,Fountoulaki, Stella,Lykakis, Ioannis N.,Armatas, Gerasimos S.
p. 4600 - 4607
(2016/03/22)

An abnormal N-heterocyclic carbene based nickel complex for catalytic reduction of nitroarenes
Herein we report the synthesis of a nickel(ii) dichloro complex bearing an abnormal N-heterocyclic carbene (aNHC). The NiCl2(aNHC)2 complex has been used as an efficient catalyst for the reduction of nitroarenes with hydrosilanes to give aromatic amines in good to excellent yields. This catalytic protocol can tolerate functional groups such as halides, alkenes or nitriles. Furthermore, the longevity of the catalyst was tested in successive catalytic cycles, which indicates a sustained catalytic activity over multiple catalytic cycles.
Vijaykumar, Gonela,Mandal, Swadhin K.
p. 7421 - 7426
(2016/06/01)

Stable and reusable platinum nanocatalyst: An efficient chemoselective reduction of nitroarenes in water
Binaphthyl stabilized Pt nanoparticles (Pt-BNP) have been synthesized, characterized, and utilized as an efficient heterogeneous catalyst for chemoselective reduction of nitroarenes at room temperature in water. Several sensitive functional groups like ketone, ester, acid, amide, halides, and nitrile were well tolerated in this chemoselective reduction. The Pt-BNP catalyst was quantitatively recovered without any major change in particle size and reactivity and then efficiently reused for five catalytic cycles.
Kotha, Surya Srinivas,Sharma, Nidhi,Sekar, Govindasamy
supporting information
p. 1410 - 1413
(2016/03/12)

Metal-Free Reduction of Aromatic Nitro Compounds to Aromatic Amines with B2pin2 in Isopropanol
A metal-free reduction of aromatic nitro compounds to the corresponding amines has been achieved by a combination of B2pin2 and KOtBu in isopropanol. A series of nitro compounds containing various reducible functional groups were chemoselectively reduced in good to excellent yields.
Lu, Hongtao,Geng, Zhiyue,Li, Jingya,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie
supporting information
p. 2774 - 2776
(2016/06/15)

A Reusable Mesoporous Nickel Nanocomposite Catalyst for the Selective Hydrogenation of Nitroarenes in the Presence of Sensitive Functional Groups
The synthesis of aromatic amines from nitroarenes through hydrogenation is an industrially and academically important reaction. In addition, the employment of base metal catalysts in reactions that are preferentially mediated by rare noble metals is a desirable aim in catalysis and an attractive element-conservation strategy. Especially appealing is the observation of novel selectivity patterns with such inexpensive metal catalysts. Herein, we report a novel mesostructured Ni nanocomposite catalyst. It is the first example of a reusable Ni catalyst that is able to hydrogenate nitroarenes selectively to anilines in the presence of highly sensitive functional groups such as C=C bonds and nitrile, aldehyde, and iodo substituents.
Hahn, Gabriela,Ewert, Julia-Katharina,Denner, Christine,Tilgner, Dominic,Kempe, Rhett
p. 2461 - 2465
(2016/08/24)

A Reusable Co Catalyst for the Selective Hydrogenation of Functionalized Nitroarenes and the Direct Synthesis of Imines and Benzimidazoles from Nitroarenes and Aldehydes
The use of abundantly available transition metals in reactions that have been preferentially mediated by rare noble metals, for example, hydrogenations, is a desirable aim in catalysis and an attractive strategy for element conservation. The observation of novel selectivity patterns with such inexpensive metal catalysts is especially appealing. Herein, we report a novel, robust, and reusable cobalt catalyst that permits the selective hydrogenation of nitroarenes in the presence of highly hydrogenation-sensitive functional groups, as well as the direct synthesis of imines from nitroarenes and aldehydes or ketones in the presence of such substituents. Furthermore, we introduce the first base-metal-mediated direct synthesis of benzimidazoles from nitroarenes and aldehydes. Functional groups that are easy to hydrogenate are again well tolerated.
Schwob, Tobias,Kempe, Rhett
supporting information
p. 15175 - 15179
(2016/11/25)

Method for synthesizing cyanoaniline through nitrobenzonitrile catalytic hydrogenation
The invention relates to a method for preparing cyanoaniline through nitrobenzonitrile catalytic hydrogenation.According to the method, in environment acceptable solvent n-heptane and CO2 expansion n-heptane, Pd/SnO2-Sb2O3 catalyzes nitrobenzonitrile to prepare cyanoaniline at the temperature of 30-120 DEG C in a hydrogenation mode, the yield of the cyanoaniline reaches 100%, and no accumulation of harmful intermediates such as benzene hydroxylamine is caused in the reaction process.Pd/SnO2Sb2O3 nearly has no catalytic activity to cyanoaniline, and therefore, after reactants are completely converted, the yield of the cyanoaniline does not reduce along with time.The CO2 expansion n-heptane serves as the solvent, and the use amount of n-heptane can be reduced.
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(2017/01/23)