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Highly organic phase soluble polyisobutylene-bound cobalt phthalocyanines as recyclable catalysts for nitroarene reduction
A cobalt phthalocyanine (CoMPc) containing covalently linked polyisobutylene (PIB) groups as phase anchors that is both highly soluble in nonpolar organic solvents and phase selectively soluble in a liquid/liquid separation step is shown to be an effective recyclable homogeneous catalyst for nitroarene reduction in a semi-thermomorphic system. Electron-donating and electron-withdrawing substituents in the nitroarene are tolerated in this aniline synthesis and the catalyst is recyclable up to 10 cycles with little leaching and no detectable loss in reactivity after 10 cycles.
Chao, Chih-Gang,Bergbreiter, David E.
p. 89 - 93
(2016)
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Synthesis and characterization of chitosan pyridyl imine palladium (CPIP) complex as green catalyst for organic transformations
In this work, the modification of chitosan using 2-acetyl pyridine has been used to prepare an intermediate, chitosan pyridyl imine (CPI), in first step and then in second step it is further reacted with Pd(OAc)2 to develop chitosan pyridyl imine palladium (CPIP) complex catalyst in a very simplistic way. The formed CPIP has been extensively characterized with respect to raw chitosan utilizing methods including FT-IR, pyrolysis GC–MS, XRD, XPS, FE-SEM, EDS, TGA-DTG and DSC. TG-DSC study suggested that the catalyst is thermally stable up to 300?°C. This catalyst shows an excellent activity in the reduction of toxic pollutant nitrobenzene to less toxic aniline. CPIP complex has also been found to give magnificent results in Suzuki–Miyaura and Heck cross-coupling reactions, and therefore, using this green catalyst, the toxic phosphine ligand can be excluded from cross-coupling reactions. This study furnishes an economic and eco-friendly catalyst for organic transformation in sustainable chemistry.
Chundawat, Narendra Singh,Pathan, Sultan,Singh, Girdhar Pal,Deuri, Arup Saha,Zarrintaj, Payam,Chauhan, Narendra Pal Singh
p. 2835 - 2850
(2021/02/11)

Development and Application of Efficient Ag-based Hydrogenation Catalysts Prepared from Rice Husk Waste
The development of strategies for the sustainable management and valorization of agricultural waste is of outmost importance. With this in mind, we report the use of rice husk (RH) as feedstock for the preparation of heterogeneous catalysts for hydrogenation reactions. The catalysts were prepared by impregnating the milled RH with a silver nitrate solution followed by carbothermal reduction. The composition and morphology of the prepared catalysts were fully assessed by IR, AAS, ICP-MS, XPS, XRD and STEM techniques. This novel bio-genic silver-based catalysts showed excellent activity and remarkable selectivity in the hydrogenation of nitro groups in both aromatic and aliphatic substrates, even in the presence of reactive functionalities like halogens, carbonyls, borate esters or nitriles. Recycling experiments showed that the catalysts can be easily recovered and reused multiple times without significant drop in performance and without requiring re-activation.
Unglaube, Felix,Kreyenschulte, Carsten Robert,Mejía, Esteban
p. 2583 - 2591
(2021/04/09)

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)

Selective Carbon-Carbon Bond Amination with Redox-Active Aminating Reagents: A Direct Approach to Anilines?
Amines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt-type rearrangement using redox-active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.
Qiu, Xu,Wang, Yachong,Su, Lingyu,Jin, Rui,Song, Song,Qin, Qixue,Li, Junhua,Zong, Baoning,Jiao, Ning
supporting information
p. 3011 - 3016
(2021/09/13)

Method for synthesizing heteroatom- substituted aromatic compound from styrene compound
The invention discloses a method for synthesizing a heteroatom-substituted aromatic compound from a styrene compound, which comprises the following steps of: mixing a styrene compound with a general formula (I) and a heteroatom-containing compound with a general formula (II), and reacting in the presence of an acid additive and an organic solvent to obtain a heteroatom-substituted compound with ageneral formula (III). According to the synthesis method disclosed by the invention, a large amount of styrene compounds are used as raw materials and react to generate aromatic amine or phenol compounds under the action of no metal catalysis; and compared with the traditional aromatic amine and phenol synthesis method, the method has the advantages of high yield, simple conditions, low waste discharge amount, no metal participation, simple reaction equipment, easiness in industrial production and the like.
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Paragraph 0148-0151

(2021/02/06)

Synthesis of Substituted Anilines from Cyclohexanones Using Pd/C-Ethylene System and Its Application to Indole Synthesis
The synthesis of anilines and indoles from cyclohexanones using a Pd/C-ethylene system is reported. A simple combination of NH4OAc and K2CO3 under nonaerobic conditions was found to be the most suitable to perform this reaction. Hydrogen transfer between cyclohexanone and ethylene generates the desired products. The reaction tolerates a variety of substitutions on the starting cyclohexanones.
Maeda, Katsumi,Matsubara, Ryosuke,Hayashi, Masahiko
supporting information
p. 1530 - 1534
(2021/03/08)

Selective primary aniline synthesis through supported Pd-catalyzed acceptorless dehydrogenative aromatization by utilizing hydrazine
By utilizing hydrazine (N2H4) as the nitrogen source in the presence of a hydroxyapatite-supported Pd nanoparticle catalyst (Pd/HAP), various primary anilines can be selectively synthesized from cyclohexanonesviaacceptorless dehydrogenative aromatization. The strong nucleophilicity of N2H4and the stability of the hydrazone intermediates can effectively suppress the formation of the undesired secondary aniline byproducts.
Lin, Wei-Chen,Yamaguchi, Kazuya,Yatabe, Takafumi
supporting information
p. 6530 - 6533
(2021/07/07)

Copper catalyzed reduction of azides with diboron under mild conditions
We report herein the first Cu catalyzed reduction of azides with B2pin2 (pin = pinacolato) as the reductant under very mild conditions. A series of primary amines and amides were obtained in moderate to excellent yields with high chemoselectivity and good functional group tolerance. This reaction can be performed with a cheap copper salt, a simple NHC ligand and a diboron reagent.
Chen, Yang,Deng, Shengqi,Gao, Yihua,Liu, Liwen,Liu, Yu,Lu, Da,Wang, Qianwen,Zhang, Xiao
supporting information

(2020/02/27)

Mild environment-friendly oxidative debenzylation of N-benzylanilines using DMSO as an oxidant
Oxidative debenzylation of N-benzyl aromatic amines using DMSO as a non-toxic oxidant and catalyzed by TsOH gave Nphenylimines, which were spontaneously hydrolyzed to form anilines and benzaldehydes in good yields. This reaction employs mild, metal-free conditions. The conditions are also suitable for the debenzylation of benzylphenylethers.
Yoshinaga, Tatsuro,Iwata, Takayuki,Shindo, Mitsuru
supporting information
p. 191 - 194
(2020/02/25)

C-H Amination of Arenes with Hydroxylamine
This Letter describes the development of a TiIII-mediated reaction for the C-H amination of arenes with hydroxylamine. This reaction is applied to a variety of electron-rich (hetero)arene substrates, including a series of natural products and pharmaceuticals. It offers the advantages of mild conditions (room temperature), fast reaction rates (30 min), compatibility with ambient moisture and air, scalability, and the use of inexpensive commercial reagents.
See, Yi Yang,Sanford, Melanie S.
supporting information
p. 2931 - 2934
(2020/04/09)

Platinum nanoparticles confined in imidazolium-based ionic polymer for assembling a microfluidic reactor with enhanced catalytic activity
A synthetic strategy is developed to grow Pt nanoparticles supported by imidazolium-based ionic polymers (Pt/ImIP-2BrB) on the inner surface of fused-silica capillary. The imidazolium-based ionic polymers ImIP-2BrB are prepared from condensation of tetrakis[4-(1-imidazolyl)phenyl]methane and 1,4-bis-bromomethyl-benzene and are employed to support Pt nanoparticles. The capillary coated with Pt/ImIP-2BrB is further assembled to achieve a catalytic micro?uidic reactor. The catalytic activity is probed in either the reduction of nitrobenzene derivatives or the hydrosilylation of phenylacetylene with triethylsilane by flowing through the micro?uidic reactor. The catalytic micro?uidic reactor demonstrates significantly enhanced activity about 2–8 times in comparison with the corresponding reactions under batch conditions. The reactor greatly reduces the amount of Pt upon achieving similar yields. It also shows good recyclability without significant decrease of the activity.
Fang, Haobin,Chen, Junxing,Xiao, Yali,Zhang, Jianyong
(2019/08/07)

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)

Method of preparing aromatic amine compound through reduced aromatic nitro compound
The invention discloses a method of preparing an aromatic amine compound through a reduced aromatic nitro compound. The method includes: in a simple condition, taking an aromatic nitro compound as a raw material, borane tetrahydrofuran as a hydrogen transfer reagent and metal salt of iron and copper which are cheap in price as a catalyst, and catalyzing the aromatic nitro compound for hydrogen transfer reaction to obtain a reduced aromatic amine compound. The method has the advantages that reaction condition is simple, yield is high, raw material universal applicability is high, the catalyst and the hydrogen transfer reagent are cheap in price and easy to obtain, and the method can still present high reproducibility during expanded amount reaction, therefore, an effective solution is provided for commercial preparation of the aromatic amine compound.
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Paragraph 0030-0034

(2019/06/27)

HETEROCYCLIC CARBOXYLIC ACID AMIDE LIGAND AND APPLICATIONS THEREOF IN COPPER CATALYZED COUPLING REACTION OF ARYL HALOGENO SUBSTITUTE
Provided are a heterocyclic carboxylic acid amide ligand and applications thereof in a copper catalyzed coupling reaction. Specifically, provided are uses of a compound represented by formula (I), definitions of radical groups being described in the specifications. The compound represented by formula (I) can be used as the ligand in the copper catalyzed coupling reaction of the aryl halogeno substitute, and is used or catalyzing the coupling reaction for forming the aryl halogeno substitute having C—N, C—O, C—S and other bonds.
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Paragraph 0266-0267

(2019/05/15)

Oxalic amide ligands, and uses thereof in copper-catalyzed coupling reaction of aryl halides
The present invention provides oxalic amide ligands and uses thereof in copper-catalyzed coupling reaction of aryl halides. Specifically, the present invention provides a use of a compound represented by formula I, wherein definitions of each group are described in the specification. The compound represented by formula I can be used as a ligand in copper-catalyzed coupling reaction of aryl halides for the formation of C—N, C—O and C—S bonds.
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Page/Page column 89-90

(2020/01/09)

COMPOUNDS FOR THIOL-TRIGGERED COS AND/OR H2S RELEASE AND METHODS OF MAKING AND USING THE SAME
Disclosed herein are embodiments of a compound that is capable of releasing COS and/or H2S upon reaction with a thiol-containing compound. The compound embodiments also can produce a detectable signal (e.g., a fluorescent signal) substantially concomitantly with COS and/or H2S release and/or can release an active agent, such as a therapeutic agent. Methods of making and using the compound embodiments also are disclosed.
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Page/Page column 35

(2019/12/25)

Selective Synthesis of Primary Anilines from NH3 and Cyclohexanones by Utilizing Preferential Adsorption of Styrene on the Pd Nanoparticle Surface
Dehydrogenative aromatization is one of the attractive alternative methods for directly synthesizing primary anilines from NH3 and cyclohexanones. However, the selective synthesis of primary anilines is quite difficult because the desired primary aniline products and the cyclohexanone substrates readily undergo condensation affording the corresponding imines (i.e., N-cyclohexylidene-anilines), followed by hydrogenation to produce N-cyclohexylanilines as the major products. In this study, primary anilines were selectively synthesized in the presence of supported Pd nanoparticle catalysts (e.g., Pd/HAP, HAP=hydroxyapatite, Ca10(PO4)6(OH)2) by utilizing competitive adsorption unique to heterogeneous catalysis; in other words, when styrene was used as a hydrogen acceptor, which preferentially adsorbs on the Pd nanoparticle surface in the presence of N-cyclohexylidene-anilines, various structurally diverse primary anilines were selectively synthesized from readily accessible NH3 and cyclohexanones. The Pd/HAP catalyst was reused several times though its catalytic performance gradually declined.
Koizumi, Yu,Jin, Xiongjie,Yatabe, Takafumi,Miyazaki, Ray,Hasegawa, Jun-ya,Nozaki, Kyoko,Mizuno, Noritaka,Yamaguchi, Kazuya
supporting information
p. 10893 - 10897
(2019/07/12)

Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage
The Br?nsted acid-catalyzed synthesis of primary amines from acetyl arenes and alkanes with C-C bond cleavage is described. Although the conversion from an acetyl group to amine has traditionally required multiple steps, the method described herein, which uses an oxime reagent as an amino group source, achieves the transformation directly via domino transoximation/Beckmann rearrangement/Pinner reaction. The method was also applied to the synthesis of γ-aminobutyric acids, such as baclophen and rolipram.
Hyodo, Kengo,Hasegawa, Genna,Maki, Hiroya,Uchida, Kingo
supporting information
p. 2818 - 2822
(2019/04/25)

Pyridyl Radical Cation for C?H Amination of Arenes
Electron-transfer photocatalysis provides access to the elusive and unprecedented N-pyridyl radical cation from selected N-substituted pyridinium reagents. The resulting C(sp2)?H functionalization of (hetero)arenes furnishes versatile intermediates for the development of valuable aminated aryl scaffolds. Mechanistic studies that include the first spectroscopic evidence of a spin-trapped N-pyridyl radical adduct implicate SET-triggered, pseudo-mesolytic cleavage of the N?X pyridinium reagents mediated by visible light.
R?ssler, Simon L.,Jelier, Benson J.,Tripet, Pascal F.,Shemet, Andrej,Jeschke, Gunnar,Togni, Antonio,Carreira, Erick M.
supporting information
p. 526 - 531
(2019/01/04)

Direct conversion of phenols into primary anilines with hydrazine catalyzed by palladium
Primary anilines are essential building blocks to synthesize various pharmaceuticals, agrochemicals, pigments, electronic materials, and others. To date, the syntheses of primary anilines mostly rely on the reduction of nitroarenes or the transition-metal-catalyzed Ullmann, Buchwald-Hartwig and Chan-Lam cross-coupling reactions with ammonia, in which non-renewable petroleum-based chemicals are typically used as feedstocks via multiple step syntheses. A long-standing scientific challenge is to synthesize various primary anilines directly from renewable sources. Herein, we report a general method to directly convert a broad range of phenols into the corresponding primary anilines with the cheap and widely available hydrazine as both amine and hydride sources with simple Pd/C as the catalyst.
Qiu, Zihang,Lv, Leiyang,Li, Jianbin,Li, Chen-Chen,Li, Chao-Jun
p. 4775 - 4781
(2019/05/16)

Manganese catalyzed hydrogenation of carbamates and urea derivatives
We report the hydrogenation of carbamates and urea derivatives, two of the most challenging carbonyl compounds to be hydrogenated, catalyzed for the first time by a complex of an earth-abundant metal. The hydrogenation reaction of these CO2-derived compounds, catalyzed by a manganese pincer complex, yields methanol in addition to amine and alcohol, which makes this methodology a sustainable alternative route for the conversion of CO2 to methanol, involving a base-metal catalyst. Moreover, the hydrogenation proceeds under mild pressure (20 bar). Our observations support a hydrogenation mechanism involving the Mn-H complex. A plausible catalytic cycle is proposed based on informative mechanistic experiments.
Das, Uttam Kumar,Kumar, Amit,Ben-David, Yehoshoa,Iron, Mark A.,Milstein, David
supporting information
p. 12962 - 12966
(2019/08/26)

Solvent-Driven Selectivity Control to Either Anilines or Dicyclohexylamines in Hydrogenation of Nitroarenes over a Bifunctional Pd/MIL-101 Catalyst
The hydrogenation of nitroarenes is one of the most important strategies to produce the corresponding anilines and dicyclohexylamines, both of which are the fundamental raw materials in the synthesis of various pharmaceuticals and fine chemicals. Nevertheless, it is still a great challenge to develop a highly versatile and flexible catalytic system to selectively generate desired amines. Herein, we report the solvent-driven selectivity control over a bifunctional Pd/MIL-101 catalyst for the hydrogenation of nitrobenzene. An almost full selectivity of 99.9% to aniline or a surprising selectivity of 99.1% to dicyclohexylamine is achieved by using dimethylformamide (DMF, a polar solvent) or n-hexane (an apolar solvent) as the solvents, respectively. It is proposed that the polarity of solvents can effectively regulate the linkage between reactants/intermediates and Pd/MIL-101, affording controllable selectivities of aniline or dicyclohexylamine at will. In addition, the Lewis acid sites in Pd/MIL-101 can also effectively activate the aromatic ring and accelerate the cross-coupling reaction of amine. This solvent-driven catalytic system also exhibits good recyclability and compatibility for a wide substrate scope in both DMF and n-hexane, showing great promise for industrial applications. This study might open an avenue for the hydrogenation of nitroarenes to selectively produce anilines or dicyclohexylamines by simply regulating the solvent polarity over a bifunctional catalyst system.
Chen, Xiaodong,Shen, Kui,Ding, Danni,Chen, Junying,Fan, Ting,Wu, Rongfang,Li, Yingwei
p. 10641 - 10648
(2018/10/31)

AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
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Paragraph 0098; 0134; 0135; 0155

(2018/03/25)

Tertiary butylation of aniline over nanosized zeolite beta catalyst
In the current paper, we report nanosized zeolite beta to be a robust and potent catalyst for tertbutylation of aniline. Nanocrystals of beta zeolite having spherical morphology were prepared via a one-pot strategy that is based on vacuum-concentration coupled hydrothermal method. The catalyst could be used in the as-synthesized form, without any further modifications. In the presence of the as-prepared catalyst, liquid-phase tert-butylation of aniline using tert-butanol as alkylating agent proceeded successfully. Reaction parameters like duration of reaction, temperature, mole ratio of substrates and quantity of catalyst were optimized. Time-dependent data obtained was subjected to kinetic studies. Detailed studies on product selectivity were conducted. The catalyst could selectively direct the formation of C–C bonds and no N-alkylated products were detected. It also demonstrated good selectivity towards mono-substitution. The catalyst could be recovered by a simple work-up plan and could then be re-used. No appreciable loss in activity was detected in consecutive runs. Thus, the nanosized beta mediated route to introduce tert-butyl group on aniline ring can be an environment-friendly alternative to the use of homogeneous catalysts.
Radhika,Selvin, Rosilda,Kakkar, Rita,Selva Roselin,Hsu, Hsiu-Ling
p. 7960 - 7968
(2018/08/09)

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)

Nickel oxide nanoparticles grafted on reduced graphene oxide (rGO/NiO) as efficient photocatalyst for reduction of nitroaromatics under visible light irradiation
Nickel oxide nanoparticles were grafted on reduced graphene oxide via simultaneous reduction of graphene oxide and nickel salt in a single step reaction. The synthesized material (rGO/NiO) was found to be efficient visible light active photocatalyst for the reduction of nitroaromatic derivatives to their corresponding amino compounds. Hydrazine monohydrate provided necessary protons and electrons for the targeted reaction. After completion of the reaction, the photocatalyst could readily be recovered by simple external magnet and could be reused for six runs without any significant loss of its activity. More importantly, the photocatalyst did not show any leaching during the reaction as confirmed by ICP-AES analysis of the recovered catalyst.
Al-Nafiey, Amer,Kumar, Anurag,Kumar, Malika,Addad, Ahmed,Sieber, Brigitte,Szunerits, Sabine,Boukherroub, Rabah,Jain, Suman L.
p. 198 - 207
(2017/01/16)

Rapid heteroatom transfer to arylmetals utilizing multifunctional reagent scaffolds
Arylmetals are highly valuable carbon nucleophiles that are readily and inexpensively prepared from aryl halides or arenes and widely used on both laboratory and industrial scales to react directly with a wide range of electrophiles. Although C-C bond formation has been a staple of organic synthesis, the direct transfer of primary amino (-NH2) and hydroxyl (-OH) groups to arylmetals in a scalable and environmentally friendly fashion remains a formidable synthetic challenge because of the absence of suitable heteroatom-transfer reagents. Here, we demonstrate the use of bench-stable N-H and N-alkyl oxaziridines derived from readily available terpenoid scaffolds as efficient multifunctional reagents for the direct primary amination and hydroxylation of structurally diverse aryl- and heteroarylmetals. This practical and scalable method provides one-step synthetic access to primary anilines and phenols at low temperature and avoids the use of transition-metal catalysts, ligands and additives, nitrogen-protecting groups, excess reagents and harsh workup conditions.
Gao, Hongyin,Zhou, Zhe,Kwon, Doo-Hyun,Coombs, James,Jones, Steven,Behnke, Nicole Erin,Ess, Daniel H.,Kürti, László
p. 681 - 688
(2017/06/30)

A Ni-Mg-Al layered triple hydroxide-supported Pd catalyst for heterogeneous acceptorless dehydrogenative aromatization
In the presence of a Ni-Mg-Al layered triple hydroxide-supported Pd catalyst, the acceptorless dehydrogenative aromatization of a wide range of cyclohexanols/cyclohexanones and cyclohexylamines efficiently proceeded to give the corresponding phenols and anilines, respectively, in moderate to high yields with the liberation of molecular hydrogen.
Jin, Xiongjie,Taniguchi, Kento,Yamaguchi, Kazuya,Nozaki, Kyoko,Mizuno, Noritaka
supporting information
p. 5267 - 5270
(2017/07/10)

Discovery of N-(Naphthalen-1-yl)-N′-alkyl Oxalamide Ligands Enables Cu-Catalyzed Aryl Amination with High Turnovers
A class of N-(naphthalen-1-yl)-N′-alkyl oxalamides have been proven to be powerful ligands, making a coupling reaction of (hetero)aryl iodides with primary amines proceed at 50 °C with only 0.01 mol % of Cu2O and ligand as well as a coupling reaction of (hetero)aryl bromides with primary amines and ammonia at 80 °C with only 0.1 mol % of Cu2O and ligand. A wide range of coupling partners work well under these conditions, thereby providing an easy to operate method for preparing (hetero)aryl amines.
Gao, Jie,Bhunia, Subhajit,Wang, Kailiang,Gan, Lu,Xia, Shanghua,Ma, Dawei
supporting information
p. 2809 - 2812
(2017/06/07)

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)

Amphipathic monolith-supported palladium catalysts for chemoselective hydrogenation and cross-coupling reactions
A palladium catalyst immobilized on an amphipathic and monolithic polystyrene-divinylbenzene polymer bearing strongly acidic cation exchange functions (sulfonic acid moieties) (Pd/CM) was developed. It was used as a catalyst for hydrogenation and ligand-free cross-coupling reactions, such as the Suzuki-Miyaura, Mizoroki-Heck, and copper- and amine-free Sonogashira-type reactions, together with a palladium catalyst supported on monolithic polymer (Pd/AM) bearing basic anion exchange functions (ammonium salt moieties), which has been in practical use for the decomposition of hydrogen peroxide produced as a byproduct during the manufacture of ultrapure water. While the Pd/CM was highly active as a catalyst for the hydrogenation and a variety of reducible functional groups could be reduced, the use of Pd/AM led to a unique chemoselective hydrogenation. Aromatic carbonyl groups were tolerant under the Pd/AM-catalyzed hydrogenation conditions, although benzyl esters, benzyl ethers, and N-Cbz groups could be smoothly hydrocracked. The cross-coupling reactions readily proceeded using either catalyst. The palladium leaching from the Pd/CM into the reaction media was never observed during the Sonogashira-type reaction, which was hardly achieved by other palladium-supported heterogeneous catalysts due to the good affinity of the palladium species with alkynes.
Monguchi, Yasunari,Wakayama, Fumika,Ueda, Shun,Ito, Ryo,Takada, Hitoshi,Inoue, Hiroshi,Nakamura, Akira,Sawama, Yoshinari,Sajiki, Hironao
p. 1833 - 1840
(2017/01/21)

Gold nanoparticles supported by imidazolium-based porous organic polymers for nitroarene reduction
Two imidazolium-based porous organic polymers (Im-POP-1 and Im-POP-2) were synthesized through the Yamamoto reaction of different molar ratios of 1,3-bis(4-bromophenyl)imidazolium bromide and tetrakis(4-bromophenyl)methane, subsequent anion exchange with HAuCl4 and reduction with NaBH4 produced well-dispersed gold nanoparticles (NPs), Au@Im-POP-1 and Au@Im-POP-2. These NPs possess a small size and narrow size distribution, their application in the reduction of nitroarenes was evaluated, and the reduction process was tracked by 13C NMR experiments for reaction mechanism studies. In comparison with gold NPs supported by a non-ionic analogue from the Yamamoto reaction of tetrakis(4-bromophenyl)methane (Au@POP-TPM), Au@Im-POP-2 exhibits high catalytic activity, good selectivity of aniline and superior recyclability in nitrobenzene reduction. The gold NPs in Au@Im-POP-2 increase slightly after four consecutive reaction runs, while an apparent agglomeration of NPs in Au@POP-TPM was observed after the second run. This research provides a new type of support for the stabilization of gold NPs and for the improvement of catalytic performances.
Su, Yanqing,Li, Xiaoju,Wang, Yangxin,Zhong, Hong,Wang, Ruihu
p. 16896 - 16903
(2016/11/09)

Base-Free Transfer Hydrogenation of Nitroarenes Catalyzed by Micro-Mesoporous Iron Oxide
An efficient and practical protocol for the transfer hydrogenation of nitroarenes was developed, which uses flower-shaped micro-mesoporous iron oxide (MMIO) with formic acid as the reducing agent and tris[(2-diphenylphosphino)-ethyl]phosphine as the ligand in the absence of an additional base. The recyclable catalytic system enables the reduction of the nitro group in a broad range of substrates to yield valuable amines and shows a high tolerance to sensitive functional groups.
Datta, Kasibhatta J.,Rathi, Anuj K.,Gawande, Manoj B.,Ranc, Vaclav,Zoppellaro, Giorgio,Varma, Rajender S.,Zboril, Radek
p. 2351 - 2355
(2016/07/28)

Facile Synthesis and Tunable Porosities of Imidazolium-Based Ionic Polymers that Contain In Situ Formed Palladium Nanoparticles
A series of porous imidazolium-based ionic polymers that contain in situ formed Pd nanoparticles (Pd@PIPs) was synthesized by a Suzuki–Miyaura cross-coupling reaction in the presence of SiO2 particles. The hierarchical porosities of Pd@PIPs can be regulated well by adjusting the dosage of SiO2. Pd nanoparticles are formed concomitantly and encapsulated uniformly within the pores of the polymers. The appropriate usage of SiO2 templates results in a clear enhancement of the catalytic activity in the hydrogenation of nitroarenes without the addition of extra Pd species. The excellent catalytic performances are attributed to abundant meso- and macropores that facilitate the mass transfer of substrates during catalytic reactions.
Wang, Yangxin,Zhong, Hong,Li, Liuyi,Wang, Ruihu
p. 2234 - 2240
(2016/07/19)

ANTIOXIDANTS AND METHODS TO MAXIMIZE PERFORMANCE
A method of preventing or reducing the level of degradation of an organic substrate is described, wherein a composition is formed that includes the organic substrate together with an effective amount of a sacrificial base and a diarylamine antioxidant.
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Page/Page column 30

(2016/09/22)

Photochemistry of N-Arylsulfonimides: An Easily Available Class of Nonionic Photoacid Generators (PAGs)
The photochemical behavior of differently substituted N-arylsulfonimides was investigated. Homolysis of the S?N bond took place as the exclusive path from the singlet state to afford both N-arylsulfonamides and photo-Fries adducts, the amount of which depended on reaction conditions and aromatic substituents. Sulfinic and sulfonic acids were released upon irradiation under deaerated and oxygenated conditions, respectively. The nature of the excited states and intermediates involved were proved by laser flash photolysis and EPR experiments. These results highlighted the potential of such compounds as nonionic photoacid generators able to photorelease up to two equivalents of a strong acid for each mole of substrate.
Torti, Edoardo,Protti, Stefano,Merli, Daniele,Dondi, Daniele,Fagnoni, Maurizio
p. 16998 - 17005
(2016/11/16)

A base-mediated self-propagative Lossen rearrangement of hydroxamic acids for the efficient and facile synthesis of aromatic and aliphatic primary amines
A variety of aromatic and aliphatic hydroxamic acids were converted to the corresponding primary amines via base-mediated rearrangement. This rearrangement could proceed with less than 1 equiv. of K2CO3 in polar solvents under thermal conditions with no external reagents. This rearrangement has several features including no external activating agents needed for promoting the rearrangement, less than one equivalent of a base is sufficient for the reaction, and a clean reaction in which only carbon dioxide is produced as a by-product. A self-propagating mechanism via an isocyanate intermediate is proposed and elementary reaction steps, namely, chain propagation reactions are supported by experiments.
Ohtsuka, Naoya,Okuno, Moriaki,Hoshino, Yujiro,Honda, Kiyoshi
p. 9046 - 9054
(2016/10/05)

Direct synthesis of anilines and nitrosobenzenes from phenols
A one-pot synthesis of anilines and nitrosobenzenes from phenols has been developed using an ipso-oxidative aromatic substitution (iSOAr) process. The products are obtained in good yields under mild and metal-free conditions. The leaving group effect on reactions that proceed through mixed quionone monoketals has also been investigated and a predictive model has been established.
St Amant,Frazier,Newmeyer,Fruehauf,Read De Alaniz
p. 5520 - 5524
(2016/07/06)

A Mild and Chemoselective Reduction of Nitro and Azo Compounds Catalyzed by a Well-Defined Mo3S4 Cluster Bearing Diamine Ligands
Herein, we report a novel well-defined diamino Mo3S4-based catalyst system for the reduction of nitroarenes and azo compounds to the corresponding anilines with silanes as reducing agents. This catalytic protocol provides a facile route to access aromatic amines under mild conditions in good to excellent yields. Notably, even anilines functionalized with other potentially reducible moieties are obtained with high selectivity. The new chemoselective catalyst of formula [Mo3S4Cl3(dmen)3](BF4) (dmen: N,N′-dimethylethylenediamine) is conveniently synthesized through coordination of the diamine ligand to the incomplete Mo3S4 cubane-type cluster core in a one-pot two-step procedure. The crystal structure of the [Mo3S4Cl3(dmen)3]+ cation confirms the formation of a single isomer in which the chlorine atom lies trans to the bridging sulfur atom to afford a C3 symmetry complex with intrinsic backbone chirality. The structure is preserved in solution, as evidenced by multinuclear NMR spectroscopy and electrospray-ionization mass spectrometric techniques.
Pedrajas, Elena,Sorribes, Iván,Junge, Kathrin,Beller, Matthias,Llusar, Rosa
p. 2675 - 2681
(2015/09/15)

Reduction of nitroarenes using CO and H2O in the presence of a nanostructured cobalt oxide/Nitrogen-Doped Graphene (NGr) catalyst
The most common route to anilines is based on the reduction of the corresponding nitroarenes. In general, hydrogen is preferred as reducing agent and numerous catalytic systems are known to achieve such transformations. Besides, the use of CO/H2O as hydrogen source offers interesting possibilities for reductions. Carbon monoxide is a cheap and abundant chemical used on industrial scale for a variety of transformations. Although the reduction of nitroarenes with CO/H2O is known in the presence of noble-metal catalysts, earth-abundant inexpensive catalysts showing high selectivity have not yet been developed. In this respect, herein we present the use of a heterogeneous cobalt oxide catalyst (Co3O4/NGr@C), which is modified by nitrogen-doped graphene layers. Using this non-noble metal catalyst nitroarenes are reduced in high yields and good chemoselectivities.
Westerhaus, Felix A.,Sorribes, Ivn,Wienh?fer, Gerrit,Junge, Kathrin,Beller, Matthias
supporting information
p. 313 - 317
(2015/03/05)

USE OF THERMALLY-TREATED SUPPORTED COBALT CATALYSTS COMPRISING A POLYCYCLIC AROMATIC STRUCTURE CONSISTING OF NITROGEN LIGANDS FOR HYROGENATING AROMATIC NITRO COMPOUNDS
The invention relates to the use of thermally-treated supported cobalt catalysts for hydrogenating aromatic nitro compounds, the cobalt catalysts having been prepared by in situ immobilization of a cobalt-amine complex on an inorganic porous support and subsequent pyrolysis, and, in the cobalt-amine complex used, cobalt being present bonded to an aromatic or heterocyclic nitrogen ligand L, the nitrogen ligand being selected so as to form a polyaromatic structure with the cobalt atom.
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Paragraph 0031; 0032

(2015/11/16)

The triple-bond metathesis of aryldiazonium salts: A prospect for dinitrogen cleavage
The {N2} unit of aryldiazonium salts undergoes unusually facile triple-bond metathesis on treatment with molybdenum or tungsten alkylidyne ate complexes endowed with triphenylsilanolate ligands. The reaction transforms the alkylidyne unit into a nitrile and the aryldiazonium entity into an imido ligand on the metal center, as unambiguously confirmed by X-ray structure analysis of two representative examples. A tungsten nitride ate complex is shown to react analogously. Since the bonding situation of an aryldiazonium salt is similar to that of metal complexes with end-on-bound dinitrogen, in which {N2}→M σ donation is dominant and electron back donation minimal, the metathesis described herein is thought to be a conceptually novel strategy toward dinitrogen cleavage devoid of any redox steps and, therefore, orthogonal to the established methods. Who knows? Although the extrusion of molecular nitrogen from aryldiazonium salts is extremely facile, the metathetic cleavage of the N-N triple bond on treatment with alkylidyne ate complexes of molybdenum or tungsten is shown to be even faster. The analogy between [Ar-N2]+ and known [M-N2] complexes makes this process a potential model for dinitrogen cleavage devoid of any redox steps.
Lackner, Aaron D.,Fürstner, Alois
p. 12814 - 12818
(2015/10/28)

Assembly of Primary (Hetero)Arylamines via CuI/Oxalic Diamide-Catalyzed Coupling of Aryl Chlorides and Ammonia
A general and practical catalytic system for aryl amination of aryl chlorides with aqueous or gaseous ammonia has been developed, with CuI as the catalyst and bisaryl oxalic diamides as the ligands. The reaction proceeds at 105-120°C to provide a diverse set of primary (hetero)aryl amines in high yields with various functional groups.
Fan, Mengyang,Zhou, Wei,Jiang, Yongwen,Ma, Dawei
supporting information
p. 5934 - 5937
(2015/12/11)

Polymethylhydrosiloxane derived palladium nanoparticles for chemo- and regioselective hydrogenation of aliphatic and aromatic nitro compounds in water
Chemo- and regioselective hydrogenation of a wide range of aliphatic, unsaturated, aromatic and heteroaromatic nitro compounds into their corresponding amines has been achieved with highly efficient polysiloxane-stabilised "Pd" nanoparticles on NAP-magnesium oxide supports using an environmentally friendly hydrogenating agent, polymethylhydrosiloxane [PMHS] in water. Highly stable and active Pd nanoparticles were prepared by the reduction of NAP-Mg-PdCl4 with PMHS, which serves as a reducing agent as well as a capping agent. The well-dispersed palladium nanoparticles on NAP-MgO catalysts also exhibit excellent regioselectivity in the hydrogenation of dinitrobenzenes to the corresponding nitroanilines. The catalyst has high durability against sintering during the hydrogenation reaction and can be reused with no loss in its activity. This journal is the Partner Organisations 2014.
Damodara, Dandu,Arundhathi, Racha,Ramesh Babu, T. Venkata,Legan, Margaret K.,Kumpaty, Hephzibah J.,Likhar, Pravin R.
p. 22567 - 22574
(2014/06/23)

Nanopalladium on amino-functionalized mesocellular foam as an efficient and recyclable catalyst for the selective transfer hydrogenation of nitroarenes to anilines
Herein, we report on the use of nanopalladium on amino-functionalized siliceous mesocellular foam as an efficient heterogeneous catalyst for the transfer hydrogenation of nitroarenes to anilines. In all cases, the protocol proved to be highly selective and favored the formation of the desired aniline as the single product in high yields with short reaction times if naturally occurring and renewable γ-terpinene was employed as the hydrogen donor. Furthermore, the catalyst displayed excellent recyclability over five cycles and negligible leaching of metal into solution, which makes it an eco-friendly and economic catalyst to perform this transformation. The scalability of the protocol was demonstrated with the reduction of 4-nitroanisole on a 2 g scale, in which p-anisidine was isolated in 98 % yield. Copyright
Verho, Oscar,Nagendiran, Anuja,Tai, Cheuk-Wai,Johnston, Eric V.,Baeckvall, Jan-E.
p. 205 - 211
(2014/01/23)

In situ formation of well-dispersed palladium nanoparticles immobilized in imidazolium-based organic ionic polymers
A new strategy for in situ generation of well-dispersed palladium nanoparticles (NPs) immobilized in imidazolium-based organic ionic polymers was presented. Without extra addition of palladium species, the as-synthesized ionic polymers showed excellent catalytic activity and good reusability in the hydrogenation of nitroarenes. the Partner Organisations 2014.
Zhao, Huaixia,Wang, Yangxin,Wang, Ruihu
supporting information
p. 10871 - 10874
(2014/10/15)

METHODS FOR PREPARING ALKYLFURANS
Provided herein are methods for preparing alkylfurans, such as 2,5-dialkylfurans and 2-alkylfurans. Furfural or 5-alkylfurfural can be reacted with aniline or diaminobenzene, or derivatives thereof, to form the corresponding imine, which can be reduced to form alkylfurans and to regenerate the aniline or diaminobenzene, or derivatives thereof. The alkylfuran may be, for example, 2,5-dimethylfuran or 2-methylfuran.
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Paragraph 0158-0160

(2014/10/04)

Hydrogenation of nitroarenes using defined iron-phosphine catalysts
A novel iron-catalyzed hydrogenation of nitroarenes to the corresponding amines is reported. An in situ combination of Fe(BF4) 2·6H2O and phosphine allows for highly selective hydrogenation of a broad range of aromatic and nitroarenes tolerating different functional groups.
Wienhoefer, Gerrit,Baseda-Krueger, Mario,Ziebart, Carolin,Westerhaus, Felix A.,Baumann, Wolfgang,Jackstell, Ralf,Junge, Kathrin,Beller, Matthias
supporting information
p. 9089 - 9091
(2013/09/24)

Electrochemical technique and copper-promoted transformations: Selective hydroxylation and amination of arylboronic acids
An efficient and selective electrosynthesis of phenols and anilines from arylboronic acids in aqueous ammonia is achieved in an undivided cell. By simply changing the concentration of aqueous ammonia and the anode potential, good yields of phenols and anilines can be obtained chemoselectively with high reaction rates. We propose that anodic oxidation could have played an important role in these transformations.
Qi, Hong-Lin,Chen, Dong-Song,Ye, Jian-Shan,Huang, Jing-Mei
p. 7482 - 7487
(2013/09/02)