- Metal-Free, Rapid, and Highly Chemoselective Reduction of Aromatic Nitro Compounds at Room Temperature
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In this study, we developed a metal-free and highly chemoselective method for the reduction of aromatic nitro compounds. This reduction was performed using tetrahydroxydiboron [B2(OH)4] as the reductant and 4,4′-bipyridine as the organocatalyst and could be completed within 5 min at room temperature. Under optimal conditions, nitroarenes with sensitive functional groups, such as vinyl, ethynyl, carbonyl, and halogen, were converted into the corresponding anilines with excellent selectivity while avoiding the undesirable reduction of the sensitive functional groups.
- Han, Min Su,Jang, Mingyeong,Lim, Taeho,Park, Byoung Yong
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p. 910 - 919
(2022/01/20)
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- Enantioselective Synthesis of Azetidines through [3 + 1]-Cycloaddition of Donor-Acceptor Aziridines with Isocyanides
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The enantioselective [3 + 1]-cycloaddition of racemic donor-acceptor (D-A) aziridines with isocyanides was first realized under mild reaction conditions using a chiral N,N′-dioxide/MgIIcomplex as catalyst, providing a facile route to enantioenriched exo-imido azetidines with good to excellent yield (up to 99%) and enantioselectivity (up to 94% ee). An obvious chiral amplification effect was observed in this system, and an explanation was elucidated based on the experimental investigation and X-ray crystal structure of the enantiomerically pure catalyst.
- Zhang, Fengcai,Sang, Xinpeng,Zhou, Yuqiao,Cao, Weidi,Feng, Xiaoming
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supporting information
p. 1513 - 1517
(2022/03/01)
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- HCl-mediated transamidation of unactivated formamides using aromatic amines in aqueous media
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We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and purification. Notably, this approach conventionally used to synthesize molecules on gram scales with excellent yields and a high tolerance for functional groups.
- Dhawan, Sanjeev,Girase, Pankaj Sanjay,Kumar, Vishal,Karpoormath, Rajshekhar
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p. 3729 - 3739
(2021/10/14)
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- Preparation and catalytic evaluation of a palladium catalyst deposited over modified clinoptilolite (Pd&at;MCP) for chemoselective N-formylation and N-acylation of amines
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Novel palladium nanoparticles stabilized by clinoptilolite as a natural inexpensive zeolite prepared and used for N-formylation and N-acylation of amines at room temperature at environmentally benign reaction conditions in good to excellent yields. Pd (II) was immobilized on the surface of clinoptilolite via facile multi-step amine functionalization to obtain a sustainable, recoverable, and highly active nano-catalyst. The structural and morphological characterizations of the catalyst carried out using XRD, FT-IR, BET and TEM techniques. Moreover, the catalyst is easily recovered using simple filtration and reused for 7 consecutive runs without any loss in activity.
- Amirsoleimani, Mina,Khalilzadeh, Mohammad A.,Zareyee, Daryoush
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- Facile N-Formylation of Amines on Magnetic Fe3O4?CuO Nanocomposites
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A facile, eco-friendly, efficient, and recyclable heterogeneous catalyst is synthesized by immobilizing copper impregnated on mesoporous magnetic nanoparticles. The surface chemistry analysis of Fe3O4?CuO nanocomposites (NCs) by XRD and XPS demonstrates the synergistic effect between Fe3O4 and CuO nanoparticles, providing mass-transfer channels for the catalytic reaction. TEM images clearly indicate the impregnation of CuO onto mesoporous Fe3O4. This hydrothermally synthesized eco-friendly and highly efficient Fe3O4?CuO NCs are applied as a magnetically retrievable heterogeneous catalyst for the N-formylation of wide range of aliphatic, aromatic, polyaromatic and heteroaromatic amines using formic acid as a formylating agent at room temperature. The catalytic activity of the NCs for N-formylation is attributable to the synergistic effect between Fe3O4 and CuO nanoparticles. The N-formylated product is further employed for the synthesis of biologically active quinolone moieties.
- Datta Khanal, Hari,Mishra, Kanchan,Rok Lee, Yong
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p. 4477 - 4484
(2021/08/30)
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- Functionalizing HY zeolite with sulfonic acid, a micro-meso structure reusable catalyst for organic transformations
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A new class of sulfonic acid functionalized HY zeolite (HY-N-SA) catalyst has been prepared and characterized by some method such as XRD, FT-IR, FESEM, TEM, TGA, NH3-TPD and N2 physisorption. The result shows the micro-meso structure for catalyst without ordering in the mesophase. Then, the HY-N-SA micro-meso structure was used as an acidic catalyst to synthesize of coumarins via Pechmann reaction and facile transformation of amines to formamides under solvent-free condition. To consider the effect of acidity and kind and size of porous on the catalyst activity, this catalyst was compared with NaY-N-SA and MCM-N-SA and pure porous material (NaY and MCM-41). The significant advantages of HY-N-SA with respect to other catalysts are short reaction times, high yields, pure products, mild conditions and easy work-up. In addition, we report an original and environmentally friendly solvent-free procedure which reusability of catalyst makes this method nearly green and environmentally friendly.
- Tavakoli, Fatemeh,Zendehdel, Mojgan
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- An Environmentally Benign, Catalyst-Free N?C Bond Cleavage/Formation of Primary, Secondary, and Tertiary Unactivated Amides
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Herein, we report an operationally simple, cheap, and catalyst-free method for the transamidation of a diverse range of unactivated amides furnishing the desired products in excellent yields. This protocol is environmentally friendly and operates under extremely mild conditions without using any promoter or additives. Significantly, this strategy has been implied in the chemoselective synthesis of a pharmaceutical molecule, paracetamol, on a gram-scale with excellent yield. We anticipate that this universally applicable strategy will be of great interest in drug discovery, biochemistry, and organic synthesis.
- Kumar, Vishal,Dhawan, Sanjeev,Girase, Pankaj Sanjay,Singh, Parvesh,Karpoormath, Rajshekhar
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p. 5627 - 5639
(2021/11/11)
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- Synthesis of aliphatic α-ketoamides from α-substituted methyl ketones: Via a Cu-catalyzed aerobic oxidative amidation
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α-Ketoamides are an important key functional group and have been used as versatile and valuable intermediates and synthons in a variety of functional group transformations. Synthetic methods for making aryl α-ketoamides as drug candidates have been greatly improved through metal-catalyzed aerobic oxidative amidations. However, the preparation of alkyl α-ketoamides through metal-catalyzed aerobic oxidative amidations has not been reported because generating α-ketoamides from aliphatic ketones with two α-carbons theoretically provides two distinct α-ketoamides. Our strategy is to activate the α-carbon by introducing an N-substituent at one of the two α-positions. The key to this strategy is how heterocyclic compounds such as triazoles and imidazoles affect the selectivity of the synthesis of the alkyl α-ketoamides. From this basic concept, and by optimizing the reaction and elucidating the mechanism of the synthesis of aryl α-ketoamides via a copper-catalyzed aerobic oxidative amidation, we prepared fourteen aliphatic α-ketoamides in high yields (48-84%). This journal is
- Cha, Hyojin,Chai, Jin Young,Chi, Dae Yoon,Kim, Hyeong Baik
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supporting information
p. 4320 - 4326
(2021/05/31)
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- DMF·HCl as a versatile and straightforward N- and O-formylating agent
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Inspired by the serendipitous isolation of N-formylpiperazines when we attempted the synthesis of a series of piperazines, we have developed a straightforward methodology for the N- and O- formylation of secondary cyclic amines, anilines and steroids, respectively. Such approach is based on the hitherto non-reported use of DMF·HCl complex, as a versatile and easily-available formylating system that can be stored without apparent loss of activity.
- Ramírez-Vázquez, Dulce G.,Vi?as-Bravo, Omar,Martínez-Pascual, Roxana,Pérez-Picaso, Lemuel,Castro-Cerritos, Karla Viridiana
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supporting information
p. 585 - 592
(2020/11/19)
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- Acid-catalyzed chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines
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Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a C[sbnd]C bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2,2-dimethoxyacetaldehyde reacted with aniline to form a new C[sbnd]N bond, in the presence of O2, via a C[sbnd]C bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new C[sbnd]O bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
- Guo, Luxia,Chen, Zihao,Zhu, Hongmei,Li, Minghao,Gu, Yanlong
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supporting information
p. 1419 - 1422
(2020/11/12)
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- Copper-Catalyzed Cascade N-Dealkylation/N-Methyl Oxidation of Aromatic Amines by Using TEMPO and Oxygen as Oxidants
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A novel tandem N-dealkylation and N-methyl aerobic oxidation of tertiary aromatic amines to N-arylformamides using copper and TEMPO has been developed. This methodology suggested an alternative synthetic route from N-methylarylamines to N-arylformamides.
- Li, Dianjun,Wang, Shihaozhi,Yang, Jiale,Yang, Jinhui
-
supporting information
p. 6768 - 6772
(2021/12/31)
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- Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C?N Framework Derived from the Integration of MOF and COF
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CoZn embedded C?N framework is prepared by the carbonization of CoZn containing MOF integrated with COF porous architecture in Ar atmosphere. The graphitic nature of porous carbon is confirmed from Raman analysis. The porosity and nanostructure information are retrieved from N2-sorption and transmission electron microscopic analysis, respectively. The incorporation of different metals and their oxidation states and types of nitrogen present in the C?N framework are confirmed from X-ray photoelectron spectroscopy. The basicity of the materials is determined from a CO2-temperature programmed desorption. ZnCo embedded C?N framework exhibits excellent activity in the selective reductive formylation using HCOOH. For comparison, more than 15 materials are prepared, and their activities are compared. Several control experiments are performed to establish a structure-activity relation. The recycling experiment, hot-filtration test, and poisoning experiment demonstrate the metal embedded porous C?N framework‘s recyclability and stability. A reaction mechanism for the reductive N-formylation of nitroaromatics is presented based on structure-activity relationship, control reactions, and physicochemical characterizations. The development of interesting MOF-COF-derived metal nanoclusters embedded C?N framework for selective reductive formylation of nitroaromatics using formic acid will be highly attractive to catalysis researchers and industrialists.
- Kumar Kar, Ashish,Srivastava, Rajendra
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p. 3174 - 3183
(2021/05/27)
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- Recyclable Oxofluorovanadate-Catalyzed Formylation of Amines by Reductive Functionalization of CO2 with Hydrosilanes
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An efficient method has been developed for the reductive amination of CO2 by using readily available and recyclable oxofluorovanadates as catalysts. Various amines are transformed into the desired N-formylated products in moderate to excellent yields at room temperature in the presence of phenylsilane. Mechanistic studies based on in situ infrared spectroscopy suggest a reaction pathway initiated through F?Si interactions. The activated phenylsilane allows for CO2 insertion to produce phenylsilyl formate, which undergoes attack by the amine to generate the target product.
- Wu, Shanxuan,Huang, Zijun,Jiang, Xiaolin,Yan, Fachao,Li, Yuehui,Du, Chen-Xia
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p. 1763 - 1766
(2021/03/01)
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- Borane-Trimethylamine Complex as a Reducing Agent for Selective Methylation and Formylation of Amines with CO2
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We report herein that a borane-trimethylamine complex worked as an efficient reducing agent for the selective methylation and formylation of amines with 1 atm CO2 under metal-free conditions. 6-Amino-2-picoline serves as a highly efficient catalyst for the methylation of various secondary amines, whereas in its absence, the formylation of primary and secondary amines was achieved in high yield with high chemoselectivity. Mechanistic studies suggest that the 6-amino-2-picoline-borane catalytic system operates like an intramolecular frustrated Lewis pair to activate CO2.
- Zhang, Yanmeng,Zhang, He,Gao, Ke
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supporting information
p. 8282 - 8286
(2021/10/25)
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- Mesoporous Sn(IV) Doping DFNS Supported BaMnO3 Nanoparticles for Formylation of Amines Using Carbon Dioxide
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Abstract: In the present paper, Sn(IV) doping DFNS (SnD) supported nanoparticles of BaMnO3 (BaMnO3/SnD) and using as a catalyst for the N-formylation of amines by CO2 hydrogenation. In this catalyst, the SnD with the ratios of Si/Sn in the range of from 6 to 50 were obtained with method of direct hydrothermal synthesis (DHS) as well as the nanoparticles of BaMnO3 were on the surfaces of SnD in situ reduced. Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM) were utilized for characterizing the nanostructures BaMnO3/SnD. It is found that the nanostructures of BaMnO3/SnD can be a nominate due to its effective and novel catalytic behavior in N-formylation of amines through hydrogenation of CO2. Graphic Abstract: [Figure not available: see fulltext.]
- Yang, Jie,Wang, Liujie,Sun, Aili,Zhiani, Rahele
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p. 573 - 581
(2020/07/27)
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- Catalyst freeN-formylation of aromatic and aliphatic amines exploiting reductive formylation of CO2using NaBH4
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Herein, we report a sustainable approach forN-formylation of aromatic as well as aliphatic amines using sodium borohydride and carbon dioxide gas. The developed approach is catalyst free, and does not need pressure or a specialized reaction assembly. The reductive formylation of CO2with sodium borohydride generates formoxy borohydride speciesin situ, as confirmed by1H and11B NMR spectroscopy. Thein situformation of formoxy borohydride species is prominent in formamide based solvents and is critical for the success of theN-formylation reactions. The formoxy borohydride is also found to promote transamidation reactions as a competitive pathway along with reductive functionalization of CO2with amine leading toN-formylation of amines.
- Kumar, Arun,Kumar, Yashwant,Mahajan, Dinesh,Sharma, Nidhi,Sharma, Pankaj
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p. 25777 - 25787
(2021/08/05)
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- Olefin functionalized IPr.HCl monomer as well as preparation method and application thereof
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The invention relates to an olefin functionalized IPr.HCl monomer, a preparation method thereof, a method for preparing an N-heterocyclic carbene functionalized organic polymer (PS-IPr-x) by using the olefin functionalized IPr.HCl monomer, and application of the N-heterocyclic carbene functionalized organic polymer as a heterogeneous catalyst for catalyzing reduction N-formylation of carbon dioxide and amine. A heterogeneous catalyst is prepared by using cheap and easily available DVB as a polymerization cross-linking agent through an AIBN-initiated olefin polymerization method, and has the advantages of low preparation cost and simple preparation method. Meanwhile, the catalytic activity of the catalyst is obviously higher than that of reported catalysts, and the catalyst has a wide practical application prospect.
- -
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Paragraph 0069-0073; 0074; 0078
(2021/06/21)
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- Palladium supported on MRGO@CoAl-LDH catalyzed reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as liquid CO and H2 source
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In the present study, a heterogeneous palladium catalyst system, Pd nanoparticles supported on MRGO@CoAl-LDH, was synthesized and employed in reductive carbonylation of nitroarenes and carbonylative Suzuki coupling reactions using formic acid as CO and H2 source. The as-obtained heterogeneous catalyst was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDAX), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The nanocatalyst was reused for 5 cycles with a negligible reduction in the yield of products. All reactions were carried out with high yields and under suitable and safe conditions. Also, we have successfully applied formic acid as a good and safe alternative to CO and H2 gases.
- Jadidi Nejad, Masoumeh,Heydari, Akbar
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- Copper promoted aerobic oxidative c(sp3)-c(sp3) bond cleavage of n-(2-(pyridin-2-yl)-ethyl)anilines
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A strategy of aerobic oxidative C(sp3)-C(sp3) bond cleavage of N-ethylaniline derivatives bearing azaarenes for the synthesis of N-aryl formamides has been developed. This approach was carried out smoothly with the CuI/TEMPO/air system to give N-aryl formamides in yields of 50-90%. With this methodology, a mutagenically active compound was constructed in 90% yield. Moreover, the reaction also provided a one-pot synthetic tool for accessing a promoter of hematopoietic stem cells by difunctionalization in 61% yield.
- Yu, Yang,Zhang, Yong,Sun, Chengyu,Shi, Lei,Wang, Wei,Li, Hao
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p. 2725 - 2732
(2020/03/11)
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- N-Formylation of amines using arylhydrazones of malononitrile and a Cu(II) complex under eco-friendly conditions at room temperature
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In this work, we report the synthesis of formamides via solvent free N-formylation of amines using known arylhydrazones of malononitrile including sodium 2-(2-(dicyanomethylene)hydrazinyl)benzenesulfonate (I), 2-(2-(dicyanomethylene)hydrazinyl) benzoic acid (II) and its Cu(II) complex (III) as catalysts at room temperature. These catalysts are highly active and the scope of the method was investigated using several heterocyclic, aromatic and aliphatic amines as substrates, which produced the corresponding formamides in high yields. The remarkable advantages of this method are the elimination of toxic solvents, operational simplicity, easy workup procedure, excellent yields and avoidance of column chromatography.
- Nasrollahzadeh, Mahmoud,Bidgoli, Nayyereh Sadat Soheili,Rocha, Bruno G.M.,Pombeiro, Armando J.L.,Mahmudov, Kamran T.
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- Efficient: N -formylation of primary aromatic amines using novel solid acid magnetic nanocatalyst
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Sulfonic acid functionalized over biguanidine fabricated silica-coated heterogeneous magnetic nanoparticles (NP?SO3H) have been synthesized, well characterized and explored for the first time, as an efficient and recyclable catalyst for N-formylation of primary amines under mild reaction conditions. Exploiting the magnetic nature of Fe3O4, the prepared catalyst was readily recovered from the reaction mixture via an external magnet. The catalyst can be reused for up to six cycles without any substantial loss of catalytic activity. The cost effectiveness, simple methodology, wide substrate tolerance, excellent yield and easy work-up are the additional advantages of present catalytic system. This journal is
- Agarwal, Alka,Awasthi, Satish K.,Yadav, Jitendra Kumar,Yadav, Priyanka
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p. 41229 - 41236
(2020/11/23)
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- Silver-Catalyzed Selective Multicomponent Coupling Reactions of Arynes with Nitriles and Isonitriles
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Pathway selective aryne-based novel multicomponent coupling reactions with isonitriles and nitriles are described. Crucial to these reactions is the formation of a silver-aryne complex, which shows differential reactivity toward isonitriles and nitriles to form two different forms of ortho-nitrilium organosilver arene species. Interception of the nitrilium of an aryne-isonitrile adduct with another isonitrile leads to the formation of benzocyclobutene-1,2-diimines, whereas the nitrilium of an aryne-nitrile adduct renders selective formation of 3H-indol-3-imines or 3-iminoindolin-2-ol depending on the structure of the nitrile employed.
- Ghorai, Sourav,Lin, Yongjia,Xia, Yuanzhi,Wink, Donald J.,Lee, Daesung
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supporting information
p. 642 - 647
(2020/01/31)
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- Mild C?F Activation in Perfluorinated Arenes through Photosensitized Insertion of Isonitriles at 350 nm
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Fluorinated compounds have become important in the fields of agrochemical industry, pharmaceutical chemistry and materials sciences. Accordingly, various methods for their preparation have been developed in the past. Fluorinated compounds can be accessed via conjugation with fluorinated building blocks, via C?H fluorination or via selective activation of perfluorinated compounds to give the partially fluorinated congeners. Especially the direct activation of C?F bonds, one of the strongest σ-bonds, still remains challenging and new strategies for C?F activation are desirable. Herein a method for the photochemical activation of aromatic C?F bonds is presented. It is shown that isonitriles selectively insert into aromatic C?F bonds while aliphatic C?F bonds remain unaffected. Mechanistic studies reveal the reaction to proceed via the indirect excitation of the isonitrile to its triplet state by photoexcited acetophenone at 350 nm. Due to the relatively mild light used, the process shows high functional group tolerance and various compounds of the class of benzimidoyl fluorides are accessible from aryl isonitriles and commercially available perfluorinated arenes. (Figure presented.).
- Weidlich, Frauke,Esumi, Naoto,Chen, Dongyang,Mück-Lichtenfeld, Christian,Zysman-Colman, Eli,Studer, Armido
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supporting information
p. 376 - 383
(2019/11/19)
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- Bis-Selenoureas for Anion Binding: A 1H NMR and Theoretical Study
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The anion binding ability of a family of bis-selenoureas L1-L3 obtained by the reaction of 1,3-bis(aminomethyl)-benzene and phenylisoselenocyanate, p-methoxyphenylisoselenocyanate and naphtylisoselenocyanate, for L1, L2, and L3, respectively, has been tested and compared to that of previously described bis-urea analogues. Results suggest that the introduction of selenium leads to an increase in the acidity of the urea NH hydrogen atoms, and therefore to a stronger affinity (more than three-fold higher) towards anion species, in particular dihydrogen phosphate, in DMSO-d6. Theoretical calculations allowed for the optimization of the adducts receptors corroborating the experimental results.
- Caltagirone, Claudia,Ciancaleoni, Gianluca,Lippolis, Vito,Mocci, Rita,Picci, Giacomo,Zielińska-B?ajet, Mariola
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p. 1389 - 1395
(2020/08/05)
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- Silver-Catalyzed, N-Formylation of Amines Using Glycol Ethers
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A silver-catalyzed protocol was found to afford the N-formylation of amines in moderate-to-good yields. Ethylene glycol-derived, oligomeric ethers were found to function as the formylating agent, with 1,4-dioxane affording the best results. This reaction does not require the use of stoichiometric activating reagents, and avoids the use of explosive reagents or toxic gases, such as CO, as the C1 synthon. Mechanistic studies indicate a single-electron transfer-based pathway. This work highlights the ability of silver to participate in unexpected reaction pathways.
- King, Bradley H.,Wang, Michelle L.,Jesse, Kate A.,Kaur, Guneet,Tran, Brianna,Walser-Kuntz, Ryan,Iafe, Robert G.,Wenzel, Anna G.
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p. 13256 - 13263
(2020/11/26)
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- Direct: N -formylation of nitroarenes with CO2
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Herein we describe a straightforward N-formylation of nitroarenes with CO2 to access N-aryl formamides exclusively in the presence of iron and hydrosilane as additives. This protocol showcases a good tolerance of a wide range of nitroarenes and nitroheteroarenes.
- Shen, Ni,Zhai, Shi-Jing,Cheung, Chi Wai,Ma, Jun-An
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supporting information
p. 9620 - 9623
(2020/09/03)
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- Selective: N-formylation/N-methylation of amines and N-formylation of amides and carbamates with carbon dioxide and hydrosilanes: Promotion of the basic counter anions of the zinc catalyst
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A catalyst composed of commercially available Zn(OAc)2 and 1,10-phenanthroline (phen) was effective in the N-formylation/N-methylation of amines using CO2 as the C1 source in the presence of hydrosilanes. An equimolar reaction of N-methylaniline with PhSiH3 under a CO2 atmosphere yielded the N-formylation product in 92% yield at 25 °C. Scale-up of the reaction using 10 mmol substrate was also successful in affording the desired product in 83% yield (1.1 g). This catalyst exhibits a high thermal stability and a turnover number (TON) of 385000 at 150 °C. In addition, the reaction of N-methylaniline in the presence of excess Ph2SiH2 produced N,N-dimethylaniline. Furthermore, our catalytic protocol was developed for the N-formylation of amides and carbamates, which have smaller pKa values and lower reactivities than the corresponding amines. The present Zn(OAc)2/phen catalyst was found to show versatility in the conversion of CO2 and amines into several functionalized organic chemicals under mild conditions. We propose that the basic counter anion (i.e., the acetate) of the catalyst activates both the Si-H and N-H bonds.
- Zhang, Qiao,Lin, Xiao-Tao,Fukaya, Norihisa,Fujitani, Tadahiro,Sato, Kazuhiko,Choi, Jun-Chul
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supporting information
p. 8414 - 8422
(2020/12/29)
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- A Practical Approach for the Transamidation of N, N-Dimethyl Amides with Primary Amines Promoted by Sodium tert-Butoxide under Solvent-Free Conditions
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A practical sodium tert-butoxide (NaO t Bu)-mediated protocol is disclosed for the transamidation of various N, N-dimethyl amides with primary amines to afford the corresponding amides in moderate to good yields at room temperature under solvent-free conditions. This protocol features a facile work-up procedure and good functional group compatibility, especially for N, N-dimethyl amides with long-chain alkyl groups and heteroatom-containing amines. Notably, a few representative gram-scale reactions proceed smoothly to furnish the desired amides in high yields, which demonstrates the potential of this process for further practical applications. Several control experiments are carried out and a plausible mechanism is provided.
- Zhang, Rui,Zhang, Jun-Chao,Zhang, Wei-Yi,He, Yu-Qing,Cheng, Hua,Chen, Cheng,Gu, Yu-Cheng
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p. 3286 - 3294
(2020/09/23)
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- A NHC-silyliumylidene cation for catalytic N?formylation of amines using carbon dioxide
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This study describes the use of a silicon(II) complex, namely, the NHC-silyliumylidene cation complex [(IMe)2SiH]I (1, IMe =:C{N(Me)C(Me)}2), to catalyze the chemoselective N-formylation of primary and secondary amines using CO2 and PhSiH3 under mild conditions to afford the corresponding formamides as a sole product (average reaction time: 4.5 h; primary amines, average yield: 95%, average TOF: 8 h?1; secondary amines, average yield: 98%, average TOF: 17 h?1). The activity of 1 and product yields outperform the currently available non-transition-metal catalysts used for this catalysis. Mechanistic studies show that the silicon(II) center in complex 1 catalyzes the C?N bond formation via a different pathway in comparison with non-transition-metal catalysts. It sequentially activates CO2, PhSiH3, and amines, which proceeds via a dihydrogen elimination mechanism, to form formamides, siloxanes, and dihydrogen gas.
- Leong, Bi-Xiang,Teo, Yeow-Chuan,Condamines, Cloe,Yang, Ming-Chung,Su, Ming-Der,So, Cheuk-Wai
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p. 14824 - 14833
(2020/12/21)
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- Application of Ag/TFPG-DMB COF in carbamates synthesis via CO2 fixation reaction and one-pot reductive N-formylation of nitroarenes under sunlight
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We have designed mesoporous AgNPs decorated COF (Ag/TFPG-DMB COF) nanomaterial which has been formed by an easy ex-situ synthetic method. The synthesized material is characterized by FTIR, PXRD, UV–vis, N2 adsorption–desorption studies, TEM, FESEM and XPS. The material showed the generation of identical mesopore at 3.9 nm. It is observed that the material can perform as both thermally and photochemically active catalyst for carbamate synthesis and one-pot reduction and N-formylation of nitroarenes respectively. The catalytic activity of the Ag/ TFPG-DMB COF nanomaterial is checked for green synthesis of carbamates from different amines and alcohols under 1 atmospheric pressure of CO2 with excellent yield (upto 95 %) as well as with high TOF value (182 h?1) and high selectivity. Additionally, the Ag/ TFPG-DMB COF nanomaterial is also applied as a potentially active photocatalyst for one-pot nitroarene reduction along with N-formylation reaction under sunlight irradiation in green reaction conditions with exceptionally high yield of formylated products upto 99 % as well as with high TOF value (762 h ?1). The catalyst efficiently reduced and formylated para-nitrophenol, a potential water pollutant, which elaborates its scope as an efficient catalyst for water purification also. The catalyst recyclability is also checked for five reaction cycles for both the reactions and the Ag/TFPG-DMB COF material showed outstanding recycling ability without any noticeable leaching of active metal or catalyst degradation.
- Biswas, Surajit,Hazra Chowdhury, Arpita,Hazra Chowdhury, Ipsita,Islam, Sk. Manirul
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- A non-catalyst non-promoter under the conditions of amide derivatives of aromatic amine with transfers the amine reaction
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The present invention discloses a non-catalyst under the condition of non-accelerator [...] amide derivatives of aromatic amine with transfers the amine reaction, yield of synthetic N - aryl amide derivatives. The method has a wide range of the substrate, its raw materials and cheap and easy to obtain acylation reagent, the reaction yield is high, one-step reaction, low cost, high reaction selectivity, simple operation and the like. Adopting this method can be gram scale can realize the high yield of the synthesis of drug molecules. Therefore, the method in the N - aryl amide derivatives of synthesis application field has very good application prospect. The method overcomes the existing technologies such as the reaction reagent toxicity is large, the need to use different type catalyst, synthesis method and the cost is high, more reaction steps, more byproducts and the like.
- -
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Paragraph 0097; 0098; 0099; 0100-0102
(2019/03/28)
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- One-pot photocalalytic reductive formylation of nitroarenes via multielectron transfer by carbon nitride in functional eutectic medium
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In the past years organic semiconductor photocatalysis has made the remarkable advances in developing efficient synthetic chemical routes to well refined structures. Until now, most efforts were focused on optimizing of the semiconductor photocatalyst, while solvents were largely ignored. Herein, we design a series of functional deep eutectic solvents (DES) with adjustable physicochemical properties – density, viscosity, glass transition temperature, and chemical activity towards reductive formylation of nitroarenes. The DES are prepared from abundant, sustainable resources, which makes them an affordable alternative to the ionic liquids, even on larger industrial scales. By combining the ammonium formate-based DES with carbon nitride photocatalyst, we enable the simultaneous six-electron reduction of nitro-compounds to the corresponding N-substituted formamides and benzimidazoles in one pot.
- Markushyna, Yevheniia,V?lkel, Antje,Savateev, Aleksandr,Antonietti, Markus,Filonenko, Svitlana
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p. 186 - 194
(2019/11/26)
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- Catalyst-Free Transamidation of Aromatic Amines with Formamide Derivatives and Tertiary Amides with Aliphatic Amines
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A simple catalyst- and promoter-free protocol has been developed for the transamidation of weakly nucleophilic aromatic amines with formamide derivatives and low-reactivity tertiary amides with aliphatic amines. This strategy is advantageous because no catalyst or promoters are needed, no additives are required, separation and purification is easy, and the reaction is scalable. Significantly, this strategy was further applied to synthesize several pharmaceutical molecules on a gram scale, and excellent yields were achieved.
- Yin, Jiawen,Zhang, Jingyu,Cai, Changqun,Deng, Guo-Jun,Gong, Hang
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supporting information
p. 387 - 392
(2019/01/11)
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- Citric acid stabilized on the surface of magnetic nanoparticles as an efficient and recyclable catalyst for transamidation of carboxamides, phthalimide, urea and thiourea with amines under neat conditions
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Abstract: Citric acid-coated magnetic nanoparticles (Fe3O4–CA NPs) were successfully prepared and characterized. This magnetic nanocatalyst was employed as an efficient, recyclable, and environmentally benign heterogeneous catalyst for the transamidation of carboxamides, phthalimide, urea and thiourea with amines. Several derivatives of formylated and transamidated products were synthesized in good to excellent yields in the presence of this catalytic system. And, the catalyst could be easily separated from the reaction mixture using an external magnet and can be reused six times without any significant loss in its catalytic activity. Graphical abstract: [Figure not available: see fulltext.].
- Arefi, Marzban,Kazemi Miraki, Maryam,Mostafalu, Ramin,Satari, Mohammad,Heydari, Akbar
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p. 393 - 400
(2019/01/28)
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- Synthesis and leishmanicidal activity of novel urea, thiourea, and selenourea derivatives of diselenides
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A novel series of thirty-one N-substituted urea, thiourea, and selenourea derivatives containing diphenyldiselenide entities were synthesized, fully characterized by spectroscopic and analytical methods, and screened for their in vitro leishmanicidal activities. The cytotoxic activity of these derivatives was tested against Leishmania infantum axenic amastigotes, and selectivity was assessed in human THP-1 cells. Thirteen of the synthesized compounds showed a significant antileishmanial activity, with 50% effective concentration (EC50) values lower than that for the reference drug miltefosine (EC50, 2.84 M). In addition, the derivatives 9, 11, 42, and 47, with EC50 between 1.1 and 1.95 M, also displayed excellent selectivity (selectivity index ranged from 12.4 to 22.7) and were tested against infected macrophages. Compound 11, a derivative with a cyclohexyl chain, exhibited the highest activity against intracellular amastigotes, with EC50 values similar to those observed for the standard drug edelfosine. Structure-activity relationship analyses revealed that N-aliphatic substitution in urea and selenourea is recommended for the leishmanicidal activity of these analogs. Preliminary studies of the mechanism of action for the hit compounds was carried out by measuring their ability to inhibit trypanothione reductase. Even though the obtained results suggest that this enzyme is not the target for most of these derivatives, their activity comparable to that of the standards and lack of toxicity in THP-1 cells highlight the potential of these compounds to be optimized for leishmaniasis treatment.
- Díaz, Marta,de Lucio, Héctor,Moreno, Esther,Espuelas, Socorro,Aydillo, Carlos,Jiménez-Ruiz, Antonio,Toro, Miguel ángel,Gutiérrez, Killian Jesús,Martínez-Merino, Victor,Cornejo, Alfonso,Palop, Juan Antonio,Sanmartín, Carmen,Planoa, Daniel
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- Novel 1,3,4-Selenadiazole-Containing Kidney-Type Glutaminase Inhibitors Showed Improved Cellular Uptake and Antitumor Activity
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Kidney-type glutaminase [KGA/isoenzyme glutaminase C (GAC)] is becoming an important tumor metabolism target in cancer chemotherapy. Its allosteric inhibitor, CB839, showed early promise in cancer therapeutics but limited efficacy in in vivo cancer models. To improve the in vivo activity, we explored a bioisostere replacement of the sulfur atom in bis-2-(5-phenylacetamido-1,2,4-thiadiazol)ethyl sulfide and CB839 analogues with selenium using a novel synthesis of the selenadiazole moiety from carboxylic acids or nitriles. The resulting selenadiazole compounds showed enhanced KGA inhibition, more potent induction of reactive oxygen species, improved inhibition of cancer cells, and higher cellular and tumor accumulation than the corresponding sulfur-containing molecules. However, both CB839 and its selenium analogues show incomplete inhibition of the tested cancer cells, and a partial reduction in tumor size was observed in both the glutamine-dependent HCT116 and aggressive H22 liver cancer xenograft models. Despite this, tumor tissue damage and prolonged survival were observed in animals treated with the selenium analogue of CB839.
- Chen, Zhao,Li, Di,Xu, Ning,Fang, Jinzhang,Yu, Yan,Hou, Wei,Ruan, Haoqiang,Zhu, Panpan,Ma, Renchao,Lu, Shiying,Cao, Danhui,Wu, Rui,Ni, Mowei,Zhang, Wei,Su, Weike,Ruan, Benfang Helen
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supporting information
p. 589 - 603
(2019/01/10)
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- Palladium-Catalyzed Diarylation of Isocyanides with Tetraarylleads for the Selective Synthesis of Imines and α-Diimines
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Using tetraaryllead compounds (PbAr4) as arylating reagents, isocyanides undergo selective diarylation in the presence of palladium catalysts such as Pd(OAc)2 or Pd(PPh3)4 to afford imines and/or α-diimines based on the isocyanide employed. With aliphatic isocyanides, imines are obtained preferentially, whereas α-diimines are formed in the case of electron-rich aromatic isocyanides. The differences in imine/α-diimine selectivity can be attributed to the stability of imidoylpalladium intermediates formed in this catalytic reaction. Compared with other arylating reagents, tetraaryllead compounds are excellent candidates for use in the selective transformations to imines and/or α-diimines, especially in terms of inhibiting the oligomerization of isocyanides, which results in a lower product selectivity in many transition-metal-catalyzed reactions of isocyanides.
- Tran, Cong Chi,Kawaguchi, Shin-Ichi,Kobiki, Yohsuke,Matsubara, Hitomi,Tran, Dat Phuc,Kodama, Shintaro,Nomoto, Akihiro,Ogawa, Akiya
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p. 11741 - 11751
(2019/10/02)
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- Synthesis of Imides, Imidates, Amidines, and Amides by Intercepting the Aryne-Isocyanide Adduct with Weak Nucleophiles
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New aryne-based multicomponent coupling reactions for the formation of functionalized aromatic compounds have been developed. Arynes generated from triynes or tetraynes through the hexadehydro Diels-Alder reaction readily react with isocyanide to generate nitrilium intermediate. Intercepting this nitrilium species with various weak nucleophile including carboxylic acids, alcohols, sulfonamides, or water generated the corresponding imides, imidates, amidines, or amides. The high regioselectivity of these transformations was mainly controlled by the substituents of the arynes.
- Ghorai, Sourav,Lee, Daesung
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supporting information
p. 7390 - 7393
(2019/10/02)
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- Visible-light-induced radical cascade cyclization of oxime esters and aryl isonitriles: Synthesis of cyclopenta[: B] quinoxalines
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A visible-light-induced radical cascade cyclization of aryl isonitriles and cyclobutanone oxime esters for the synthesis of cyclopenta[b]quinoxalines has been accomplished for the first time. The key to the success of this process was the integration of the in situ-formed nitrile radical followed by the cascade radical isonitrile/nitrile insertion-cyclization. The easy introduction of substituents for both substrates and the high functional group tolerance of the reaction make it an efficient strategy to give various quinoxaline derivatives in moderate to good yields.
- Yuan, Yao,Dong, Wu-Heng,Gao, Xiao-Shuang,Xie, Xiao-Min,Zhang, Zhao-Guo
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supporting information
p. 11900 - 11903
(2019/10/11)
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- Direct conversion of carboxylic acids to various nitrogen-containing compounds in the one-pot exploiting curtius rearrangement
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Herein we report, a single-pot multistep conversion of inactivated carboxylic acids to various N-containing compounds using a common synthetic methodology. The developed methodology rendered the use of carboxylic acids as a direct surrogate of primary amines, for the synthesis of primary ureas, secondary/tertiary ureas, O/S-carbamates, benzoyl ureas, amides, and N-formyls, exploiting the Curtius reaction. This approach has a potential to provide a diversified library of N-containing compounds, starting from a single carboxylic acid, based on the selection of the nucleophile.
- Kumar, Arun,Kumar, Naveen,Sharma, Ritika,Bhargava, Gaurav,Mahajan, Dinesh
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p. 11323 - 11334
(2019/09/10)
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- Selective formylation or methylation of amines using carbon dioxide catalysed by a rhodium perimidine-based NHC complex
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Carbon dioxide can play a vital role as a sustainable feedstock for chemical synthesis. To be viable, the employed protocol should be as mild as possible. Herein we report a methodology to incorporate CO2 into primary, secondary, aromatic or alkyl amines catalysed by a Rh(i) complex bearing a perimidine-based NHC/phosphine pincer ligand. The periminide-based ligand belongs to a class of 6-membered NHC ligand accessed through chelate-assisted double C-H activation. N-Formylation and -methylation of amines were performed using a balloon of CO2, and phenylsilane as the reducing agent. Product selectivity between formylated and methylated products was tuned by changing the solvent, reaction temperature and the quantity of phenylsilane used. Medium to excellent conversions, as well as tolerance to a range of functional groups, were achieved. Stoichiometric reactions with reactants employed in catalysis and time course studies suggested that formylation and methylation reactions of interest begin with hydrosilylation of CO2 followed by reaction with amine substrates.
- Lam, Raphael H.,McQueen, Caitlin M. A.,Pernik, Indrek,McBurney, Roy T.,Hill, Anthony F.,Messerle, Barbara A.
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supporting information
p. 538 - 549
(2019/02/14)
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- An efficient method for the N-formylation of amines under catalyst- and additive-free conditions
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A simple catalyst- and additive-free method for the N-formylation of amines has been developed. The advantages of this protocol include a wide range of functional group tolerance, high efficiency and a lack of required extra promoters under mild conditions. This convenient strategy will provide a facile synthesis towards N-formamide natural products and pharmaceutical derivatives. A mechanism that involves difluorocarbene is proposed for this reaction.
- Xu, Zhuo-Wei,Xu, Wen-Yi,Pei, Xiao-Jun,Tang, Fei,Feng, Yi-Si
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supporting information
p. 1254 - 1258
(2019/04/10)
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- Mn-Catalyzed Selective Double and Mono-N-Formylation and N-Methylation of Amines by using CO2
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Functionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2. In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N-formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.
- Huang, Zijun,Jiang, Xiaolin,Zhou, Shaofang,Yang, Peiju,Du, Chen-Xia,Li, Yuehui
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p. 3054 - 3059
(2019/04/10)
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- KOtBu-Promoted Transition-Metal-Free Transamidation of Primary and Tertiary Amides with Amines
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This work discloses transamidation of primary and tertiary amides with a range of aryl, heteroaryl, and aliphatic amines using potassium tert-butoxide. The reaction proceeds at room temperature under transition-metal-free conditions providing secondary amides in high yields. Moreover, reaction of cyclopropyl amine with tertiary amides proceeds with ring-opening to provide a rapid access to enamides.
- Ghosh, Tridev,Jana, Snehasish,Dash, Jyotirmayee
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supporting information
p. 6690 - 6694
(2019/09/12)
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- N,N-coordinated palladium complex with meta-carborane ligand and preparation and application of palladium complex
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The invention relates to an N,N-coordinated palladium complex with a meta-carborane ligand and preparation and application of the palladium complex. A preparation method of the palladium complex comprises the following steps that (1) an n-BuLi solution is added into a meta-carborane solution and then a reaction is performed at a room temperature for 30-60 min; (2) 3-chloromethylpyridine is added and reacts at the room temperature for 3-5 h; (3) PdCl2 is added and reacts at the room temperature for 2-5 h, and the palladium complex is obtained through post-treatment; and the palladium complex isused for catalyzing an arylamine formylation reaction to prepare an arylamine formamide compound. Compared with the prior art, the synthesis process of the palladium complex is simple and green, andhas excellent selectivity and a high yield; and the palladium complex has the characteristics such as stable physicochemical properties and thermal stability, and exhibits excellent catalytic activityin the arylamine formylation reaction.
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Paragraph 0049-0052
(2019/11/12)
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- NH4I-promoted N-acylation of amines via the transamidation of DMF and DMA under metal-free conditions
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An unprecedented NH4I-promoted N-formylation and N-acetylization of various amines with dimethylformamide (DMF)and dimethylacetamide (DMA)has been developed. This protocol shows broad substrate scope for aromatic, aliphatic, and heterocyclic amines, which provides a metal-free strategy for N-acylation featuring mild reaction conditions, as well as inexpensive and readily available starting materials.
- Chen, Jiahui,Jia, Jing,Guo, Ziyi,Zhang, Jitan,Xie, Meihua
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supporting information
p. 1426 - 1429
(2019/05/06)
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- Potassium tert-Butoxide Prompted Highly Efficient Transamidation and Its Coordination Radical Mechanism
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A simple and highly efficient protocol was developed for the transamidation of N,N-disubstituted amides with primary amines in the presence of tBuOK, affording desired products in good to excellent yields. This reaction proceeded under nitrogen atmosphere and featured extensive substrate tolerance. Experimental investigation suggested that a coordination radical process enhanced this transformation.
- Tan, Zhiyong,Li, Zhenhua,Ma, Yao,Qin, Jinjing,Yu, Chuanming
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p. 4538 - 4545
(2019/07/18)
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- Modified Graphene Oxide Based Zinc Composite: an Efficient Catalyst for N-formylation and Carbamate Formation Reactions Through CO2 Fixation
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Catalytic fixation of CO2 through chemical reactions is always a challenging task of synthetic chemistry. This paper represents the design and synthesis of an eco-friendly low cost zinc metal containing heterogeneous catalyst of aminically modified Graphene Oxide. Characterization of the catalyst has been carried out by Raman and FTIR spectra, AAS, XRD, TEM, SEM, EDX and N2 adsorption desorption studies. It was found that the catalyst was very proficient for the CO2 fixation through N-formylation and carbamate formation reactions of amines. Catalytic N-formylation reaction of both aromatic and aliphatic amines gave high yield of corresponding formylated products in presence of polymethylhydrosiloxane (PMHS) as reducing agent under 1 bar CO2 pressure and mild temperature. Formation of carbamates from aniline or its derivatives and alkyl/aryl bromide with good product selectivity was also achieved under same CO2 pressure in presence of our synthesized catalyst at room temperature with solvent-free condition. The catalyst is reusable and e?cient even after six cycles.
- Khatun, Resmin,Biswas, Surajit,Islam, Sarikul,Biswas, Imdadul Haque,Riyajuddin, Sk,Ghosh, Kaushik,Islam, Sk Manirul
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supporting information
p. 1303 - 1312
(2019/01/25)
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- MXene (Ti3C2) Vacancy-Confined Single-Atom Catalyst for Efficient Functionalization of CO2
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A central topic in single-atom catalysis is building strong interactions between single atoms and the support for stabilization. Herein we report the preparation of stabilized single-atom catalysts via a simultaneous self-reduction stabilization process at room temperature using ultrathin two-dimensional Ti3-xC2TyMXene nanosheets characterized by abundant Ti-deficit vacancy defects and a high reducing capability. The single atoms therein form strong metal-carbon bonds with the Ti3-xC2Ty support and are therefore stabilized onto the sites previously occupied by Ti. Pt-based single-atom catalyst (SAC) Pt1/Ti3-xC2Ty offers a green route to utilizing greenhouse gas CO2, via the formylation of amines, as a C1 source in organic synthesis. DFT calculations reveal that, compared to Pt nanoparticles, the single Pt atoms on Ti3-xC2Ty support feature partial positive charges and atomic dispersion, which helps to significantly decrease the adsorption energy and activation energy of silane, CO2, and aniline, thereby boosting catalytic performance. We believe that these results would open up new opportunities for the fabrication of SACs and the applications of MXenes in organic synthesis.
- Zhao, Di,Chen, Zheng,Yang, Wenjuan,Liu, Shoujie,Zhang, Xun,Yu, Yi,Cheong, Weng-Chon,Zheng, Lirong,Ren, Fuqiang,Ying, Guobing,Cao, Xing,Wang, Dingsheng,Peng, Qing,Wang, Guoxiu,Chen, Chen
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supporting information
p. 4086 - 4093
(2019/02/26)
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