- Design and synthesis of 3,5-substituted 1,2,4-oxadiazoles as catalytic inhibitors of human DNA topoisomerase IIα
-
Cancer constitutes a group of diseases linked to abnormal cell growth that can potentially spread to other parts of the body and is one of the most common causes of death. The molecular motors - DNA topoisomerases - that enable topological changes of the DNA molecule are one of the most established targets of cancer therapies. Due to known limitations of established topo II poisons such as cardiotoxicity, induction of secondary malignancies and recognized cancer cell resistance, an emerging group of catalytic topo II inhibitors attempts to circumvent these challenges. Currently, this approach comprises several subgroups of mechanistically diverse inhibitors, one of which are compounds that act by binding to their ATPase domain. In this study we have designed, synthesized and characterized a new series of 3,5-substituted 1,2,4-oxadiazoles that act as catalytic inhibitors of human topo IIα. The introduction of the substituted rigid substitutions on the oxadiazole backbone was intended to enhance the interactions with the ATP binding site. In the inhibition assays selected compounds revealed a new class of catalytic inhibitors targeting this molecular motor and showed binding to the isolated topo IIα ATPase domain. The predicted inhibitor binding geometries were evaluated in molecular dynamics simulations and subsequently dynophore models were derived, which provided a deeper insight into molecular recognition with its macromolecular target. Selected compounds also displayed in vitro cytotoxicity on the investigated MCF-7 cancer cell line and did not induce double-strand breaks (DSB), thus displaying a mechanism of action diverse from the topo II poisons also on the cellular level. The substituted oxadiazoles thus comprise a chemical class of interesting compounds that are synthetically fully amenable for further optimization to anticancer drugs.
- Dolenc, Marija Sollner,Loboda, Kaja Bergant,Perdih, Andrej,Valjavec, Katja,Wolber, Gerhard,?tampar, Martina,?egura, Bojana,Filipi?, Metka
-
-
Read Online
- Amine-Linked Covalent Organic Frameworks as a Platform for Postsynthetic Structure Interconversion and Pore-Wall Modification
-
Covalent organic frameworks have emerged as a powerful synthetic platform for installing and interconverting dedicated molecular functions on a crystalline polymeric backbone with atomic precision. Here, we present a novel strategy to directly access amine-linked covalent organic frameworks, which serve as a scaffold enabling pore-wall modification and linkage-interconversion by new synthetic methods based on Leuckart-Wallach reduction with formic acid and ammonium formate. Frameworks connected entirely by secondary amine linkages, mixed amine/imine bonds, and partially formylated amine linkages are obtained in a single step from imine-linked frameworks or directly from corresponding linkers in a one-pot crystallization-reduction approach. The new, 2D amine-linked covalent organic frameworks, rPI-3-COF, rTTI-COF, and rPy1P-COF, are obtained with high crystallinity and large surface areas. Secondary amines, installed as reactive sites on the pore wall, enable further postsynthetic functionalization to access tailored covalent organic frameworks, with increased hydrolytic stability, as potential heterogeneous catalysts.
- Grunenberg, Lars,Savasci, G?kcen,Terban, Maxwell W.,Duppel, Viola,Moudrakovski, Igor,Etter, Martin,Dinnebier, Robert E.,Ochsenfeld, Christian,Lotsch, Bettina V.
-
supporting information
p. 3430 - 3438
(2021/04/07)
-
- Preparation method of green visible light catalyzed acetamide compound
-
The invention discloses a preparation method of a green visible light catalyzed acetamide compound, wherein the method takes an LED lamp as a light source to provide energy, and takes aromatic amine and fatty amine which are economical and easy to obtain and 2,3-butanedione which can be purchased in the market as reaction substrates. Compared with the prior art, the method disclosed by the invention has the following advantages: 1) a green, efficient, energy-saving and environment-friendly visible light catalysis reaction mode is adopted; 2) the reaction system is simple, the substrate range is wide, and a metal catalyst and a dehydrating agent do not need to be added; 3) the reaction yield is high; 4) reaction conditions are mild; 5) the operation is relatively simple; and 6) raw materials are cheap and easily available.
- -
-
Paragraph 0030-0031
(2021/12/02)
-
- Ethyl 2-Cyano-2-(2-nitrobenzenesulfonyloxyimino) Acetate (ortho-NosylOXY)-Mediated Double Beckmann Rearrangement of Ketoximes under Microwave Irradiation: A Mechanistic Perception
-
A method for Beckmann rearrangement using ethyl 2-cyano-2-(2-nitrobenzenesulfonyloxyimino) acetate (o-NosylOXY) under microwave irradiation is reported. Ketoximes (19 examples) are converted to the corresponding amides/lactams with 69–97% yields in ~10 minutes without any Lewis acid or co-catalyst. This is an example of halogen-free organocatalytic Beckmann rearrangement. Nuclear magnetic resonance (NMR)- and high-resolution mass spectrometry (HRMS)-based detailed mechanistic investigation suggest that o-NosylOXY acts as an initiator. Such initiators are reported before based on density functional theory (DFT) calculations. However, we report here the HRMS signatures of two transient intermediates, the nitrilium ion and the nitrilium ion's dimeric species. Rigorous NMR-based investigation of the reaction mechanism is performed. Our results indicate that the reported Beckmann rearrangement proceeds via two consecutive rearrangements. (Figure presented.).
- Dev, Dharm,Kalita, Tapasi,Mondal, Tanmay,Mandal, Bhubaneswar
-
p. 1427 - 1435
(2021/01/04)
-
- A Molecular Iron-Based System for Divergent Bond Activation: Controlling the Reactivity of Aldehydes
-
The direct synthesis of amides and nitriles from readily available aldehyde precursors provides access to functional groups of major synthetic utility. To date, most reliable catalytic methods have typically been optimized to supply one product exclusively. Herein, we describe an approach centered on an operationally simple iron-based system that, depending on the reaction conditions, selectively addresses either the C=O or C-H bond of aldehydes. This way, two divergent reaction pathways can be opened to furnish both products in high yields and selectivities under mild reaction conditions. The catalyst system takes advantage of iron's dual reactivity capable of acting as (1) a Lewis acid and (2) a nitrene transfer platform to govern the aldehyde building block. The present transformation offers a rare control over the selectivity on the basis of the iron system's ionic nature. This approach expands the repertoire of protocols for amide and nitrile synthesis and shows that fine adjustments of the catalyst system's molecular environment can supply control over bond activation processes, thus providing easy access to various products from primary building blocks.
- Chatterjee, Basujit,Jena, Soumyashree,Chugh, Vishal,Weyhermüller, Thomas,Werlé, Christophe
-
p. 7176 - 7185
(2021/06/30)
-
- Efficient nitriding reagent and application thereof
-
The invention discloses an efficient nitriding reagent and application thereof, wherein the nitriding reagent comprises nitrogen oxide, an active agent, a reducing agent and an organic solvent. By applying the nitriding reagent, nitrogen-containing compounds such as amide, nitrile and the like can be produced, and the method is simple in condition, low in waste discharge amount and simple in reaction equipment.
- -
-
Paragraph 0215-0218
(2021/03/31)
-
- Enhanced catalytic activity of one-dimensional CdS @TiO2 core-shell nanocomposites for selective organic transformations under visible LED irradiation
-
In this study, we are interested in the photocatalytic activity under visible LED irradiation of one- dimensional (1D) CdS @TiO2 core–shell nanocomposites (CSNs) prepared through a facile and convenient method. For the synthesis of 1D CdS@TiO2 core/shell structure, titania source (Tetrabutyl titanate) was hydrolyzed by water vapor transmission on the surface of CdS nanowires (NWs) which were prepared via solvothermal method. The characterization of 1D CdS@TiO2 core–shell nanocomposites (CdS@TiO2 CSNs) was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis spectroscopy, and UV–Vis diffuse reflectance spectroscopy (DRS). The as-synthesized sample was utilized for the selective reduction of nitro compounds to benzimidazole and anilide, and also the reduction of benzophenones to alcohol under blue LED irradiation. The 1D CdS@TiO2 CSNs exhibited enhanced photoactivity compared with the pure TiO2, CdS nanowires and commercial TiO2-P25. The excellent reusability of the photocatalyst was examined for six runs. The results demonstrated that the prepared sample has the potential to provide a promising visible light-driven photocatalyst for other organic transformations.
- Eskandari, Parvin,Kazemi, Foad,Ramdar, Moosa,Zand, Zahra
-
-
- Electrochemical formation of: N, N ′-diarylhydrazines by dehydrogenative N-N homocoupling reaction
-
Hydrazines represent a class of compounds of high interest due to their applicability as versatile starting materials in many important transformations. Herein, we report a synthetic approach to hydrazine derivatives using commercially available anilines and an anodic dehydrogenative N-N coupling reaction as the key step.
- Breising, Valentina M.,Kayser, Jacob M.,Kehl, Anton,Schollmeyer, Dieter,Liermann, Johannes C.,Waldvogel, Siegfried R.
-
supporting information
p. 4348 - 4351
(2020/04/27)
-
- Iron-Promoted Decarboxylation of Arylacetic Acids for the Synthesis of Aromatic Nitriles with Sodium Nitrite as the Nitrogen Source
-
A new and effective method was developed for the synthesis of aromatic nitriles from arylacetic acids by using NaNO 2as the nitrogen source and Fe(OTf) 3as the promoter at 50 °C. A series of arylacetic acids underwent this transformation to give the targeted products in yields of 51-90%. Because of the mild conditions, the reaction is compatible with a broad range of functional groups, including ester, carboxy, hydroxy, acetamido, halo, nitro, cyano, methoxy, and even highly reactive formyl groups.
- Shen, Zhenpeng,Liu, Wenbo,Tian, Xinzhe,Zhao, Zhe,Ren, Yun-Lai
-
supporting information
p. 1805 - 1808
(2020/11/02)
-
- Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species
-
Cyano-containing compounds constitute important pharmaceuticals, agrochemicals and organic materials. Traditional cyanation methods often rely on the use of toxic metal cyanides which have serious disposal, storage and transportation issues. Therefore, there is an increasing need to develop general and efficient catalytic methods for cyanide-free production of nitriles. Here we report the reductive cyanation of organic chlorides using CO2/NH3 as the electrophilic CN source. The use of tridentate phosphine ligand Triphos allows for the nickel-catalyzed cyanation of a broad array of aryl and aliphatic chlorides to produce the desired nitrile products in good yields, and with excellent functional group tolerance. Cheap and bench-stable urea was also shown as suitable CN source, suggesting promising application potential. Mechanistic studies imply that Triphos-Ni(I) species are responsible for the reductive C-C coupling approach involving isocyanate intermediates. This method expands the application potential of reductive cyanation in the synthesis of functionalized nitrile compounds under cyanide-free conditions, which is valuable for safe synthesis of (isotope-labeled) drugs.
- Dong, Yanan,Li, Yuehui,Yang, Peiju,Zhao, Shizhen
-
-
- Organophotoredox assisted cyanation of bromoarenes: via silyl-radical-mediated bromine abstraction
-
The insertion of a nitrile (-CN) group into arenes through the direct functionalization of the C(sp2)-Br bond is a challenging reaction. Herein, we report an organophotoredox method for the cyanation of aryl bromides using the organic photoredox catalyst 4CzIPN and tosyl cyanide (TsCN) as the nitrile source. A photogenerated silyl radical, via a single electron transfer (SET) mechanism, was employed to abstract bromine from aryl bromide to provide an aryl radical, which was concomitantly intercepted by TsCN to afford the aromatic nitrile. A range of substrates containing electron-donating and -withdrawing groups was demonstrated to undergo cyanation at room temperature in good yields.
- Shah, Sk. Sheriff,Shee, Maniklal,Singh, N. D. Pradeep
-
supporting information
p. 4240 - 4243
(2020/04/22)
-
- Nickel-Catalyzed Cyanation of Aryl Halides and Hydrocyanation of Alkynes via C-CN Bond Cleavage and Cyano Transfer
-
We report nickel-catalyzed cyanation and hydrocyanation methods to prepare aryl nitriles and vinyl nitriles from aryl halides and alkynes, respectively. Using inexpensive and nontoxic 4-cyanopyridine N-oxide as the cyano shuttle, the methods provide an efficient approach to prepare aryl cyanides and vinyl nitriles under mild and operationally simple reaction conditions with a broad range of functional group tolerances. In hydrocyanation of alkynes, the method demonstrated good regioselectivity, producing predominantly E- or Z-alkenyl nitriles in a controlled manner and exclusively Markovnikov vinyl nitriles when internal diaryl alkynes and terminal alkynes were applied as the substrates, respectively. The preliminary mechanistic investigation indicated that the C-CN bond cleavage process is promoted by oxidative addition to the nickel(I) complex in the cyanation of aryl halides, and further studies via a series of deuterium exchange experiments indicated that water serves as the hydrogen source for the hydrocyanation of alkynes.
- Chen, Hui,Sun, Shuhao,Liu, Yahu A.,Liao, Xuebin
-
p. 1397 - 1405
(2020/02/04)
-
- Phenysilane and Silicon Tetraacetate: Versatile Promotors for Amide Synthesis
-
Phenylsilane was reevaluated as a useful coupling reagent for amide synthesis. At room temperature, a wide range of amides and peptides were obtained in good to excellent yields (up to 99 %). For the first time, Weinreb amides synthesis mediated by a hydrosilane were also documented. Comparative experiments with various acetoxysilanes suggested the involvement of a phenyl-triacyloxysilane. From this mechanistic study, silicon tetraacetate was shown as an efficient amine acylating agent.
- Morisset, Eléonore,Chardon, Aurélien,Rouden, Jacques,Blanchet, Jér?me
-
supporting information
p. 388 - 392
(2020/01/24)
-
- A convenient reagent for the conversion of aldoximes into nitriles and isonitriles
-
For the dehydroxylation of aldoximes with 4-nitro-1-((trifluoromethyl)sulfonyl)-imidazole (NTSI), slight modifications of reaction conditions resulted in significantly different reaction paths to provide either nitriles or isonitriles. The challenging conversion of aldoximes into isonitriles was achieved under mild conditions.
- Zhang, Wei,Lin, Jin-Hong,Zhang, Pengfei,Xiao, Ji-Chang
-
supporting information
p. 6221 - 6224
(2020/06/29)
-
- Method for converting aromatic aldehyde into aromatic nitrile by using sulfur powder promoted inorganic ammonium as nitrogen source (by machine translation)
-
The invention discloses a method for converting aromatic aldehyde into aromatic nitrile. The method is conversion of high yield of aromatic aldehyde one-pot reaction of sulfur powder promoted inorganic ammonium as a nitrogen source into aromatic nitrile. The method has the advantages of no need of metal participation, no need of strong oxide, compatibility of reaction to air, easiness in amplification to a gram scale and the like, and overcomes the problems of harsh reaction conditions, complex operation, low functional group compatibility and the like in the prior art. (by machine translation)
- -
-
Paragraph 0060; 0061
(2020/09/12)
-
- HCl·DMPU-assisted one-pot and metal-free conversion of aldehydes to nitriles
-
We report an efficient HCl·DMPU assisted one-pot conversion of aldehydes into nitriles. The use of HCl·DMPU as both an acidic source as well as a non-nucleophilic base constitutes an environmentally mild alternative for the preparation of nitriles. Our protocol proceeds smoothly without the use of toxic reagents and metal catalysts. Diverse functionalized aromatic, aliphatic and allylic aldehydes incorporating various functional groups were successfully converted to nitriles in excellent to quantitative yields. This protocol is characterized by a broad substrate scope, mild reaction conditions, and high scalability. This journal is
- Hammond, Gerald B.,Mudshinge, Sagar R.,Potnis, Chinmay S.,Xu, Bo
-
supporting information
p. 4161 - 4164
(2020/07/14)
-
- Nitromethane as a nitrogen donor in Schmidt-type formation of amides and nitriles
-
The Schmidt reaction has been an efficient and widely used synthetic approach to amides and nitriles since its discovery in 1923. However, its application often entails the use of volatile, potentially explosive, and highly toxic azide reagents. Here, we report a sequence whereby triflic anhydride and formic and acetic acids activate the bulk chemical nitromethane to serve as a nitrogen donor in place of azides in Schmidt-like reactions. This protocol further expands the substrate scope to alkynes and simple alkyl benzenes for the preparation of amides and nitriles.
- Jiao, Ning,Liu, Jianzhong,Qiu, Xu,Song, Song,Wei, Jialiang,Wen, Xiaojin,Zhang, Cheng,Zhang, Ziyao
-
supporting information
p. 281 - 285
(2020/01/28)
-
- A one pot protocol to convert nitro-arenes into: N-aryl amides
-
A two-step one pot, experimentally simple protocol, based on readily available and inexpensive reagents allowed the conversion of nitro-arenes directly to N-aryl amides. A metal-free reduction of the nitro group, mediated by trichlorosilane, followed by the addition of an anhydride afforded the corresponding N-aryl carboxyamide, that was isolated after a simple aqueous work up in good-excellent yields. When the methodology was applied to the reaction with γ-butyrolactone, the desired N-aryl butanamide derivative was obtained, featuring a chlorine atom at the γ-position, a functionalized handle that can be used for further synthetic manipulation of the reaction product. Such an intermediate has already been employed as a key advanced precursor of pharmaceutically active compounds.
- Massolo, Elisabetta,Pirola, Margherita,Puglisi, Alessandra,Rossi, Sergio,Benaglia, Maurizio
-
p. 4040 - 4044
(2020/02/04)
-
- Iodine and Br?nsted acid catalyzed C–C bond cleavage of 1,3-diketones for the acylation of amines
-
A metal-free N-acylation method of anilines with 1,3-diketones has been developed, by using iodine and p-toluene sulfonic acid as the co-catalysts. The reaction can proceed in 1,4-dioxane at elevated temperature to produce the corresponding amides with 48–89% yields. Further, the gram-scale experiment was carried out under the standard conditions and the possible mechanism was proposed.
- Zhou, Xiao-Yu,Chen, Xia,Yang, Dan
-
supporting information
p. 177 - 184
(2019/11/26)
-
- Liquid-phase hydrogenation of nitriles to amines facilitated by a co(ii)/zn(0) pair: a ligand-free catalytic protocol
-
The given report introduces a simple and user-friendly in situ method for the production of catalytically active cobalt particles. The approach circumvents the use of air-and moisture-sensitive reductants as well as the application of anhydrous Co-precursor salts. Accordingly, the described catalytic system is readily assembled under open-flask conditions by simply combining the components in the reaction vessel. Therefore, the arduous charging procedure of the reaction autoclave in a glovebox under an inert gas atmosphere is no longer necessary. In fact, the catalytically active material is obtained upon treatment of readily available Co(OAc)2·4 H2O with benign commercial Zn powder. The catalytic performance of the resultant material was tested in the heterogeneous hydrogenation of nitriles to the corresponding primary amines. Both activity and selectivity of the cobalt catalyst are significantly enhanced if a triflate-based Lewis acid and ammonia is added to the reaction mixture.
- Timelthaler, Daniel,Topf, Christoph
-
p. 11604 - 11611
(2019/10/02)
-
- 1-Aryl-3-(4-methoxybenzyl)ureas as potentially irreversible glycogen synthase kinase 3 inhibitors: Synthesis and biological evaluation
-
Glycogen synthase kinase 3 (GSK-3)has become known for its multifactorial involvement in the pathogenesis of Alzheimer's disease. In this study, a benzothiazole- and benzimidazole set of 1-aryl-3-(4-methoxybenzyl)ureas were synthesised as proposed Cys199-targeted covalent inhibitors of GSK-3β, through the incorporation of an electrophilic warhead onto their ring scaffolds. The nitrile-substituted benzimidazolylurea 2b (IC50 = 0.086 ± 0.023 μM)and halomethylketone-substituted benzimidazolylurea 9b (IC50 = 0.13 ± 0.060 μM)displayed high GSK-3β inhibitory activity, in comparison to reference inhibitor AR-A014418 (1, IC50 = 0.072 ± 0.043)in our assay. The results suggest further investigation of 2b and 9b as potential covalent inhibitors of GSK-3β, since a targeted interaction might provide improved kinase-selectivity.
- Venter, Jana,Perez, Concepción,van Otterlo, Willem A.L.,Martínez, Ana,Blackie, Margaret A.L.
-
p. 1597 - 1600
(2019/05/02)
-
- An unsymmetrical covalent organic polymer for catalytic amide synthesis
-
Herein, we present the first report on the Covalent Organic Polymer (COP) directed non-classical synthesis of an amide bond. An economical route has been chosen for the synthesis of APC-COP using p-aminophenol and cyanuric chloride. APC-COP acts as a smart, valuable and sustainable catalyst for efficient access to the amide bond under mild conditions at room temperature in 30 min. APC-COP exhibits selectivity towards carboxylic acids over esters. The key features of this protocol involve the variety of parameters, viz. wider substrate scope, no use of additive and recyclability, which makes this approach highly desirable in gramscale synthesis. Moreover, we have shown the practical utility of the present method in the catalytic synthesis of paracetamol.
- Yadav, Deepika,Awasthi, Satish Kumar
-
p. 179 - 186
(2019/12/28)
-
- Palladium-Catalyzed Amidation and Amination of (Hetero)aryl Chlorides under Homogeneous Conditions Enabled by a Soluble DBU/NaTFA Dual-Base System
-
The palladium-catalyzed coupling of aryl and heteroaryl chlorides with primary amides under mild homogeneous reaction conditions is reported. Successful C-N coupling is enabled by the use of a unique "dual-base" system consisting of DBU and NaTFA, which serve as proton acceptor and halide scavenger, respectively, using low catalyst loadings (0.5 mol %) with readily available, air-stable palladium precatalysts. The DBU/NaTFA system also enables the room-temperature coupling of primary aryl amines with aryl chlorides and is tolerant of a variety of base-sensitive functional groups.
- Beutner, Gregory L.,Coombs, John R.,Green, Rebecca A.,Inankur, Bahar,Lin, Dong,Qiu, Jun,Roberts, Frederick,Simmons, Eric M.,Wisniewski, Steven R.
-
supporting information
p. 1529 - 1537
(2019/09/04)
-
- Synthesis of Arylamides via Ritter-Type Cleavage of Solid-Supported Aryltriazenes
-
A novel route for the synthesis of N-arylamides via the cleavage of aryltriazenes with alkyl or aryl nitriles is presented. We developed a variation of the Ritter reaction that allows the use of acetonitrile as solvent and reagent in reactions with solid-supported precursors. The reaction was optimized for the generation of N-aryl acetamides using a diverse range of immobilized building blocks including o-, m-, and p-substituted aryltriazenes. The cleavage via the Ritter-type conversion was combined with an on-bead cross-coupling reaction of halogen-substituted aryltriazenes with pyrazoles. Additionally, the synthesis of on-bead generated arylboronic ester-substituted triazenes was shown. The developed procedure was further expanded to use other commercially available nitriles, such as acrylonitrile, benzonitrile, and chlorinated alkyl nitriles as suitable reagents for a Ritter-type cleavage of the prepared triazene linkers.
- Wippert, Nicolai A.,Jung, Nicole,Br?se, Stefan
-
supporting information
p. 568 - 572
(2019/09/03)
-
- SO2F2-Activated Efficient Beckmann Rearrangement of Ketoximes for Accessing Amides and Lactams
-
A novel, mild and practical protocol for the efficient activation of the Beckmann rearrangement utilizing the readily available and economical sulfuryl fluoride (SO2F2 gas) has been developed. The substrate scope of the operationally simple methodology has been demonstrated by 37 examples with good to nearly quantitative isolated yields (over 90 % yield in most cases) in a short time, including B(OH)2, COOH, NH2, and OH substituted substrates. A tentative mechanism was proposed involving formation and elimination of key intermediate, sulfonyl ester.
- Zhang, Guofu,Zhao, Yiyong,Xuan, Lidi,Ding, Chengrong
-
supporting information
p. 4911 - 4915
(2019/07/31)
-
- Cascade Process for Direct Transformation of Aldehydes (RCHO) to Nitriles (RCN) Using Inorganic Reagents NH2OH/Na2CO3/SO2F2 in DMSO
-
A simple, mild, and practical process for direct conversion of aldehydes to nitriles was developed feathering a wide substrate scope and great functional group tolerability (52 examples, over 90% yield in most cases) using inorganic reagents (NH2OH/Na2CO3/SO2F2) in DMSO. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable nitriles in a pot, atom, and step-economical manner without transition metals. This protocol will serve as a robust tool for the installation of cyano-moieties to complicated molecules.
- Fang, Wan-Yin,Qin, Hua-Li
-
p. 5803 - 5812
(2019/05/14)
-
- Ni-Mediated Generation of "cN" Unit from Formamide and Its Catalysis in the Cyanation Reactions
-
The in situ generation of a "cyano" unit from readily available organic precursors is of high interest in synthetic chemistry. Herein, we report the first example of Ni-mediated dehydration of formamide to form "CN" and its subsequent catalytic applications in the hydrocyanation of alkynes and cyanation of aryl halides. Formamide can serve as a convenient source for the nitrile unit, in that it releases water as the only byproduct.
- Yang, Luo,Liu, Yu-Ting,Park, Yoonsu,Park, Sung-Woo,Chang, Sukbok
-
p. 3360 - 3365
(2019/03/26)
-
- Sulfuryl Fluoride Mediated Conversion of Aldehydes to Nitriles
-
Aliphatic, aromatic, and heteroaromatic aldehydes were readily converted to corresponding nitriles in a one-pot reaction sequence with hydroxylamine and sulfuryl fluoride. The reaction proceeds at room temperature, does not require metal catalysts and special precautions, and produces nitriles in excellent yields. It is compatible with a variety of functional groups, can be performed in aqueous and organic solvents, and is readily scalable to multigram quantities. Mild conditions and high selectivity of the reaction enabled the construction of polyfunctional probes containing nitrile, alkyne, azide, and fluorosulfate groups for further orthogonal derivatization.
- Gurjar, Jitendra,Bater, Jorick,Fokin, Valery V.
-
supporting information
p. 1906 - 1909
(2019/01/24)
-
- Visible light-induced direct conversion of aldehydes into nitriles in aqueous medium using Co@g-C3N4 as photocatalyst
-
Unprecedented Co@g-C3N4 catalyzed visible light driven efficient conversion of a variety of aldehydes into corresponding nitriles is reported. Operational simplicity, excellent yield of pure products (87–94%), ambient reaction condition, using aqueous methanol as solvent, visible-light photocatalysis are the salient features of envisaged methodology for direct conversion of aldehydes into nitriles. Furthermore, reusability of Co@g-C3N4 was checked up to five runs and it was noticed that there was no substantial change in morphology as well as the catalytic efficiency of catalyst.
- Verma, Fooleswar,Shukla, Prashant,Bhardiya, Smita R.,Singh, Manorama,Rai, Ankita,Rai, Vijai K.
-
-
- Potassium tert-Butoxide Prompted Highly Efficient Transamidation and Its Coordination Radical Mechanism
-
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
-
p. 4538 - 4545
(2019/07/18)
-
- KOtBu-Promoted Transition-Metal-Free Transamidation of Primary and Tertiary Amides with Amines
-
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
-
supporting information
p. 6690 - 6694
(2019/09/12)
-
- A carboxamide is the cyanogen source of aromatic nitrile to the preparation method of the (by machine translation)
-
The invention discloses a method for preparing aromatic nitrile, is under the action of the nickel catalyst, in order to carboxamide is the cyanogen source, and with various substituents haloarene coupled reactions, preparing aromatic nitrile. The reaction temperature is 100 - 160 °C, the reaction time is 6 - 24 hours. It overcomes the traditional aromatic nitrile of the synthesis method operation of complex steps, requires the use of a toxic, more expensive, functionalization of the cyanogen source as the reaction raw material and the like. Compared with the traditional method, this method is simple to use cheap, green non-toxic of the formamide is cyano sources; without the need of external dehydrating agent, formamide in the nickel catalyst of the catalytic dehydration at the same time, with a nickel catalyst in coordination with the halogenated aromatic hydrocyanation, more economic, high-efficiency, environmental protection; at the same time the method exhibits good substrate universality, to air, moisture, light are not sensitive, high yield, product separation and purification is simple, with wide application. (by machine translation)
- -
-
Paragraph 0015; 0016; 0017; 0018-0024; 0116; 0117-0119
(2019/05/08)
-
- Synthesis and antimicrobial activity of glycosylated 2-Aryl?5?amidinobenzimidazoles
-
A series of new glycosylated 2-aryl-5-amidinobenzimidazoles derived from four different carbohydrates (D-glucose, D-galactose, N-acetyl-D-glucosamine and lactose) were synthesized by the condensation of the appropriate 4-formyl-3-methoxyphenyl glycoside with 4-amidino- or 4-N-isopropylamidino-ortho-phenylenediamine hydrochloride. All the compounds were properly characterized by high resolution mass spectrometry, uni- and bidimensional1H and13C nuclear magnetic resonance and then were evaluated for their antibacterial and antifungal potential. Considering the antifungal potential of them, two derivatives were active against Candida parapsilosis at 96.4 μmol L-1 and another was active against this same strain at 83.5 μmol L-1. In addition, one benzamidine showed activity against Candida glabrata at 97 μmol L-1. Considering the antibacterial potential of these compounds, six of them showed better activity against three different stains: three of them with IC50 of 96.4, 97 and 83.5 μmol L-1 against Gram-positive Micrococcus luteus, the other two with IC50 96.5 and 96.4 μmol L-1 against Gram-positive Enterococcus faecalis and one against Gram-negative Escherichia coli at 90.5 μmol L-1. These findings suggest this structural pattern can be employed for design of more potent agents for discovery of new antimicrobial drug candidates.
- de Souza, Thiago B.,Oliver, Josidel C.,Gomes, Ana Paula B.,Arag?o, Cícero Flávio S.,Ferreira, Leandro S.,Nogueira, Fernando Henrique A.,Dias, Amanda Latércia T.,Alves, Ricardo J.
-
p. 1304 - 1317
(2018/05/07)
-
- Regioselective nitration of anilines with Fe(NO3)3·9H2O as a promoter and a nitro source
-
An efficient Fe(NO3)3·9H2O promoted ortho-nitration reaction of aniline derivatives has been developed. This reaction may go through a nitrogen dioxide radical (NO2) intermediate, which is generated by the thermal decomposition of iron(iii) nitrate. The practicality of the present method using nontoxic and inexpensive iron reagents has been shown by the broad substrate scope and applications.
- Gao, Yang,Mao, Yuanyou,Zhang, Biwei,Zhan, Yingying,Huo, Yanping
-
supporting information
p. 3881 - 3884
(2018/06/08)
-
- Catalytic Cyanation Using CO2 and NH3
-
Li and co-workers describe the catalytic cyanation of organic halides with CO2 and NH3. In the presence of Cu2O/DABCO as the catalyst, a variety of aromatic bromides and iodides were transformed to the desired nitrile products with broad functional-group tolerance. Both 13C- and/or 15N-labeled nitriles were obtained conveniently with appropriately isotope-labeled CO2 and NH3. Construction of functionalized chemical compounds from small molecules in a highly selective and efficient manner is crucial for sustainable development. The chemical-based manufacturing sector of the future should aim to produce chemicals from very simple and abundant resources, just as nature uses CO2 and N2 to generate sugars, amino acids, and so forth. In practice, however, the utilization of CO2 for the generation of industrial products, such as drugs and related intermediates, still remains a major challenge. Here, we describe the facile cyanide-free production of high-value nitriles with CO2 and NH3 as the sole sources of carbon and nitrogen, respectively. This practical and catalytic methodology provides a unique strategy for the utilization of small molecules for sustainable and cost-effective applications. Selective cyanation of aryl halides was achieved with CO2 and NH3 as the only sources of carbon and nitrogen, respectively. In the presence of Cu catalysts under low pressure (3 atm), a variety of aromatic iodides and bromides were transformed to the desired nitrile products without the use of toxic metal cyanides. Notably, olefins, esters, amides, alcohols, and amino groups were tolerated. Mechanistic studies suggest that Cu(III)-aryl insertion by isocyanate intermediates is involved. [13C,15N]-labeled nitriles were conveniently accessible from the respective isotope-labeled CO2 and NH3 via this methodology.
- Wang, Hua,Dong, Yanan,Zheng, Chaonan,Sandoval, Christian A.,Wang, Xue,Makha, Mohamed,Li, Yuehui
-
supporting information
p. 2883 - 2893
(2019/01/05)
-
- Cyaniding method for preparing nitrile compound
-
The invention provides a cyaniding method for preparing a nitrile compound. Organic halide or pseudohalide, CO2 and NH3 which are low in price and are easily obtained and a reducing agent react, a selective cyaniding reaction is conducted in the presence of a transition metal catalyst, and the target product namely organic the nitrile compound is obtained. According to the cyaniding method for preparing the nitrile compound, a new reaction route is used, through a CO2 and NH3 reaction of metal catalysis, dehalogenation cyaniding or quasi halide cyaniding of halide or pseudohalide is directly achieved through a one-pot method, the problem is solved that a traditional cyanation reaction needs equivalent toxic cyanide, a new direct and convenient method for preparing isotope-labeled nitrile compounds is provided at the same time, and the method can be applied to medicine, tracing, biology and medicine research and development.
- -
-
Paragraph 0095-0097
(2018/05/30)
-
- Palladium-Catalyzed Synthesis of Aryl Nitriles: Using α-Iminonitrile as Cyano Source for Aryl Halide Cyanations
-
An efficient and ligand-free palladium-catalyzed exchange reaction to synthesize aryl nitriles by using α-iminonitrile as a starting reagent has been developed. This methodology provides an optional method for the synthesis of aryl nitriles with moderate to good yields. At the same time, this approach is adaptable for many substrates.
- Shi, Yu-Long,Yuan, Qing,Chen, Zhen-Bang,Zhang, Fang-Ling,Liu, Kui,Zhu, Yong-Ming
-
supporting information
p. 359 - 363
(2017/11/15)
-
- Selective Oxidative Coupling Reaction of Isocyanides Using Peroxide as Switchable Alkylating and Alkoxylating Reagent
-
A switchable oxidative coupling reaction of isocyanide and peroxide has been disclosed. In the presence of iron catalyst, the coupling reaction affords N-arylacetamides in good yields. By simply replacing the iron with copper catalyst, another different coupling reaction takes place in which peroxide can serve as alkoxylating source. This protocol represents a new fundamental coupling of two basic chemicals involving C?C and C?O bond-forming process. The unusual reactivity of an isocyano group in a radical reaction acting formally as an amidoyl synthon has also been well established. The experiment outcome reveals that aromatic isocyanides are particularly compatible reaction partners in present coupling reaction, whereas no desired products are observed when aliphatic isocyanides are used. (Figure presented.).
- Zhang, Xinglu,Liu, Zhiqiang,Gao, Yu,Li, Feng,Tian, Yaming,Li, Chunju,Jia, Xueshun,Li, Jian
-
supporting information
p. 272 - 277
(2017/11/13)
-
- Practical CuCl/DABCO/4-HO-TEMPO-catalyzed oxidative synthesis of nitriles from alcohols with air as oxidant
-
A mild and efficient methodology for the direct oxidative synthesis of nitriles from easily available alcohols and aqueous ammonia by employing CuCl/DABCO/4-HO-TEMPO as the catalysts is described. This protocol uses the air as a green oxidant and aqueous ammonia as the nitrogen source at room temperature. A variety of aryl, heterocyclic and allylic alcohols are smoothly converted into the corresponding nitriles in good to excellent yields.
- Hu, Yongke,Chen, Lei,Li, Bindong
-
supporting information
p. 464 - 466
(2017/11/13)
-
- Direct and Catalytic Amide Synthesis from Ketones via Transoximation and Beckmann Rearrangement under Mild Conditions
-
The Br?nsted acid-catalyzed synthesis of secondary amides from ketones under mild conditions is described via transoximation and Beckmann rearrangement using O-protected oximes as more stable equivalents of explosive O-protected hydroxylamines. This methodology could be applied to highly rearrangement-selective amide synthesis from α-branched alkyl aryl ketones and performed on a 1-g scale. The presence of water is essential for this reaction, and its role was clarified by isotope-labeling experiments.
- Hyodo, Kengo,Hasegawa, Genna,Oishi, Naoki,Kuroda, Kazuma,Uchida, Kingo
-
p. 13080 - 13087
(2018/11/02)
-
- Nickel-Catalyzed Cyanation of Phenol Derivatives with Zn(CN)2 Involving C-O Bond Cleavage
-
An efficient nickel-catalyzed cyanation of aryl sulfonates, fluorosulfonates, and sulfamates with Zn(CN)2 was developed, which provides a facile access to the nitrile products in generally good to excellent yields. The reaction is accomplished by using NiII complex as the precatalyst and DMAP as the additive. The method also displays wide functional group compatibility; for example, keto, methoxy, N,N-dimethylamino, cyano, ester, and pyridyl groups are well-tolerated during the reaction process.
- Gan, Yi,Wang, Gaonan,Xie, Xin,Liu, Yuanhong
-
p. 14036 - 14048
(2018/11/03)
-
- Monoprotected l-Amino Acid (l-MPAA), Accelerated Bromination, Chlorination, and Iodination of C(sp2)?H Bonds by Iridium(III) Catalysis
-
Halogenated arenes are important structural motifs commonly found in biologically active molecules and used for a variety of transformations in organic synthesis. Herein, we report the mono-protected l-amino acid (l-MPAA) accelerated iridium(III)-catalyzed halogenation of (hetero)anilides at room temperature. This reaction constitutes the first example of an iridium(III)/l-MPAA-catalyzed general halogenation of (hetero)arenes through C(sp2)?H activation. Furthermore, we demonstrate the potential utility of our method through its use in the synthesis of a quinolone derivative.
- Kathiravan, Subban,Nicholls, Ian A.
-
supporting information
p. 7031 - 7036
(2017/05/29)
-
- Efficient Heterogeneous Gold(I)-Catalyzed Direct C(sp2)–C(sp) Bond Functionalization of Arylalkynes through a Nitrogenation Process to Amides
-
The first heterogeneous gold(I)-catalyzed direct C(sp2)–C(sp) bond functionalization of arylalkynes through a nitrogenation process to amides has been achieved by using an ordered mesoporous silica (MCM-41)-immobilized phosphine gold(I) complex [MCM-41-PPh3-AuCl] as catalyst and silver carbonate (Ag2CO3) as cocatalyst with trimethylsilyl azide (TMSN3) as a nitrogen source, yielding a variety of amides in moderate to excellent yields under mild conditions. This heterogeneous phosphine gold(I) complex shows the same turnover numbers as the homogeneous chloro(triphenylphosphine)gold(I) (Ph3PAuCl) and can easily be recovered by simple filtration of the reaction solution and recycled at least eight times without significant loss of activity, providing a novel, efficient, practical and economic method for the synthesis of amides from alkynes. (Figure presented.).
- Nie, Quan,Yi, Feiyan,Huang, Bin,Cai, Mingzhong
-
p. 3968 - 3976
(2017/11/20)
-
- Wavelength Selective Generation of Aryl Radicals and Aryl Cations for Metal-Free Photoarylations
-
Photochemical reactions have become an important tool for organic chemists. Visible (solar) light can be conveniently adopted, however, only when using colored organic compounds or in photocatalyzed processes induced by visible light absorbing photocatalysts. Herein we demonstrate that a photolabile, colored moiety could be incorporated in a colorless organic compound with the aim of generating highly reactive intermediates upon exposure to visible (solar) light. Arylazo sulfones, colored thermally stable derivatives of aryl diazonium salts, were used as valuable substrates for the photoinduced metal-free synthesis of (hetero)biaryls with no need of a (photo)catalyst or of other additives to promote the reaction. Noteworthy, selective generation of aryl radicals and aryl cations can be attained at will by varying the irradiation conditions (visible light for the former and UVA light for the latter).
- Crespi, Stefano,Protti, Stefano,Fagnoni, Maurizio
-
p. 9612 - 9619
(2016/11/02)
-
- Cyanation of Phenol Derivatives with Aminoacetonitriles by Nickel Catalysis
-
Generation of useful arylnitrile structures from simple aromatic feedstock chemicals represents a fundamentally important reaction in chemical synthesis. The first nickel-catalyzed cyanation of phenol derivatives with metal-free cyanating agents, aminoacetonitriles, is described. A nickel-based catalytic system consisting of a unique diphosphine ligand such as dcype or dcypt enables the cyanation of versatile phenol derivatives such as aryl carbamates and aryl pivalates. The use of aminoacetonitriles as a cyanating agent leads to an environmentally and easy-to-use method for arylnitrile synthesis.
- Takise, Ryosuke,Itami, Kenichiro,Yamaguchi, Junichiro
-
supporting information
p. 4428 - 4431
(2016/10/12)
-
- Photo-Fries rearrangement of aryl acetamides: Regioselectivity induced by the aqueous micellar green environment
-
Photochemical reactions tend to give more than one photoproduct. However, such a reaction can be a powerful synthetic tool when it is possible to conduct it in regioselective conditions yielding a single photoproduct. Water-surfactant solutions as reaction media can be considered as an approach in this context because they show products with different features than those from isotropic solutions. Here we describe results obtained from studying the effect on the prototypical photoreaction, known as the photo-Fries reaction of several substituted acetanilides and α-naphthyl acetamide within surfactant micelles (ionic and non-ionic micelles). This reaction involves homolytic cleavage of a C-N bond to yield a singlet radical pair. The surfactant micelles control the rotational and translational mobility of the radical pair, resulting in noticeable photoproduct selectivity.
- Iguchi, Daniela,Erra-Balsells, Rosa,Bonesi, Sergio M.
-
p. 105 - 116
(2016/01/20)
-
- Fragmentation of Protonated N-(3-Aminophenyl)Benzamide and Its Derivatives in Gas Phase
-
An ion of m/z 110.06036 (ion formula [C6H8NO]+; error: 0.32 mDa) was observed in the collision induced dissociation tandem mass spectrometry experiments of protonated N-(3-aminophenyl)benzamide, which is a rearrangement product ion purportedly through nitrogen-oxygen (N–O) exchange. The N–O exchange rearrangement was confirmed by the MS/MS spectrum of protonated N-(3-aminophenyl)-O18-benzamide, where the rearranged ion, [C6H8NO18]+ of m/z 112 was available because of the presence of O18. Theoretical calculations using Density Functional Theory (DFT) at B3LYP/6-31?g(d) level suggest that an ion-neutral complex containing a water molecule and a nitrilium ion was formed via a transition state (TS-1), followed by the water molecule migrating to the anilide ring, eventually leading to the formation of the rearranged ion of m/z 110. The rearrangement can be generalized to other protonated amide compounds with electron-donating groups at the meta position, such as, –OH, –CH3, –OCH3, –NH(CH3)2, –NH-Ph, and –NHCOCH3, all of which show the corresponding rearranged ions in MS/MS spectra. However, the protonated amide compounds containing electron-withdrawing groups, including –Cl, –Br, –CN, –NO2, and –CF3, at the meta position did not display this type of rearrangement during dissociation. Additionally, effects of various acyl groups on the rearrangement were investigated. It was found that the rearrangement can be enhanced by substitution on the ring of the benzoyl with electron-withdrawing groups. [Figure not available: see fulltext.]
- Zu, Chengli,Mukhopadhyay, Sukrit,Hanley, Patrick S.,Xia, Shijing,Bell, Bruce M.,Grigg, David,Gilbert, Jeffrey R.,O’Brien, John P.
-
p. 917 - 926
(2016/05/02)
-
- Potassium Thioacids Mediated Selective Amide and Peptide Constructions Enabled by Visible Light Photoredox Catalysis
-
A remarkable visible-light-promoted photoredox catalytic methodology involved with amines and eco-friendly potassium thioacids for amide formation was uncovered. This approach can mimic the natural coenzyme acetyl-CoA to selectively acylate amines without affecting other functional groups such as alcohols, phenols, esters, among others. The developed strategy may hold great potential for a comprehensive display of biologically interesting peptide synthesis and amino acid modification through a diacyl disulfide intermediate.
- Liu, Hongxin,Zhao, Liyun,Yuan, Yunfei,Xu, Zhifang,Chen, Kai,Qiu, Shengxiang,Tan, Haibo
-
p. 1732 - 1736
(2016/03/15)
-
- New tetrazolic azo dyes linked to (thio)barbiturate and electron-rich aromatics as potential antimicrobial agents
-
A series of new tetrazolic azo dyes based on (thio)barbiturate and electron-rich aromatics were synthesized in excellent yield. The electron-donor and tetrazole ring moieties were linked by a p-phenylazo bridge and the structural characterizations were achieved by FT IR, 1H and 13C NMR, and UV-visible spectrometry. The antibacterial activity of the synthesized compounds was tested against gram-positive and gram-negative bacterial strains, namely Acinetobacter calcoaceticus (ATCC23055), Escherichia coli (ATCC2592), Pseudomonas aeruginosa (ATCC27853), and Staphylococcus aureus (ATCC25923). As a result, potential antimicrobial effects were seen for some of the synthesized compounds.
- Pesyan, Nader Noroozi,Soleimani, Davoud,Jazani, Nima Hosseini
-
p. 998 - 1011
(2015/10/29)
-
- Photocatalytic synthesis of anilides from nitrobenzenes under visible light irradiation: 2 in 1 reaction
-
An efficient method has been developed for the synthesis of a series of anilides via a two in one reaction of nitrobenzenes with anhydride in the presence of TiO2 as a nanocatalyst and photocatalyst under sunlight or blue LED irradiation. In this method simultaneously, nitrobenzenes convert to the corresponding anilines via photocatalytic reduction on the TiO2 surface, and a condensation of aniline with the anhydride performed on the Lewis acid site of the TiO2 surface. Interestingly amidation step leads to the promotion of better reaction and good selectivity in reduction of nitrocompounds. This method is simple, rapid, high yield, and green.
- Zand, Zahra,Kazemi, Foad,Partovi, Adel
-
-