- On the Nature of C(sp3)-C(sp2) Bond Formation in Nickel-Catalyzed Tertiary Radical Cross-Couplings: A Case Study of Ni/Photoredox Catalytic Cross-Coupling of Alkyl Radicals and Aryl Halides
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The merger of photoredox and nickel catalysis has enabled the construction of quaternary centers. However, the mechanism, role of the ligand, and effect of the spin state for this transformation and related Ni-catalyzed cross-couplings involving tertiary alkyl radicals in combination with bipyridine and diketonate ligands remain unknown. Several mechanisms have been proposed, all invoking a key Ni(III) species prior to undergoing irreversible inner-sphere reductive elimination. In this work, we have used open-shell dispersion-corrected DFT calculations, quasi-classical dynamics calculations, and experiments to study in detail the mechanism of carbon-carbon bond formation in Ni bipyridine- A nd diketonate-based catalytic systems. These calculations revealed that access to high spin states (e.g., triplet spin state tetrahedral Ni(II) species) is critical for effective radical cross-coupling of tertiary alkyl radicals. Further, these calculations revealed a disparate mechanism for the C-C bond formation. Specifically, contrary to the neutral Ni-bipyridyl system, diketonate ligands lead directly to the corresponding tertiary radical cross-coupling products via an outer-sphere reductive elimination step via triplet spin state from the Ni(III) intermediates. Implications to related Ni-catalyzed radical cross-couplings and the design of new transformations are discussed.
- Badir, Shorouk O.,Gutierrez, Osvaldo,Molander, Gary A.,Song, Zhihui,Yuan, Mingbin
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- A Facile Displacement of Tertiary Nitro Group by Hydrogen with Sodium Hydrogentelluride
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Sodium hydrogentelluride is a useful reagent for replacement of a class of tertiary nitro group by hydrogen.
- Suzuki, Hitomi,Takaoka, Koji,Osuka, Atsuhiro
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Read Online
- Highly Efficient Oxidative Cyanation of Aldehydes to Nitriles over Se,S,N-tri-Doped Hierarchically Porous Carbon Nanosheets
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Oxidative cyanation of aldehydes provides a promising strategy for the cyanide-free synthesis of organic nitriles. Design of robust and cost-effective catalysts is the key for this route. Herein, we designed a series of Se,S,N-tri-doped carbon nanosheets with a hierarchical porous structure (denoted as Se,S,N-CNs-x, x represents the pyrolysis temperature). It was found that the obtained Se,S,N-CNs-1000 was very selective and efficient for oxidative cyanation of various aldehydes including those containing other oxidizable groups into the corresponding nitriles using ammonia as the nitrogen resource below 100 °C. Detailed investigations revealed that the excellent performance of Se,S,N-CNs-1000 originated mainly from the graphitic-N species with lower electron density and synergistic effect between the Se, S, N, and C in the catalyst. Besides, the hierarchically porous structure could also promote the reaction. Notably, the unique feature of this metal-free catalyst is that it tolerated other oxidizable groups, and showed no activity on further reaction of the products, thereby resulting in high selectivity. As far as we know, this is the first work for the synthesis of nitriles via oxidative cyanation of aldehydes over heterogeneous metal-free catalysts.
- Hua, Manli,Song, Jinliang,Huang, Xin,Liu, Huizhen,Fan, Honglei,Wang, Weitao,He, Zhenhong,Liu, Zhaotie,Han, Buxing
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supporting information
p. 21479 - 21485
(2021/08/23)
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- A Molecular Iron-Based System for Divergent Bond Activation: Controlling the Reactivity of Aldehydes
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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
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p. 7176 - 7185
(2021/06/30)
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- One pot synthesis of aryl nitriles from aromatic aldehydes in a water environment
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In this study, we found a green method to obtain aryl nitriles from aromatic aldehyde in water. This simple process was modified from a conventional method. Compared with those approaches, we used water as the solvent instead of harmful chemical reagents. In this one-pot conversion, we got twenty-five aryl nitriles conveniently with pollution to the environment being minimized. Furthermore, we confirmed the reaction mechanism by capturing the intermediates, aldoximes.
- Chen, Qingqing,Han, Hongwei,Lin, Hongyan,Ma, Xiaopeng,Qi, Jinliang,Wang, Xiaoming,Yang, Yonghua,Zhou, Ziling
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p. 24232 - 24237
(2021/07/29)
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- Enabling Metallophotoredox Catalysis in Parallel Solution-Phase Synthesis Using Disintegrating Reagent Tablets
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Compressed tablets containing a mixture of a photocatalyst, a nickel catalyst, an inorganic base, and an inert excipient are employed as a fast, safe, and user-friendly chemical delivery system for two different metallophotoredox-catalyzed reactions. This delivery method simplifies the preparation of compound libraries using photoredox chemistry in a parallel setting. The reagent tablets were successfully applied to late-stage functionalization of drug-like intermediates. These tablets can be prepared with various reagents and catalysts in different sizes and be stored on the bench thanks to blister packaging.
- Borlinghaus, Niginia,Sch?nfeld, Barbara,Heitz, Stephanie,Klee, Johanna,Vukeli?, Stella,Braje, Wilfried M.,Jolit, Anais
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p. 16535 - 16547
(2021/12/02)
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- Selective oxidation of alcohols to nitriles with high-efficient Co-[Bmim]Br/C catalyst system
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An efficient method for catalyzing the ammoxidation of aromatic alcohols to aromatic nitriles was developed, in which a new heterogeneous catalyst based on transition metal elements was employed, the new catalyst was named Co-[Bmim]Br/C-700 and then characterized by X-ray photo-electronic spectroscopy, transmission electron microscope and X-ray diffraction. The reaction was carried out by two consecutive dehydrogenations under the catalysis of Co-[Bmim]Br/C-700, which catalytically oxidized the alcohol to the aldehyde, and then the aldehyde was subjected to ammoxidation to the nitrile. The catalyst system was suitable for a wide range of substrates and nitriles obtained in high yields, especially, the conversion rate of benzyl alcohol, 4-methoxybenzyl alcohol, 4-chlorobenzyl alcohol and 4-nitrobenzyl alcohol reached 100%. The substitution of ammonia and oxygen for toxic cyanide to participate in the reaction accords with the theory of green chemistry.
- Xia, Yu-Yan,Lv, Qing-Yang,Yuan, Hua,Wang, Jia-Yi
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p. 3957 - 3964
(2021/04/09)
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- HCl·DMPU-assisted one-pot and metal-free conversion of aldehydes to nitriles
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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
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supporting information
p. 4161 - 4164
(2020/07/14)
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- Dehydrogenation of Primary Alkyl Azides to Nitriles Catalyzed by Pincer Iridium/Ruthenium Complexes
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Pincer metal complexes exhibit superior catalytic activity in the dehydrogenation of plain alkanes, but find limited application in the dehydrogenation of functionalized organic molecules. Starting from easily accessible primary alkyl azides, here we report an efficient dehydrogenation of azides to nitriles using pincer iridium or ruthenium complexes as the catalysts. This method offers a route to cyanide-free preparation of nitriles without carbon chain elongation and without the use of strong oxidants. Both benzyl and linear aliphatic azides can be dehydrogenated with tert-butylethylene as the hydrogen acceptor to afford nitriles in moderate to high yields. Various functional groups can be tolerated, and the H?C?C?H bond dehydrogenation does not occur for linear alkyl azide substrates. Furthermore, the pincer Ir catalytic system was found to catalyze the direct azide dehydrogenation without the use of a sacrificial hydrogen acceptor.
- Gan, Lan,Jia, Xiangqing,Fang, Huaquan,Liu, Guixia,Huang, Zheng
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p. 3661 - 3665
(2020/06/02)
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- Vilsmeier-Haack reagent mediated synthetic transformations with an immobilized iridium complex photoredox catalyst
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An immobilized iridium complex photocatalyst Ir(ppy)2(PDVB-py) was synthesized by immobilization of the iridium complex onto the nanoporous vinylpyridine-divinylbenzene copolymer (PDVB-py). Its application for the synthesis of amides, nitriles, and anhydrides was reported via reactions under the action of the visible-light-driven in situ generated Vilsmeier-Haack reagent from CBr4 in DMF. The results showed that this heterogeneous photocatalyst has extremely high activity and excellent stability to be recycled five times.
- Zhi, Peng,Xi, Zi-Wei,Wang, Dan-Yan,Wang, Wei,Liang, Xue-Zheng,Tao, Fei-Fei,Shen, Run-Pu,Shen, Yong-Miao
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p. 709 - 717
(2019/01/10)
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- Dual Ligand-Enabled Nondirected C-H Cyanation of Arenes
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Aromatic nitriles are key structural units in organic chemistry and, therefore, highly attractive targets for C-H activation. Herein, the development of an arene-limited, nondirected C-H cyanation based on the use of two cooperatively acting commercially available ligands is reported. The reaction enables the cyanation of arenes by C-H activation in the absence of directing groups and is therefore complementary to established approaches.
- Chen, Hao,Mondal, Arup,Wedi, Philipp,Van Gemmeren, Manuel
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p. 1979 - 1984
(2019/02/19)
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- Ligand-Promoted Non-Directed C?H Cyanation of Arenes
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This article reports the first example of a 2-pyridone accelerated non-directed C?H cyanation with an arene as the limiting reagent. This protocol is compatible with a broad scope of arenes, including advanced intermediates, drug molecules, and natural products. A kinetic isotope experiment (kH/kD=4.40) indicates that the C?H bond cleavage is the rate-limiting step. Also, the reaction is readily scalable, further showcasing the synthetic utility of this method.
- Liu, Luo-Yan,Yeung, Kap-Sun,Yu, Jin-Quan
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supporting information
p. 2199 - 2202
(2019/01/24)
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- Oxidant free conversion of alcohols to nitriles over Ni-based catalysts
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Organic nitriles are significant and versatile industrial feedstocks, but their conventional synthetic protocols require hazardous starting materials and/or harsh reaction conditions posing environmental and health risks. Herein, we established a Ni-based catalytic system to convert primary alcohols to nitriles with ammonia gas as the sole nitrogen source under oxidant-free conditions at merely 190-230 °C. Based on isotope labelling experiments, in situ DRIFTS and control experiments, the reaction pathway was identified to follow a dehydrogenation-imination-dehydrogenation sequence, with α-carbon C-H bond breakage as the rate determining step. Ni is superior to all noble metal catalysts tested, due to its excellent dehydrogenation ability that is not inhibited by NH3. The support plays an auxiliary role, promoting the reaction between aldehyde and ammonia to form imine as a critical intermediate. Ni/Al2O3 catalyst prepared via a deposition-precipitation method, featuring both excellent dispersion of metallic Ni and suitable acid sites, enabled alcohol transformation into nitrile under unprecedented low temperature. Various alcohols were converted into their corresponding nitriles in high conversions and yields (both up to 99%), while the catalyst kept 90% of its original activity after 48 hours in the stability test, highlighting the wide applicability and the robustness of the catalytic system.
- Wang, Yunzhu,Furukawa, Shinya,Zhang, Zhang,Torrente-Murciano, Laura,Khan, Saif A.,Yan, Ning
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- Identification of an Active NiCu Catalyst for Nitrile Synthesis from Alcohol
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Development of heterogeneous catalysts for alcohol transformation into nitriles under oxidant-free conditions is a challenge. Considering the C-H activation on α-carbon of primary alcohols is the rate-determining step, decreasing the activation energy of C-H activation is critical in order to enhance the catalytic activity. Several NiM/Al2O3 bimetallic catalysts were synthesized and scrutinized in catalytic transformation of 1-butanol to butyronitrile. Ni-Cu was identified as a suitable combination with the optimized Ni0.5Cu0.5/Al2O3 catalyst exhibiting 10 times higher turnover frequency than Ni/Al2O3 catalyst. X-ray absorption spectroscopy (XAS) and high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) revealed that the NiCu particles in the catalyst exist in the form of homogeneous alloys with an average size of 8.3 nm, providing an experimental foundation to build up a catalyst model for further density functional theory (DFT) calculations. Calculations were done over a series of NiM catalysts, and the experimentally observed activity trend could be rationalized by the Br?nsted-Evans-Polanyi (BEP) principle, i.e., catalysts that afford reduced reaction energy also feature lower activation barriers. The calculated activation energy (Ea) for C-H activation with coadsorbed NH3 dropped from 63.4 kJ/mol on pure Ni catalyst to 49.9 kJ/mol on the most active NiCu-2 site in NiCu bimetallic catalyst, in good agreement with the experimentally measured activation energy values. The Ni0.5Cu0.5/Al2O3 catalyst was further employed to convert 11 primary alcohols into nitriles with high to near-quantitative yields, at a Ni loading 10 times less than that of the conventional Ni/Al2O3 catalyst.
- Wang, Yunzhu,Furukawa, Shinya,Yan, Ning
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p. 6681 - 6691
(2019/07/12)
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- Enhanced catalytic activity of cobalt nanoparticles encapsulated with an N-doped porous carbon shell derived from hollow ZIF-8 for efficient synthesis of nitriles from primary alcohols in water
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A cobalt catalyst derived from a unique core-shell structure based on hollow ZIF-8 and ZIF-67 (ZIF-67@ZIF-8) is prepared, which exhibits excellent catalytic efficiency for the synthesis of nitriles from alcohols in water under mild conditions (1 atm O2, 50 °C) owing to its large BET surface area, high pore volume, high basicity and hydrophilicity.
- Sun, Kang-Kang,Sun, Jia-Lin,Lu, Guo-Ping,Cai, Chun
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supporting information
p. 4334 - 4340
(2019/08/21)
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- An effective preparation of both 1,3-diketones and nitriles from alkynones with oximes as hydroxide sources
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An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
- Chen, Pei,Zhang, Qian-Qian,Guo, Jia,Chen, Lu-Lu,Wang, Yan-Bo,Zhang, Xiao
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p. 6958 - 6966
(2018/10/02)
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- Radical-Based C?C Bond-Forming Processes Enabled by the Photoexcitation of 4-Alkyl-1,4-dihydropyridines
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We report herein that 4-alkyl-1,4-dihydropyridines (alkyl-DHPs) can directly reach an electronically excited state upon light absorption and trigger the generation of C(sp3)-centered radicals without the need for an external photocatalyst. Selective excitation with a violet-light-emitting diode turns alkyl-DHPs into strong reducing agents that can activate reagents through single-electron transfer manifolds while undergoing homolytic cleavage to generate radicals. We used this photochemical dual-reactivity profile to trigger radical-based carbon–carbon bond-forming processes, including nickel-catalyzed cross-coupling reactions.
- Buzzetti, Luca,Prieto, Alexis,Roy, Sudipta Raha,Melchiorre, Paolo
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supporting information
p. 15039 - 15043
(2017/11/20)
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- Iron-Catalyzed Isopropylation of Electron-Deficient Aryl and Heteroaryl Chlorides
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Traditional methods for the preparation of secondary alkyl-substituted aryl and heteroaryl chlorides challenge both selectivity and functional group tolerance. This contribution describes the use of statistical design of experiments to develop an effective procedure for the preparation of isopropyl-substituted (hetero)arenes with minimal isopropyl to n-propyl isomerization. The reaction tolerates electronically diverse aryl chloride coupling partners, with excellent conversion observed for strongly electron-deficient aromatic rings, such as esters and amides. Electron-rich systems, including methyl- and methoxy-substituted aryl chlorides, were found to be less reactive. Furthermore, the reaction was found to be most successful when heteroaryl chlorides were submitted to the cross-coupling protocol. By mapping substituent effects on reaction selectivity, we were able to show that electron-deficient aryl chlorides are essential for efficient coupling, and use electronic structure calculations to predict the likelihood of successful coupling through the estimation of the electron affinity of each aryl chloride. Moderate isolated yields were achieved with selected aryl chlorides, and moderate to good isolated yields were obtained for all the heteroaryl chlorides coupled. Excellent selectivity was observed when a 2,6-dichloroquinoline was used, allowing mono-substitution on a challenging substrate. (Figure presented.).
- Sanderson, James N.,Dominey, Andrew P.,Percy, Jonathan M.
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p. 1007 - 1017
(2017/03/27)
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- An efficient synthesis of nitrile, tetrazole and urea from carbonyl compounds
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An efficient conversion of carbonyl compounds (aldehydes and ketones) to nitrile, tetrazole, and urea was developed with the use of a POCl3 and sodium azide mixture using a convergent and microwave method. This is the first report on the direct conversion of ketone to urea. The synthesized compounds were characterized by 1H NMR, 13C NMR, mass and IR spectroscopies and were found to be in agreement with reported compounds.
- Sribalan, Rajendran,Sangili, Arumugam,Banuppriya, Govindharasu,Padmini, Vediappen
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p. 3414 - 3421
(2017/07/13)
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- Direct synthesis of nitriles from aldehydes and hydroxylamine hydrochloride catalyzed by a HAP@AEPH2-SO3H Nanocatalyst
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We describe an efficient method for the direct preparation of nitriles from aldehydes and hydroxylamine hydrochloride catalyzed by sulfonated nanohydroxyapatite functionalized by 2-aminoethyl dihydrogen phosphate (HAP@AEPH2-SO3H) as an eco-friendly and recyclable solid acid nanocatalyst. In this protocol the use of a solid acid nanocatalyst provides a green, useful, and rapid method for the preparation of nitriles in excellent yields. In addition, the notable feature of this methodolgy is that the synthesized nanocatalyst can be recovered and reused five times without any noticeable loss of efficiency.
- Masjed, Samane Memar,Akhlaghinia, Batool,Zarghani, Monireh,Razavi, Nasrin
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- Manganese-Catalyzed Cross-Coupling of Aryl Halides and Grignard Reagents by a Radical Mechanism
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The substrate scope and the mechanism have been investigated for the MnCl2-catalyzed cross-coupling reaction between aryl halides and Grignard reagents. The transformation proceeds rapidly and in good yield when the aryl halide component is an aryl chloride containing a cyano or an ester group in the para position or a cyano group in the ortho position. A range of other substituents gave no conversion of the aryl halide or led to the formation of side products. A broader scope was observed for the Grignard reagents, where a variety of alkyl- and arylmagnesium chlorides participated in the coupling. Two radical-clock experiments were carried out, and in both cases an intermediate aryl radical was successfully trapped. The cross-coupling reaction is therefore believed to proceed by an SRN1 mechanism, with a triorganomanganate complex serving as the most likely nucleophile and single-electron donor. Other mechanistic scenarios were excluded based on the substrate scope of the aryl halide.
- Antonacci, Giuseppe,Ahlburg, Andreas,Fristrup, Peter,Norrby, Per-Ola,Madsen, Robert
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p. 4758 - 4764
(2017/09/07)
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- A method for synthesizing fragrant nitrile (by machine translation)
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The invention relates to a method for synthesizing fragrant nitrile. The method is to 2 - cyano - 3 - ethoxy ethyl acrylate is cyanogen source, phenyl boronic acid compound or the relevent aniline compound as a raw material, in order to copper salt as promoter, in order to peroxide as the oxidizing agent, to the organic solvent as a solvent, in air or oxygen atmosphere, raising the temperature to 80 - 150 °C stirring reaction for 12 - 48 hours, after the reaction cooled to room temperature, filtered, concentrated to get the crude product is distilled under reduced pressure, by column chromatography purification to obtain series of said aromatic nitrile compounds. The invention aromatic nitriles synthetic method of the compound safe and simple operation, material is easy to obtain, low cost, good adaptability to the functional group, to the substrate and wide adaptability, environment friendly, favorable to industrial production, in the medical, organic synthesis in wide application. (by machine translation)
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Paragraph 0068; 0069
(2017/08/25)
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- Pd Catalysis in Cyanide-Free Synthesis of Nitriles from Haloarenes via Isoxazolines
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A method to obtain aryl nitriles from the corresponding halides by Pd catalysis, in the absence of any cyanide source, is reported. The reaction of an aryl halide, ethyl nitroacetate, and an olefin readily delivers an aromatic nitrile. A variety of aryl iodides/bromides have been converted into the corresponding cyanoarenes in fair to excellent yields. The reaction likely involves the following steps: (a) Pd-catalyzed α-arylation of ethyl nitroacetate; (b) nitrile oxide formation; (c) [3 + 2]-cycloaddition with an olefin to provide an isoxazoline; (d) isoxazoline cleavage to benzonitrile formation.
- Maestri, Giovanni,Ca?eque, Tatiana,Della Ca, Nicola,Derat, Etienne,Catellani, Marta,Chiusoli, Gian Paolo,Malacria, Max
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supporting information
p. 6108 - 6111
(2016/12/09)
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- Copper Iodide Mediated Cyanation of Arylboronic Acids and Aryl Iodides with Ethyl (Ethoxymethylene)cyanoacetate as Cyanating Agent
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An efficient copper iodide mediated cyanation of arylboronic acids and aryl iodides with ethyl (ethoxymethylene)cyanoacetate as cyanating agent has been developed. The reaction involves a C(sp2)-CN bond cleavage and tolerates a wide range of functional groups, affording the corresponding aryl nitriles in moderate to excellent yields.
- Qi, Chaorong,Hu, Xiaohan,He, Haitao
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supporting information
p. 1979 - 1982
(2016/08/09)
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- Visible-Light-Mediated Aromatic Substitution Reactions of Cyanoarenes with 4-Alkyl-1,4-dihydropyridines through Double Carbon-Carbon Bond Cleavage
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Novel aromatic substitution reactions of cyanoarenes with 4-alkyl-1,4-dihydropyridines as alkylating reagents in the presence of a catalytic amount of a photoredox catalyst proceed smoothly to give the corresponding alkyl-substituted arenes in good to high yields. The present reaction system realizes a novel C-C bond-forming reaction between two fragments generated from the C-C bond-cleavage reactions of two independent substrates.
- Nakajima, Kazunari,Nojima, Sunao,Sakata, Ken,Nishibayashi, Yoshiaki
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p. 1028 - 1032
(2016/04/05)
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- Synthesis of aryl dihydrothiazol acyl shikonin ester derivatives as anticancer agents through microtubule stabilization
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The high incidence of cancer and the side effects of traditional anticancer drugs motivate the search for new and more effective anticancer drugs. In this study, we synthesized 17 kinds of aryl dihydrothiazol acyl shikonin ester derivatives and evaluated their anticancer activity through MTT assay. Among them, C13 showed better antiproliferation activity with IC50 = 3.14 ± 0.21 μM against HeLa cells than shikonin (IC50 = 5.75 ± 0.47 μM). We then performed PI staining assay, cell cycle distribution, and cell apoptosis analysis for C13 and found that it can cause cell arrest in G2/M phase, which leads to cell apoptosis. This derivative can also reduce the adhesive ability of HeLa cells. Docking simulation and confocal microscopy assay results further indicated that C13 could bind well to the tubulin at paclitaxel binding site, leading to tubulin polymerization and mitotic disruption.
- Lin, Hong-Yan,Li, Zi-Kang,Bai, Li-Fei,Baloch, Shahla Karim,Wang, Fang,Qiu, Han-Yue,Wang, Xue,Qi, Jin-Liang,Yang, Raong-Wu,Wang, Xiao-Ming,Yang, Yong-Hua
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- Practical Synthesis of N -(Diphenylmethyl)- and N -(1-Adamantyl)amides Directly from Aldehydes via a One-Pot Schmidt and Ritter Reaction Sequence
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Nonoxidative and noncoupling reaction conditions have been developed for the synthesis of N-(diphenylmethyl)- and N-(1-adamantyl)amide derivatives directly from aldehydes by employing the concept of a Schmidt and Ritter reaction sequence in a one-pot operation. The reagent mixture consisting of sodium azide and HBF4·OEt2 in acetic acid converts the aldehydes into their respective nitrile analogues which in situ undergo the Ritter reaction with diphenylmethanol or 1-adamantanol to afford the corresponding N-(diphenylmethyl)- or N-(1-adamantyl)amide derivatives in very good yields. The method does not require column chromatographic purification for isolation of the products. With its simple reaction procedure and easy product purification technique, this method outshines earlier conventional two-step methods.
- Hazarika, Nabajyoti,Baishya, Gakul,Phukan, Prodeep
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p. 2851 - 2859
(2015/09/15)
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- "Nanorust"-catalyzed benign oxidation of amines for selective synthesis of nitriles
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Organic nitriles constitute key precursors and central intermediates in organic synthesis. In addition, nitriles represent a versatile motif found in numerous medicinally and biologically important compounds. Generally, these nitriles are synthesized by traditional cyanation procedures using toxic cyanides. Herein, we report the selective and environmentally benign oxidative conversion of primary amines for the synthesis of structurally diverse aromatic, aliphatic and heterocyclic nitriles using a reusable "nanorust" (nanoscale Fe2O3)-based catalysts applying molecular oxygen.
- Jagadeesh, Rajenahally V.,Junge, Henrik,Beller, Matthias
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- Copper immobilized on aminated ferrite nanoparticles by 2-aminoethyl dihydrogen phosphate (Fe3O4@AEPH2-CuII) catalyses the conversion of aldoximes to nitriles
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CuII immobilized on aminated ferrite nanoparticles by 2-aminoethyl dihydrogen phosphate (Fe3O4@AEPH2-CuII) was prepared and characterized using FT-IR, TGA, TEM, EDX, VSM, XRD, CHN and ICP techniques. The easily prepared heterogeneous nanocatalyst demonstrated a significant catalytic performance for the transformation of aldoximes to nitriles that is far superior to previously reported methods. The reaction allows for the conversion of a wide variety of aldoximes including aromatic, aliphatic and heterocyclic aldoximes in good to excellent yields (50-98%). High efficiency, mild reaction conditions, easy work-up, operational simplicity, simple purification of products and safe handling of the catalyst are important advantages of this method. In addition, the environmentally benign heterogeneous nanocatalyst can be easily recovered from reaction mixtures using an external magnet and reused several times without any loss of activity.
- Zarghani, Monireh,Akhlaghinia, Batool
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p. 683 - 689
(2015/09/28)
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- Acetonitrile as a cyanating reagent: Cu-catalyzed cyanation of arenes
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A novel approach to the Cu-catalyzed cyanation of simple arenes using acetonitrile as an attractive cyano source has been documented. The C-H functionalization of arenes without directing groups involves a sequential iodination/cyanation to give the desired aromatic nitriles in good yields. A highly efficient Cu/TEMPO system for acetonitrile C-CN bond cleavage has been discovered. TEMPO is used as a cheap oxidant and enables the reaction to be catalytic in copper. Moreover, TEMPOCH2CN 6 has been identified as the active cyanating agent and shows high reactivity for forming the -CN moiety.
- Zhu, Yamin,Zhao, Mengdi,Lu, Wenkui,Li, Linyi,Shen, Zengming
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supporting information
p. 2602 - 2605
(2015/06/16)
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- Self-catalyzed direct amidation of ketones: A sustainable procedure for acetaminophen synthesis
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High yielding amination of ketones and benzaldehyde in acid-less conditions has been conducted on several ketones to achieve amides and nitriles. The reactivity of the selected substrates showed to depend on both oximation and Beckmann rearrangement reaction rates. Oximation allows the in-situ production of hydrochloric acid that enables Beckmann rearrangement of the oxime to form the corresponding amide or nitrile. It is noteworthy that, using this one-pot synthetic approach, N-acetyl-4-aminophenol (acetaminophen drug), can be easily synthesized starting from 4-hydroxy-acetophenone in high yield. Acetanilide and ε-caprolactam can be also efficiently synthesized employing this synthetic procedure.
- Rancan, Elia,Aricò, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- Self-catalyzed direct amidation of ketones: A sustainable procedure for acetaminophen synthesis
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High yielding amination of ketones and benzaldehyde in acid-less conditions has been conducted on several ketones to achieve amides and nitriles. The reactivity of the selected substrates showed to depend on both oximation and Beckmann rearrangement reaction rates. Oximation allows the in-situ production of hydrochloric acid that enables Beckmann rearrangement of the oxime to form the corresponding amide or nitrile. It is noteworthy that, using this one-pot synthetic approach, N-acetyl-4-aminophenol (acetaminophen drug), can be easily synthesized starting from 4-hydroxy-acetophenone in high yield. Acetanilide and ε-caprolactam can be also efficiently synthesized employing this synthetic procedure.
- Rancan, Elia,Aricò, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- One-pot oximation-Beckmann rearrangement of ketones and aldehydes to amides of industrial interest: Acetanilide, caprolactam and acetaminophen
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High yielding one-pot oximation-Beckmann rearrangement of ketones to amides in ktrifluoroacetic acid has been conducted on several ketones and aldehydes. The substrate reactivity showed to depend on both oximation and Beckmann rearrangement reaction rate. In this synthetic procedure, trifluoroacetic acid acts as solvent, acid catalyst and organocatalyst and can be easily recycled.
- Aricò, Fabio,Quartarone, Giuseppe,Rancan, Elia,Ronchin, Lucio,Tundo, Pietro,Vavasori, Andrea
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- Mild negishi cross-coupling reactions catalyzed by acenaphthoimidazolylidene palladium complexes at low catalyst loadings
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Considering that the strong σ-donor property of ylidenes derived from π-extended imidazolium salts is conducive to increasing the catalytic activity of the resulting palladium N-heterocyclic carbene complexes, robust acenaphthoimidazol-ylidene palladium complexes 3a-c with varying bulky substituted groups were prepared from the corresponding acenaphthoimidazolium chlorides by heating with PdCl2 and K2CO3 in neat 3-chloropyridine in satisfactory yields. Even at a catalyst loading as low as 0.25 mol %, complex 3a exhibited extremely high catalytic activity toward Negishi cross-coupling of alkylzinc reagents with a wide range of (hetero)aryl halides under mild reaction conditions within 30 min. Besides a great number of bromoarenes, various less expensive and inactive (hetero)aryl chlorides were coupled successfully with the alkyl- and arylzinc reagents, in which active functional groups (such as -NH2) were well tolerated even in one-pot dicoupling transformations without protection. In addition, in the case of coupling with secondary alkylzinc reagents, undesired β-hydride elimination leading to isomerized linear products was efficaciously suppressed. The catalyst system also displayed superiority in the construction of heterobiaryls through the coupling of heteroarylzinc reagents and heterocylic chloroarenes which were hardly accessible from the corresponding organoboron reagents by Suzuki-coupling reactions. Therefore, the protocol described in this paper represents a mild, general, and scalable approach to access various structurally intriguing and functionalized (hetero)aryls.
- Liu, Zelong,Dong, Ningning,Xu, Mizhi,Sun, Zheming,Tu, Tao
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p. 7436 - 7444
(2013/09/02)
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- Copper-catalyzed synthesis of nitriles by aerobic oxidative reaction of alcohols and ammonium formate
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An efficient methodology has been developed for the synthesis of nitriles through an aerobic oxidative reaction of alcohols and ammonium formate with copper as a homogeneous catalyst under a normal air atmosphere and solvent-free conditions. This protocol uses the air as a green oxidant and ammonium formate as the nitrogen source. A wide range of substrates were well tolerated in the reaction that gave water as a byproduct. A facile protocol, which uses copper as an effective homogeneous catalyst, has been developed for the oxidative synthesis of nitriles from alcohols and ammonium formate. This system uses air as a green oxidant and produces water as an environmentally benign side product. Copyright
- Yadav, Dilip Kumar T.,Bhanage, Bhalchandra M.
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p. 5106 - 5110
(2013/11/06)
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- Direct synthesis of nitriles from alcohols or aldehydes using H 5IO 6/KI in aqueous ammonia
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The oxidative conversion of alcohols or aldehydes to the corresponding nitriles in moderate to good yields was easily achieved by treatment of H 5IO6 and KI in aqueous NH3. This simple and one-pot system provides easy workup and separation of the product. Copyright
- Ghorbani-Choghamarani, Arash,Sardari, Sara,Zolfigol, Mohammad Ali,Hajjami, Maryam
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p. 52 - 58,7
(2020/08/24)
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- Acetohydroxamic acid: A new reagent for efficient synthesis of nitriles directly from aldehydes using Bi(OTf)3 as the catalyst
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An efficient method for the preparation of nitriles directly from aldehydes by reaction with AHA using Bi(OTf)3 as the catalyst is described. Bi(OTf)3 is shown to be an efficient catalyst also for the conversion of aldoximes into nitriles.
- Sridhar, Madabhushi,Reddy, Mallu Kishore Kumar,Sairam, Vangipuram Venkata,Raveendra, Jillella,Godala, Kondal Reddy,Narsaiah, Chinthala,Ramanaiah, Beeram China,Reddy, Cirandur Suresh
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experimental part
p. 3421 - 3424
(2012/08/08)
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- Pd-PEPPSI-IPentCl: A highly effective catalyst for the selective cross-coupling of secondary organozinc reagents
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No migration? No problem. A series of new N-heterocyclic carbene based Pd complexes has been created and evaluated in the Negishi cross-coupling of aryl and heteroaryl chlorides, bromides, and triflates with a variety of secondary alkylzinc reagents (see scheme). The direct elimination product is nearly exclusively formed; in most examples there is no migratory insertion at all. Copyright
- Pompeo, Matthew,Hadei, Niloufar,Organ, Michael G.,Froese, Robert D. J.
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supporting information
p. 11354 - 11357,4
(2012/12/12)
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- Pd-PEPPSI-IPentCl: A highly effective catalyst for the selective cross-coupling of secondary organozinc reagents
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No migration? No problem! A series of new N-heterocyclic carbene based Pd complexes has been created and evaluated in the Negishi cross-coupling of aryl and heteroaryl chlorides, bromides, and triflates with a variety of secondary alkylzinc reagents (see scheme). The direct elimination product is nearly exclusively formed; in most examples there is no migratory insertion at all. Copyright
- Pompeo, Matthew,Froese, Robert D. J.,Hadei, Niloufar,Organ, Michael G.
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supporting information
p. 11354 - 11357
(2013/01/15)
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- PTERIDINONES AS INHIBITORS OF POLO - LIKE KINASE
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The present invention provides compounds having a structure according to Formula (I) or a salt or solvate thereof, wherein ring A, X, R1, R2, R3, R4, R5 and R6, are defined herein. The invention further provides pharmaceutical compositions including the compounds of the invention and methods of making and using the compounds and compositions of the invention, e.g., in the treatment and prevention of various disorders, such as Parkinson's disease.
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- A simple and one-pot oxidative conversion of alcohols or aldehydes to the nitriles using NaIO4/KI in Aqueous NH3
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Sodium periodate (NaIO4) and potassium iodide (KI) in aqueous ammonia has been used for the one-pot synthesis of nitriles from the corresponding aldehydes and alcohols in moderate to good yield. This transformation, proceeds via an in situ oxidation- imination-aldimine oxidation sequence.
- Zolfigol, Mohammad Ali,Hajjami, Maryam,Ghorbani-Choghamarani, Arash
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experimental part
p. 4191 - 4194
(2012/02/16)
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- High temperature vapor phase reactions of nitrogen trifluoride with benzylic substrates
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At temperatures around 400°C, nitrogen trifluoride (NF3) readily reacts with benzylic substrates. Products vary with the substrate, but are all the result of difluoroamination at the benzylic position. Toluene and ethylbenzene produce benzonitrile. Cumene produces α-methylstyrene. Diphenylmethane produces benzanilide. Little or no direct fluorination or radical dimerization is observed.
- Belter, Randolph K.
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experimental part
p. 318 - 322
(2011/06/26)
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- Negishi cross-coupling of secondary alkylzinc halides with aryl/heteroaryl halides using Pd-PEPPSI-IPent
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Pd-PEPPSI-IPent has proven to be an excellent catalyst for the Negishi cross-coupling reaction of secondary alkylzinc reagents with a wide variety of aryl/heteroaryl halides. Importantly, β-hydride elimination/migratory insertion of the organometallic leading to the production of isomeric coupling products has been significantly reduced using the highly-hindered Ipent ligand.
- Alimsiz, Seluk,Organ, Michael G.
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supporting information; experimental part
p. 5181 - 5183
(2011/06/09)
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- Palladium-catalyzed cyanation of aryl bromides using phosphine-free pyridyl-hydrazone ligands
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Palladium-catalyzed cyanation of aryl bromides with potassium hexacyanoferrate(II) trihydrate, K4[Fe(CN)6] ·3H2O as the cyanide source gave benzonitrile derivatives using a catalytic amount of Pd(OCOCF3)2 in DMF at 110 °C with phosphine-free pyridyl-hydrazone ligand 2c in good yields. The Japan Institute of Heterocyclic Chemistry.
- Mino, Takashi,Koizumi, Tomoko,Shibuya, Masanori,Hirai, Kiminori,Sakamoto, Masami,Fujita, Tsutomu
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experimental part
p. 163 - 169
(2011/04/22)
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- Cross-coupling reactions through the intramolecular activation of Alkyl(triorgano)silanes
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(Figure Presented) Cross-Si-ing the Jordan: Cross-coupling reactions of 2-(2-hydroxyprop-2-yl)phenylsubstituted alkylsilanes with a variety of aryl halides proceed in the presence of palladium and copper catalysts. The use of K3PO4 base allows for highly chemoselective alkyl coupling with both primary and secondary alkyl groups (Alk).
- Nakao, Yoshiaki,Takeda, Masahide,Matsumoto, Takuya,Hiyama, Tamejiro
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supporting information; scheme or table
p. 4447 - 4450
(2010/08/19)
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- Negishi coupling of secondary alkylzinc halides with aryl bromides and chlorides
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(Chemical Equation Presented) An efficient palladium-catalyzed process has been developed for Negishi coupling of secondary alkylzinc halides with a wide range of aryl bromides and activated aryl chlorides. A palladium catalyst composed of a new biaryldialkylphosphine ligand, CPhos, effectively promotes the rate of the reductive elimination step relative to the rate of the undesired β-hydride elimination. The broad substrate scope and excellent ratio of the desired secondary to the undesired primary coupling product make this method a powerful and reliable tool forC(sp3)-C(sp2) bond formation.
- Han, Chong,Buchwald, Stephen L.
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supporting information; experimental part
p. 7532 - 7533
(2009/10/16)
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- A facile one-pot conversion of aldehydes into nitriles
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A facile one-pot synthesis of nitriles starting with aldehydes has been developed employing hydroxylamine hydrochloride in dimethylsulfoxide at 100C.
- Chill, Samuel T.,Mebane, Robert C.
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scheme or table
p. 3601 - 3606
(2009/12/04)
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- Catalytic oxidative conversion of alcohols, aldehydes and amines into nitriles using KI/I2-TBHP system
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The oxidative conversion of alcohols, aldehydes and amines to give corresponding nitriles in excellent yields was easily achieved by the catalytic amount of KI or I2 in combination with TBHP as an external oxidant. This non-transition metal catalyst is cost effective and provides easy work-up and separation of the product.
- Rajender Reddy,Uma Maheswari,Venkateshwar,Prashanthi,Lakshmi Kantam
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supporting information; experimental part
p. 2050 - 2053
(2009/09/06)
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- Convenient conversion of aldoximes into nitriles with N-chlorosuccinimide and pyridine
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Benzaldehyde oximes substituted with electron-donating groups are dehydrated to the corresponding benzonitriles by N-chlorosuccinimide/pyridine in acetonitrile. Benzaldehyde oxime itself and alkanal oximes afford the corresponding aldehydes. Thieme Stuttgart.
- Gucma, Miroslaw,Golebiewski, W. Marek
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scheme or table
p. 1997 - 1999
(2009/04/03)
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- Conversion of aldoximes into nitriles with raney nickel in refluxing 2-propanol
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Aldoximes are readily dehydrated to nitriles with Raney nickel in refluxing 2-propanol. Copyright Taylor & Francis Group, LLC.
- Zuidema, Daniel R.,Dennison, Ami L.,Park, Elizabeth Y.,Mebane, Robert C.
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p. 3810 - 3815
(2008/12/23)
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- New fragmentation of 2-isoxazoline-5-carboxylic acid chlorides
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A novel base promoted degradation of 3-aryl-2-isoxazoline-5-carboxylic acid chlorides to aryl nitriles has been discovered.
- Golebiewski,Gucma
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p. 509 - 513
(2007/10/03)
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