- Mutagenicity and aromatic amine content of fumes from heated cooking oils produced in Taiwan
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According to toxicological studies, there are several unidentified mutagens derived from cooking oil fumes appearing in kitchens of Chinese homes where women daily prepare food. Data are limited to an analysis of aromatic amines from cooking oil fumes, which are known to be carcinogenic for bladder cancer. Fume samples from three different commercial cooking oils frequently used in Taiwan were collected and analysed for mutagenicity in the almonella/microsome assay. Aromatic amines were extracted from the samples and identified by HPLC and confirmed by gas chromatography/mass spectrometry (GC/MS). Extracts from three cooking oil fumes were found to be mutagenic in the presence of S-9 mix. All samples contained 2-naphthylamine (2-NA) and 4-aminobiphenyl (4-ABP). Concentrations of 2-NA and 4-ABP were 31.5 and 35.7 μg/m3 in fumes from sunflower oil, 31.9 and 26.4 mg/m3 in vegetable oil, and 48.3 and 23.3 μg/m3 in refined-lard oil, respectively. Mutagenicities of the three cooking oil condensates were significantly reduced (P 0.05) by adding the antioxidant catechin (CAT) into the oils before heating. Significant difference existed between the amounts of aromatic amines with and without adding CAT (P 0.05). These results indicate that exposure to cooking oil fumes in Taiwan might be an important but controllable risk factor in the aetiology of bladder cancer. 1999 Published by Elsevier Science Ltd. All rights reserved.
- Chiang, Tai-An,Pei-Fen, Wu,Ying, Liao Su,Wang, Li-Fang,Ko, Ying Chin
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Read Online
- Novel aminopeptidase specific for glycine from Actinomucor elegans.
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Glycyl aminopeptidase was purified 600-fold from a cell extract of Actinomucor elegans by ammonium sulfate fractionation and sequential chromatography on DEAE-Toyopearl, Toyopearl HW65C, and FPLC-Superdex 200 HR, with recovery of 3.3% of the activity. The enzyme highly specifically hydrolyzed Gly-X (amino acid, peptide, or arylamide) bonds. The enzyme hydrolyzed other amino acid residues but at a rate of less than one fifth that with Gly. The order was Gly >> Ala >> Met > Arg > Ser > Leu. The Km value for glycyl-2-naphthylamide was 0.24 mM. The enzyme was most active at pH 8.0 with glycyl-2-naphthylamide as the substrate and its optimal temperature was 40 degrees C. The enzyme was inhibited by iodoacetic acid, and p-chloromercuribenzoate but not done by diisopropylfluorophosphate, o-phenanthroline, or EDTA. Magnesium and calcium had no effect on enzymic activity, but the activity was suppressed by cadmium, zinc, and copper ions. The molecular mass was estimated to be 320 kDa by gel filtration on FPLC-Superdex 200 HR and 56.5 kDa by SDS-PAGE, so the enzyme probably was a hexamer.
- Ito, Kiyoshi,Ma, Xiaohang,Azmi, Nik,Huang, Hua-Shan,Fujii, Mikio,Yoshimoto, Tadashi
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Read Online
- Selective Carbon-Carbon Bond Amination with Redox-Active Aminating Reagents: A Direct Approach to Anilines?
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Amines are among the most fundamental motifs in chemical synthesis, and the introduction of amine building blocks via selective C—C bond cleavage allows the construction of nitrogen compounds from simple hydrocarbons through direct skeleton modification. Herein, we report a novel method for the preparation of anilines from alkylarenes via Schmidt-type rearrangement using redox-active amination reagents, which are easily prepared from hydroxylamine. Primary amines and secondary amines were prepared from corresponding alkylarenes or benzyl alcohols under mild conditions. Good compatibility and valuable applications of the transformation were also displayed.
- Qiu, Xu,Wang, Yachong,Su, Lingyu,Jin, Rui,Song, Song,Qin, Qixue,Li, Junhua,Zong, Baoning,Jiao, Ning
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p. 3011 - 3016
(2021/09/13)
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- Novel environment-friendly production process for preparing amine product and H - acid through silane chemical reduction of several nitro compounds
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The invention relates to the field of new materials for fine chemicals, and relates to a reduction reaction of a series of nitro compounds, in particular to m-nitroaniline. Several particular important amine compounds such as m-phenylenediamine, 5 - amino o-cresol, 2 - methyl p-phenylenediamine, 1/2 - naphthylamine, H - acid amine and 2, 4, 6 - trimethyl-M-phenylenediamine are prepared from the corresponding mono-or double-nitro compound precursors with a new environmental protection production process technology of and acids derived from the novel process technology. H.
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Paragraph 0046-0048
(2021/09/08)
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- Composite of β-cyclodextrin and bentonite clay: a promising support for Pd immobilization and developing a catalyst for hydrogenation of nitroarenes under mild reaction condition
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In attempt to take advantages of naturally occurring compounds for the catalysis, a novel composite composed of β-cyclodextrin, dendrimer and bentonite clay is fabricated and utilized as a support for the stabilization of Pd nanoparticles. To prepare the support, bentonite is amino functionalized and then successively reacted with 2,4,6-trichloro-1,3,5-triazine and ethylenediamine to furnish a dendrimer of generation II on bentonite. Afterwards, the terminal functionalities of the dendrimer were adorned with cyclodextrin. Bentonite played role in the heterogenation of the catalyst and improvement of the stability of the composite while, cyclodextrins served as molecular shuttles and capping agent for the as-prepared Pd nanoparticles. Dendrimer with multi nitrogen atoms, on the other hand, improved Pd anchoring through electrostatic interactions. The catalyst was applied for the hydrogenation of nitroarenes under mild reaction condition in aqueous media in a selective manner. Notably, the catalyst could be recovered and reused repeatedly.
- Koohestani, Fatemeh,Sadjadi, Samahe
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supporting information
(2020/12/21)
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- A convenient Hofmann reaction of carboxamides and cyclic imides mediated by trihaloisocyanuric acids
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A simple, efficient and pot-economic approach in a single vessel has been developed for conversion of aromatic and aliphatic carboxamides into primary amines with one fewer carbom atom (Hofmann reaction) in 38–89 % yield by reacting with trichloro- or tribromoisocyanuric acid and sodium hydroxide in aqueous acetonitrile. Under the same reaction conditions, cyclic imides gave amino acids (69–83 %). The role of the trihaloisocyanuric acids is the in situ generation of N-haloamides, key-intermediates for the Hofmann reaction. The scalability of the methodology was demonstrated by a multigram-scale transformation of phthalimide into anthranilic acid in 77 % yield.
- Bastos, Gustavo A.,de Mattos, Marcio C.S.
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- Copper-Catalysed Electrophilic Amination of Aryl(alkenyl) Boronic Acids with Nitrogen-Containing Hypervalent Iodine (III) Reagent
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A copper-catalysed electrophilic N-imination of aryl(alkenyl) boronic acids with a stable hypervalent iodine(III) reagent containing a transferable (diarylmethylene)amino group is developed. The electrophilic C?N cross-coupling reaction proceeds smoothly at room temperature under oxidant-free and base-free conditions, which is further characterized by the broad functional group compatibility, thereof, extending the N-electrophile scope of electrophilic C?N cross-coupling outside the limitation of N?O and N?Cl reagents. (Figure presented.).
- Hu, Yuanyuan,Zheng, Songlin,Fan, Wu,Yuan, Weiming
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supporting information
p. 4701 - 4707
(2021/08/23)
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- Method for synthesizing heteroatom- substituted aromatic compound from styrene compound
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The invention discloses a method for synthesizing a heteroatom-substituted aromatic compound from a styrene compound, which comprises the following steps of: mixing a styrene compound with a general formula (I) and a heteroatom-containing compound with a general formula (II), and reacting in the presence of an acid additive and an organic solvent to obtain a heteroatom-substituted compound with ageneral formula (III). According to the synthesis method disclosed by the invention, a large amount of styrene compounds are used as raw materials and react to generate aromatic amine or phenol compounds under the action of no metal catalysis; and compared with the traditional aromatic amine and phenol synthesis method, the method has the advantages of high yield, simple conditions, low waste discharge amount, no metal participation, simple reaction equipment, easiness in industrial production and the like.
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Paragraph 0288-0291
(2021/02/06)
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- Synthesis of Substituted Anilines from Cyclohexanones Using Pd/C-Ethylene System and Its Application to Indole Synthesis
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The synthesis of anilines and indoles from cyclohexanones using a Pd/C-ethylene system is reported. A simple combination of NH4OAc and K2CO3 under nonaerobic conditions was found to be the most suitable to perform this reaction. Hydrogen transfer between cyclohexanone and ethylene generates the desired products. The reaction tolerates a variety of substitutions on the starting cyclohexanones.
- Maeda, Katsumi,Matsubara, Ryosuke,Hayashi, Masahiko
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supporting information
p. 1530 - 1534
(2021/03/08)
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- Metabolic Fate of the Isocyanide Moiety: Are Isocyanides Pharmacophore Groups Neglected by Medicinal Chemists?
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Despite the isolation of hundreds of bioactive isocyanides from terrestrial fungi and bacteria as well as marine organisms, the isocyanide functionality has so far received little attention from a medicinal chemistry standpoint. The widespread tenet that isocyanides are chemically and metabolically unstable has restricted bioactivity studies to their antifouling properties and technical applications. In order to confirm or refute this idea, the hepatic metabolism of six model isocyanides was investigated. Aromatic and primary isocyanides turned out to be unstable and metabolically labile, but secondary and tertiary isocyanides resisted metabolization, showing, in some cases, cytochrome P450 inhibitory properties. The potential therefore exists for the secondary and tertiary isocyanides to qualify them as pharmacophore groups, in particular as war-heads for metalloenzyme inhibition because of their potent metal-coordinating properties.
- Aprile, Silvio,Galli, Ubaldina,Grosa, Giorgio,Tron, Gian Cesare,Purghè, Beatrice
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p. 955 - 966
(2020/05/18)
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- Mono/Dual Amination of Phenols with Amines in Water
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We herein describe a practical direct amination of phenols through a palladium-catalyzed hydrogen-transfer-mediated activation method to synthesize the secondary and tertiary amines. In this conversion, environmentally friendly water and inexpensive ammonium formate were used as solvent and reductant, respectively. A range of amines, including aliphatic amines, aniline, secondary amines, and diamines, could be coupled effectively by this method to achieve mono/dual amination and cyclization of phenols. This study not only provides a green and mild strategy for the synthesis of secondary and tertiary naphthylamines but also expands the synthesis of chloroquine in organic chemistry.
- Liang, Wanyi,Xie, Feng,Yang, Zhihai,Zeng, Zheng,Xia, Chuanjiang,Li, Yibiao,Zhu, Zhongzhi,Chen, Xiuwen
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supporting information
p. 8291 - 8295
(2020/10/12)
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- Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes by Chiral Sulfide-Catalyzed Electrophilic Carbothiolation of Alkynes
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The enantioselective construction of axially chiral compounds by electrophilic carbothiolation of alkynes is disclosed for the first time. This enantioselective transformation is enabled by the use of a Ts-protected bifunctional sulfide catalyst and Ms-protected ortho-alkynylaryl amines (Ts=tosyl; Ms=mesyl). Both electrophilic arylthiolating and electrophilic trifluoromethylthiolating reagents are suitable for this reaction. The obtained products of axially chiral vinyl–aryl amino sulfides can be easily converted into biaryl amino sulfides, biaryl amino sulfoxides, biaryl amines, vinyl–aryl amines, and other valuable difunctionalized compounds.
- Ji, Jieying,Jiang, Quanbin,Liang, Yaoyu,Luo, Jie,Zhang, Xiaoyan,Zhao, Xiaodan
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supporting information
p. 4959 - 4964
(2020/02/11)
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- Commercially Available CuO Catalyzed Hydrogenation of Nitroarenes Using Ammonia Borane as a Hydrogen Source
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Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high-cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support-free, excellent chemoselectivity, low-cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction.
- Du, Jialei,Chen, Jie,Xia, Hehuan,Zhao, Yiwei,Wang, Fang,Liu, Hong,Zhou, Weijia,Wang, Bin
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p. 2426 - 2430
(2020/03/30)
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- Hollow Nano-Mesosilica Spheres Containing Rhodium Nanoparticles Supported on Nitrogen-Doped Carbon: An Efficient Catalyst for the Reduction of Nitroarenes under Mild Conditions
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Atom efficiency, low temperature, low pressure, and a nontoxic hydrogen source as a reducing agent are ideal reaction conditions for the reduction of nitroarenes. In this work, an efficient catalyst comprising hollow nano-mesosilica spheres loaded with Rh nanoparticles supported on nitrogen-doped carbon was developed. Rh nanoparticles were stabilized and uniformly dispersed by nitrogen atoms, and the inner N-doped carbon shell was used to adsorb reaction substrates and improve catalytic activity. The catalyst showed remarkable activity (maximum yield at 1.5 h) and selectivity (100 %) for the reduction of nitrobenzene at lower temperature (80 °C), atmospheric pressure (1 atm), and without base under aqueous conditions. Moreover, the hydrothermal stability of this nanocatalyst was better than other catalysts in boiling water at 100 °C for 48 h and effectively prevented the aggregation and leaching of Rh NPs during the reaction.
- Wang, Shihan,Dai, Jinyu,Shi, Zhiqiang,Xiong, Zeshan,Zhang, Zongtao,Qiu, Shilun,Wang, Runwei
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p. 247 - 253
(2020/01/25)
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- Discovery and characterization of an acridine radical photoreductant
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Photoinduced electron transfer (PET) is a phenomenon whereby the absorption of light by a chemical species provides an energetic driving force for an electron-transfer reaction1–4. This mechanism is relevant in many areas of chemistry, including the study of natural and artificial photosynthesis, photovoltaics and photosensitive materials. In recent years, research in the area of photoredox catalysis has enabled the use of PET for the catalytic generation of both neutral and charged organic free-radical species. These technologies have enabled previously inaccessible chemical transformations and have been widely used in both academic and industrial settings. Such reactions are often catalysed by visible-light-absorbing organic molecules or transition-metal complexes of ruthenium, iridium, chromium or copper5,6. Although various closed-shell organic molecules have been shown to behave as competent electron-transfer catalysts in photoredox reactions, there are only limited reports of PET reactions involving neutral organic radicals as excited-state donors or acceptors. This is unsurprising because the lifetimes of doublet excited states of neutral organic radicals are typically several orders of magnitude shorter than the singlet lifetimes of known transition-metal photoredox catalysts7–11. Here we document the discovery, characterization and reactivity of a neutral acridine radical with a maximum excited-state oxidation potential of ?3.36 volts versus a saturated calomel electrode, which is similarly reducing to elemental lithium, making this radical one of the most potent chemical reductants reported12. Spectroscopic, computational and chemical studies indicate that the formation of a twisted intramolecular charge-transfer species enables the population of higher-energy doublet excited states, leading to the observed potent photoreducing behaviour. We demonstrate that this catalytically generated PET catalyst facilitates several chemical reactions that typically require alkali metal reductants and can be used in other organic transformations that require dissolving metal reductants.
- MacKenzie, Ian A.,Wang, Leifeng,Onuska, Nicholas P. R.,Williams, Olivia F.,Begam, Khadiza,Moran, Andrew M.,Dunietz, Barry D.,Nicewicz, David A.
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- Copper-Catalyzed Aerobic Oxidation of Amines to Benzothiazoles via Cross Coupling of Amines and Arene Thiolation Sequence
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A one-pot three-component synthesis of benzothiazoles has been developed using the copper-catalyzed aerobic cross coupling of amines followed by arene thiolation using elemental sulfur. The dual roles of elemental sulfur and CuCl(OH)-TMEDA in the aerobic amine oxidation and the aniline thiolation enable the facile access to benzothiazole derivatives from readily available starting materials. The operational simplicity of the current promiscuous catalyst system suggests the high synthetic potential in the preparation of heterocyclic compounds. (Figure presented.).
- Kim, Jihyeon,Oh, Kyungsoo
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supporting information
p. 3576 - 3582
(2020/08/05)
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- Heterogeneous photocatalysis of azides: Extending nitrene photochemistry to longer wavelengths
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The photodecomposition of azides to generate nitrenes usually requires wavelengths in the 300 nm region. In this study, we show that this reaction can be readily performed in the UVA region (368 nm) when catalyzed by Pd-decorated TiO2. In aqueous medium the reaction leads to amines, with water acting as the H source; however, in non-protic and non-nucleophilic media, such as acetonitrile, nitrenes recombine to yield azo compounds, while azirine-mediated trapping occurs in the presence of nucleophiles. The heterogeneous process facilitates catalyst separation while showing great chemoselectivity and high yields.
- Argüello, Juan E.,Lanterna, Anabel E.,Lemir, Ignacio D.,Scaiano, Juan C.
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supporting information
p. 10239 - 10242
(2020/10/02)
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- PRODUCTION METHOD OF PRIMARY AMINE COMPOUND
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PROBLEM TO BE SOLVED: To provide a simple production method of a primary amine compound unnecessary for complicated procedures and toxic sodium azide or the like. SOLUTION: A production method of a primary amine compound includes a step for reacting a ketone compound and an oxime compound in the presence of alcohol and an acid catalyst. Preferably, the acid catalyst is hydrochloric acid, sulfuric acid, methanesulfonic acid, camphorsulfonic acid, a tosyl acid hydrate, trifluoromethane sulfonic acid or a boron trifluoride diethyl ether complex. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0031-0034
(2019/09/20)
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- Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage
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The Br?nsted acid-catalyzed synthesis of primary amines from acetyl arenes and alkanes with C-C bond cleavage is described. Although the conversion from an acetyl group to amine has traditionally required multiple steps, the method described herein, which uses an oxime reagent as an amino group source, achieves the transformation directly via domino transoximation/Beckmann rearrangement/Pinner reaction. The method was also applied to the synthesis of γ-aminobutyric acids, such as baclophen and rolipram.
- Hyodo, Kengo,Hasegawa, Genna,Maki, Hiroya,Uchida, Kingo
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supporting information
p. 2818 - 2822
(2019/04/25)
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- Direct conversion of phenols into primary anilines with hydrazine catalyzed by palladium
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Primary anilines are essential building blocks to synthesize various pharmaceuticals, agrochemicals, pigments, electronic materials, and others. To date, the syntheses of primary anilines mostly rely on the reduction of nitroarenes or the transition-metal-catalyzed Ullmann, Buchwald-Hartwig and Chan-Lam cross-coupling reactions with ammonia, in which non-renewable petroleum-based chemicals are typically used as feedstocks via multiple step syntheses. A long-standing scientific challenge is to synthesize various primary anilines directly from renewable sources. Herein, we report a general method to directly convert a broad range of phenols into the corresponding primary anilines with the cheap and widely available hydrazine as both amine and hydride sources with simple Pd/C as the catalyst.
- Qiu, Zihang,Lv, Leiyang,Li, Jianbin,Li, Chen-Chen,Li, Chao-Jun
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p. 4775 - 4781
(2019/05/16)
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- Pyridyl Radical Cation for C?H Amination of Arenes
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Electron-transfer photocatalysis provides access to the elusive and unprecedented N-pyridyl radical cation from selected N-substituted pyridinium reagents. The resulting C(sp2)?H functionalization of (hetero)arenes furnishes versatile intermediates for the development of valuable aminated aryl scaffolds. Mechanistic studies that include the first spectroscopic evidence of a spin-trapped N-pyridyl radical adduct implicate SET-triggered, pseudo-mesolytic cleavage of the N?X pyridinium reagents mediated by visible light.
- R?ssler, Simon L.,Jelier, Benson J.,Tripet, Pascal F.,Shemet, Andrej,Jeschke, Gunnar,Togni, Antonio,Carreira, Erick M.
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supporting information
p. 526 - 531
(2019/01/04)
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- Enzyme kinetics in crowded solutions from isothermal titration calorimetry
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Isothermal titration calorimetry (ITC) is a universal technique that directly measures the heat absorbed or released in a process. ITC is typically used to determine thermodynamic parameters of association of molecules without the need to label them. However, ITC is still rarely applied to study chemical reactions catalyzed by enzymes. In addition, these few studies of enzyme kinetic measurements that have been performed were in diluted solutions. Yet, to estimate realistic kinetic parameters, we have to account for the fact that enzymatic reactions in cells occur in a crowded environment because cells contain 200–400 g/L of macromolecular crowders such as proteins, ribosomes and lipids. Thus we expanded the ITC application for solutions mimicking the cellular environment by adding various macromolecular crowders. We investigated how these crowders affect the kinetics of trypsin-catalyzed reactions and determined the Michaelis-Menten parameters for hydrolysis of two trypsin substrates: Nα-benzoyl-L-arginine ethyl ester (BAEE) and Nα-benzoyl-DL-arginine β-naphthylamide (BANA). Since ITC enables investigations of complex and turbid solutions with label-free reagents, it seems a perfect technique for kinetic analyses in crowded solutions. ITC also offers the opportunity to control enzyme-crowder and substrate-crowder interactions.
- Maximova, Ksenia,Wojtczak, Jakub,Trylska, Joanna
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- Direct ortho-Selective Amination of 2-Naphthol and Its Analogues with Hydrazines
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Described herein is a regioselective ortho-amination of 2-naphthol and its analogues with substituted hydrazines. It provides a direct methodology for the synthesis of N-arylaminated naphthol derivatives without the formation of related 1,1′-biaryl-2,2′-diamine or carbazole byproducts. Specifically, using N,N-disubstituted hydrazine precursors, N-unsubstituted ortho-aminated derivatives and related secondary amines can be formed in ethylene glycol in moderate to excellent yields. Variation of substrates to N,N′-diarylhydrazines and N-methyl-N,N′-diarylhydrazines led to N-aryl-1-amino-2-naphthol compounds. It is noted that biologically interesting indazole motifs can be facilely created by the reaction of N,N′-dialkylhydrazines with 2-naphthols. These ortho-amination reactions have the advantage of one-pot operation without the use of transition metal catalysts.
- Jia, Lei,Tang, Qiang,Luo, Meiming,Zeng, Xiaoming
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p. 5082 - 5091
(2018/05/15)
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- Microbial degradation of amino acid-containing compounds using the microcystin-degrading bacterial strain B-9
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Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins produced by fungi. Among the tested mycotoxins, only ochratoxin A was completely hydrolyzed to provide the constituents ochratoxin α and L-phenylalanine, and levels of fumonisin B1 gradually decreased after 96 h. However, although drugs including antibiotics released into the aquatic environment were applied for microbial degradation using strain B-9, no degradation occurred. These results suggest that strain B-9 can only degrade amino acid-containing compounds. As expected, the tested compounds with amide and ester bonds, such as 3,4-dimethyl hippuric acid and 4-benzyl aspartate, were readily hydrolyzed by strain B-9, although the sulfonamides remained unchanged. The ester compounds were characteristically and rapidly hydrolyzed as soon as they came into contact with strain B-9. Furthermore, the degradation of amide and ester compounds with amino acids was not inhibited by the addition of ethylenediaminetetraacetic acid (EDTA), indicating that the responsible enzyme was not MlrC. These results suggest that strain B-9 possesses an additional hydrolytic enzyme that should be designated as MlrE, as well as an esterase.
- Jin, Haiyan,Hiraoka, Yoshiko,Okuma, Yurie,Hashimoto, Elisabete Hiromi,Kurita, Miki,Anas, Andrea Roxanne J.,Uemura, Hitoshi,Tsuji, Kiyomi,Harada, Ken-Ichi
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- Simple Nickel Salts for the Amination of (Hetero)aryl Bromides and Iodides with Lithium Bis(trimethylsilyl)amide
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Recent developments in the chemistry of C-N bond formation and the synthesis of anilines have allowed for the use of first-row transition metals to catalyze these transformations. Much of the progress in this area has been driven by comprehensive screening for privileged/tailored ligands, which can be costly and not readily available in a research laboratory setting. In this communication we report a protocol in which simple nickel salts catalyze the C-N cross-coupling reaction between (hetero)aryl bromides and iodides with lithium bis(trimethylsilyl)amide without the need for any additive ligand. This method is amenable to low nickel catalyst loadings (1%) as well as gram-scale reactions. Because of the good functional group tolerance and compatibility with heterocyclic moieties, this method is useful for academic laboratory settings where access to tailored ligands and noble-metal catalysts could be challenging.
- Martinez, Gabriel Espinosa,Nugent, Joseph W.,Fout, Alison R.
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supporting information
p. 2941 - 2944
(2018/09/21)
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- AMINATION AND HYDROXYLATION OF ARYLMETAL COMPOUNDS
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In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.
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Paragraph 0097; 0098; 0134; 0135; 0146
(2018/03/25)
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- Nickel-Catalyzed Cross-Coupling of Ammonia or Primary Alkylamines with (Hetero)aryl Sulfamates, Carbamates, or Pivalates
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A catalyst system capable of effecting the cross-coupling of ammonia or primary alkylamines with (hetero)aryl sulfamates, carbamates, or pivalates is reported for the first time. The air-stable nickel(II) pre-catalyst C1 tolerates a broad spectrum of heterocyclic functionality within both reaction partners, as well as ether, nitrile, pyrrole, trifluoromethyl, and boronate ester substituents. In the case of reactions involving primary alkylamines and (hetero)aryl sulfamates and carbamates, room-temperature cross-couplings were achieved.
- MacQueen, Preston M.,Stradiotto, Mark
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supporting information
p. 1652 - 1656
(2017/08/11)
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- Nickel-Catalyzed Decarbonylative Silylation, Borylation, and Amination of Arylamides via a Deamidative Reaction Pathway
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A nickel-catalyzed decarbonylative silylation, borylation, and amination of amides has been developed. This new methodology allows the direct interconversion of amides to arylsilanes, arylboronates, and arylamines and enables a facile route for carbon-heteroatom bond formations in a straightforward and mild fashion.
- Lee, Shao-Chi,Guo, Lin,Yue, Huifeng,Liao, Hsuan-Hung,Rueping, Magnus
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p. 2594 - 2598
(2017/10/31)
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- Iron-Catalyzed Intramolecular Aminations of C(sp3)?H Bonds in Alkylaryl Azides
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The nucleophilic iron complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the direct intramolecular amination of unactivated C(sp3)?H bonds in alkylaryl azides, which results in the formation of substituted indoline and tetrahydroquinoline derivatives.
- Alt, Isabel T.,Guttroff, Claudia,Plietker, Bernd
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supporting information
p. 10582 - 10586
(2017/08/22)
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- Nickel-Catalyzed Synthesis of Primary Aryl and Heteroaryl Amines via C-O Bond Cleavage
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A nickel-catalyzed protocol for the conversion of aryl and heteroaryl alcohol derivatives to primary and secondary aromatic amines via C(sp2)-O bond cleavage is described. The new amination protocol can be applied to a range of substrates bearing diverse functional groups and uses readily available benzophenone imines as an effective nitrogen source.
- Yue, Huifeng,Guo, Lin,Liu, Xiangqian,Rueping, Magnus
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p. 1788 - 1791
(2017/04/11)
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- Copper-Based Intermetallic Electride Catalyst for Chemoselective Hydrogenation Reactions
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The development of transition metal intermetallic compounds, in which active sites are incorporated in lattice frameworks, has great potential for modulating the local structure and the electronic properties of active sites, and enhancing the catalytic activity and stability. Here we report that a new copper-based intermetallic electride catalyst, LaCu0.67Si1.33, in which Cu sites activated by anionic electrons with low work function are atomically dispersed in the lattice framework and affords selective hydrogenation of nitroarenes with above 40-times higher turnover frequencies (TOFs up to 5084 h-1) than well-studied metal-loaded catalysts. Kinetic analysis utilizing isotope effect reveals that the cleavage of the H-H bond is the rate-determining step. Surprisingly, the high carrier density and low work function (LWF) properties of LaCu0.67Si1.33 enable the activation of hydrogen molecules with extreme low activation energy (Ea = 14.8 kJ·mol-1). Furthermore, preferential adsorption of nitroarenes via a nitro group is achieved by high oxygen affinity of LaCu0.67Si1.33 surface, resulting in high chemoselectivity. The present efficient catalyst can further trigger the hydrogenation of other oxygen-containing functional groups such as aldehydes and ketones with high activities. These findings demonstrate that the transition metals incorporated in the specific lattice site function as catalytically active centers and surpass the conventional metal-loaded catalysts in activity and stability.
- Ye, Tian-Nan,Lu, Yangfan,Li, Jiang,Nakao, Takuya,Yang, Hongsheng,Tada, Tomofumi,Kitano, Masaaki,Hosono, Hideo
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p. 17089 - 17097
(2017/12/06)
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- Rapid heteroatom transfer to arylmetals utilizing multifunctional reagent scaffolds
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Arylmetals are highly valuable carbon nucleophiles that are readily and inexpensively prepared from aryl halides or arenes and widely used on both laboratory and industrial scales to react directly with a wide range of electrophiles. Although C-C bond formation has been a staple of organic synthesis, the direct transfer of primary amino (-NH2) and hydroxyl (-OH) groups to arylmetals in a scalable and environmentally friendly fashion remains a formidable synthetic challenge because of the absence of suitable heteroatom-transfer reagents. Here, we demonstrate the use of bench-stable N-H and N-alkyl oxaziridines derived from readily available terpenoid scaffolds as efficient multifunctional reagents for the direct primary amination and hydroxylation of structurally diverse aryl- and heteroarylmetals. This practical and scalable method provides one-step synthetic access to primary anilines and phenols at low temperature and avoids the use of transition-metal catalysts, ligands and additives, nitrogen-protecting groups, excess reagents and harsh workup conditions.
- Gao, Hongyin,Zhou, Zhe,Kwon, Doo-Hyun,Coombs, James,Jones, Steven,Behnke, Nicole Erin,Ess, Daniel H.,Kürti, László
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p. 681 - 688
(2017/06/30)
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- Nickel-Catalyzed Amination of Aryl Carbamates with Ammonia
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Aryl carbamates were employed in the nickel-catalyzed monoarylation of ammonia. The applied, well-defined single-component nickel(II) precatalyst contains a Josiphos ligand, is air-stable, and operates without any ancillary reductant. This catalyst system
- Schranck, Johannes,Furer, Patrick,Hartmann, Veronika,Tlili, Anis
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supporting information
p. 3496 - 3500
(2017/07/04)
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- Catalytic Ester and Amide to Amine Interconversion: Nickel-Catalyzed Decarbonylative Amination of Esters and Amides by C?O and C?C Bond Activation
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An efficient nickel-catalyzed decarbonylative amination reaction of aryl and heteroaryl esters has been achieved for the first time. The new amination protocol allows the direct interconversion of esters and amides into the corresponding amines and represents a good alternative to classical rearrangements as well as cross coupling reactions.
- Yue, Huifeng,Guo, Lin,Liao, Hsuan-Hung,Cai, Yunfei,Zhu, Chen,Rueping, Magnus
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p. 4282 - 4285
(2017/04/03)
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- Sonication and Microwave-Assisted Primary Amination of Potassium- Aryltrifluoroborates and Phenylboronic Acids under Metal-Free Conditions
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The transition-metal-free generation of a series of primary arylamines from potassium aryltrifluoroborates and phenylboronic acids- is reported. The method uses a mild, inexpensive source of nitrogen (hydroxylamine-O-sulfonic acid) in cooperation with aqueous sodium hydroxide in acetonitrile. Both a sonication and a microwave-assisted method were developed, which are capable of converting ArBF3K functionalities into primary arylamines (ArNH2) in isolated yields of up to 78% (10 examples for each method). This report represents the first general method for the conversion of aryltrifluoroborates into primary arylamines under mild, transition-metal-free conditions in moderate to very good yields. The method is applicable to a wide array of substrates containing electron-donating, electron-neutral, or electron-withdrawing substituents. Both the sonication and microwave methods were also applied to the generation of anilines from phenylboronic acids in isolated yields of up to 96% (12 examples for each method) that were superior to existing room temperature methods in terms of yield, while also offering much shorter reaction times (15 min vs 16 h). In particular, the microwave method is the first to allow for the conversion of arylboronic acids containing strongly electron-withdrawing substituents into the corresponding anilines in good yields, along with electron-donating- substituents in very good to excellent yields.
- Kuik, Dale,McCubbin, J. Adam,Tranmer, Geoffrey K.
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p. 2555 - 2561
(2017/05/22)
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- Simple and convenient copper-catalyzed amination of aryl halides to primary arylamines using NH4OH
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In this study, we investigated the direct synthesis of primary arylamines from aryl iodides and bromides by Cu-catalyzed amination using ammonium hydroxide (27% NH3in H2O) as nucleophile. In this article, two protocols are described: (1) a variety of aryl halides were treated with CuI (10?mol?%) and DMEDA (15?mol?%) in NH4OH/DMSO, or (2) with only CuI (10?mol?%) in NH4OH/PEG300. In each case, the desired primary arylamines were obtained in excellent yields. Although DMEDA and PEG have previously been employed as a ligand or solvent, respectively, the substrates were limited or additional ligands were required for successful conversion. Notably, our new protocols do not require additional inorganic bases, whereas previous methods have used a base. As such, these new protocols are one of the most simple, convenient, and efficient methods that have been reported, to date.
- Jung, Hee Seon,Yun, Taeil,Cho, Yungyeong,Jeon, Heung Bae
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p. 5988 - 5993
(2016/09/16)
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- Chemoselective transfer hydrogenation of nitroarenes by highly dispersed Ni-Co BMNPs
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Highly dispread Ni-Co bimetallic nanoparticles (Ni-Co BMNPs) are synthesized and applied as an efficient catalyst in the chemoselective transfer hydrogenation of nitroarenes (CTH) using hydrazine hydrate as the hydrogen donor. The BMNPs can efficiently catalyze the reduction reaction without any additives under mild conditions with high TOF. Significantly higher activity is achieved when compared with corresponding single-component catalysts, optimal composition of the Ni-Co BMNPs was screened which was proved to be crucial in both the selectivity and yields. Excellent performance of Ni-Co BMNPs can be ascribed to the improved dispersion of active sites on the BMNPs surface (compared with Ni NPs) and the electron transfer from cobalt to nickel.
- Zhang, Jia-Wei,Lu, Guo-Ping,Cai, Chun
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- Heterogeneous sono-Fenton-like process using nanostructured pyrite prepared by Ar glow discharge plasma for treatment of a textile dye
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The plasma-treated pyrite (PTP) nanostructures were prepared from natural pyrite (NP) utilizing argon plasma due to its sputtering and cleaning effects resulting in more active surface area. The NP and PTP were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) methods. The performance of the PTP was greater than NP for treatment of Reactive Red 84 (RR84) by the heterogeneous sono-Fenton process. The optimum amounts of main operational parameters were obtained as PTP of 4 g/L, initial dye concentration of 10 mg/L, pH of 5, and ultrasonic power of 300 W after 120 min of reaction time. Also, the effects of enhancers, and inorganic salts and t-butanol as hydroxyl radical scavengers on the degradation efficiency were investigated. Gas chromatography-mass spectroscopy analysis (GC-MS) was applied for detection of some degradation intermediates. Environmentally friendly plasma modification of the NP, in situ production of H2O2 and OH radicals, low leached iron concentration and repeated reusability at the milder pH are the significant benefits of the PTP utilization.
- Khataee, Alireza,Gholami, Peyman,Vahid, Behrouz
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p. 213 - 225
(2015/10/19)
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- Synthesis, Structure, and Photochemical Behavior of [5]Heli-viologen Isomers
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The syntheses of isomeric helical viologens that have potential applications in supramolecular chemistry and catalysis have been developed. The structures of the molecules and their solid-state packing motifs have been determined by X-ray crystallography. Computational studies demonstrate that the magnitude of their racemization barriers is primarily determined by the identity of the helical scaffold and is insensitive to the placement of the viologen functional group. The isomers are similar in their photophysical behavior but very different in their photochemical behavior.
- Zhang, Xiaoping,Clennan, Edward L.,Arulsamy, Navamoney,Weber, Rachael,Weber, Jacob
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p. 5474 - 5486
(2016/07/13)
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- Concise synthesis of 12a-methyl-11-aryl-1,2-dihydrobenzo[f]pyrrolo[1,2-a]quinolin-3(12aH)-ones as racemic 14-azaestrogen analogs
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A concise method for the synthesis of 14-azasteroid analogs with angular methyl group at C-13 of the steroidal nucleus has been reported in this paper. We have developed an interesting cascade reaction of arylacetylenes and N-(naphthalen-2-yl)pent-4-ynamides under gold (III)-catalysis to produce novel tetracyclic 12a-methyl-11-aryl-1,2-dihydrobenzo[f]pyrrolo[1,2-a]quinolin-3(12aH)-ones which may be viewed as 14-azaestrogen analogs.
- Abdelkhalik, Ashraf M.,Paul, Nawal K.,Jha, Amitabh
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p. 107 - 113
(2015/04/14)
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- Reduction of nitroarenes using CO and H2O in the presence of a nanostructured cobalt oxide/Nitrogen-Doped Graphene (NGr) catalyst
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The most common route to anilines is based on the reduction of the corresponding nitroarenes. In general, hydrogen is preferred as reducing agent and numerous catalytic systems are known to achieve such transformations. Besides, the use of CO/H2O as hydrogen source offers interesting possibilities for reductions. Carbon monoxide is a cheap and abundant chemical used on industrial scale for a variety of transformations. Although the reduction of nitroarenes with CO/H2O is known in the presence of noble-metal catalysts, earth-abundant inexpensive catalysts showing high selectivity have not yet been developed. In this respect, herein we present the use of a heterogeneous cobalt oxide catalyst (Co3O4/NGr@C), which is modified by nitrogen-doped graphene layers. Using this non-noble metal catalyst nitroarenes are reduced in high yields and good chemoselectivities.
- Westerhaus, Felix A.,Sorribes, Ivn,Wienh?fer, Gerrit,Junge, Kathrin,Beller, Matthias
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supporting information
p. 313 - 317
(2015/03/05)
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- Nickel-catalyzed amination of Aryl chlorides with ammonia or ammonium salts
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The nickel-catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well-defined single-component nickel(0) precatalyst containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts. Simple alternative: The title reaction, which results in primary arylamines, is catalyzed by well-defined single-component nickel(0) precatalysts containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.
- Green, Rebecca A.,Hartwig, John F.
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supporting information
p. 3768 - 3772
(2015/03/18)
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- Palladium-catalyzed domino C-H/N-H functionalization: An efficient approach to nitrogen-bridged heteroacenes
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Palladium-catalyzed domino C-H/N-H functionalization for the synthesis of novel nitrogen-bridged thienoacenes and 10H-benzo[4,5]thieno[3,2-b]indole derivatives from dihaloarene is reported. This domino sequence consists of initial C-H functionalization of the benzo[b]thiophene moiety, followed by Buchwald-Hartwig coupling. This transformation is also useful for the synthesis of highly π-extended compounds. Extended heteroacenes: A twofold arylation protocol for the efficient synthesis of 9H-benzo[4,5]thieno[3,2-b]thieno[3,4-d]pyrroles and 10H-benzo[4,5]thieno[3,2-b]indoles was developed (see scheme). The selectivity of this novel sequence allows the construction of highly π-extended heteroacenes.
- Kamimoto, Natsuyo,Schollmeyer, Dieter,Mitsudo, Koichi,Suga, Seiji,Waldvogel, Siegfried R.
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supporting information
p. 8257 - 8261
(2015/05/27)
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- Transition-metal-free access to primary anilines from boronic acids and a common +NH2 equivalent
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Diversely substituted anilines are prepared by treatment of functionalized arylboronic acids with a common, inexpensive source of electrophilic nitrogen (H2N-OSO3H, HSA) under basic aqueous conditions. Electron-rich substrates are found to be the most reactive by this method. However, even moderately electron-poor substrates are well tolerated under the room temperature conditions. Sterically hindered substrates appear to be equally effective compared to unhindered ones. Highly electron-deficient substrates afford product in very low yields at room temperature, but moderate to good yields are obtained at refluxing temperatures. Our method is also amenable to electrophilic amination of several common boronic acid derivatives (e.g., pinacol esters). We demonstrate that it can be combined with metal-halogen exchange reactions or a variety of directed ortho metalation protocols in a "one-pot" sequence for the synthesis of aromatic amines with unique substitution patterns. DFT studies, in combination with experimental results, suggest that the reaction occurs via base-mediated activation of HSA, followed by 1,2 aryl B-N migration. This mode of activation appears to be critical for the success of the reaction and allows, for the first time, a general, electrophilic amination of boronic acids at ambient temperature.
- Voth, Samantha,Hollett, Joshua W.,Mccubbin, J. Adam
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p. 2545 - 2553
(2015/03/18)
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- Exploring the Catalytic Reactivity of Nickel Phosphine-Phosphite Complexes
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In this study, we present an investigation into various nickel phosphite and phosphite-phosphine complexes for use in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions and the ammonia arylation reaction. In these coupling reactions, it was discovered that the Ni[P(OEt)3]4, (dppf)Ni[P(OPh)3]2, and (binap)Ni[P(OPh)3]2 catalysts were the most effective. In addition, an optimisation process for these catalytic systems as well as functional group compatibility are discussed.
- Kampmann, Sven S.,Man, Nikki Y. T.,McKinley, Allan J.,Koutsantonis, George A.,Stewart, Scott G.
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p. 1842 - 1853
(2015/12/26)
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- Metal and base free synthesis of primary amines via ipso amination of organoboronic acids mediated by [bis(trifluoroacetoxy)iodo]benzene (PIFA)
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A metal and base free synthesis of primary amines has been developed at ambient temperature through ipso amination of diversely functionalized organoboronic acids, employing a combination of [bis(trifluoroacetoxy)iodo]benzene (PIFA)-N-bromosuccinimide (NBS) and methoxyamine hydrochloride as the aminating reagent. The amines were primarily obtained as their trifluoroacetate salts which on subsequent aqueous alkaline work up provided the corresponding free amines. The combination of PIFA-NBS is found to be the mildest choice compared to the commonly used strong bases (e.g. n-BuLi, Cs2CO3) for activating the aminating agent. The reaction is expected to proceed via activation of the aminating reagent followed by B-N 1,2-aryl migration.
- Chatterjee, Nachiketa,Goswami, Avijit
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supporting information
p. 7940 - 7945
(2015/07/27)
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- A synthetic and mechanistic investigation into the cobalt(i) catalyzed amination of aryl halides
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Employing first-row transition metals in catalytic two-electron transformations remains a synthetic challenge. In order to overcome the common and often deleterious single-electron reactivity, an electron rich ligand was targeted on cobalt. Herein, we report the Co(i) catalyzed amination of aryl halides with lithium hexamethyldisilazide. This transformation features (PPh3)3CoCl (1) as the catalyst and affords structurally diverse and electronically varied primary arylamines in good chemical yields, with the scope of the reaction featuring arylamines that cannot be synthesized via traditional metal-catalyzed amination routes, including 4-aminophenylboronic acid pinacol ester. Stoichiometric reactivity revealed that (PPh3)2CoN(SiMe3)2 (2) is likely generated within the catalytic cycle and could be independently synthesized from the reaction of (PPh3)3CoCl with LiN(SiMe3)2. Catalytic reactivity featuring the Co-amide complex, (PPh3)2CoN(SiMe3)2, showed that it is a competent catalyst, implying that the (PPh3)3CoCl may be serving as a pre-catalyst in the reaction. Both stoichiometric and kinetic studies support the catalytic cycle involving a Co(i) complex. Catalytic reactions featuring Co(ii) complexes resulted in undesired biaryl formation, a product that is not observed under standard catalytic conditions and any productive catalytic reactivity likely arises from an in situ reduction of Co(ii) to Co(i). A Hammett study was carried out to differentiate between a closed-shell or radical mechanism, the results of which are consistent with the proposed closed-shell mechanism. Initial studies indicate that this reactivity may be expanded to other bulky nucleophiles. This journal is
- Brennan, Marshall R.,Kim, Dongyoung,Fout, Alison R.
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p. 4831 - 4839
(2015/02/19)
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- Activity of leucine aminopeptidase of Telchin licus licus: An important insect pest of sugarcane
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The enzymatic activity of leucine aminopeptidase (EC 3.4.11.1) from the intestinal tract of sugarcane giant borer (Telchin licus licus) was assayed by using a simple and sensitive spectrophotometric assay that uses L-leucyl-2-naphthylamide as substrate. In this assay, L-leucyl-2-naphthylamide is hydrolyzed to produce 2-naphthylamine and Lleucine. The product 2-naphthylamine reacts with Fast Black K and can be monitored using a continuous spectrophotometric measurement at 590 nm. The data on the kinetic parameters indicates that the Km for the L-leucyl-2-naphthylamide at pH 7.0 was found to be lower than those found for other LAP substrates. The Km and Vmax for the LAP were determined to be 84.03 βM and 357.14 enzymatic units mg-1, respectively. A noticeable difference of LAP activity between the two insect orders tested was observed. This method could be used to screen for natural LAP inhibitors.
- Valencia, Jorge W. Arboleda,De Sá, Maria Fátima Grossi,Jiménez, Arnubio Valencia
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p. 535 - 541
(2014/05/20)
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- Synthesis of triaryls: Hydroxy and amine dinaphthyl and diphenanthryl aryls by one-pot electron-transfer nucleophilic substitution reactions
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A new one-pot synthetic route to achieve the preparation of hydroxy and amine binaphthyl and biphenanthryl aryls is here reported. This approach involves the reaction of 1,4-bromoiodobenzene, 4,4′-diiodobiphenyl, and 1,4- and 1,5-diiodonaphthalene with the anions of 2-naphthylamine, 2-naphthol, and 9-phenanthrylamine under irradiation in liquid ammonia. The reactions proceed to afford triaryl derivatives in moderate to good yields (～45% of 1,4-phenylene- and 1,4-naphthylene-1,1′-dinaphthalen-2-ols as well as 1,4-phenylene-1,1′-dinaphthalen-2-amine and 10,10′-diphenanthren-9- amine). Lower yields (27%) of polyaryl derivatives are obtained by reaction of 4,4′-diiodobiphenyl with anions of 2-naphthol and 9-phenanthrylamine.
- Jimenez, Liliana B.,Torres, Natalia V.,Borioni, José L.,Pierini, Adriana B.
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supporting information
p. 3614 - 3620
(2014/05/20)
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- Nickel nanoparticles as efficient catalyst for electron transfer reactions
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The catalytic efficiency of nickel nanoparticles was investigated in some electron transfer reactions. The nanoparticles brought about rapid roomtemperature reduction of a number of nitro aromatics in an aqueous medium with high chemoselectivity and also helped to speed up redox reaction of Fe(CN)-36and S2O-23. In addition, interesting results were obtained for microwave assisted decolourization of azo dye. The reactions were monitored through UV-Vis spectroscopy. The present study has additional advantages of reusability of catalysts and aqueous medium. The ultimate goal was to assess the suitability of low cost nanocatalyst for electron transfer reactions under aqueous conditions. Springer Science+Business Media New York 2013.
- Rathore, Puran Singh,Patidar, Rajesh,Rathore, Sonika,Thakore, Sonal
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p. 439 - 446
(2014/06/24)
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- Palladium-catalyzed amination of aryl chlorides and bromides with ammonium salts
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We report the palladium-catalyzed coupling of aryl halides with ammonia and gaseous amines as their ammonium salts. The coupling of aryl chlorides and ortho-substituted aryl bromides with ammonium sulfate forms anilines with higher selectivity for the primary arylamine over the diarylamine than couplings with ammonia in dioxane. The resting state for the reactions of aryl chlorides is different from the resting state for the reactions of aryl bromides, and this change in resting states is proposed to account for a difference in selectivities for reactions of the two haloarenes.
- Green, Rebecca A.,Hartwig, John F.
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supporting information
p. 4388 - 4391
(2015/01/08)
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- Reduction of hydrazines to amines with low-valent titanium reagent
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The N,N bond cleavage in hydrazines to amines via low-valent titanium reagent prepared in situ by treatment of TiCl4 with Mg powder in THF or CH2Cl2-Et2O is described. The reaction proceeds smoothly under mild conditions to afford amines in good to excellent yields with diverse functional group tolerance such as chloride, methoxyl, benzyloxyl, ester, acyl, as well as C,C double bonds and benzyl-nitrogen bonds. ARKAT-USA, Inc.
- Ren, Fang,Zhang, Yan,Hu, Lan,Luo, Meiming
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p. 165 - 173
(2013/06/27)
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