80-28-4Relevant academic research and scientific papers
Identification of a Nitrenoid Reductive Elimination Pathway in Nickel-Catalyzed C-N Cross-Coupling
Dudra, Samantha L.,Ferguson, Michael J.,Johnson, Erin R.,McGuire, Ryan T.,Simon, Connor M.,Stradiotto, Mark
, p. 1475 - 1480 (2022/02/07)
Whereas the (bisphosphine)Ni-catalyzed C-N cross-coupling of (hetero)aryl (pseudo)halides with NH nucleophiles represents a useful method for the synthesis of (hetero)anilines, our mechanistic understanding of such cross-couplings is incomplete, especially regarding key C-N reductive elimination steps that are often invoked as turnover-limiting. In this combined experimental and computational study, we provide evidence of a bifurcated C-N reductive elimination pathway for cross-couplings of tBuNH2 and (aryl′)SO2NH2 employing (L1)Ni(aryl)Cl as the precatalyst (L1 = PhPAd-DalPhos). In contrast with direct C-N reductive elimination that proceeds from the nickel alkylamido complex (L1)Ni(aryl)(NHtBu), we provide evidence of a previously undocumented base-promoted pathway involving deprotonation of the nickel sulfonamido complex (L1)Ni(aryl)(NHSO2(aryl′)) to give the anionic nickel nitrenoid species [(L1)Ni(aryl)(NSO2(aryl′))]-, from which C-N reductive elimination occurs preferentially.
Lewis Acid Regulated Divergent Catalytic Reaction between Quinone Imine Ketals (QIKs) and 1,3-Dicarbonyl Compounds: Switchable Access to Multiple Products Including 2-Aryl-1,3-Dicarbonyl Compounds, Indoles, and Benzofurans
Chen, Xingyu,Lu, Sixian,Deng, Ping,Chang, Xiaoqiang,Zhao, Yifan,Ma, Yue,Zhang, Dong,Xia, Fei,Yang, Lan,Wang, Jigang,Sun, Peng
supporting information, p. 94 - 102 (2021/10/05)
A catalytic Lewis acid regulated reaction between quinone imine ketals (QIKs) and 1,3-dicarbonyl compounds provides a divergent and tunable approach to a variety of skeletons, including a series of 2-aryl-1,3-dicarbonyl compounds, indoles, and benzofurans. The use of lithium chloride and ferrous bromide gives C3- or C2-alkylation products of the QIKs. The combination of ferrous bromide and trifluoromethanesulfonic acid delivers indole derivatives. Sequential hydrolysis and C3-alkylation occur in the presence of ytterbium (III) trifluoromethanesulfonate and stoichiometric amounts of water. When the reaction is performed with trifluoromethanesulfonic acid and stoichiometric amounts of water, benzofuran is obtained. This protocol utilizes mild conditions, exhibits regio- and chemoselectivity, and has broad functional group tolerance. (Figure presented.).
Synthesis of magnetic chitosan supported metformin-Cu(II) complex as a recyclable catalyst for N-arylation of primary sulfonamides
Ahmadpoor, Fatemeh,Nasrollahzadeh, Mahmoud,Nezafat, Zahra,Pakzad, Khatereh
, (2021/06/25)
The application of chitosan, which has received much attention as a natural polymer and effective support, has many advantages such as biodegradability and biocompatibility. In this study, the immobilization of a copper complex on the magnetic chitosan bearing metformin ligand has been developed through immobilizing structurally defined metformin with long tail of (3-chloropropyl)trimethoxysilane (TMOS). The synthesized Fe3O4-chitosan@metformin-Cu(II) complex (Fe3O4-CS@Met-Cu(II)) was used as an effective, reusable and magnetic catalyst in the N-arylation of different derivatives of primary sulfonamides with arylboronic acids in ethanol. The primary sulfonamides were prepared from the reaction of sulfonyl chlorides with sodium cyanate in water under ultrasonic irradiation. Utilizing a wide variety of substrates in EtOH as a green solvent, high yields of the primary and secondary sulfonamides, easy work-up along with the excellent recovery and reusability of the catalyst, make this process a simple, economic and environmentally benign method. The synthesized Fe3O4-CS@Met-Cu(II) was characterized using various techniques such as XRD (X-ray diffraction), EDS (energy-dispersive X-ray spectroscopy), elemental mapping, TEM (transmission electron microscopy), FESEM (field emission scanning electron microscopy), VSM (vibrating sample magnetometer), ICP-MS (inductively coupled plasma mass spectroscopy), TGA (thermogravimetric analysis) and FT-IR (Fourier-transform infrared spectroscopy) analyses. The catalyst can be recycled and reused 5 times with no considerable loss of catalytic activity.
Method for synthesizing P-chloroO-toluidine
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Paragraph 0090-0091, (2021/10/05)
The invention discloses a method for synthesizing p-chloroo-toluidine, which comprises the following steps: synthesizing o-toluidine and a protective agent in an organic solvent to obtain an amino-protected intermediate. The amino protected intermediate is added into hydrochloric acid, an oxidant is added for chlorination reaction, and a chlorination product is obtained. The chlorinated product is removed and the amino protecting group is removed to give p-chloroo-toluidine. The method for synthesizing p-chloroo-toluidine provided by the invention is high in yield, simple to operate, less in three wastes, high in product content and good in quality, and can be suitable for industrial mass production.
Z-Selective Fluoroalkenylation of (Hetero)Aromatic Systems by Iodonium Reagents in Palladium-Catalyzed Directed C?H Activation
Bényei, Attila,Domján, Attila,Egyed, Orsolya,Gonda, Zsombor,Novák, Zoltán,Sályi, Gerg?,Tóth, Balázs L.
supporting information, (2021/11/09)
The direct and catalytic incorporation of fluorine containing molecular motifs into organic compounds resulting high-value added chemicals represents a rapidly evolving part of synthetic methodologies, thus this area is in the focus of pharmaceutical and agrochemical research. Herein we report a stereoselective procedure for direct fluorovinylation of aromatic and heteroaromatic scaffolds. This methodology development has been realized by palladium-catalyzed ortho C?H activation reaction of aniline derivatives featuring the regioselectivity via directing groups such as secondary of tertiary amides, ureas or ketones. The application of non-symmetrical aryl(fluoroalkenyl)-iodonium salts as fluoroalkenylating agents allowed mild reaction conditions in general for this transformation. The scope and limitations have been thoroughly investigated and the feasibility has been demonstrated by more than 50 examples.
KCC-1 aminopropyl-functionalized supported on iron oxide magnetic nanoparticles as a novel magnetic nanocatalyst for the green and efficient synthesis of sulfonamide derivatives
Azizi, Sajjad,Shadjou, Nasrin,Hasanzadeh, Mohammad
, (2019/11/22)
A new magnetic nanocatalyst (Fe3O4@KCC-1-npr-NH2) was synthesized directly through the reaction of Fe3O4@KCC-1 with (3-aminopropyl) triethoxysilane (APTES) using a hydrothermal protocol. Prepared nanocomposite was used as a magnetically reusable nanocatalyst for an efficient synthesis of a broad range of sulfonamide derivatives in water as a green solvent at room temperature and the products are collected by filtration with excellent yields (85–97%). The nanocatalyst could be remarkably recovered and reused after ten times without any significant decrease in activity. This mild and simple synthesis method offers some advantages including short reaction time, high yield and simple work-up procedure.
Selective C(sp2)-H Amination Catalyzed by High-Valent Cobalt(III)/(IV)-bpy Complex Immobilized on Silica Nanoparticles
Budnikova, Yulia,Bochkova, Olga,Khrizanforov, Mikhail,Nizameev, Irek,Kholin, Kirill,Gryaznova, Tatyana,Laskin, Artem,Dudkina, Yulia,Strekalova, Sofia,Fedorenko, Svetlana,Kononov, Aleksandr,Mustafina, Asia
, p. 5615 - 5624 (2019/11/11)
High-valent cobaltIV-bpy complex stabilized in silica matrix was detected as catalytically active form and intermediate in cobalt-mediated oxidative C?H/NH cross-coupling reaction. These CoIV species prepared by electrooxidation of CoIII(bpy)3-doped silica nanoparticles (SNs) at relatively low anodic potentials have demonstrated high catalytic activity. Both size and architecture of the SNs are highlighted as the factors beyond the complex structure affecting its oxidation potential and catalytic efficiency. The factors have been optimized for the catalyst with high efficiency, easy separation and reusability for 7 times at least. The optimal nanocatalyst (1 mol%) provides 100 % conversion of reactants in a single step of ligand-directed coupling of H2NTs with arenes under electrochemical regeneration conditions. The results emphasize both synthetic route for efficient embedding of CoIII(bpy)3 into silica support and the electrochemical generation of CoIV complexes as a facile route for developing the efficient nanocatalyst of oxidative functionalization. The observed reactivity has the potential in development of Co-catalyzed coupling reactions.
Copper-catalyzed redox coupling of nitroarenes with sodium sulfinates
Liu, Saiwen,Chen, Ru,Zhang, Jin
, (2019/05/02)
A simple copper-catalyzed redox coupling of sodium sulfinates and nitroarenes is described. In this process, abundant and stable nitroarenes serve as both the nitrogen sources and oxidants, and sodium sulfinates act as both reactants and reductants. A variety of aromatic sulfonamides were obtained in moderate to good yields with broad substrate scope. No external additive is employed for this kind of transformation.
Synthetic method for 2-amino-4'-fluoro-benzophenone
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Paragraph 0050-0052; 0055-0057; 0060-0062; 0065-0067; 0071, (2019/04/17)
The invention discloses a synthetic method for 2-amino-4'-fluoro-benzophenone. The method comprises the following steps: subjecting o-toluidine and tosyl chloride to an amidation reaction to obtain 4-methyl-N-(2-methylphenyl) benzenesulfonamide; then performing chlorination by a chlorine gas, producing a Friedel-Crafts reaction with fluorobenzene, and obtaining N-(2-(4-fluorobenzoyl)phenyl)-4-toluenesulfonamide; and finally obtaining the 2-amino-4'-fluoro-benzophenone by deprotection of concentrated sulfuric acid. The synthetic method is cheap and easily available in starting material, is lowin cost, is convenient to operate, is suitable for industrial production, is green and environmentally friendly in synthetic route, and is high in yield, and the purity of the 2-amino-4'-fluoro-benzophenone obtained by preparation is good.
Lewis Base Promoted, Direct 1,4-Conjugate Addition to Quinone Imine Ketals: Efficient Access to Unsymmetrical Diaryl Sulfones
Liu, Teng,Liu, Jianjun,Shen, Xianfu,Xu, Jianbin,Nian, Beifang,He, Ni,Zeng, Shunqun,Cheng, Feixiang
, p. 1365 - 1376 (2019/03/08)
An alternative approach with eco-friendliness and high efficiency for the preparation of unsymmetrical diaryl sulfones has been developed. The strategy takes advantage of the reaction of sulfonyl hydrazides with quinone imine ketals catalyzed by DABCO (triethylenediamine) in ethanol. This transformation proceeds via a Lewis base promoted, direct 1,4-conjugate addition/sulfonylation/alcohol elimination reaction sequence. The protocol provides an efficient approach to access an array of diverse unsymmetrical diaryl and heterodiaryl sulfones, aryl alkyl sulfones and aryl vinyl sulfones in good to excellent yields.
