613-62-7Relevant academic research and scientific papers
Selective O -alkylation of 2-naphthol using phosphonium-based ionic liquid as the phase transfer catalyst
Yadav, Ganapati D.,Tekale, Smruti P.
, p. 722 - 727 (2010)
The selective preparation of O-alkylated aromatic products from substituted phenol and naphthols is challenging. The O-alkylation of 2-naphthol with benzyl chloride has been studied in this work using phosphonium-based ionic liquids as catalysts such as trihexyl(tetradecyl)phosphonium chloride (THTDPC), trihexyl(tetradecyl)phosphonium bromide (THTDPB), trihexyl(tetradecyl) phosphonium decanoate (THTDPD), and trihexyl(tetradecyl)phosphonium hexafluorophosphate (THTDPH). This is a liquid-liquid phase-transfer-catalysed reaction with reuse of catalyst. The effects of various parameters such as agitation speed, various phosphonium-based ionic liquids, phase volume ratio, catalyst concentration, NaOH concentration, mole ratio of starting materials, and temperature were studied systematically to understand the conversion patterns and the selectivity of the desired product. A mechanism of the reaction and a kinetic model are proposed.
Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate
Yabuta, Tatsushi,Hayashi, Masahiko,Matsubara, Ryosuke
, p. 2545 - 2555 (2021/02/01)
Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (Ered -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs2CO3 was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs2CO3 via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs2CO3 made this otherwise formidable SET event possible.
Transition-Metal-Free and Base-Promoted Carbon-Heteroatom Bond Formation via C-N Cleavage of Benzyl Ammonium Salts
Liu, Long,Tang, Yuanyuan,Wang, Kunyu,Huang, Tianzeng,Chen, Tieqiao
, p. 4159 - 4170 (2021/03/09)
A facile and general method for constructing carbon-heteroatom (C-P, C-O, C-S, and C-N) bonds via C-N cleavage of benzyl ammonium salts under transition-metal-free conditions was reported. The combination of t-BuOK and 18-crown-6 enabled a wide range of substituted benzyl ammonium salts to couple readily with different kinds of heteroatom nucleophiles, i.e. hydrogen phosphoryl compounds, alcohols, thiols, and amines. Good functional group tolerance was demonstrated. The scale-up reaction and one-pot synthesis were also successfully performed.
Cross-Coupling Reactions of Aryl Halides with Primary and Secondary Aliphatic Alcohols Catalyzed by an O,N,N-Coordinated Nickel Complex
Hashimoto, Toru,Shiota, Keisuke,Funatsu, Kei,Yamaguchi, Yoshitaka
supporting information, p. 1625 - 1630 (2021/01/26)
A synthesis of alkyl aryl ethers was achieved via the cross-coupling of aryl halides with primary and secondary aliphatic alcohols catalyzed by a bench-stable nickel complex supported by a monoanionic O,N,N-tridentate ligand. This nickel-catalyzed reaction proceeds smoothly in the absence of a phosphine ligand, affording alkyl aryl ethers in moderate to good yields. (Figure presented.).
Enantioselective Ni-Catalyzed Electrochemical Synthesis of Biaryl Atropisomers
Chen, Song,Chen, Yue-Gang,Gao, Pei-Sen,Liu, Dong,Ma, Hong-Xing,Mei, Tian-Sheng,Qiu, Hui,Shuai, Bin,Wang, Yun-Zhao
, p. 9872 - 9878 (2020/06/27)
A scalable enantioselective nickel-catalyzed electrochemical reductive homocoupling of aryl bromides has been developed, affording enantioenriched axially chiral biaryls in good yield under mild conditions using electricity as a reductant in an undivided cell. Common metal reductants such as Mn or Zn powder resulted in significantly lower yields in the absence of electric current under otherwise identical conditions, underscoring the enhanced reactivity provided by the combination of transition metal catalysis and electrochemistry.
Gold(i)-catalyzed Nicholas reaction with aromatic molecules utilizing a bifunctional propargyl dicobalt hexacarbonyl complex
Okamura, Toshitaka,Fujiki, Shogo,Iwabuchi, Yoshiharu,Kanoh, Naoki
supporting information, p. 8522 - 8526 (2019/10/02)
A benchtop-stable reagent for the catalytic Nicholas reaction was developed. By combining a propargyl dicobalt hexacarbonyl cluster with an ortho-alkynylbenzoate unit and a fluorous tag, introduction of a propargyl hexacarbonyl complex on various aromatic compounds having acid- or base-sensitive functional groups becomes possible by using a gold(i) catalyst. In addition, the presence of a fluorous tag facilitates convenient separation of the target products from byproducts.
Iodine(III)-Mediated, Controlled Di- or Monoiodination of Phenols
Satkar, Yuvraj,Yera-Ledesma, Luisa F.,Mali, Narendra,Patil, Dipak,Segura-Quezada, Luis A.,Ramírez-Morales, Perla I.,Solorio-Alvarado, César R.,Navarro-Santos, Pedro
, p. 4149 - 4164 (2019/04/30)
An oxidative procedure for the electrophilic iodination of phenols was developed by using iodosylbenzene as a nontoxic iodine(III)-based oxidant and ammonium iodide as a cheap iodine atom source. A totally controlled monoiodination was achieved by buffering the reaction medium with K3PO4. This protocol proceeds with short reaction times, at mild temperatures, in an open flask, and generally with high yields. Gram-scale reactions, as well as the scope of this protocol, were explored with electron-rich and electron-poor phenols as well as heterocycles. Quantum chemistry calculations revealed PhII(OH)·NH3 to be the most plausible iodinating active species as a reactive "I+" synthon. In light of the relevance of the iodoarene moiety, we present herein a practical, efficient, and simple procedure with a broad functional group scope that allows access to the iodoarene core unit.
Preparation method of thermal paper sensitizer benzyl-2-naphthyl ether
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Paragraph 0026-0046, (2019/10/02)
The invention relates to a preparation method of a thermal paper sensitizer benzyl-2-naphthyl ether. According to the preparation method, benzyl alcohol and 2-bromonaphthalene are used as raw materials, N-tetrahydropyrrole acetic acid is used as a ligand, and Cu (I) or Cu (II) is used as a catalyst in the presence of alkali and a solvent to prepare benzyl-2-naphthyl ether. The preparation method comprises the steps of S1, uniformly mixing and stirring 2-bromonaphthalene and a certain quantity of the solvent, and then sequentially adding a certain quantity of alkalis, the catalyst, the ligand and benzyl alcohol; S2, controlling the reaction temperature and time and stirring the reactants during a reaction; S3, after the reaction is finished, recovering the solvent, adding a certain amount of water and an organic solvent, extracting a water phase with the organic solvent several times, combining organic phases, and sequentially performing washing with water and a sodium carbonate water solution; S4, performing drying, filtering, decolorizing and distilling on the combined organic phase after washing is finished to obtain a crude product, and recrystallizing and drying the crude product to obtain a finished product. According to the method, the production cost is greatly reduced after benzyl alcohol and 2-bromonaphthalene are used as the reaction raw materials, and the method hasa high implementation value and great social and economic benefits.
Electrochemical C-H cyanation of electron-rich (Hetero)arenes
Hayrapetyan, Davit,Rit, Raja K.,Kratz, Markus,Tschulik, Kristina,Goo?en, Lukas J.
supporting information, p. 11288 - 11291 (2018/10/20)
A straightforward method for the electrochemical C-H cyanation of arenes and heteroarenes that proceeds at room temperature in MeOH, with NaCN as the reagent in a simple, open, undivided electrochemical cell is reported. The platinum electrodes are passivated by ad-sorbed cyanide, which allows conversion of an exceptionally broad range of electron-rich substrates all the way down to dialkyl arenes. The cyanide electrolyte can be replenished with HCN, opening opportunities for salt-free industrial C-H cyanation.
Hydrodehalogenation of Haloarenes by a Sodium Hydride–Iodide Composite
Ong, Derek Yiren,Tejo, Ciputra,Xu, Kai,Hirao, Hajime,Chiba, Shunsuke
supporting information, p. 1840 - 1844 (2017/02/05)
A simple protocol for hydrodebromination and -deiodination of halo(hetero)arenes was enabled by sodium hydride (NaH) in the presence of lithium iodide (LiI). Mechanistic studies showed that an unusual concerted nucleophilic aromatic substitution operates in the present process.
