- Production of Copolyester Monomers from Plant-Based Acrylate and Acetaldehyde
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PCTA is an important copolyester that has been widely used in our daily necessities. Currently, its monomers are industrially produced from petroleum-derived xylene. To reduce the reliance on fossil energy, we herein disclose an alternative route to acces
- Yuan, Lin,Hu, Yancheng,Zhao, Zhitong,Li, Guangyi,Wang, Aiqin,Cong, Yu,Wang, Feng,Zhang, Tao,Li, Ning
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supporting information
(2021/12/14)
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- Vitamin B1-catalyzed aerobic oxidative esterification of aromatic aldehydes with alcohols
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A straightforward aerobic oxidative esterification of aryl aldehydes with alcohols has been developed for the synthesis of substituted esters by employing vitamin B1 as a cost-effective, metal-free, and eco-friendly NHC catalyst. Air is used as a green terminal oxidant. The reaction is a useful addition to the existing NHC-catalytic oxidative esterification.
- Chu, Xue-Qiang,Ge, Danhua,Luo, Xin-Long,Xu, Pei,Yu, Zi-Lun
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supporting information
p. 30937 - 30942
(2021/11/19)
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- N-Heterocyclic Carbene Catalyzed Ester Synthesis from Organic Halides through Incorporation of Oxygen Atoms from Air
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Oxygenation reactions with molecular oxygen (O2) as the oxygen source provides a green and straightforward strategy for the construction of O-containing compounds. Demonstrated here is a novel N-heterocyclic carbene (NHC) catalyzed oxidative transformation of simple and readily available organic halides into valuable esters through the incorporation of O-atoms from O2. Mechanistic studies prove that the deoxy Breslow intermediate generated in situ is oxidized to a Breslow intermediate for further transformation by this oxidative protocol. This method broadens the field of NHC catalysis and promotes oxygenation reactions with O2.
- Tan, Hui,Wang, Shen-An,Yan, Zixi,Liu, Jianzhong,Wei, Jialiang,Song, Song,Jiao, Ning
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supporting information
p. 2140 - 2144
(2020/12/01)
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- Visible-Light-Promoted Metal-Free Synthesis of (Hetero)Aromatic Nitriles from C(sp3)?H Bonds**
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The metal-free activation of C(sp3)?H bonds to value-added products is of paramount importance in organic synthesis. We report the use of the commercially available organic dye 2,4,6-triphenylpyrylium tetrafluoroborate (TPP) for the conversion of methylarenes to the corresponding aryl nitriles via a photocatalytic process. Applying this methodology, a variety of cyanobenzenes have been synthesized in good to excellent yield under metal- and cyanide-free conditions. We demonstrate the scope of the method with over 50 examples including late-stage functionalization of drug molecules (celecoxib) and complex structures such as l-menthol, amino acids, and cholesterol derivatives. Furthermore, the presented synthetic protocol is applicable for gram-scale reactions. In addition to methylarenes, selected examples for the cyanation of aldehydes, alcohols and oximes are demonstrated as well. Detailed mechanistic investigations have been carried out using time-resolved luminescence quenching studies, control experiments, and NMR spectroscopy as well as kinetic studies, all supporting the proposed catalytic cycle.
- Murugesan, Kathiravan,Donabauer, Karsten,K?nig, Burkhard
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p. 2439 - 2445
(2020/12/07)
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- Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst
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Herein, a Grubbs-catalyzed route for the synthesis of nitriles via the aerobic oxidation of primary amines is reported. This reaction accommodates a variety of substrates, including simple primary amines, sterically hindered β,β-disubstituted amines, allylamine, benzylamines, and α-amino esters. Reaction compatibility with various functionalities is also noted, particularly with alkenes, alkynes, halogens, esters, silyl ethers, and free hydroxyl groups. The nitriles were also synthesized via the oxidation of imines generated from aldehydes and NH4OAc in situ. (Figure presented.).
- Utsumi, Tatsuki,Noda, Kenta,Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
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supporting information
p. 3583 - 3588
(2020/08/05)
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- Difluorocarbene-Based Cyanation of Aryl Iodides
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A large number of efficient cyanation methods have been developed because of the wide range of applications of nitriles, but conventional methods usually suffer from the need for a toxic cyanation reagent. Although difluorocarbene chemistry has received increasing attention, the use of difluorocarbene as a sources of the nitrile carbon for nitrile groups remains largely unexplored. We describe a difluorocarbene-based cyanation of aryl iodides promoted by a cheap copper source, Cu(NO 3) 2 ·2.5H 2 O, under an air atmosphere. Ph 3 P + CF 2 CO 2-, an easily available and shelf-stable difluorocarbene reagent, and NaNH 2 are used as the carbon source and the nitrogen source for the nitrile group, respectively. The cyanation protocol is attractive because no toxic reagent is used and performing the reactions under an air atmosphere is operationally convenient.
- Cao, Yu-Cai,Du, Ruo-Bing,Fu, Zhi-Hong,Guo, Yu,Lin, Jin-Hong,Xiao, Ji-Chang,Xiao, Xuan,Yao, Xu,Zhang, Yin-Xiang,Zheng, Xing
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supporting information
p. 713 - 717
(2020/04/08)
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- Zn-catalyzed cyanation of aryl iodides
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We report the first example of zinc-catalyzed cyanation of aryl iodides with formamide as the cyanogen source. The transformation was promoted by the bisphosphine Nixantphos ligand. Under optimized conditions, a variety of electron-donating and electron-withdrawing aryl iodides were converted into nitrile products in good to excellent yields. This approach is an exceedingly simple and benign method for the synthesis of aryl nitriles and is likely to proceed via a dinuclear Zn-concerted catalysis.
- Zhao, Lulu,Dong, Yanan,Xia, Qiangqiang,Bai, Jianfei,Li, Yuehui
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p. 6471 - 6477
(2020/06/08)
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- Acyl Cyanides as Bifunctional Reagent: Application in Copper-Catalyzed Cyanoamidation and Cyanoesterification Reaction
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Cu-catalyzed domino decyanation and cyanation reaction of acyl cyanides with amines or alcohols have been developed. The cyano sources were generated in situ via C-CN cleavage yielding the corresponding cyano substituted amides or esters in moderate to excellent yields. This approach features a cheap copper catalyst, domino decyanation and cyanation reaction, readily available starting materials, broad substrate scope, operational simplicity, and the potential for further transformation of the cyano group.
- Chen, Zhengwang,Wen, Xiaowei,Zheng, Weiping,He, Ruolan,Chen, Dou,Cao, Dingsheng,Long, Lipeng,Ye, Min
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p. 5691 - 5701
(2020/04/10)
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- Nickel-Catalyzed Cyanation of Aryl Halides and Hydrocyanation of Alkynes via C-CN Bond Cleavage and Cyano Transfer
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We report nickel-catalyzed cyanation and hydrocyanation methods to prepare aryl nitriles and vinyl nitriles from aryl halides and alkynes, respectively. Using inexpensive and nontoxic 4-cyanopyridine N-oxide as the cyano shuttle, the methods provide an efficient approach to prepare aryl cyanides and vinyl nitriles under mild and operationally simple reaction conditions with a broad range of functional group tolerances. In hydrocyanation of alkynes, the method demonstrated good regioselectivity, producing predominantly E- or Z-alkenyl nitriles in a controlled manner and exclusively Markovnikov vinyl nitriles when internal diaryl alkynes and terminal alkynes were applied as the substrates, respectively. The preliminary mechanistic investigation indicated that the C-CN bond cleavage process is promoted by oxidative addition to the nickel(I) complex in the cyanation of aryl halides, and further studies via a series of deuterium exchange experiments indicated that water serves as the hydrogen source for the hydrocyanation of alkynes.
- Chen, Hui,Sun, Shuhao,Liu, Yahu A.,Liao, Xuebin
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p. 1397 - 1405
(2020/02/04)
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- Electrocarboxylation of halobenzonitriles: An environmentally friendly synthesis of phthalate derivatives
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This manuscript presents an efficient approach for producing high valuable compounds using CO2 as building block. The methodology employed is based on electrochemical techniques, which allow performing eco-friendly chemistry solutions and maintaining the aim of offering a potential long-term strategy for reducing the CO2 emissions in the atmosphere, while obtaining useful compounds, such as aromatic acids and phthalate derivatives. This work describes the electrochemical reduction behavior of 4-halobenzonitrile compounds using Glassy Carbon and Silver as cathodes under inert and carbon dioxide atmosphere. Controlled potential electrolysis of 4-halobenzonitriles under CO2 allows obtaining, in very good yields, the corresponding mono- and di-carboxylated organic compounds in CO2-saturated solutions of dimethylformamide containing 0.1 M of tetrabutylammonium tetrafluoroborate. Electro-catalytic effects are seen when Ag is used a cathode, which give very high yields, especially as regards di-carboxylated products. The methodology offers a new “green” route for the synthesis of different phthalate derivatives, which can be potentially used for making plastic polymers in a more environmentally friendly way.
- Reche, Irene,Mena, Silvia,Gallardo, Iluminada,Guirado, Gonzalo
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- Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
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A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO 2 F 2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.
- Qin, Hua-Li,S Alharbi, Njud,Wang, Shi-Meng
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p. 3901 - 3907
(2019/10/11)
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- Design and synthesis of new norfloxacin-1,3,4-oxadiazole hybrids as antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA)
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Toward the search of new antibacterial agents to control methicillin-resistant Staphylococcus aureus (MRSA), a class of new norfloxacin-1,3,4-oxadiazole hybrids were designed and synthesized. Antibacterial activities against drug-sensitive bacteria S. aureus and clinical drug resistant isolates of MRSA were evaluated. Compound 5k exhibited excellent antibacterial activities against S. aureus (MIC: 2 μg/mL) and MRSA1–3 (MIC: 0.25–1 μg/mL). The time-kill kinetics demonstrated that compound 5k had an advantage over commonly used antibiotics vancomycin in killing S. aureus and MRSA. Moreover, compound 5k could inhibit the bacteria and destroy their membranes in a short time, and showed very low cytotoxicity to NRK-52E cells. Some interesting structure-activity relationships (SARs) were also discussed. These results indicated that these norfloxacin-1,3,4-oxadiazole hybrids could be further developed into new antibacterial agents against MRSA.
- Guo, Yong,Xu, Ting,Bao, Chongnan,Liu, Zhiyan,Fan, Jiangping,Yang, Ruige,Qin, Shangshang
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- 1,10-Phenanthroline- or Electron-Promoted Cyanation of Aryl Iodides
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A 1,10-phenanthroline-promoted cyanation of aryl iodides has been developed. 1,10-Phenanthroline worked as an organocatalyst for the reaction of aryl iodides with tetraalkylammonium cyanide to afford aryl cyanides. A similar reaction occurred through an electroreductive process.
- Hirata, Takayuki,Mandai, Hiroki,Midorikawa, Koji,Mitsudo, Koichi,Suga, Seiji,Yoshioka, Kazuki
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supporting information
p. 1209 - 1214
(2019/06/08)
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- Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
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Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
- Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
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supporting information
p. 19257 - 19262
(2019/12/02)
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- Preparation method and application of 4-formaldehyde oxime ethyl benzoate
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The invention provides a preparation method of 4-formaldehyde oxime ethyl benzoate. The preparation method comprises the following steps: S1, dissolving 4-bromobenzoic acid in ethanol, and then addingan acyl chloride reagent for reaction to obtain yellow 4-ethyl bromobenzoate; S2, dissolving the 4-ethyl bromobenzoate in an amide solvent, and then adding a cyanation reagent for reaction to obtain4-ethyl cyanobenzoate; S3, dissolving the 4-ethyl cyanobenzoate with an alcohol reagent, and then adding hydroxylamine hydrochloride, alkali and water for reaction, and performing concentration underreduced pressure to obatin a solid of the 4-formaldehyde oxime ethyl benzoate. The preparation method solves the problems of long process route, cumbersome operation, harsh reaction conditions, high preparation cost, high production safety risk, troublesome posttreatment and the like in an original process. The synthetic process route of the preparation method disclosed by the invention is short;the reaction conditions are mild; the operation is simple; the raw materials required for the reaction are cheap and easy to obtain; the solvent used can be recycled; the production cost is lower; thepreparation method is suitable for large-scale industrial production.
- -
-
Paragraph 0017
(2019/07/04)
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- Catalytic Cyanation Using CO2 and NH3
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Li and co-workers describe the catalytic cyanation of organic halides with CO2 and NH3. In the presence of Cu2O/DABCO as the catalyst, a variety of aromatic bromides and iodides were transformed to the desired nitrile products with broad functional-group tolerance. Both 13C- and/or 15N-labeled nitriles were obtained conveniently with appropriately isotope-labeled CO2 and NH3. Construction of functionalized chemical compounds from small molecules in a highly selective and efficient manner is crucial for sustainable development. The chemical-based manufacturing sector of the future should aim to produce chemicals from very simple and abundant resources, just as nature uses CO2 and N2 to generate sugars, amino acids, and so forth. In practice, however, the utilization of CO2 for the generation of industrial products, such as drugs and related intermediates, still remains a major challenge. Here, we describe the facile cyanide-free production of high-value nitriles with CO2 and NH3 as the sole sources of carbon and nitrogen, respectively. This practical and catalytic methodology provides a unique strategy for the utilization of small molecules for sustainable and cost-effective applications. Selective cyanation of aryl halides was achieved with CO2 and NH3 as the only sources of carbon and nitrogen, respectively. In the presence of Cu catalysts under low pressure (3 atm), a variety of aromatic iodides and bromides were transformed to the desired nitrile products without the use of toxic metal cyanides. Notably, olefins, esters, amides, alcohols, and amino groups were tolerated. Mechanistic studies suggest that Cu(III)-aryl insertion by isocyanate intermediates is involved. [13C,15N]-labeled nitriles were conveniently accessible from the respective isotope-labeled CO2 and NH3 via this methodology.
- Wang, Hua,Dong, Yanan,Zheng, Chaonan,Sandoval, Christian A.,Wang, Xue,Makha, Mohamed,Li, Yuehui
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supporting information
p. 2883 - 2893
(2019/01/05)
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- Cyaniding method for preparing nitrile compound
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The invention provides a cyaniding method for preparing a nitrile compound. Organic halide or pseudohalide, CO2 and NH3 which are low in price and are easily obtained and a reducing agent react, a selective cyaniding reaction is conducted in the presence of a transition metal catalyst, and the target product namely organic the nitrile compound is obtained. According to the cyaniding method for preparing the nitrile compound, a new reaction route is used, through a CO2 and NH3 reaction of metal catalysis, dehalogenation cyaniding or quasi halide cyaniding of halide or pseudohalide is directly achieved through a one-pot method, the problem is solved that a traditional cyanation reaction needs equivalent toxic cyanide, a new direct and convenient method for preparing isotope-labeled nitrile compounds is provided at the same time, and the method can be applied to medicine, tracing, biology and medicine research and development.
- -
-
Paragraph 0062-0064
(2018/05/30)
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- Synthesis, characterization and catalytic performances of benzimidazolin-2-iminato actinide (IV) complexes in the Tishchenko reactions for symmetrical and unsymmetrical esters
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A new family of benzimdazolin-2-iminato actinide?(IV) complexes [(Bim7-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (3), Th (4)) and [(Bim4-MeDipp/MeN)An(N(SiMe3)2)3] (An = U (5), Th (6)) were synthesized and their solid state structures were established by single-crystal X-ray diffraction analysis. The catalytic performances of complexes 3–6 towards the homo- and cross-coupling of aldehydes (Tishchenko reaction) were studied and the thorium complexes 4 and 6 displayed moderate to high activities for the production of the corresponding symmetric and unsymmetrical esters. Coupling of aldehyde and alcohols, known as the tandem proton-transfer esterification, and the intermolecular coupling reaction between aldehyde and trifluoromethylketones were also investigated by these thorium complexes, indicating a complementary method to obtain unsymmetrical esters selectively. Plausible mechanisms for these reactions are proposed based on stoichiometric studies.
- Liu, Heng,Khononov, Maxim,Fridman, Natalia,Tamm, Matthias,Eisen, Moris S.
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p. 123 - 137
(2017/10/25)
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- Chemoselective and Metal-Free Synthesis of Aryl Esters from the Corresponding Benzylic Alcohols in Aqueous Medium Using TBHP/TBAI as an Efficient Catalytic System
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A novel and transition-metal-free strategy has been developed for the synthesis of aryl esters starting from corresponding benzylic primary alcohols as the exclusive substrates using tert -butyl hydroperoxide (TBHP) as a terminal oxidant in the presence of catalytic amount of tetrabutylammonium iodide (TBAI) and imidazole, where the aliphatic alcohols remained unaffected. These reactions are highly chemoselective and associated with high yield and wide applicability accommodating a wide range of substituents. Excellent chemoselectivity has also been demonstrated through intramolecular competition experiments. This protocol can be considered as an important analogue of Tishchenko reaction using benzylic alcohols as the substrates instead of benzaldehydes.
- Nandy, Sneha,Ghatak, Avishek,Das, Asit Kumar,Bhar, Sanjay
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p. 2208 - 2212
(2018/10/02)
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- Broadly Applicable Ytterbium-Catalyzed Esterification, Hydrolysis, and Amidation of Imides
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An efficient, broadly applicable, operationally simple, and divergent process for the transformation of imides into a range of carboxylic acid derivatives under mild conditions is reported. By simply using catalytic amounts of ytterbium(III) triflate as a Lewis acid promoter in the presence of alcohols, water, amines, or N,O-dimethylhydroxylamine, a broad range of imides is smoothly and readily converted to the corresponding esters, carboxylic acids, amides, and Weinreb amides in good yields. This method notably enables an easy cleavage of oxazolidinone-based auxiliaries.
- Guissart, Céline,Barros, Andre,Rosa Barata, Luis,Evano, Gwilherm
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supporting information
p. 5098 - 5102
(2018/09/13)
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- Palladium-Catalyzed Synthesis of Aryl Nitriles: Using α-Iminonitrile as Cyano Source for Aryl Halide Cyanations
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An efficient and ligand-free palladium-catalyzed exchange reaction to synthesize aryl nitriles by using α-iminonitrile as a starting reagent has been developed. This methodology provides an optional method for the synthesis of aryl nitriles with moderate to good yields. At the same time, this approach is adaptable for many substrates.
- Shi, Yu-Long,Yuan, Qing,Chen, Zhen-Bang,Zhang, Fang-Ling,Liu, Kui,Zhu, Yong-Ming
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supporting information
p. 359 - 363
(2017/11/15)
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- Preparation method of aromatic nitrile compound or heteroaromatic nitrile compound
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The invention discloses a preparation method of an aromatic nitrile compound or a heteroaromatic nitrile compound. The preparation method comprises: under the protection of an inert gas, in a solvent,under the actions of a nickel catalyst, a ligand, metal zinc and an additive, carrying out a reaction on a cyanation reagent and halogenated aromatic hydrocarbon or halogenated heteroaromatic hydrocarbon. According to the present invention, by using the inexpensive and easily-available nickel catalyst and the ligand, the halogenated aromatic hydrocarbon or halogenated heteroaromatic hydrocarbon,especially the chlorinated aromatic hydrocarbon or chlorinated heteroaromatic hydrocarbon with characteristics of low price, easy obtaining and low reaction activity can mildly and efficiently react with the cyanation reagent with low toxicity to prepare the aromatic nitrile compound or heteroaromatic nitrile compound; and the preparation method has advantages of simple operation, mildness, high efficiency and the like, and further has characteristics of good functional group compatibility, good universality of substrate and the like.
- -
-
Paragraph 0043; 0045; 0169-0171
(2018/11/03)
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- SO2F2-Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide
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A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.
- Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2323 - 2331
(2017/09/06)
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- Room Temperature Carbonylation of (Hetero) Aryl Pentafluorobenzenesulfonates and Triflates using Palladium-Cobalt Bimetallic Catalyst: Dual Role of Cobalt Carbonyl
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An efficient method for the carbonylation of (hetero) aryl pentafluorobenzenesulfonates and triflates under exceptionally mild conditions using palladium/dicobalt octacarbonyl [Pd/Co2(CO)8] has been developed. Besides acting as carbon monoxide (CO) source, Co2(CO)8enhances the reaction rate by accelerating the CO insertion through an in situ generated bimetallic palladium cobalt tetracarbonyl [Pd-Co(CO)4] complex. Under the optimized reaction condition, carbonylation of a wide range of activated and deactivated, as well as sterically hindered and heteroaromatic, substrates proceeded efficiently at room temperature. The high chemoselectivity and improved synthesis of biologically relevant Isoguvacine and Lazabemide intermediates highlights its scope as a valuable synthetic method. The generality of this protocol was further extended to other electrophiles (bromides, chlorides and tosylates). (Figure presented.).
- Joseph, Jayan T.,Sajith, Ayyiliath M.,Ningegowda, Revanna C.,Shashikanth, Sheena
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supporting information
p. 419 - 425
(2017/02/10)
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- Graphene Oxide: An Efficient Acid Catalyst for the Construction of Esters from Acids and Alcohols
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Graphene oxide was found to be an efficient and reusable acid catalyst for the esterification reaction. A wide range of aliphatic and aromatic acids and alcohols were compatible with the standard conditions and afforded the corresponding products in good yields. The heterogeneous catalyst can be easily recovered and recycled in dichloro-ethane solvent with good catalytic activity.
- Chen, Zhengwang,Wen, Yuelu,Fu, Yejuan,Chen, Hai,Ye, Min,Luo, Guotian
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supporting information
p. 981 - 985
(2017/05/05)
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- Cyanation of aromatic/vinylic boronic acids with α-cyanoacetates
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A friendly protocol is reported to achieve cyanation of aromatic and vinylic boronic acids using nontoxic and readily available α-cyanoacetates as a cyano source under aerobic conditions. Many aryl/vinyl boronic acids (as well as some iodides and bromides) are amenable substrates to give aryl nitriles and acrylonitriles. This cyanation method provides a safe and operationally convenient alternative to traditional ones requiring toxic cyanide salts.
- Wang, Xian-Jin,Zhang, Song-Lin
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supporting information
p. 14826 - 14830
(2017/12/15)
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- Ex situ generation of stoichiometric HCN and its application in the Pd-catalysed cyanation of aryl bromides: Evidence for a transmetallation step between two oxidative addition Pd-complexes
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A protocol for the Pd-catalysed cyanation of aryl bromides using near stoichiometric and gaseous hydrogen cyanide is reported for the first time. A two-chamber reactor was adopted for the safe liberation of ex situ generated HCN in a closed environment, which proved highly efficient in the Ni-catalysed hydrocyanation as the test reaction. Subsequently, this setup was exploited for converting a range of aryl and heteroaryl bromides (28 examples) directly into the corresponding benzonitriles in high yields, without the need for cyanide salts. Cyanation was achieved employing the Pd(0) precatalyst, P(tBu)3-Pd-G3 and a weak base, potassium acetate, in a dioxane-water solvent mixture. The methodology was also suitable for the synthesis of 13C-labelled benzonitriles with ex situ generated 13C-hydrogen cyanide. Stoichiometric studies with the metal complexes were undertaken to delineate the mechanism for this catalytic transformation. Treatment of Pd(P(tBu)3)2 with H13CN in THF provided two Pd-hydride complexes, (P(tBu)3)2Pd(H)(13CN), and [(P(tBu)3)Pd(H)]2Pd(13CN)4, both of which were isolated and characterised by NMR spectroscopy and X-ray crystal structure analysis. When the same reaction was performed in a THF : water mixture in the presence of KOAc, only (P(tBu)3)2Pd(H)(13CN) was formed. Subjection of this cyano hydride metal complex with the oxidative addition complex (P(tBu)3)Pd(Ph)(Br) in a 1 : 1 ratio in THF led to a transmetallation step with the formation of (P(tBu)3)2Pd(H)(Br) and 13C-benzonitrile from a reductive elimination step. These experiments suggest the possibility of a catalytic cycle involving initially the formation of two Pd(ii)-species from the oxidative addition of LnPd(0) into HCN and an aryl bromide followed by a transmetallation step to LnPd(Ar)(CN) and LnPd(H)(Br), which both reductively eliminate, the latter in the presence of KOAc, to generate the benzonitrile and LnPd(0).
- Kristensen, Steffan K.,Eikeland, Espen Z.,Taarning, Esben,Lindhardt, Anders T.,Skrydstrup, Troels
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p. 8094 - 8105
(2017/11/27)
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- Photoinduced Copper(I)-Catalyzed Cyanation of Aromatic Halides at Room Temperature
-
The first photoinduced copper(I)-catalyzed cyanation of aromatic halides at room temperature has been developed. The sp2 cyanation reaction exhibits outstanding tolerance to functional groups including primary amines and carboxylic acids, and chemoselectivity to SN2-reactive alkyl chlorides. Mechanistic investigations indicate that the reaction occurs via a single-electron transfer (SET) between the aryl halide and an excited copper(I) cyanide catalytic intermediate. (Figure presented.).
- Kim, Kicheol,Hong, Soon Hyeok
-
supporting information
p. 2345 - 2351
(2017/07/22)
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- Cobalt-Catalyzed Esterification of Amides
-
The first cobalt-catalyzed amide activation of N-Boc-amides, and their conversion into esters, is reported here. This new methodology presents a very practical process that does not require an inert atmosphere, uses an inexpensive cobalt catalyst, and proceeds under mild reaction conditions. This catalytic system has a broad substrate scope and has been shown to be highly efficient, with catalyst loadings as low as 1 mol %.
- Bourne-Branchu, Yann,Gosmini, Corinne,Danoun, Grégory
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supporting information
p. 10043 - 10047
(2017/08/01)
-
- General and Mild Nickel-Catalyzed Cyanation of Aryl/Heteroaryl Chlorides with Zn(CN)2: Key Roles of DMAP
-
A new and general nickel-catalyzed cyanation of hetero(aryl) chlorides using less toxic Zn(CN)2 as the cyanide source has been developed. The reaction relies on the use of inexpensive NiCl2·6H2O/dppf/Zn as the catalytic system and DMAP as the additive, allowing the cyanation to occur under mild reaction conditions (50-80 °C) with wide functional group tolerance. DMAP was found to be crucial for successful transformation, and the reaction likely proceeds via a Ni(0)/Ni(II) catalysis based on mechanistic studies. The method was also successfully extended to aryl bromides and aryl iodides.
- Zhang, Xingjie,Xia, Aiyou,Chen, Haoyi,Liu, Yuanhong
-
supporting information
p. 2118 - 2121
(2017/04/27)
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- N-Heterocyclic carbene-mediated redox condensation of alcohols
-
N-Heterocyclic carbenes (NHCs) with a variety of oxidants promote the Mitsunobu-type coupling reactions of alcohols with phenols, carboxylic acids, and phthalimide. Experiments using a chiral alcohol indicate that these reactions proceed via SN1 or SN2 pathways depending on the polarity of the used solvents. The NHCs are consumed as reducing reagents to form their oxides as readily separable byproducts.
- Kato, Terumasa,Matsuoka, Shin-Ichi,Suzuki, Masato
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supporting information
p. 8569 - 8572
(2016/07/13)
-
- Synthesis of novel benzohydrazides bearing 4-[3-methyl-4-(methylsulfonyl)pyridin-2-yl] moiety as potential antibacterial agents
-
This work reports the synthesis and antibacterial activity of novel hydrazone derivatives 8a-k bearing 4-[3-methyl-4-(methylsulfonyl)pyridin- 2-yl] moiety. Spectroscopic techniques like 1H NMR, mass and IR tools was utilized for the characterization of these hydrazone derivatives. The synthesized hydrazone derivatives were tested against a set of bacterial strains, namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes by paper disc diffusion method. Compounds 8b, 8d, 8e, 8f, 8h, 8i showed good antibacterial activity against the test organisms.
- Saidugari, Swamy,Rao, V. Lakshmana,Vidya,Ram,Balram
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p. 639 - 643
(2016/01/20)
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- Synthesis and antibacterial activity of some new quinaxaline-benzohydrazides
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Quinoxalines have been found to exhibit various biological activities such as antibacterial, antifungal, anti-tubercular, anxiolytic, anticancer, antioxidant, anti-inflammatory, anti-HIV, antihelmintic and anticonvulsant. The present study aims towards synthesis, characterization and determination of antimicrobial susceptibility testing of various novel quinoxaline derivatives. The quinoxaline-benzohydrazides 6a-m have been obtained by the condensation of quinoxaline-2-carboxaldehyde 4 with various benzohydrazides 5a-m in ethanol at reflux temperature. All the newly synthesized quinoxaline-benzohydrazide derivatives have been characterized by 1H NMR, IR and mass spectroscopic analysis. The synthesized quinoxaline-benzohydrazides 6a-m have been screened for antibacterial activity. Most of the compounds show significant antibacterial activity.
- Haripriya,Laxminarayana,Thirumala Chary
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p. 207 - 212
(2017/01/18)
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- Cleavage of the Carbon–Carbon Triple Bonds of Arylacetylenes for the Synthesis of Arylnitriles without a Metal Catalyst
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Cleavage of the carbon–carbon triple bonds of alkynes was achieved, which led to the synthesis of arylnitriles under transition-metal-free conditions. A vast range of terminal alkyne substrates underwent this reaction to provide the corresponding nitriles in moderate to good yields with good functional group tolerance.
- Lin, Yuanguang,Song, Qiuling
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p. 3056 - 3059
(2016/07/12)
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- South (S)- and north (N)-methanocarba-7-deazaadenosine analogues as inhibitors of human adenosine kinase
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Adenosine kinase (AdK) inhibitors raise endogenous adenosine levels, particularly in disease states, and have potential for treatment of seizures, neurodegeneration, and inflammation. On the basis of the South (S) ribose conformation and molecular dynamics (MD) analysis of nucleoside inhibitors bound in AdK X-ray crystallographic structures, (S)- and North (N)-methanocarba (bicyclo[3.1.0]hexane) derivatives of known inhibitors were prepared and compared as human (h) AdK inhibitors. 5′-Hydroxy (34, MRS4202 (S); 55, MRS4380 (N)) and 5′-deoxy 38a (MRS4203 (S)) analogues, containing 7- and N6-NH phenyl groups in 7-deazaadenine, robustly inhibited AdK activity (IC50 ~ 100 nM), while the 5′-hydroxy derivative 30 lacking the phenyl substituents was weak. Docking in the hAdK X-ray structure and MD simulation suggested a mode of binding similar to 5′-deoxy-5-iodotubercidin and other known inhibitors. Thus, a structure-based design approach for further potency enhancement is possible. The potent AdK inhibitors in this study are ready to be further tested in animal models of epilepsy.
- Toti, Kiran S.,Osborne, Danielle,Ciancetta, Antonella,Boison, Detlev,Jacobson, Kenneth A.
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supporting information
p. 6860 - 6877
(2016/08/05)
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- The application of NCTS (N-cyano-N-phenyl-p-toluenesulfonamide) in palladium-catalyzed cyanation of arenediazonium tetrafluoroborates and aryl halides
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Using NCTS (N-cyano-N-phenyl-p-toluenesulfonamide) as an electrophilic cyanation reagent, palladium-catalyzed cyanation of arenediazonium tetrafluoroborates and aryl halides was achieved under mild conditions. The method allowed the effective synthesis of various aryl nitriles in suitable yields via a coupling reaction.
- Li, Jizhen,Xu, Wenbin,Ding, Junshuai,Lee, Kuo-Hsiung
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supporting information
p. 1205 - 1209
(2016/03/01)
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- BENZENE SULFONAMIDES AS CCR9 INHIBITORS
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The present invention relates to compounds useful as CCR9 modulators, to compositions containing them, to methods of making them, and to methods of using them. In particular, the present invention relates to compounds capable of modulating the function of the CCR9 receptor by acting as partial agonists, antagonists or inverse agonists. Such compounds may be useful to treat, prevent or ameliorate a disease or condition associated with CCR9 activation, including inflammatory and immune disorder diseases or conditions such as inflammatory bowel diseases (IBD).
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Page/Page column 86
(2015/07/15)
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- Cobalt-Catalyzed Electrophilic Cyanation of Arylzinc Halides with N-Cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS)
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The cobalt-catalyzed cross-coupling of organozinc bromides with N-cyano-N-phenyl-p-methylbenzenesulfonamide (NCTS) is described. The same cobalt catalyst, cobalt(II) bromide, was used for both the synthesis of the organozinc species and the cross-coupling reaction. However in this case, a catalytic amount of zinc dust is necessary in the second step to release the low-valent cobalt. Under these mild conditions, moderate to excellent yields of different benzonitriles were obtained.
- Cai, Yingxiao,Qian, Xin,Rrat, Alice,Auffrant, Audrey,Gosmini, Corinne
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supporting information
p. 3419 - 3423
(2016/01/25)
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- Palladium-Catalyzed Carbonylations of Arylboronic Acids: Synthesis of Arylcarboxylic Acid Ethyl Esters
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An approach for the palladium-catalyzed ethoxycarbonylations of arylboronic acids using diethyl pyrocarbonate as carbon monoxide/carbon dioxide (CO/CO2) surrogate in moderate to good yields has been investigated.
- Liang, Apeng,Han, Shuaijun,Wang, Liang,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
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supporting information
p. 3104 - 3108
(2015/11/03)
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- Acid Chloride Synthesis by the Palladium-Catalyzed Chlorocarbonylation of Aryl Bromides
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We report a palladium-catalyzed method to synthesize acid chlorides by the chlorocarbonylation of aryl bromides. Mechanistic studies suggest the combination of sterically encumbered PtBu3 and CO coordination to palladium can rapidly equilibrate the oxidative addition/reductive elimination of carbon-halogen bonds. This provides a useful method to assemble highly reactive acid chlorides from stable and available reagents, and can be coupled with subsequent nucleophilic reactions to generate new classes of carbonylated products. The Good, the Bad and the Bulky! By employing a sterically encumbered phosphine ligand, tri-tert-butyl phosphine, under palladium catalysis inert aryl bromides are chlorocarbonylated to create reactive acid chlorides by reversible carbon-halogen bond reductive elimination. This general platform allows for an expanded scope of the Heck carbonylation reaction to include previously incompatible nucleophiles.
- Quesnel, Jeffrey S.,Kayser, Laure V.,Fabrikant, Alexander,Arndtsen, Bruce A.
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supporting information
p. 9550 - 9555
(2015/06/30)
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- Mild palladium-catalyzed cyanation of (hetero)aryl halides and triflates in aqueous media
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A mild, efficient, and low-temperature palladium-catalyzed cyanation of (hetero)aryl halides and triflates is reported. Previous palladium-catalyzed cyanations of (hetero)aryl halides have required higher temperatures to achieve good catalytic activity. This current reaction allows the cyanation of a general scope of (hetero)aryl halides and triflates at 2-5 mol % catalyst loadings with temperatures ranging from rt to 40 °C. This mild method was applied to the synthesis of lersivirine, a reverse transcriptase inhibitor.
- Cohen, Daniel T.,Buchwald, Stephen L.
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supporting information
p. 202 - 205
(2015/01/30)
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- Expedient carbonylation of aryl halides in aqueous or neat condition
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An expedient and versatile, microwave-assisted procedure for the carbonylation of aryl halides with boronic acids, alcohols or amines in water or under neat conditions has been developed. The reaction is catalyzed by fluorous, oxime-based palladacycle 1 that shows an excellent recyclable property and low levels of Pd leaching. To demonstrate the usefulness of the protocol, we applied it to the preparation of compounds of pharmaceutical interest, including a precursor of the reverse transcriptase inhibitor, niacin, benzocaine and butamben.
- Ang, Wei Jie,Lo, Lee-Chiang,Lam, Yulin
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p. 8545 - 8558
(2014/12/11)
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- Polymer supported Pd catalyzed carbonylation of aryl bromides for the synthesis of aryl esters and amides
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A polymer-anchored palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the alkoxycarbonylation and aminocarbonylation reactions. These carbonylation reactions were carried out for various substituted aryl bromides using alcohols and amines. Both the reactions were optimized by varying the bases, temperature and solvents. These experiments were carried out under high CO pressure. The catalyst was very stable and can be facilely recovered and reused six times without a significant decrease in its activity and selectivity. the Partner Organisations 2014.
- Islam, Sk Manirul,Ghosh, Kajari,Roy, Anupam Singha,Molla, Rostam Ali
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p. 38986 - 38999
(2014/11/07)
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- One-pot transformation of methylarenes into aromatic nitriles with inorganic metal-free reagents
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Various methylarenes were transformed into the corresponding aromatic nitriles in good to moderate yields by the treatment with aq. HBr and aq. H 2O2, followed by reaction with molecular iodine and aq. ammonia in a one-pot procedure. The present reaction is a useful, practical, transition-metal-free, and organic-reagent-free method for the preparation of aromatic nitriles from methylarenes. Various methylarenes were treated with aq. HBr and aq. H2O2 under warming conditions and/or irradiation conditions, followed by the reaction with molecular iodine and aq. ammonia, to provide the corresponding aromatic nitriles, in a one-pot procedure. The present reaction was carried out under metal-free and organic-reagent-free conditions. Copyright
- Kawagoe, Yuhsuke,Moriyama, Katsuhiko,Togo, Hideo
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p. 4115 - 4122
(2014/07/08)
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- Highly selective trifluoroacetic ester/ketone metathesis: An efficient approach to trifluoromethyl ketones and esters
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A highly selective and atom efficient 'trifluoroacetic ester/ketone metathesis' has been sincerely witnessed. Enolizable alkyl (at least two non-hydrogen atoms) aryl ketones were found to react readily with ethyl trifluoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones (TFMKs), and aromatic acid esters, which were quite different from the general Claisen condensation products, 1,3-diketones. The outcome of the reaction between ketone and ethyl trifluoroacetate is strongly related to the structures of substrates, the steric congestion caused by alkyl group is in favor of the C-C bond cleavage. DFT investigation further disclosed that the metathesis reaction was a kinetically favored pathway. Using only a slight excess of cheap trifluoromethylation reagent, simple operation and mild conditions make it a practical method for preparation of TFMKs on large scale, as well as a new choice of converting aryl alkyl ketones to aromatic acid esters.
- Zhou, Yuhan,Yang, Dongmei,Luo, Gen,Zhao, Yilong,Luo, Yi,Xue, Na,Qu, Jingping
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p. 4668 - 4674
(2014/06/23)
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- Kinetic study on nucleophilic substitution reactions of 4-Nitrophenyl X-Substituted-Benzoates with potassium ethoxide: Reaction mechanism and role of K+ Ion
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A kinetic study on nucleophilic substitution reactions of 4-nitrophenyl X-substituted-benzoates (7a-i) with EtOK in anhydrous ethanol at 25.0 ± 0.1 °C is reported. The plots of pseudo-first-order rate constants (kobsd) vs. [EtOK] curve upward. Dissection of kobsd into the second-order rate constants for the reactions with the dissociated EtOV and ion-paired EtOK (i.e., kEtO-and kEtOK, respectively) has revealed that the ion-paired EtOK is more reactive than the dissociated EtOV. Hammett plots for the reactions of 7a-i with the dissociated EtOV and ion-paired EtOK exhibit excellent linear correlations with aX = 3.00 and 2.47, respectively. The reactions have been suggested to proceed through a stepwise mechanism in which departure of the leaving-group occurs after the RDS. The correlation of the kEtOK/kEtO{ ratio with the aX constants exhibits excellent linearity with a slope of V0.53. It is concluded that the ion-paired EtOK catalyzes the reaction by increasing the electrophilicity of the reaction center rather than by enhancing the nucleofugality of the leaving group.
- Kim, Song-I,Kim, Min-Young,Um, Ik-Hwan
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p. 225 - 230
(2014/02/14)
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- Efficient palladium-catalyzed cyanation of aryl/heteroaryl bromides with K4[Fe(CN)6] in t-BuOH-H2O using tris(2-morpholinophenyl)phosphine as a ligand
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A practical method for the synthesis of various aryl/heteroaryl nitriles using non-toxic K4[Fe(CN)6] as the cyanide source is described. The cyanation of aryl/heteroaryl bromides with K4[Fe(CN) 6] proceeded smoothly in the presence of a Pd/tris(2- morpholinophenyl)phosphine (L5) catalyst under mild conditions. The corresponding aryl/heteroaryl nitriles were produced in good to excellent yields. The Royal Society of Chemistry 2013.
- Zou, Tao,Feng, Xiujuan,Liu, Hesong,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
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p. 20379 - 20384
(2013/11/06)
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- A general, practical palladium-catalyzed cyanation of (hetero)aryl chlorides and bromides
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Playing it safe: The nontoxic cyanide source K4[Fe(CN) 6]×3 H2O can be used for the cyanation of (hetero)aryl halides. The application of palladacycle catalysts prevents poisoning during catalyst formation, thereby allowing for low catalyst loadings, fast reaction times, and wide heterocyclic substrate scope.
- Senecal, Todd D.,Shu, Wei,Buchwald, Stephen L.
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supporting information
p. 10035 - 10039
(2013/10/01)
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- One-pot transformation of carboxylic acids into nitriles
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A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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p. 5886 - 5892
(2013/09/23)
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- Copper- and silver-mediated cyanation of aryl iodides using ddq as cyanide source
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A new copper and silver-mediated cyanation of aryl iodides with DDQ as a cyanide source is achieved, providing nitriles with good yields. This new approach represents a safe method leading to aryl nitriles. A new copper and silver-mediated cyanation of aryl iodides with DDQ as a cyanide source is achieved.
- Zheng, Kui,Yu, Peng,Chen, Shuyou,Chen, Fen,Cheng, Jiang
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supporting information
p. 449 - 452
(2013/08/25)
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