- On-Demand Generation and Use in Continuous Synthesis of the Ambiphilic Nitrogen Source Chloramine
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Herein, we demonstrate the on-demand synthesis of chloramine from aqueous ammonia and sodium hypochlorite solutions, and its subsequent utilization as an ambiphilic nitrogen source in continuous-flow synthesis. Despite its advantages in cost and atom economy, chloramine has not seen widespread use in batch synthesis due to its unstable and hazardous nature. Continuous-flow chemistry, however, provides an excellent platform for generating and handling chloramine in a safe, reliable, and inexpensive manner. Unsaturated aldehydes are converted to valuable aziridines and nitriles, and thioethers are converted to sulfoxides, in moderate to good yields and exceedingly short reaction times. In this telescoped process, chloramine is generated in situ and immediately used, providing safe and efficient conditions for reaction scale-up while mitigating the issue of its decomposition over time.
- Danahy, Kelley E.,Styduhar, Evan D.,Fodness, Aria M.,Heckman, Laurel M.,Jamison, Timothy F.
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supporting information
p. 8392 - 8395
(2020/11/18)
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- Synthesis, characterization, catalytic and biological application of half-sandwich ruthenium complexes bearing hemilabile (κ2-: C, S)-thioether-functionalised NHC ligands
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A series of cationic Ru(ii)(η6-p-cymene) complexes with thioether-functionalised N-heterocyclic carbene ligands have been prepared and fully characterized. Steric and electronic influence of the R thioether substituent on the coordination of the sulfur atom was investigated. The molecular structure of three of them has been determined by means of X-ray diffractrometry and confirmed the bidentate (κ2-C,S) coordination mode of the ligand. Interestingly, only a single diastereomer, as an enantiomeric couple, was observed in the solid state for complexes 1c, 1i and 1j. DFT calculations established a low energy inversion barrier between the two diastereomers through a sulfur pyramidal inversion pathway with R donating group while a dissociative/associative mechanism is more likely with R substituents that contain electron withdrawing group, thus suggesting that the only species observed by the 1H-NMR correspond to an average resonance position of a fluxional mixtures of isomers. All these complexes were found to catalyse the oxydant-free double dehydrogenation of primary amine into nitrile. Ru complex bearing NHC-functionalised S-tBu group was further investigated in a wide range of amines and was found more selective for alkyl amine substrates than for benzylamine derivatives. Finally, preliminary results of the biological effects on various human cancer cells of four selected Ru complexes are reported.
- Achard, Thierry,Bellemin-Laponnaz, Stéphane,Chen, Weiguang,Egly, Julien,Maisse-Francois, Aline,Poblador-Bahamonde, Amalia I.
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supporting information
p. 3243 - 3252
(2020/03/19)
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- Easy Ruthenium-Catalysed Oxidation of Primary Amines to Nitriles under Oxidant-Free Conditions
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A dehydrogenation of primary amine to give the corresponding nitrile under oxidant- and base-free conditions catalysed by simple [Ru(p-cym)Cl2]2 with no extra ligand is reported. The system is highly selective for alkyl amines, whereas benzylamine derivatives gave the nitrile product together with the imine in a ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity.
- Achard, Thierry,Egly, Julien,Sigrist, Michel,Maisse-Fran?ois, Aline,Bellemin-Laponnaz, Stéphane
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supporting information
p. 13271 - 13274
(2019/10/21)
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- Stable and reusable nanoscale Fe2O3-catalyzed aerobic oxidation process for the selective synthesis of nitriles and primary amides
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The sustainable introduction of nitrogen moieties in the form of nitrile or amide groups in functionalized molecules is of fundamental interest because nitrogen-containing motifs are found in a large number of life science molecules, natural products and materials. Hence, the synthesis and functionalization of nitriles and amides from easily available starting materials using cost-effective catalysts and green reagents is highly desired. In this regard, herein we report the nanoscale iron oxide-catalyzed environmentally benign synthesis of nitriles and primary amides from aldehydes and aqueous ammonia in the presence of 1 bar O2 or air. Under mild reaction conditions, this iron-catalyzed aerobic oxidation process proceeds to synthesise functionalized and structurally diverse aromatic, aliphatic and heterocyclic nitriles. Additionally, applying this iron-based protocol, primary amides have also been prepared in a water medium.
- Murugesan, Kathiravan,Senthamarai, Thirusangumurugan,Sohail, Manzar,Sharif, Muhammad,Kalevaru, Narayana V.,Jagadeesh, Rajenahally V.
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supporting information
p. 266 - 273
(2018/01/12)
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- Selective aerobic oxidation of benzylic amines to aryl nitriles catalyzed by CuBr2/N-methyl imidazole
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A convenient and efficient copper-catalyzed aerobic oxidation of primary amines to aryl nitriles was described. Various benzylic and allylic amines were selectively oxidized to the corresponding nitriles in high yields using CuBr2/NMI as the catalyst and O2 as the oxidant. The oxidation reaction profiles monitored by 1H NMR disclosed the scenario of the reaction path as well as the role of the additives. The addition of NMI increased the rate of reaction and suppressed the hydrolysis and the deamination.
- Shen, Yifan,Zhou, Yu,Jiang, Lili,Ding, Guangni,Luo, Luo,Zhang, Zhaoguo,Xie, Xiaomin
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p. 4266 - 4271
(2018/07/06)
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- PROCESS FOR THE MANUFACTURE OF HYDROGENATED NITRILES
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The present invention relates to the manufacture and the use of specific organic compounds of formula (II) wherein n is either 1 or 2, and wherein R1 is linear C1-4 alkyl or branched C3-4 alkyl, wherein R2 is hydrogen or linear C1-4 alkyl or branched C3-4 alkyl, as aroma ingredients in flavors and fragrances. Furthermore the invention relates to new specific organic compounds and their synthesis, as well as to flavor and fragrance formulations comprising at least one of the specific organic compounds.
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Page/Page column 22
(2015/03/13)
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- Cu/nitroxyl-catalyzed aerobic oxidation of primary amines into nitriles at room temperature
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An efficient catalytic method has been developed for aerobic oxidation of primary amines to the corresponding nitriles. The reactions proceed at room temperature and employ a catalyst consisting of (4,4′-tBu 2bpy)CuI/ABNO (ABNO = 9-azabicyclo[3.3.1]nonan-3-one-N-oxyl). The reactions exhibit excellent functional group compatibility and substrate scope and are effective with benzylic, allylic, and aliphatic amines. Preliminary mechanistic studies suggest that aerobic oxidation of the Cu catalyst is the turnover-limiting step of the reaction.
- Kim, Jinho,Stahl, Shannon S.
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p. 1652 - 1656
(2013/07/26)
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- Highly practical synthesis of nitriles and heterocycles from alcohols under mild conditions by aerobic double dehydrogenative catalysis
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A mild, aerobic, catalytic process for obtaining nitriles directly from alcohols and aqueous ammonia is described. The reaction proceeds via a dehydrogenation cascade mediated by catalytic CuI, bpy, and TEMPO in the presence of O2. The substrate scope is broad including various functionalized aromatic and aliphatic alcohols. This protocol enabled the one-pot synthesis of various biaryl heterocycles directly from commercially available alcohols.
- Yin, Weiyu,Wang, Chengming,Huang, Yong
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supporting information
p. 1850 - 1853
(2013/06/04)
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- MTO catalyzed oxidation of aldehyde N,N-dimethylhydrazones with hydrogen peroxide: High yield formation of nitriles and N-methylene-N-methyl N-oxide
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N,N-Dimethylhydrazones of aldehydes react with hydrogen peroxide at -50 °C in the presence of catalytic amounts of methyltrioxorhenium (MTO) to give in high yield the corresponding nitriles and N-methylene-N-methyl N-oxide.
- Rudler, Henri,Denise, Bernard
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p. 2145 - 2146
(2007/10/03)
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