103-14-0Relevant academic research and scientific papers
Chemoenzymatic polycondensation of para-benzylamino phenol
Yildirim, Pinar,Gokturk, Ersen,Turac, Ersen,Demir, Haci O,Sahmetlioglu, Ertugrul
, p. 610 - 619 (2016)
Para-Benzylamine substituted oligophenol was synthesized via enzymatic oxidative polycondensation of 4-(benzylamino)phenol (BAP). Polymerization involved only the phenolic moiety without oxidizing the sec-amine (benzylamine) group. Chemoselective polycondensation of BAP monomer using HRP enzyme yielded oligophenol with sec-amine functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polycondensation were studied. Optimum polymerization process with the highest yield (63 %) and molecular weight (Mn = 5000, degree of polymerization ≈ 25) was achieved using the EtOH/buffer (pH 5.0; 1 : 1 vol. ratio) at 25 °C in 24 h under air. Characterization of the oligomer was accomplished by 1H NMR and 13C NMR, Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis), cyclic voltammetry (CV) and thermogravimetric analysis (TGA). The polymerization process involved the elimination of hydrogen from BAP, and phenolic-OH end groups of the oligo(BAP), confirmed using 1H NMR and FT-IR analyses. The oligomer backbone possessed phenylene and oxyphenylene repeat units, and the resulting oligomer was highly soluble in common organic solvents such as acetone, CHCl3, 1,4-dioxane, N,N-dimethylformamide (DMF), tetrahydrofurane (THF) and dimethylsulfoxide (DMSO). Oligo(BAP) was thermally stable and exhibited 5 % and 50 % mass loss determined by thermogravimetric analysis at 247°C and 852°C, respectively.
Unprecedented catalytic performance in amine syntheses: Via Pd/g-C3N4 catalyst-assisted transfer hydrogenation
Xu, Xingliang,Luo, Jiajun,Li, Liping,Zhang, Dan,Wang, Yan,Li, Guangshe
, p. 2038 - 2046 (2018)
The preparation of amine compounds is very important for both the chemical industry and renewable feedstock processing. Nevertheless, difficulties remain in finding a catalytic system that is sufficiently active and environmentally benign for producing amine compounds. In this work, we report that g-C3N4 nanosheets as support materials can significantly boost the efficiency of Pd nanoparticles for the reduction of nitro compounds to primary amines. Using formic acid as a hydrogen donor and water as a solvent, the optimized 5 wt% Pd/g-C3N4 catalyst exhibited an unprecedented performance in the conversion of nitrobenzene into aniline (achieving almost full conversion with an extremely high turnover frequency of 4770 h-1 at room temperature), yielding the best activity ever reported for heterogeneously catalyzing nitro compound reduction. Pd/g-C3N4 catalyst was also active for the one-pot reductive amination of carbonyl compounds with nitro compounds to obtain the corresponding secondary amines with excellent selectivity (>90%). We proposed that the protic N-H+ and hydridic Pd-H- on Pd/g-C3N4 are the active species for the transfer hydrogenation reaction of nitro compounds. Furthermore, Pd/g-C3N4 catalyst was highly stable with a wide scope in the syntheses of various amine compounds. This work will open up a new approach for the transfer hydrogenations of nitro compounds to produce primary or secondary amines in green chemistry.
Direct one-pot reductive amination of aldehydes with nitroarenes in a domino fashion: Catalysis by gum-acacia-stabilized palladium nanoparticles
Sreedhar,Surendra Reddy,Keerthi Devi
, p. 8806 - 8809 (2009)
(Figure Presented) This note describes the direct reductive amination of carbonyl compounds with nitroarenes using gum acacia-palladiumnanoparticles, employing molecular hydrogenas the reductant. This methodology is found to be applicable to both aliphatic and aromatic aldehydes and a wide range of nitroarenes. The operational simplicity and the mild reaction conditions add to the value of this method as a practical alternative to the reductive amination of carbonyl compounds.
Highly selective room-temperature copper-catalyzed C-N coupling reactions
Shafir, Alexandr,Buchwald, Stephen L.
, p. 8742 - 8743 (2006)
Through the use of cyclic β-diketones as supporting ligands, the copper-catalyzed coupling of aryl iodides with aliphatic amines occurs at room temperature in as little as 1 h. These high reaction rates allow for the coupling of a wide range of aryl and heteroaryl iodides at room temperature. This method is highly tolerant of a number of reactive functional groups, including -Br and aromatic -NH2 as well as phenolic and aliphatic -OH. The high selectivity of the CuI-β-diketone catalyst for aliphatic amines represents a useful complement to the palladium-based methods. Copyright
Simple reversible fixation of a magnetic catalyst in a continuous flow system: Ultrafast reduction of nitroarenes and subsequent reductive amination using ammonia borane
Byun, Sangmoon,Cho, Ahra,Kang, Dong Yun,Kim, B. Moon,Kim, Ha Joon,Kim, Hong Won,Kim, Seong Min,Lei, Cao,Park, Jin Kyoon
, p. 944 - 949 (2020)
Continuous reductive amination of aldehydes with nitroarenes over a Pd-Pt-Fe3O4 catalyst was performed. We used NH3BH3 as not only a hydrogen source for nitro reduction, but also a reductant for imine reduction. Secondary aromatic amines were obtained in the continuous flow reaction in good to excellent yields.
Ultrathin platinum nanowire catalysts for direct C-N coupling of carbonyls with aromatic nitro compounds under 1 bar of hydrogen
Hu, Lei,Cao, Xueqin,Ge, Danhua,Hong, Haiyan,Guo, Zhiqiang,Chen, Liang,Sun, Xuhui,Tang, Jianxin,Zheng, Junwei,Lu, Jianmei,Gu, Hongwei
, p. 14283 - 14287 (2011)
Traditionally important in the pharmaceutical, agrochemical, and synthetic dye industries, C-N coupling has proved useful for the preparation of a number of valuable organic compounds. Here, a new method for the direct one-pot reductive C-N coupling from carbonyl and aromatic nitro compounds is described. Employing ultrathin platinum nanowires as the catalyst and hydrogen as the reducing agent, N-alkylamines were achieved in high yields. Debenzylation products were not detected after prolonged reaction times. Time-dependent analysis, ReactIR spectroscopy and DFT calculations revealed that the C-N coupling proceeded through a different mechanism than traditional "reductive amination." N-Alkylamines were directly obtained by intermolecular dehydration over platinum nanowires under a hydrogen atmosphere, instead of intramolecular water elimination and imine hydrogenation.
One-pot synthesis of secondary amine via photoalkylation of nitroarenes with benzyl alcohol over Pd/monolayer H1.07Ti1.73O4·H2O nanosheets
Song, Yujie,Wang, Hao,Liang, Shijing,Yu, Yan,Li, Liuyi,Wu, Ling
, p. 105 - 115 (2018)
The photoalkylation of nitroarenes with benzyl alcohols in one pot at room temperature and 1 atm N2 was achieved over the Pd/H1.07Ti1.73O4·H2O nanosheets. The sample shows efficient photocatalytic activity with high conversion of nitrobenzene (99%) and selectivity of secondary amine (85%). This flexible photocatalytic system is also applicable to other nitroarenes with high efficiency. Results of in situ FTIR, DRS, and in situ ESR revealed that the benzyl alcohol and nitrobenzene molecules can bind with the surface Lewis and Br?nsted acid sites in the catalyst via the H–O?Ti and NO2?H–O–Ti species. The formation of surface coordination species results in not only the activation of reactant molecules via surface electron transfer, but also the expanded visible light absorption of the catalyst. Moreover, in situ ESR suggested that the surface coordination can also facilitate the formation of oxygen vacancies in catalysts, which can greatly promote the exposure of Lewis sites and enhance the activation of reactant molecules. Finally, a possible hydrogen transfer strategy over the sample is proposed on a molecular level.
Direct reductive amination of aldehydes and ketones mediated by a thiourea derivative as an organocatalyst
Huang, Yi-Bo,Cai, Chun
, p. 686 - 688 (2009)
The direct reductive arylamination of arylaldehydes and ketones has been achieved using a selective imine activation by a hydrogen bond of a thiourea derivative. This mild, acid- and metal-free process requires a catalytic amount of N N′-bis[3,5-bis(trifluoromethyl)phenyl]thiourea, the Hantzsch 1,4-dihydropydine diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate as hydride source and activated 5A-molecule sieve as dehydrant. The method is adaptable for the synthesis of various amines.
Green synthesis and catalytic properties of palladium nanoparticles for the direct reductive amination of aldehydes and hydrogenation of unsaturated ketones
Nasrollahzadeh, Mahmoud
, p. 5544 - 5550 (2014)
This paper reports on the synthesis and use of palladium nanoparticles as heterogeneous catalysts for the reductive amination of aldehydes and hydrogenation of unsaturated ketones. This method has the advantages of high yields, simple methodology and easy work up. The catalyst can be recovered and reused several times without significant loss of catalytic activity. This journal is
Efficient photocatalytic one-pot hydrogenation and N-alkylation of nitrobenzenes/benzonitriles with alcohols over Pd/MOFs: Effect of the crystal morphology & “quasi-MOF” structure
Bian, Fengxia,Cheng, Hongmei,Jiang, Heyan,Liu, Xingyan,Long, Xingyu,Yang, Chaofen
, p. 121 - 131 (2020)
One-pot multi-step reactions over visible-light induced catalysis feature the sustainable green process. Here, ligand structure change and 2-MI coordinated modulation were adapted to adjust the crystal size, morphology and crystalline structure of Fe-MOFs; double solvent impregnation was employed for the Pd loading; “quasi-MOF” materials with retained morphology were formed with calcination under N2. Above modified materials were employed as multifunctional photocatalysts for highly efficient one-pot hydrogenation and N-alkylation of nitrobenzenes or benzonitriles with alcohols after in situ Pd photoreduction. Photocatalytic performance was evidently affected by the Fe-MOFs crystal size, morphology, crystalline structure alteration and “quasi-MOF” construction. One-pot hydrogenation and N-alkylation of benzonitriles with alcohols was achieved with excellent catalytic performance firstly in heteroegeneous catalysis. Reaction mechanism was proposed with the assistance of in situ DRIFTS.
