3034-32-0Relevant academic research and scientific papers
Zn(II) pyridinyl amine complexes, synthesis and crystal structure studies: A comparative study of the effect of nuclearity and benzoate type on the ring-opening polymerization of cyclic esters
Akintayo, Damilola C.,Jonnalagadda, Sreekantha B.,Munzeiwa, Wisdom A.,Omondi, Bernard
, (2021/12/21)
A series of N-(pyridinylmethyl)aniline Zn(II) carboxylate complexes were synthesized and fully characterized by NMR, IR, mass spectroscopy and elemental analysis. The reaction of the N-(pyridin-4-ylmethyl)aniline ligand (L1) with Zn(II) acetate and benzoi
Cobalt encapsulated in N?doped graphene sheet for one-pot reductive amination to synthesize secondary amines
Liu, Lin,Li, Wenxiu,Qi, Ran,Zhu, Qingqing,Li, Jing,Fang, Yuzhen,Kong, Xiangjin
, (2021/03/14)
To develop an efficient base-metal reductive amination catalyst for synthesis of secondary amines is still a major challenge. In this study, an efficient N-doped graphene sheet-coated cobalt catalyst (Co@CN-800) was developed through a simple pyrolysis process, which could gave 99.5 % yield of N-benzylaniline by one-pot reductive amination of nitrobenzene with benzaldehyde during at least 5 cycles. Catalyst characterization and control experiments confirmed that the robust catalytic performance of the catalyst is probably due to the synergy effect of in situ generated Co-Nx encapsulated in N?doped graphene layer and appropriate meso-pore structure. Additionally, The substrate adaptability of the catalyst was proved since a variety of corresponding secondary amines were smoothly obtained under relatively mild conditions, which makes the secondary amine synthesis strategy based on Co@CN-800 shows excellent application prospect.
Efficient One-Pot Reductive Aminations of Carbonyl Compounds with Aquivion-Fe as a Recyclable Catalyst and Sodium Borohydride
Airoldi, Veronica,Piccolo, Oreste,Roda, Gabriella,Appiani, Rebecca,Bavo, Francesco,Tassini, Riccardo,Paganelli, Stefano,Arnoldi, Sebastiano,Pallavicini, Marco,Bolchi, Cristiano
supporting information, p. 162 - 168 (2019/12/11)
A one-pot reductive amination of aldehydes and ketones with NaBH4 was developed with a view to providing efficient, economical and greener synthetic conditions. A recyclable iron-based Lewis catalyst, Aquivion-Fe, was used to promote imine formation in cyclopentyl methyl ether, followed by the addition of a small amount of methanol to the reaction mixture to enable C=N reduction by NaBH4. The protocol, applied to a wide number of amines and carbonyl compounds, resulted in ever complete conversion of these latter with excellent chemoselectivity towards the expected amination products in the most cases. Isolated yields, determined for a selection of the screened substrates, were found consistent with the previously obtained conversion and selectivity data. Cinacalcet, an important active pharmaceutical ingredient, was efficiently prepared by the title procedure.
Solvent-Free N-Alkylation and Dehydrogenative Coupling Catalyzed by a Highly Active Pincer-Nickel Complex
Arora, Vinay,Dutta, Moumita,Das, Kanu,Das, Babulal,Srivastava, Hemant Kumar,Srivastava, Hemant Kumar,Kumar, Akshai,Kumar, Akshai
, p. 2162 - 2176 (2020/06/05)
The synthesis and characterization of a pincer-nickel complex of the type (iPr2NNN)NiCl2(CH3CN) is reported here. We have demonstrated the utility of this pincer-nickel complex (0.02 and 0.002 mol %) for the catalytic N-alkylation of amines using various alcohols. Under solvent-free conditions, while the highest yield (ca. 90%) was obtained for the alkylation of 2-aminopyridine with naphthyl-1-methanol, excellent turnovers (34000 TONs) were observed for the alkylation of 2-aminopyridine with 4-methoxybenzyl alcohol. To demonstrate the synthetic utility of these systems, high-yield reactions (up to 98%) have been probed for representative substrates with a higher loading of the pincer-nickel catalyst (4 mol %). DFT studies indicate that while β-hydride elimination is the RDS for alcohol dehydrogenation, the N-alkylated product can be formed either via hydrogenation with a rate-determining σ-bond metathesis or by alcoholysis that has imine insertion as the RDS. All of the corresponding resting states have been observed by HRMS (ESI) analysis. The labeling experiments are also complementary to DFT studies and show evidence for the involvement of the benzylic C-H bond in the RDS with a kCHH/kCHD value of about 2.5. This method has been applied to accomplish efficient (2000 TONs) dehydrogenative coupling leading to various benzimidazoles.
Direct electrochemical reductive amination between aldehydes and amines with a H/D-donor solvent
Chen, Lu,Hong, Huanliang,Hu, Jinhui,Huang, Yubing,Li, Yibiao,Liang, Gen,Pu, Suyun,Zhu, Zhongzhi,Zou, Zirong
supporting information, p. 5832 - 5837 (2020/11/03)
A novel electrochemical synthesis protocol has been achieved for reductive amination between aldehydes and amines in undivided cells at room temperature. Under metal-free and external-reductant-free electrolysis conditions, various important secondary amine products are obtained in moderate-to-high yields. Deuterium-labeling experiments have demonstrated that low-toxicity DMSO acts both as a solvent and a H-donor in the reaction. On this basis, various deuterium-labeled products with good-to-excellent D-incorporation have been synthesized by using DMSO-d6 as a solvent. Furthermore, a molecule with GR-antagonistic activity has been synthesized through further sulfonylation.
A Biphasic Medium Slows Down the Transfer Hydrogenation and Allows a Selective Catalytic Deuterium Labeling of Amines from Imines Mediated by a Ru?H/D+ Exchange in D2O
Ruiz-Casta?eda, Margarita,Carrión, M. Carmen,Santos, Lucía,Manzano, Blanca R.,Espino, Gustavo,Jalón, Félix A.
, p. 5541 - 5550 (2018/12/11)
The transfer hydrogenation (TH) of several aldimines has been studied using [RuCl(p-cymene)(dmbpy)]BF4, 1, (dmbpy=4,4′-dimethyl-2,2′-bipyridine) as a precatalyst. Both neat water and a biphasic water/toluene mixture (w/t) have been successfully used as solvents. In the w/t medium the corresponding precursors, amine and aldehyde, were also used as substrates for a transfer hydrogenative reductive amination. Selective deuterium labeling of the resulting alkylated amines was the main goal of this work. On using D2O the D-content in the amine was negligible but a high level of D-incorporation was achieved in D2O/toluene. According to calculations, this is due to the effect of the relative rates of the hydride transfer and that of the RuH/D+ exchange. The incorporation of deuterium increases with time as a consequence of the reduction in the hydride transfer rate as the substrate concentration diminishes. The recyclability assays performed reflect the importance of pH in the selectivity of the TH towards the imine or the aldehyde resulting from imine hydrolysis.
Unmodified Fe3O4 nanostructure promoted with external magnetic field: safe, magnetically recoverable, and efficient nanocatalyst for N- and C-alkylation reactions in green conditions
Rafiee, Ezzat,Joshaghani, Mohammad,Abadi, Parvaneh Ghaderi-Shekhi
, p. 2503 - 2522 (2018/01/04)
Transition metal compounds have emerged as suitable catalysts for organic reactions. Magnetic compounds as soft Lewis acids can be used as catalysts for organic reactions. In this report, the Fe3O4 nanostructures were obtained from Fe2+ and Fe3+-salts, under an external magnetic field (EMF) without any protective agent. The X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy tools were used to characterize these magnetic compounds. The two-dimensional (2-D, it showed nanometric size in the two dimensions, nanorod structure) Fe3O4 compound showed high catalytic activity and stability in N- and C-alkylation reactions. A diverse range of N- and C-alkylation products were obtained in moderate to high yield under green and mild conditions in air. Also the N- and C-alkylation products can be obtained with different selectivity and yield by exposure reactions with EMF. Results of alkylation reactions showed that the presence of Fe(II) and Fe(III) species on the surface of magnetic catalysts (phase structure of magnetic compounds) are essential as very cheap active sites. Also, morphology of magnetic catalysts had influence on their catalytic performances. After the reaction, the catalyst/product(s) separation could be easily achieved with an external magnet and more than 95% of catalyst could be recovered. The catalyst was reused at least four times without any loss of its high catalytic activity for N- and C-alkylation reactions.
Design, synthesis and biological evaluation of GPR55 agonists
Fakhouri, Lara,Cook, Christopher D.,Al-Huniti, Mohammed H.,Console-Bram, Linda M.,Hurst, Dow P.,Spano, Michael B.S.,Nasrallah, Daniel J.,Caron, Marc G.,Barak, Larry S.,Reggio, Patricia H.,Abood, Mary E.,Croatt, Mitchell P.
, p. 4355 - 4367 (2017/07/22)
GPR55, a G protein-coupled receptor, is an attractive target to alleviate inflammatory and neuropathic pain and treat osteoporosis and cancer. Identifying a potent and selective ligand will aid to further establish the specific physiological roles and pharmacology of the receptor. Towards this goal, a targeted library of 22 compounds was synthesized in a modular fashion to obtain structure-activity relationship information. The general route consisted of coupling a variety of p-aminophenyl sulfonamides to isothiocyanates to form acylthioureas. For the synthesis of a known naphthyl ethyl alcohol motif, route modification led to a shorter and more efficient process. The 22 analogues were analyzed for their ability to serve as agonists at GPR55 and valuable information for both ends of the molecule was ascertained.
One-pot Reductive Amination of carbonyl Compounds with Nitro Compounds by Transfer Hydrogenation over Co–Nx as catalyst
Zhou, Peng,Zhang, Zehui
, p. 1892 - 1897 (2017/05/16)
A new method was developed for the synthesis of secondary amines through the one-pot reductive amination of carbonyl compounds with nitro compounds using formic acid as the hydrogen donor over a heterogeneous non-noble-metal catalyst (Co-Nx/C-800-AT, generated by the pyrolysis of the cobalt phthalocyanine/silica composite at 800°C under a N2 atmosphere and subsequent etching by HF). Both nitrogen and cobalt were of considerable importance in the transfer hydrogenation reactions with formic acid.
One-pot reductive amination of carbonyl compounds with nitro compounds with CO/H2O as the hydrogen donor over non-noble cobalt catalyst
Zhou, Peng,Yu, Changlin,Jiang, Liang,Lv, Kangle,Zhang, Zehui
, p. 264 - 273 (2017/06/23)
The one-pot reductive amination of carbonyl compounds with nitro compounds over heterogeneous non-noble metal catalysts was developed for the first time by transfer hydrogenation with CO/H2O as the hydrogen donor. Nitrogen-doped carbon supported cobalt nanoparticles were observed to be active toward this reaction, affording structurally-diverse secondary amines with high yields. Kinetic studies revealed that the transfer hydrogenation of imines (C[dbnd]N bonds) was the rate-determining step. Reaction mechanism studies indicated that both nitrogen and cobalt nanoparticles were important for the transfer hydrogenation with CO/H2O to generate the proton (N[sbnd]H+) and hydride (Co[sbnd]H?) as the active species. Furthermore, the heterogeneous cobalt catalyst was highly stable without the loss of its catalytic activity during the recycling experiments.
