33331-19-0Relevant academic research and scientific papers
Hydroboration and reductive amination of ketones and aldehydes with HBpin by a bench stable Pd(ii)-catalyst
Biswas, Bhaskar,Devadkar, Ajitrao Kisan,Gupta, Puneet,Joshi, Mayank,Mahato, Shreya,Panda, Tarun K.,Rawal, Parveen,Roy Choudhury, Angshuman
supporting information, p. 1103 - 1111 (2022/02/11)
A palladium(ii) complex [(κ4-{1,2-C6H4(NCH-C6H4O)2}Pd] (1) supported by a dianionic salen ligand [1,2-C6H4(NCH-C6H4O)2]2- (L) was synthesised and used as a molecular pre-catalyst in the hydroboration of aldehydes and ketones. The molecular structure of Pd(ii) complex 1 was established by single-crystal X-ray diffraction analysis. Complex 1 was tested as a competent pre-catalyst in the hydroboration of aldehydes and ketones with pinacolborane (HBpin) to produce corresponding boronate esters in excellent yields at ambient temperature under solvent-free conditions. Further, the complex 1 proved to be a competent catalyst in the reductive amination of aldehydes with HBpin and primary amines under mild and solvent-free conditions to afford a high yield (up to 97%) of corresponding secondary amines. Both protocols provided high conversion, superior selectivity and broad substrate scope, from electron-withdrawing to electron-donating and heterocyclic substitutions. A computational study based on density functional theory (DFT) revealed a reaction mechanism for Pd-catalysed hydroboration of carbonyl species in the presence of HBpin. The protocols also uncovered the dual role of HBpin in achieving the hydroboration reaction.
Catalytic Hydroboration and Reductive Amination of Carbonyl Compounds by HBpin using a Zinc Promoter
Banerjee, Indrani,Gupta, Puneet,Kumar, Ravi,Pada Nayek, Hari,Panda, Tarun K.,Rawal, Parveen
supporting information, (2022/02/05)
The chemoselective hydroboration of aldehydes and ketones, catalyzed by Zinc(II) complexes [κ2-(PyCH=NR)ZnX2] [R=CPh3, X=Cl (1) and R=Dipp (2,6-diisoropylphenyl) and X=I (2)], in the presence of pinacolborane (HBpin) at ambient temperature and under solvent-free conditions, which produced the corresponding boronate esters in high yield, is reported. Zinc metal complexes 1 and 2 were derived in 80–90% yield from the reaction of iminopyridine [PyCH=NR] with anhydrous zinc dichloride in dichloromethane at room temperature. The solid-state structures of both zinc complexes were confirmed using X-ray crystallography. Zinc complex 1 was also used as a competent pre-catalyst in the reductive amination of carbonyl compounds with HBpin under mild and solvent-free conditions to afford a high yield (up to 97%) of the corresponding secondary amines. The wider substrate scope of both reactions was explored. Catalytic protocols using zinc as a pre-catalyst demonstrated an atom-economic and green method with diverse substrates bearing excellent functional group tolerance. Computational studies established a plausible mechanism for catalytic hydroboration.
High-Throughput Screening of Reductive Amination Reactions Using Desorption Electrospray Ionization Mass Spectrometry
Cooks, R. Graham,Ferreira, Christina R.,Li, Yangjie,Logsdon, David L.,Paschoal Sobreira, Tiago Jose,Thompson, David H.
supporting information, p. 1647 - 1657 (2020/10/26)
This study describes the latest generation of a high-throughput screening system that is capable of screening thousands of organic reactions in a single day. This system combines a liquid handling robot with desorption electrospray ionization (DESI) mass spectrometry (MS) for a rapid reaction mixture preparation, accelerated synthesis, and automated MS analysis. A total of 3840 unique reductive amination reactions were screened to demonstrate the throughputs that are capable with the system. Products, byproducts, and intermediates were all monitored in full-scan mass spectra, generating a complete view of the reaction progress. Tandem mass spectrometry experiments were conducted to verify the identity of the products formed. The amine and electrophile reactivity trends represented in the data match what is expected from theory, indicating that the system accurately models the reaction performance. The DESI results correlated well with those generated using more traditional mass spectrometry techniques like liquid chromatography-mass spectrometry, validating the data generated by the system.
Design, synthesis and identification of N, N-dibenzylcinnamamide (DBC) derivatives as novel ligands for α-synuclein fibrils by SPR evaluation system
Chen, Yan-Fei,Bian, Jiang,Zhang, Peng,Bu, Lu-Lu,Shen, Yan,Yu, Wen-Bo,Lu, Xiu-Hong,Lin, Xin,Ye, De-Yong,Wang, Jian,Chu, Yong
, (2020/02/22)
PET imaging of α-synuclein (α-syn) deposition in the brain will be an effective tool for earlier diagnosis of Parkinson's disease (PD) due to α-syn aggregation is the widely accepted biomarker for PD. However, the necessary PET radiotracer for imaging is clinically unavailable until now. The lead compound discovery is the first key step for the study. Herein, we initially established an efficient biologically evaluation system well in high throughput based on SPR technology, and identified a novel class of N, N-dibenzylcinnamamide (DBC) compounds as α-syn ligands through the assay. These compounds were proved to have high affinities against α-syn aggregates (KD D) has been acquired, indicating its potential as a new lead compound for developing PET radiotracer.
Compound capable of being strongly bound with alpha-synuclein aggregate, and preparation method and use of compound
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Paragraph 0027; 0029-0031; 0066-0068, (2019/08/30)
The invention belongs to the technical field of medicine, and relates to a compound with a structural general formula I, and a preparation method and use of the compound. In the formula I, R1 is selected from phenyl, substituted phenyl, pyridyl and pyrimidinyl, and i is selected from 0 to 2, and is an integer; R2 is selected from alkyl, phenyl, substituted phenyl and 5-6-membered aromatic heterocyclic rings, and m is selected from 0 to 5, and is an integer; and R3 is selected from phenyl and substituted phenyl, and n is selected from 0 to 3, and is an integer. The compound comprises a cis-isomer, a trans-isomer or a mixture of the cis-isomer and the trans-isomer of the compound with the formula I structure. The compound can be strongly bound to an alpha-synuclein aggregate, can be used asan imaging tracer for the image technology such as PET, SPECT and the like, or can be used for preparing an imaging tracer and a composition containing the imaging tracer, the compound can be used forparticularly detecting Parkinson's disease or neurological disorders associated with the misfolding and aggregation of alpha-synuclein, and the compound has very good application prospects.
Facile synthesis of 4-substituted 1,2,4,5-tetrahydro-1,4-benzodiazepin-3-ones by reductive cyclization of 2-chloro-N-(2-nitrobenzyl)acetamides
Sasiambarrena, Leandro D.,Barri, Ivan A.,Fraga, Guido G.,Bravo, Rodolfo D.,Ponzinibbio, Agustín
supporting information, p. 264 - 267 (2019/01/04)
A facile and efficient method was developed for the synthesis of 1,2,4,5-tetrahydro-1,4-benzodiazepine-3-ones from 2-chloro-N-(2-nitrobenzyl)acetamides through a reductive cyclization using iron-ammonium chloride in ethanol–water in good yields. This method provides a simple approach to these benzodiazepine-3-ones which are of high value in the field of medicinal chemistry research.
Unsymmetrical triazolyl-naphthyridinyl-pyridine bridged highly active copper complexes supported on reduced graphene oxide and their application in water
Hu, Wenkang,Zhang, Yilin,Zhu, Haiyan,Ye, Dongdong,Wang, Dawei
supporting information, p. 5345 - 5351 (2019/10/11)
A novel unsymmetrical triazolyl-naphthyridinyl-pyridine ligand was designed and synthesized, and employed in the synthesis of a heterogeneous copper complex on reduced graphene oxide. The resulting copper composite was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX). This supported copper catalyst containing unsymmetrical triazolyl-naphthyridinyl-pyridine (only 0.1 mol%) showed excellent catalytic activity in water with good recyclability. Various functionalized quinoline derivatives were successfully synthesized in high yields through the green strategy in water. Other heterocyclic compounds, such as pyridine, 2-(pyridin-2-yl)quinoline, 1,8-naphthyridine, 5,6-dihydronaphtho[1,2-b][1,8]naphthyridine and 2-(pyridin-2-yl)-1,8-naphthyridine derivatives, were achieved in water with more than 80% yields. Mechanism studies revealed that this transformation occurs via dehydrogenation, condensation, and transfer hydrogenation and dehydrogenation processes which was supported by a deuterium labeling experiment.
A microwave-assisted SmI2-catalyzed direct N-alkylation of anilines with alcohols
Gour, Jitendra,Gatadi, Srikanth,Malasala, Satyaveni,Yaddanpudi, Madhavi Venkata,Nanduri, Srinivas
, p. 7488 - 7494 (2019/06/14)
A new protocol for the alkylation of aromatic amines has been described using alcohols in the presence of SmI2 as a catalyst with the generation of water as the sole byproduct. The reaction proceeds under MW conditions and selectively generates monoalkylated amines. This protocol features a broad substrate scope and good functional-group tolerance with moderate to high yields.
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.
A Biphilic Phosphetane Catalyzes N-N Bond-Forming Cadogan Heterocyclization via PIII/PV = O Redox Cycling
Nykaza, Trevor V.,Harrison, Tyler S.,Ghosh, Avipsa,Putnik, Rachel A.,Radosevich, Alexander T.
supporting information, p. 6839 - 6842 (2017/05/29)
A small-ring phosphacycle, 1,2,2,3,4,4-hexamethylphosphetane, is found to catalyze deoxygenative N-N bond-forming Cadogan heterocyclization of o-nitrobenzaldimines, o-nitroazobenzenes, and related substrates in the presence of hydrosilane terminal reductant. The reaction provides a chemoselective catalytic synthesis of 2H-indazoles, 2H-benzotriazoles, and related fused heterocyclic systems with good functional group compatibility. On the basis of both stoichiometric and catalytic mechanistic experiments, the reaction is proposed to proceed via catalytic PIII/PV = O cycling, where DFT modeling suggests a turnover-limiting (3+1) cheletropic addition between the phosphetane catalyst and nitroarene substrate. Strain/distortion analysis of the (3+1) transition structure highlights the controlling role of frontier orbital effects underpinning the catalytic performance of the phosphetane.
