5350-57-2Relevant academic research and scientific papers
Keto-salicylaldehyde azine: Asymmetric substituent effect on their optical properties via electron-donating group insertion
Tong, Jialin,Zhang, Kexin,Wang, Jing,Li, Hui,Zhou, Fan,Wang, Zhiming,Zhang, Xiaojuan,Tang, Ben Zhong
, p. 996 - 1001 (2020)
Organic fluorescent probes have attracted increasing attention owing to their high sensitivity and recognition ability, structurally adjustable flexibility and manifestation in the form of visualization. Salicylaldehyde azine (SAA) and its derivatives exhibit a great potential for practical applications, but the synthesis of SAA asymmetric compounds in low yields, serving multiple functions, is cumbersome. As an alternative building block, Keto-Salicylaldehyde Azine (KSA) was developed by our group for constructing various AIEgens via an excited state intramolecular proton transfer (ESIPT) process to detect some cellular organelles and specific metal ions. For illuminating the structure-property relationship of the two asymmetric sides in a KSA unit, DPAS was employed as a model and the N,N-diethyl group with electron-donating effects was introduced on its salicylaldehyde side (S-terminal) and diphenylketone side (K-terminal). Three new derivatives were obtained and showed different photophysical properties, particularly in AIE performance and metal ion responsiveness, implying that their intrinsic electronic structure can be easily affected by the asymmetric substitution effect. Therefore, this study is a meaningful and valuable reference for KSA modification on expanding fluorescent probes with various functions via the purposeful regulation of their chemical structure, by either modifying the K-terminal or the S-terminal.
Anti-glycemic potential of benzophenone thio/semicarbazone derivatives: synthesis, enzyme inhibition and ligand docking studies
Arshia,Fayyaz, Sharmeen,Shaikh, Muniza,Khan, Khalid Mohammed,Choudhary, M. Iqbal
, (2021)
Inhibition of dipeptidyl peptidase-IV (DPP-IV) has been identified as a promising approach for the treatment of type 2 diabetes mellitus (T2DM). Therefore, development of DPP-IV inhibitors with new chemical scaffold is of utmost importance to medicinal chemistry. In the present study, we identified benzophenone thio- and semicarbazone scaffolds as novel DPP-IV inhibitors. For that purpose, benzophenone thio- and semicarbazone were synthesized through a 2-step reaction. These newly synthetic derivatives were characterized by different spectroscopic techniques, including HREI-MS and NMR. whereas stereochemistry of the iminic bond was predicted by NOESY experiments. Thio- and semicarbazones derivatives were evaluated for their DPP-IV inhibitory potential and found to exhibit a good to moderate enzyme inhibitory activity. Most active and non-cytotoxic derivatives were further evaluated for their DPP-IV inhibitory potential in in cellulo model. The binding sites as well as affinity of active compounds for DPP- IV enzyme were predicted by in silico studies, and compared to a standard drug, sitagliptin. Pharmacophore studies of thio- and semicarbazones derivatives 1–29 suggest that substitution of aryl group, particularly a lipophilic substituents at C-4″ of benzene ring, and a hydroxyl at C-4′ strongly influenced the DPP-IV inhibitory activity. Compound 9 showed the highest inhibitory activity (IC50 = 15.0 ± 0.6 μM), whereas compounds 10, 17, 12, 14 and 23 showed a moderate activity with IC50 values in the range of 28.9–39.2 μM. This study identifies thio- and semicarbazones as new classes of DPP-IV inhibitors which may translate into safe and effective therapeutics for a better management of type 2 diabetes. Communicated by Ramaswamy H. Sarma.
Electrochemical Studies of Diazoalkanes: The Formation and Decomposition of Ph2C=N2(radical-anion) and Ph2C=N22-
Cheng, Spencer,Hawley, M. Dale
, p. 3799 - 3804 (1986)
Ph2C=N2 undergoes successive one-electron reductions in DMF-0.1 M (CH3)4NBF4 at subambient temperatures to give a relatively stable anion radical and an unstable dianion.In the absence of added proton donors, Ph2C=N22- undergoes rapid reaction to give an unobserved intermediate, believed to be Ph2CH-, that reacts with Ph2C=N2 to give Ph2CHN-N=CPh2(radical) (k = 5*104 M*s-1 at -37 deg C).Ph2C=N2(radical-anion) reacts under these conditions by abstraction of a hydrogen atom from a component of the solvent-electrolyte system (k = 0.4 s-1 at -23 deg C) to give Ph2C=NNH- as a longer lived intermediate.This species subsequently reacts with Ph2C=N2, giving first Ph2CHN-N=CPh2 and then the final product, Ph2C=NN=CPh2.The transformation of Ph2C=N2 into Ph2C=NN=CPh2 occurs by a chain process and is initiated by both Ph2C=NNH- and Ph2CHN-N=CPh2.Ph2C=NNH- and Ph2CHN-N=CPh2 are proposed to react with Ph2C=N2 by pathways that transfer hydride ion, either directly or indirectly, from the anion to the central carbon of Ph2C=N2.The final steps in the propagation cycle involve the loss of N2 from Ph2CHN2- and the subsequent coupling of Ph2CH- with Ph2C=N2 to regenerate Ph2CHN-N=CPh2.Ph2C=N2(radical-anion) and Ph2(C=N22- behave as ambient bases in the presence of Broensted acids which can effect their protonation and afford, depending upon whether the central carbon or the terminal nitrogen is protonated, Ph2CH2 or Ph2C=NNH2, respectively.The fraction of Ph2C=NNH2 formed increases with decreasing pKa of the proton donor.
Synthesis and physical studies of coumarin-based chemosensor for cyanide ions
Devendhiran, Tamiloli,Kumarasamy, Keerthika,Lin, Mei-Ching,Yang, Yu Xuan
, (2021/10/12)
A series of novel coumarin-based chemosensor azine derivatives L1, L2 and L3 were synthesized and characterized by various spectroscopic methods such as 1H NMR, mass spectrometry, FT-IR and elemental analysis. The sensing property of the sensor L derivatives was confirmed by the UV–Vis absorption, emission spectra and the naked eye sensing. The sensor L derivatives showed the absorption band at 320–330 nm. The fluorescence emission band was observed at 550–560 nm. In the presence of CN? ions, the chemosensor L derivatives show the “turn-on” fluorescence response over the other competing anions such as Br?, I?, HSO4?, ClO4? and PF6?, and the new absorption band appeared at 385 nm and the emission band also shifted to the blue region at 440 nm. The sensor L derivatives bind to cyanide ions in a 1:1 binding stoichiometry calculated from the job's plot experiments. The detection limit of sensor L1 towards CN? was 5.79 × 10?8 M. Additionally, the binding constant was determined to be 1.0209 × 106 M?1 from the Benesi-Heilbrand equation. The theoretical calculations were performed by Gaussian 9 software. The sensing mechanism of the interaction between the cyanide ion and imine carbon was confirmed by the 1H NMR titration method and mass spectra.
POLYAROMATIC UREA DERIVATIVES AND THEIR USE IN THE TREATMENT OF MUSCLE DISEASES
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Page/Page column 125, (2021/01/29)
The current invention provides urea derivatives, in particular compounds having the core structure heteroaryl-NH-CO-NH-aryl-O- heteroaryl, for use in treating, ameliorating, delaying, curing and/ or preventing a disease or condition associated with muscle cells and/or satellite cells, such as Duchenne muscular dystrophy, Becker muscular dystrophy, cachexia or sarcopenia.
Dehalogenative Cross-Coupling of gem-Difluoroalkenes with Alkyl Halides via a Silyl Radical-Mediated Process
Tian, Hao,Yang, Shaoxiang,Wang, Xiaochen,Xu, Wentao,Liu, Yuxiu,Li, Yongqiang,Wang, Qingmin
supporting information, p. 12772 - 12782 (2021/09/13)
Herein, we describe a convenient general protocol for monofluoroalkenylation reactions of alkyl bromides involving cooperative visible-light photoredox catalysis and halogen abstraction. Mechanistic experiments showed that the products were generated by selective cross-coupling of aliphatic radicals with fluoroalkenyl radicals. Silyl radical-mediated halogen abstraction enabled the protocol to be used for the monofluoroalkenylation of a broad range of alkyl and heteroaryl halides. The protocol could be carried out on a gram scale and was applied to cholesterol, indicating its utility for late-stage monofluoroalkenylation reactions.
Photochemical Carbene Transfer Reactions of Aryl/Aryl Diazoalkanes—Experiment and Theory**
Jana, Sripati,Pei, Chao,Empel, Claire,Koenigs, Rene M.
supporting information, p. 13271 - 13279 (2021/05/10)
Controlling the reactivity of carbene intermediates is a key parameter in the development of selective carbene transfer reactions and is usually achieved by metal complexes via singlet metal-carbene intermediates. In this combined experimental and computational studies, we show that the reactivity of free diaryl carbenes can be controlled by the electronic properties of the substituents without the need of external additives. The introduction of electron-donating and -withdrawing groups results in a significant perturbation of singlet triplet energy splitting of the diaryl carbene intermediate and of activation energies of consecutive carbene transfer reactions. This strategy now overcomes a long-standing paradigm in the reactivity of diaryl carbenes and allows the realization of highly chemoselective carbene transfer reactions with alkynes. We could show that free diaryl carbenes can be readily accessed via photolysis of the corresponding diazo compounds and that these carbenes can undergo highly chemoselective cyclopropenation, cascade, or C?H functionalization reactions. Experimental and theoretical mechanistic analyses confirm the participation of different carbene spin states and rationalize for the observed reactivity.
Oxime Ether Synthesis through O-H Functionalization of Oximes with Diazo Esters under Blue LED Irradiation
Li, Qian,Cai, Bao-Gui,Li, Lei,Xuan, Jun
supporting information, p. 6951 - 6955 (2021/09/02)
A green and sustainable oxime ether formation method via the visible-light-promoted O-H functionalization of oximes with diazo esters is described. The reaction occurs under very mild conditions (catalyst- and additive-free) with a high yield and a high functional group tolerance. When the reaction was performed with a cyclic ether as the solvent (e.g., THF, 1,4-dioxane, tetrahydropyran, ect.), an interesting photochemical three-component reaction product was obtained in good yields.
Copper-Mediated Cross-Coupling of Diazo Compounds with Sulfinates
Wang, Qian,Liu, An,Wang, Yan,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 6919 - 6924 (2021/09/11)
A copper-mediated cross-coupling reaction between a diazo compound and a sodium alkane(arene)sulfinate gives a sulfone as the product. This reaction proceeds under mild conditions and features excellent functional group compatibility. A wide range of sodium alkane(arene)sulfinates were successfully applied in this chemistry. Mechanistic studies revealed that the overall reaction efficiency of the sulfinates was in line with their nucleophilicity in this reaction.
Silver-Catalyzed N-H Functionalization of Aryl/Aryl Diazoalkanes with Anilines
He, Feifei,Empel, Claire,Koenigs, Rene M.
supporting information, p. 6719 - 6723 (2021/09/13)
Herein, we report on the N-H functionalization reaction of primary and secondary anilines with diaryldiazoalkanes using simple AgPF6 as catalyst. We demonstrated broad applicability in the reaction of diaryldiazoalkanes with different anilines (31 examples, up to 97% yield). Furthermore, we propose a possible reaction mechanism for the N-H functionalization.
