3991-75-1Relevant academic research and scientific papers
Practical Chemoselective Acylation: Organocatalytic Chemodivergent Esterification and Amidation of Amino Alcohols with N-Carbonylimidazoles
Brown, Hailee,Heller, Stephen T.,Light, Christina,Medlin, Abigail,Nelson, Hope,Richard, William
supporting information, p. 22818 - 22825 (2021/09/13)
Chemoselective transformations are a cornerstone of efficient organic synthesis; however, achieving this goal for even simple transformations, such as acylation reactions, is often a challenge. We report that N-carbonylimidazoles enable catalytic chemodivergent aniline or alcohol acylation in the presence of pyridinium ions or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), respectively. Both acylation reactions display high and broad chemoselectivity for the target group. Unprecedented levels of chemoselectivity were observed in the DBU-catalyzed esterification: A single esterification product was obtained from a molecule containing primary aniline, alcohol, phenol, secondary amide, and N?H indole groups. These acylation reactions are highly practical as they involve only readily available, inexpensive, and relatively safe reagents; can be performed on a multigram scale; and can be used on carboxylic acids directly by in situ formation of the acylimidazole electrophile.
Silver-Catalyzed Acyl Nitrene Transfer Reactions Involving Dioxazolones: Direct Assembly of N-Acylureas
Yang, Zheng-Lin,Xu, Xin-Liang,Chen, Xue-Rong,Mao, Zhi-Feng,Zhou, Yi-Feng
supporting information, p. 648 - 652 (2020/12/21)
Dioxazolones and isocyanides are useful synthetic building blocks, and have attracted significant attention from researchers. However, the silver-catalyzed nitrene transfer reaction of dioxazolones has not been investigated to date. Herein, a silver-catalyzed acyl nitrene transfer reaction involving dioxazolones, isocyanides, and water was realized in the presence of Ag2O to afford a series of N-acylureas in moderate to good yields.
Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
Bai, Feifei,Fang, Jianguo,Song, Zi-Long,Zhang, Baoxin
, p. 2214 - 2231 (2020/03/06)
Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine-or H2O2-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
Ketoreductase catalyzed stereoselective bioreduction of α-nitro ketones
Wang, Zexu,Wu, Xiaofan,Li, Zhining,Huang, Zedu,Chen, Fener
supporting information, p. 3575 - 3580 (2019/04/14)
We report here the stereoselective bioreduction of α-nitro ketones catalyzed by ketoreductases (KREDs) with publicly known sequences. YGL039w and RasADH/SyADH were able to reduce 23 class I substrates (1-aryl-2-nitro-1-ethanone (1)) and ten class II substrates (1-aryloxy-3-nitro-2-propanone (4)) to furnish both enantiomers of the corresponding β-nitro alcohols, with good-to-excellent conversions (up to >99%) and enantioselectivities (up to >99% ee) being achieved in most cases. To the best of our knowledge, KRED-mediated reduction of class II α-nitro ketones (1-aryloxy-3-nitro-2-propanone (4)) is unprecedented. Select β-nitro alcohols, including the synthetic intermediates of bioactive molecules (R)-tembamide, (S)-tembamide, (S)-moprolol, (S)-toliprolol and (S)-propanolol, were stereoselectively synthesized in preparative scale with 42% to 90% isolated yields, showcasing the practical potential of our developed system in organic synthesis. Finally, the advantage of using KREDs with known sequence was demonstrated by whole-cell catalysis, in which β-nitro alcohol (R)-2k, the key synthetic intermediate of hypoglycemic natural product (R)-tembamide, was produced in a space-time yield of 178 g L?1 d?1 as well as 95% ee by employing the whole cells of a recombinant E. coli strain coexpressing RasADH and glucose dehydrogenase as the biocatalyst.
A convenient synthesis of 2-acyl benzothiazoles/thiazoles from benzothiazole/thiazole and N,N'-carbonyldiimidazole activated carboxylic acids
Huang, Tonghui,Wu, Xin,Yu, Yongbo,An, Lin,Yin, Xiaoxing
supporting information, p. 1667 - 1670 (2019/06/04)
A convenient and efficient strategy for the synthesis of 2-acyl benzothiazoles/thiazoles has been developed. The treatment of benzothiazole/thiazole with allylic Grignard reagents readily generates the corresponding 2-Grignard reagents, which is followed by a reaction with N,N'-carbonyldiimidazole activated carboxylic acids to afford various 2-acyl benzothiazoles/thiazoles products. The synthetic method is applicable to a wide array of carboxylic acids and allows easy access to 2-acyl benzothiazoles/thiazoles with considerable yields under mild reaction conditions.
Biology-oriented drug synthesis (BIODS): In vitro β-glucuronidase inhibitory and in silico studies on 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl carboxylate derivatives
Salar, Uzma,Khan, Khalid Mohammed,Taha, Muhammad,Ismail, Nor Hadiani,Ali, Basharat,Qurat-ul-Ain,Perveen, Shahnaz,Ghufran, Mehreen,Wadood, Abdul
, p. 1289 - 1299 (2016/12/06)
Current study is based on the biology-oriented drug synthesis (BIODS) of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl aryl carboxylate derivatives 1–26, by treating metronidazole with different aryl and hetero-aryl carboxylic acids in the presence of 1,1'-carbonyl diimidazole (CDI) as a coupling agent. Structures of all synthetic derivatives were confirmed with the help of various spectroscopic techniques such as EI-MS,1H -NMR and13C NMR. CHN elemental analyses were also found in agreement with the calculated values. Synthetic derivatives were evaluated to check their β-glucuronidase inhibitory activity which revealed that except few derivatives, all demonstrated good inhibition in the range of IC50= 1.20 ± 0.01–60.30 ± 1.40 μM as compared to the standard D-saccharic acid 1,4-lactone (IC50= 48.38 ± 1.05 μM). Compounds 1, 3, 4, 6, 9–19, and 21–24 were found to be potent analogs and showed superior activity than standard. Limited structure-activity relationship is suggested that the molecules having electron withdrawing groups like NO2, F, Cl, and Br, were displayed better activity than the compounds with electron donating groups such as Me, OMe and BuO. To verify these interpretations, in silico study was also performed, a good correlation was observed between bioactivities and docking studies.
Organo-functionalized trimethoxysilanes featuring thioester linkage: Synthetic and UV–Vis spectral investigations
Singh, Gurjaspreet,Rani, Sunita,Saroa, Amandeep,Arora, Aanchal
, p. 1 - 11 (2018/03/27)
The current work reveals a series of new organo-functionalized trimethoxysilanes (OfTMS) linked via a 3C tether to the thioester group along with the inclusion of versatile aromatic and heteroaromatic sequences. The synthetic procedure implicates the one-pot thioesterification reaction of the precursor carboxylic acids (1a-r) with 3-mercaptopropyltrimethoxysilane (MPTMS), stimulated by 1,1′-carbonyldiimidazole (CDI). The OfTMS have been attentively characterized by elemental analysis, infrared and [1H, 13C] NMR spectroscopic techniques. The UV–Vis absorption behaviour demonstrates that the alkoxysilanes possess high sensitivity to the changes caused in the environment on account of different substitutions. Furthermore, the solvent effect on the absorption spectra has been scrutinized and quantified using the Kamlet-Taft approach. Importantly, the fabricated stable alkoxysilanes can be aspired for advance applications in the field of material science.
Ultrasound-assisted, convenient and widely applicable 1,1′-carbonyl-diimidazole-mediated "One-pot" syntheses of acyl/sulfonyl hydrazines
Khan, Khalid Mohammed,Salar, Uzma,Fakhri, Muhammad Imran,Taha, Muhammad,Hameed, Abdul,Perveen, Shahnaz,Voelter, Wolfgang
, p. 637 - 644 (2015/11/09)
Acyl / sulfonyl hydrazines were synthesized in a one-pot reaction from carboxylic acid/aryl sulfonic acid in the presence of 1,1′-carbonyl diimidazole (CDI) under ultrasound as well as under conventional heating. The reaction was performed on diverse organic molecules including simple benzoic acid (1), electron-donating and electron-withdrawing substituted benzoic acids, biologically active compounds like coumarin-3-carboxylic acid (12), 7-hydroxycoumarin-4-acetic acid (13), and therapeutic drugs like ibuprofen (14), flurbiprofen (15), naproxen (16) or tricyclic adamantane carboxylic acid (17). Benzene sulfonic acid (18) and its derivatives (19, 20, 21 and 22) were used to prepare corresponding sulfonyl hydrazide. All products were synthesized in very good yield via ultrasonic irradiation method and characterized by spectroscopic techniques including EIMS, 1H NMR, 13C NMR, IR. The method was found very simple, facile, efficient and high yielding (>90).
DBU catalysis of N,N'-carbonyldiimidazole-mediated amidations
Larrlvee-Aboussafy, Claude,Jones, Brian P.,Price, Kristin E.,Hardink, Mark A.,McLaughlin, Robert W.,Lillie, Brett M.,Hawkins, Joel M.,Vaidyanathan, Rajappa
supporting information; experimental part, p. 324 - 327 (2010/03/24)
(Figure presented) 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) has been found to catalyze the amidatlon of acyl imidazoles. The rate acceleration is especially evident with traditionally unreactlve, electron-deficient anilines. DBU is readily available and o
Indium-mediated one-pot synthesis of benzoxazoles or oxazoles from 2-nitrophenols or 1-aryl-2-nitroethanones
Lee, Jung June,Kim, Jihye,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
experimental part, p. 8821 - 8831 (2009/12/26)
One-pot reduction-triggered heterocyclizations from 2-nitrophenols to benzoxazoles and from 1-aryl-2-nitroethanones to oxazoles were investigated. In the presence of indium/AcOH in benzene at reflux, 2-nitrophenols and R-C(OMe)3 (R=H, Me, Ph) produced excellent yields of corresponding benzoxazoles within an hour. Similarly, 1-aryl-2-nitroethanones and Ph-C(OMe)3 in the presence of indium/AcOH in acetonitrile transformed into the corresponding oxazoles with good yields.
