90172-63-7Relevant articles and documents
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.
Synthesis of 3-nitroindoles by sequential paired electrolysis
Kilmartin, Paul A.,Lindsay, Ashley C.,Sperry, Jonathan
supporting information, p. 7903 - 7913 (2021/09/28)
3-Nitroindoles are synthetically versatile intermediates but current methods for the preparation hinder their widespread application. Herein, we report that nitroenamines undergo electrochemical cyclisation to 3-nitroindoles in the presence of potassium iodide. Detailed control experiments and cyclic voltammogram studies infer the reaction proceedsviaa sequential paired electrolysis process, beginning with anodic oxidation of iodide (I?) to the iodine radical (I˙), which facilitates cyclisation of the nitroenamine to give a 3-nitroindolinyl radical. Cathodic reduction and protonation generates a 3-nitroindoline that upon oxidation forms the 3-nitroindole.
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.
Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids
Betori, Rick C.,Davies, Anna V.,Fitzpatrick, Keegan P.,Scheidt, Karl A.
supporting information, p. 9143 - 9148 (2020/03/30)
As a key element in the construction of complex organic scaffolds, the formation of C?C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C?C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.
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.
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.
An efficient synthesis of 1,3,7-triazaspiro[4.4]nonane-2,4-dione derivatives and antimicrobial activity thereof
Krolenko, Konstantin Yu.,Silin, Olexiy V.,Vlasov, Sergiy V.,Zhuravel, Irina O.,Kovalenko, Sergiy M.
, p. 472 - 477 (2015/10/19)
Efficient methods for the synthesis of 1,3,7-triazaspiro[4.4]nonane-2,4-dione derivatives possessing an unsaturated pyrrolidine cycle have been developed affording intermediates and target compounds in high yields not requiring additional purification. Antimicrobial activity of the synthesized compounds was studied.
SAR studies on 1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles as inhibitors of Mtb shikimate dehydrogenase for the development of novel antitubercular agents
Li, Ziqiang,Liu, Yishuang,Bai, Xiaoguang,Deng, Qi,Wang, Juxian,Zhang, Guoning,Xiao, Chunling,Mei, Yaning,Wang, Yucheng
, p. 97089 - 97101 (2015/12/01)
Shikimate dehydrogenase, an essential protein for the biosynthesis of the chorismate end product, is a highly promising therapeutic target, especially for the discovery and development of new-generation anti-TB agents. Following up the identification of one lead 3,6-disubstituted 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole (1), targeting Mt SD in our previous study, an extensive SAR study for optimization of the lead compound was performed through systematic modification of the 3 and 6 positions. This study has successfully led to the discovery of two highly potent advanced leads 6d-4, 6c-4 and several other compounds with comparable potencies (6d-4, MIC-H37Rv = 0.5 μg mL-1; MIC-MDRTB = 4.0 μg mL-1; MIC-RDRTB = 0.5 μg mL-1; Mt SD-IC50 = 14.20 μg mL-1; and 6c-4, MIC-H37Rv = 0.5 μg mL-1; MIC-MDRTB = 4.0 μg mL-1; MIC-RDRTB = 1.0 μg mL-1; Mt SD-IC50 = 6.82 μg mL-1). These advanced lead compounds possess a para-halogen phenyl at the 3 position. In vitro Mt SD inhibitory assay indicates that Mt SD is the target for their antitubercular activity. Moreover, the BacT/ALERT 3D liquid culture technology and in vitro Mt SD inhibitory assay were initially applied.
N-methylimidazole-catalyzed synthesis of carbamates from hydroxamic acids via the lossen rearrangement
Yoganathan, Sabesan,Miller, Scott J.
supporting information, p. 602 - 605 (2013/04/11)
An efficient, one-pot, N-methylimidazole (NMI) accelerated synthesis of aromatic and aliphatic carbamates via the Lossen rearrangement is reported. NMI is a catalyst for the conversion of isocyanate intermediates to the carbamates. Moreover, the utility of arylsulfonyl chloride in combination with NMI minimizes the formation of often-observed hydroxamate-isocyanate dimers during the sequence. Under the present conditions, lowering of temperatures is also possible, enabling a mild protocol.
CDI-mediated monoacylation of symmetrical diamines and selective acylation of primary amines of unsymmetrical diamines
Verma, Sanjeev K.,Ghorpade, Ramarao,Pratap, Ajay,Kaushik
experimental part, p. 326 - 329 (2012/04/10)
A highly efficient and green protocol for monoacylation of symmetrical diamines and chemoselective acylation of primary amines of unsymmetrical diamines has been developed.
