scholarly journals Review on the Synthesis of Pyrazine and Its Derivatives

2017 ◽  
Vol 7 (2) ◽  
pp. 60-75 ◽  
Author(s):  
KOK TONG ONG ◽  
ZHI-QIANG LIU ◽  
MENG GUAN TAY
Keyword(s):  
Maillard Reaction ◽  
Condensation Reaction ◽  
Acid Catalyst ◽  
Ring Closure ◽  
Synthetic Approach ◽  
Main Function ◽  
Metal Catalysis ◽  
Raw Foods ◽  
Living Organisms ◽  
Synthetic Approaches

Pyrazine is a kind of natural product which can be found in plants, animals, insects, marine organisms andmicroorganisms. The main function of pyrazine in living organisms is used as flavor of the raw foods. Pyrazine and its derivatives were also produced in industries mainly for fragrance, flavor and pharmaceutical applications. This review describes the historical development of pyrazine including the discovery and synthesis, to the recent synthetic approach of pyrazinium. In general, six synthetic approaches namely condensation reaction, ring closure, metal catalysis, green reaction, Maillard reaction and acid catalyst on N-substitution have been reviewed in this paper. The first five approaches are mainly aimed for the substitution at 2, 3, 5 and 6 positions in pyrazine ring, whereas the last approach is specifically for 1 and 4 positions in pyrazine. Keywords: Diazine, pyrazine, and Maillard reaction

scholarly journals Total Syntheses of Pladienolide-Derived Spliceosome Modulators

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5938
Author(s):  
Jaehoon Sim ◽  
Eunbin Jang ◽  
Hyun Jin Kim ◽  
Hongjun Jeon
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Structural Features ◽  
Synthetic Approach ◽  
Synthetic Analog ◽  
Phase I Clinical Trials ◽  
Total Syntheses ◽  
Naturally Occurring ◽  
Anti Cancer ◽  
Synthetic Approaches

Pladienolides, an emerging class of naturally occurring spliceosome modulators, exhibit interesting structural features, such as highly substituted 12-membered macrocycles and epoxide-containing diene side chains. The potential of pladienolides as anti-cancer agents is confirmed by H3B-8800, a synthetic analog of this natural product class, which is currently under Phase I clinical trials. Since its isolation in 2004 and the first total synthesis in 2007, a dozen total syntheses and synthetic approaches toward the pladienolide class have been reported to date. This review focuses on the eight completed total syntheses of naturally occurring pladienolides or their synthetic analogs, in addition to a synthetic approach to the main framework of the natural product.

scholarly journals Bio-inspired synthetic approaches: from hierarchical, hybrid supramolecular assemblies to CaCO3-based microspheres

2017 ◽  
Vol 46 (19) ◽  
pp. 6456-6463 ◽  
Author(s):  
Bartosz Marzec ◽  
Lei Zhang ◽  
Nianyong Zhu ◽  
Wolfgang Schmitt
Keyword(s):  
Supramolecular Assemblies ◽  
Supramolecular System ◽  
Synthetic Approach ◽  
Synthetic Approaches

A bio-inspired synthetic approach to Ca(ii)-based coordination assemblies is reported; the supramolecular system was used as habit modifier for CaCO3 materials.

scholarly journals Recent Advances in Synthesis of 4-Arylcoumarins

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2417 ◽  
Author(s):  
Jong-Wha Jung ◽  
Nam-Jung Kim ◽  
Hwayoung Yun ◽  
Young Han
Keyword(s):  
Biological Activities ◽  
Synthetic Methods ◽  
Metal Catalysis ◽  
Naturally Occurring ◽  
Recent Advances ◽  
Formation Type ◽  
Privileged Scaffold ◽  
Acid Catalyzed ◽  
A Minor ◽  
Synthetic Approaches

4-Arylcoumarins (4-aryl-2H-1-benzopyran-2-one), also known as neoflavones, comprise a minor subclass of naturally occurring flavonoids. Because of their broad-spectrum biological activities, arylcoumarins have been attracting the attention of the organic and medicinal chemistry communities, and are considered as an important privileged scaffold. Since the development of Pechmann condensation, a classical acid-catalyzed condensation between phenol and β-keto-carboxylic acid, several versatile and efficient synthetic approaches for 4-arylcoumarins have been reported. This review summarizes recent advances in the synthesis of the 4-arylcoumarin scaffold by classifying them based on the final bond-formation type. In particular, synthetic methods executed under mild and highly efficient conditions, such as solvent-free reactions and transition metal catalysis, are highlighted.

scholarly journals Fabrication of Hollow Silica Nanospheres with Ultra-High Acid Density for Efficient Heterogeneous Catalysis

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 481 ◽  
Author(s):  
Xiaoli Zhang ◽  
Juan Wei ◽  
Xiaoming Zhang
Keyword(s):  
Sulfonic Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Hollow Structure ◽  
Acid Catalyst ◽  
Acid Strength ◽  
Silica Nanospheres ◽  
Hollow Silica ◽  
High Acid ◽  
Hollow Silica Nanospheres

Hollow silica nanospheres with ultra-high acid density were fabricated successfully via sulfonation of phenyl-functionalized hollow silica nanospheres, which were synthesized through a single micelle (F127 (EO106PO70EO106))-templated method, with phenyltrimethoxysilane and tetramethoxysilane (TMOS) as silane precursors under neutral conditions. The density of sulfonic acid reached as high as 1.97 mmol/g. The characterization results of 31P-NMR using triethylphosphine oxide as a probe molecule suggested that the acid strength of hybrid solid acids could be systematically tuned by tuning the content of sulfonic acid and higher acid density results in stronger acid strength. Attributed to the unique hollow structure and high-acid density, the sulfonic acid-functionalized hollow silica nanospheres exhibited good catalytic performance in the condensation reaction of benzaldehyde with ethylene glycol. Notably, this study found that the catalytic activity was significantly influenced by the acid density and the ultra-high acid loading was beneficial for the activity due to the enhanced acid strength. This novel solid-acid catalyst also showed good recyclability and could be reused for at least 11 runs.

Nanosized sulfated zirconia as solid acid catalyst for the synthesis of 2-substituted benzimidazoles

2013 ◽  
Vol 67 (5) ◽  
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Mohammad Hajihakimi
Keyword(s):  
Sulfated Zirconia ◽  
Tetragonal Phase ◽  
Solid Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Ft Ir

AbstractThe condensation reaction of o-phenylenediamine and arylaldehydes was investigated in the presence of nanosized sulfated zirconia (SO42−-ZrO2) as the solid acid catalyst. Nanosized SO42−-ZrO2 was prepared and characterized by the XRD, FT-IR, and SEM techniques. The results confirm good stabilization of the tetragonal phase of zirconia in the presence of sulfate. Reusability experiments showed partial deactivation of the catalyst after each run; good reusability can be achieved after calcinations of the recovered catalyst before its reuse.

Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by Perchlorated Zirconia (HClO4/ZrO2) nanoparticles as a novel solid acid catalyst

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Seyed Yousef Mosavian
Keyword(s):  
Solid Acid ◽  
Condensation Reaction ◽  
Solid Acid Catalyst ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Catalytic Performance ◽  
Acid Sites ◽  
Zro2 Nanoparticles ◽  
Calcination Temperatures ◽  
Aldehydes And Ketones

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.

scholarly journals Incorporation of 3-Aminobenzanthrone into 2′-Deoxyoligonucleotides and Its Impact on Duplex Stability

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Mark Lukin ◽  
Tanya Zaliznyak ◽  
Francis Johnson ◽  
Carlos R. de los Santos
Keyword(s):  
Dna Adducts ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Helical Structure ◽  
Environmental Pollutant ◽  
Synthetic Approach ◽  
Amino Groups ◽  
Double Helical Structure ◽  
Duplex Stability ◽  
Living Organisms

3-Nitrobenzanthrone (3NBA), an environmental pollutant and potent mutagen, causes DNA damage via the reaction of its metabolically activated form with the exocyclic amino groups of purines and the C-8 position of guanine. The present work describes a synthetic approach to the preparation of oligomeric 2′-deoxyribonucleotides containing a 2-(2′-deoxyguanosin-N2-yl)-3-aminobenzanthrone moiety, one of the major DNA adducts found in tissues of living organisms exposed to 3NBA. The NMR spectra indicate that the damaged oligodeoxyribonucleotide is capable of forming a regular double helical structure with the polyaromatic moiety assuming a single conformation at room temperature; the spectra suggest that the 3ABA moiety resides in the duplex minor groove pointing toward the 5′-end of the modified strand. Thermodynamic studies show that the dG(N2)-3ABA lesion has a stabilizing effect on the damaged duplex, a fact that correlates well with the long persistence of this damage in living organisms.

Antimony(III) chloride impregnated on alumina — An efficient and economical Lewis acid catalyst for one-pot synthesis of dihydropyrimidinones under solvent-free conditions

2006 ◽  
Vol 84 (3) ◽  
pp. 433-437 ◽  
Author(s):  
Kamal K Kapoor ◽  
Bilal A Ganai ◽  
Satish Kumar ◽  
Charanjeet S Andotra
Keyword(s):  
Lewis Acid ◽  
Condensation Reaction ◽  
Thermal Conditions ◽  
Acid Catalyst ◽  
Solvent Free ◽  
One Pot ◽  
One Pot Synthesis ◽  
Solvent Free Conditions ◽  
Lewis Acid Catalyst

The antimony(III) chloride impregnated on alumina efficiently catalyses a one-pot, three-component condensation reaction among an aldehyde, a β-ketoester, and urea or thiourea to afford the corresponding dihydropyrimidinones in good to excellent yields. The reactions are probed in microwave (MW), ultrasonic, and thermal conditions and the best results are found using MW under solvent-free conditions.Key words: Biginelli dihydropyrimidinones synthesis, SbCl3–Al2O3, MW, sonication, solid supported.

scholarly journals Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

2014 ◽  
Vol 10 ◽  
pp. 1596-1602 ◽  
Author(s):  
Anastasia S Kostyuchenko ◽  
Vyacheslav L.Yurpalov ◽  
Aleksandra Kurowska ◽  
Wojciech Domagala ◽  
Adam Pron ◽  
...  
Keyword(s):  
Good Yield ◽  
Ring Closure ◽  
Quantum Yields ◽  
Synthetic Approach ◽  
Structural Elements ◽  
Target Molecule ◽  
Synthetic Strategy ◽  
Donor Acceptor ◽  
Synthetic Routes ◽  
Derivatives Of

A new synthetic approach towards the preparation of functionalised, soluble, donor–acceptor (DA) alkylbithiophene derivatives of oxadiazole, thiadiazole and triazole is reported. Taking advantage of the Fiesselmann reaction, reactive bithiophene synthons having alkyl or alkoxy substituents at designated positions are prepared. Following a synthetic strategy, featuring the bottom-up approach, sequential structural elements are built, starting from a simple thiophene compound, until the target molecule is obtained, all in good yield. Supplementing the well established methods of oxadiazole and thiadiazole synthesis, efficient ring closure reaction affording a 4H-1,2,4-triazole unit is presented. All target ambipolar compounds display strong photoluminescence with measured quantum yields up to 0.59. Modification of the demonstrated synthetic routes may be exploited for the preparation of longer, specifically functionalised oligothiophenes, coupled to other heteroaromatic cores.

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