Search

1H-Pyrrole reacted with lactone-type 2,3-furandione derivatives in anhydrous diethyl ether at room temperature to give a series of derivatives of pyrrolizinone (which is among the most important alkaloid skeletons) in a single step without a catalyst. Pyrrolizinone derivatives with a variety of substituents, such as phenyl, substituted phenyl, thienyl, trifluoromethyl, naphthyl, biphenylyl, ester, or oxalate, were obtained. The reaction of an equimolar amount of pyrrole gave pyrrolizinones, whereas an excess of pyrrole gave pyrrolizino[1,2-a]pyrrolizin-5-ones containing a skeleton that had not previously been reported. The purified molecules were obtained in yields of up to 91%. One cyclization process was carried out on a gram scale, yielding 0.952 g (71%) of the corresponding product.

A novel unsymmetrical zinc phthalocyanine complex (PCA-ZnPc-3) containing six 2,6-diphenylphenoxy donor groups and pyrazole-3-carboxylic acid anchoring group has been synthesized and used as a sensitizer for dye-sensitized solar cells (DSSCs). The optical, electrochemical and photovoltaic characteristics were evaluated and compared with the dyes containing the same anchoring group and tert-butyl (PCA-ZnPc-1) or hexylsulfanyl (PCA-ZnPc-2) donor groups, developed by our group. The DSSC with PCA-ZnPc-3 exhibited a higher power conversion efficiency (PCE) of 2.04% as compared to that of PCA-ZnPc-1 (PCE = 1.74%) and PCA-ZnPc-2 (PCE = 1.89%). This enhancement in efficiency may be ascribed to the less dye aggregation and appropriate dye coverage. These results suggest that the incorporation of 2,6-diphenylphenoxy into pyrazole-3-carboxylic acid-based zinc phthalocyanine sensitizers can improve photovoltaic performance of DSSCs.

A new sensor, based on boramidic acid-bounded MWCNTs (Multi-walled carbon nanotubes), was synthesized in three simple steps. Modification of the sensor surface was accomplished using boric acid in which the boron atom is adjacent to the NH group. Characterization, electrochemical behaviors, and stability of newly modified nanosensor were completed using SEM (scanning electron microscope), TEM (Transmission electron microscope), CV (cyclic voltammetry), EIS (electron impedance), DTA (Differential thermal analysis), and XPS (X-ray photoelectron spectroscopy). SEM and TEM analysis were confirmed the modified surface of the nanosensor. The stability of the newly synthesized sensor was also designated that the initial weight loss occurred between 50-145 degrees C was corresponded to the degradation of both ethylene diamine and boric acid. According to the EIS study, the Nyquist plot of the MWCNTs-NH-B (OH)(2)/GC electrode displayed a 0.435 k omega Rct with a smaller semicircle than the bare GC (6.57 k omega). The electrochemical behavior of dopamine was investigated using cyclic and square wave voltammetry (0.1 M phosphate buffer solution-pH 7.4). The diffusion-controlled process was determined when the oxidation of dopamine was studied. The detection limit of dopamine was found to be 5.1 nM. An actual sample study was done using the developed analytical method, and the detection of dopamine in urine was successfully performed. This study is the first example of boramidic acid-modified multi-walled carbon nanotubes

C-2 and C-5 substituted imidazole skeleton was synthesized through a one-pot two-step strategy. Synthesized molecule emits the light on ESIPT (excited-state intramolecular proton transfer). This molecule was utilized for its proton donor ability, and we have observed that fluoride and cyanide ions can be detected selectively. Different cations and anions were selected to observe the response of the synthesized molecule. However, there were not any fluorometric and colorimetric response except for fluoride and cyanide ions. Detection limits of fluoride and cyanide ions were found to be 9.22 mu M and 11.48 mu M, respectively. H-1-NMR spectra for the solution of the sensor and TBAF (tetrabuthylammoniumfluoride) were used for the identification of [L](-)[HF2](-) species. 3 equiv. TBAF saturated the solution of the sensor in d(6)-DMSO, and some of the proton resonances shifted to upfield due to the through-bond effect. The disappearance of NH proton with 0.5 equiv. TBAF or TBACN (tetrabuthylammoniumcyanide) showed that there was a proton abstraction by fluoride and cyanide ions, instead of the hydrogen bond. Solid-state application was utilized, and paper test strips were applied. Emission differences emerged when the sensor loaded strips were reacted with TBAF. Time resolved experiments revealed that solution of the sensor and TBAF in DMSO have multiexponential decay, and one of the lifetime was measured as 13.4 ns.

thtgerIn this study, Mitsunobu reagent, DEAD (diethyl azodicarbox-ylate) and PPh3, and ethyl-oxalamide derivatives of 2-amino-phenol were reacted under mild reaction conditions. As a resultof the cyclization reaction, benzoxazole derivatives bearing anester group in the C-2 position were obtained in a one-potprotocol. It was observed that the electron-donating groups atthe C-5 position and the electron-withdrawing groups at the C-6 position of the benzene ring increased the yield of the cyclicproduct. It was found that the cyclization does not occur whenthe carboxylic acid group is substituted in the benzene ring.The cyclization reaction we performed preferred the 5-endo-trigreaction instead of the 6-exo-trig. This experimental result wasexamined in detail with density functional theory (DFT)calculations as well. A computational exploration is presentedherein that elucidates the detailed mechanism for Huisgenzwitterion‘s reaction with ethyl-oxalamide derivatives of 2-aminophenol. Potential alternative mechanisms were modeledwith DFT calculations via CPCM/M06-2X/6-311+ +G(d,p)//B3LYP/6-31+ G(d,p) level method in tetrahydrofuran to under-stand shed light on the mechanism. Our computational resultsare in good agreement with experimental findings thatbenzoxazole derivatives are the sole products in this reaction

© 2021 Wiley-VCH GmbHTen different N-propargyl pyrrole derivatives having various substituents at the C-2 position were synthesized. These derivatives were converted into indolizine derivatives by the [2+2] cycloaddition reaction of pyrrole N-allene, forming in situ, by heating in PrOH in basic medium. The structures were characterized by NMR and X-ray crystallography. The N-propargylated derivatives smoothly underwent intermolecular cyclizations to produce indolizine derivatives in good yields. We proposed a radical mechanism for the dimerization. Reaction of an allene product with butylated hydroxytoluene (BHT), a radical scavenger, did not give any dimerization product. This result supports the radical reaction.

A manageable, one-pot, and high-yield protocol for synthesising highly reactive spiroindolenine derivatives is reported. Spiroindolenines are furnished by a reaction between DCC (dicyclohexylcarbodiimide) and indole-3-butenoic acid derivatives. The protocol proposed here involves the construction of a carbon-carbon bond through intramolecular domino cyclisation. The reaction mechanism for spirocyclisation is discussed; both NMR and X-ray analysis were used to verify the structure of spiroindolenine. The applied strategy allowed the formation of spiroindolenine with a dione substructure, which is an unknown compound with a spirocyclic nucleus. Further reactions of spiroindolenines with di-amines, a primary amine, and alcohol have been reported, and new types of indole derivatives, such as indoloquinoxalines, where the spirocentre atom undergoes a nucleophilic attack, are yielded.

Au-iii-promoted cyclization reaction of ynone-oxime derivatives furnished 4H-1,2-oxazine ring under mild reaction conditions. When an alcohol is present in the reaction media, it was attached to the oxazine ring by the second activation of cyclic intermediate with a gold catalyst. Cholesterol, propargyl alcohol, phenol, and some of the different alcohol derivatives with alkyl chain were bonded to the oxazine ring in good yields. While amine derivatives did not attach to the ring under optimized reaction conditions, the molecule with the thiol group deactivated the gold catalyst under the same reaction conditions and did not give any cyclic products. With the obtained cyclization protocol, 11 unknown oxazine derivatives were synthesized and characterized. The proposed cyclization mechanism was drawn according to the two independent control experiments, DFT optimization, and NBO charges.

Makale, WOS:000904967000006, Tetracyclic molecules show important properties such as biological activities and fluorescence sensors. Hence, in this study, we have reported unknown tetracyclic skeleton. N -propargylated C-2 and C-4 disubstituted imidazole derivatives were reacted by 2-aminomethyl piperidine without using any transition metal. The reaction unveiled 16 different imidazo[1,2-a]pyrido[1 ' ,2 ' :3,4]imidazo[2,1-c]pyrazine skeletons. Cyclization reaction tolerated phenyl, naphthyl, bi-phenyl, 2-thienyl, and many substituents on the benzene ring such as OMe, CF 3 , and halogens. We have uncovered the exact structure of the tetracyclic skeleton using single-crystal X-ray analysis. Significant fluorescence emission of tetracyclic molecules was investigated, and derivatives bearing electron-withdrawing groups, CF 3 , and the 2-thienyl group possessed a bathochromic effect (shift to longer wavelength) which was confirmed by not only steady-state experiments but HOMOs and LUMOs calculations. The antimicrobial effects of the synthesized molecules on six different or ganisms were tested. Considerable activities of molecules 5p and 5n on many organisms were determined. Docking modeling and Lipinski, Ghose, and Veber compatibility studies of two different molecules were performed., Scientific and Technological Research Council of Türkiye (TUBITAK)

Starting from the 3,5-dimethyl pyrazole ring and acetophenone derivatives, five different N-propargylated C-3 substituted pyrazoles were obtained. These derivatives were reacted with different amine derivatives using Cs2CO3 in methanol and 11 different pyrazolo [1,5-a] pyrazine-4(5H)-one derivatives were obtained, which are not found in the literature. The cytotoxic effects of these derivatives in the A549 cell line were investigated. The 160 mu M concentration of two derivatives was found to increase cell death rate to 50%, and two derivatives increased cell death rate by up to 40%. The structure-activity relationship (SAR) study revealed an amide group with a long alkyl chain and benzene ring with a p-CF3 group could be important for efficiency. With theoretical ADMET studies of pyrazolopyrazine derivatives, pharmacokinetic phases were predicted to be suitable.

Graphene oxide (GO) and their natural/synthetic composites are encouraging tools for humanity. There is a need to address critical challenges and potential risk possibilities in GO-based architectures, which have a wide range of uses. In this study, ecotoxicological levels as well as GO-based nanoparticle synthesis, characterization, interaction mechanism and toxicity detection levels for potential biomedical applications were determined on zebrafish (Danio rerio). The effects of GO-ED-BA NP (graphene oxide-boramidic acid nano particles) which was characterized by FT-IR, SEM, TEM, and BET on survival rate, morphological abnormalities (yolk sac edema, lordosis/kyphosis, pericardial edema, and tail malformation), hatching rate as well as neuronal degeneration /necrosis, 8 OHdG and TNF-alpha expression were observed in D. rerio embryos and larvae. In the obtained findings, it was determined that the toxicity profile of GO-ED-BA NP appeared similar, in high-dose application with single GO use, causing a cytotoxic, pro-inflammatory response and triggering oxidative stress. However, increased malformation rates and mortality at the highest concentration were due to nanoparticle sizes and GO. The presence of boramidic acid unit on graphene nanostructure changed the GO's toxicity profile and positively directed the proinflammatory and oxidative stress response. Synthesizing of graphene oxide-boramidic acid and its toxicity panels compared to graphene oxide are reported for the first time in this study.

Even though natural products or crops have been more common and popular in the recent, the chemicals without side-effects have been also addressed in various fields of industries due to possibility obtaining the large quantity and more bio-efficacy. In that context, many drugs have been developed for antibacterial activities but the over-uses of those relevant drugs have caused that microorganisms have adapted and evolved resistance against those drugs. Those lead to the researchers to focus on newly synthesized or functionalized molecules. In that context, nanotechnology, especially modified nanocarbon tubes (NCTs), are of the great interest of the various industries. Along with the current study, multi-walled carbon nanotubes (MWCNTs) were functionalized with three steps. Firstly, the carbon nanotube with a carboxylic acid tip on its surface was commercially purchased and then converted into acyl chloride, and later converted into a more reactive group. Then, the nucleophilic amino group such as diethylene triamine is bonded onto the carbon nanotube. Finally, after the carbon nanotube material with amine groups was functionalized with boric acid, carbon nanotube molecules carrying boric acid molecules were synthesized. Following modification and functionalization of MWCNTs, the newly synthesized molecules were characterized using FT-IR, SEM, TEM and XPS. After chemical characterization, the relevant molecules were screened for their anti-bacterial activities in comparison to those of well-known antibiotics. For anti-bacterial assays, molecules were tested against K. pneumoniae, E. coli, P.aeruginosa, S. aureus and B. subtilis. Concerning the findings of the antibacterial assays, concentrations of 40 and 80 μg /mL exhibited a range of activities but in parallel with those of standard antibiotics whereas the lower concentration, viz. 5, 10 and 20 μg / mL did not exhibit any activities. The highest activity was noted for 80 μg / mL, in comparison to those of antibiotics and other concentrations, against B. subtilis, with a 23 mm inhibition zone.

Green chemistry is a fascinating research area due to its respect to environment and effectiveness for more purified organic compounds, which will be active pharmaceuticals. Twelve principles of green chemistry should be obeyed, and these principles can manage the researchers to enhance productivity and reduce hazardous effects on human health. Active pharmaceutical ingredients (API) should have adequate purity due to their use in human health. Any contamination coming from adopted protocols can influence the product. These disadvantages increase further purification protocols, which led to using more power, chemicals, and increase product cost. All these disadvantages can be dropped using green chemistry principles. Around the world, pharmaceutical industries afford to do green protocol due to human health and product costs. These aims led them to find out new and greener synthetic protocols that can be utilized on an industrial scale. These protocols are imperative and can be transferred in research and development, which have been progressed in the university or other industries. In this chapter, we desire to exhibit the heart of green chemistry for pharmaceutical industries and show how they succeeded in green protocols. These protocols will be discussed in terms of their effectiveness and advantages in API. Opinion shows that green chemistry principles can save the cost of about 65.5 billion by 2020. The most direct and straightforward way to employ green chemistry in pharmaceuticals is to employ eco-friendly, nonhazardous, reproducible, and cost-effective solvents and catalysts in the synthesis of drug molecules and researches involving synthetic chemistry. Also, flow chemistry will be a powerful tool for the synthesis of API, as well.

N-Heterocycles are essential frameworks, mentioned in countless scientific works, that open a large gate into biologically active compounds; they are mentioned in medicinal chemistry as vital scaffolds. N-Heterocycles can be synthesized via many pathways, especially catalytic reactions that favor green chemistry principles. In catalytic approaches, copper has received special attention from scientists since it is more abundant than other metals, has lower toxicity, and can be handled easily. Copper-catalyzed cyclization reactions serve in many scientific fields, and these reactions resulting in N-heterocycles are of particular interest to the pharmaceutical industry, because many active medicinal ingredients can be synthesized using different copper catalysts. The importance of copper and its support in the synthesis of N-heterocycles was the impetus behind this chapter, and many examples are given of the synthesis of N-heterocycles in which copper catalysts were used. The presence of amine- and phosphine-based ligands for different selectivities, total synthesis using copper, synthesis of pharmaceutical products on gram scale, and biological activities of the mentioned N-heterocycles are all discussed in this chapter.

ABS T R A C T Appropriate synthesis methods gave six different indole derivatives substituted at the C-2 or C-3 position. ESIPT emission capacities of these derivatives were investigated. It was concluded that the indole derivative containing the 1,2-dicarbonyl group at the C-2 position has ESIPT emission. Although adding water to the DMSO solution of the ESIPT-based molecule (9:1) resulted in ESIPT quenching, steady-state measurements in MeOH did not occur ESIPT quenching. TD-DFT calculation for uncovering the ESIPT mechanism emerged that the ESIPT mechanism occurred as a barrierless process. The X-ray analysis and DFT conformational analysis revealed that NH and CO groups involving proton transfer mechanisms are in the cis position. A mono-exponential decay was observed in DMSO and MeOH solutions, in which lifetimes were measured as 6.1 and 5.5 ns, respectively. pH studies revealed that acidic and basic solutions of molecule 7 did not influence ESIPT emission.

A series of tetrasubstituted pyrazole-3-carboxamides (3a–c) and pyrazole-3-carbonyl thioureides (6a–c) were synthesized and their structures characterized by IR, NMR and elemental analysis. The antibacterial potential against specific Gram-positive and Gram-negative strains and the antifungal activities of all novel compounds were investigated. Structure–activity relationships (SAR) studies and some theoretical parameters (ClogP, CMR, PSA and ESP) of the compounds were performed on these two pyrazole derivatives. Pyrazole-3-carboxylate ester 2 was used for the synthesis of the carboxamide derivatives. The reactions of pyrazole-3-carbonyl isothiocyanate 5 with appropriate chiral amino alcohols were utilized for synthesizing the thioureide derivatives. Both of these types of pyrazole derivatives including a chiral moiety exhibited pronounced antibacterial activities. According to the present in vitro study, some of the promising compounds might be new candidates for a new generation of antibacterial drugs. © 2018 Serbian Chemical Society. All rights reserved. Firat University Scientific Research Projects Management Unit MSÜ14--EMF-G05 Acknowledgements. The authors thank to the Management Unit of Scientific Research Projects of Muş Alparslan University (MSÜBAP) for financial support under Project MSÜ14--EMF-G05. The authors thank Dr. Abdullah Dalar for his valuable comments and corrections in the antimicrobial section.

In this study, a series of asymmetric aryl 1,3-dicarbonyl compounds were synthesized and their enol forms were observed via experimental data and theoretical calculations. According to the 1H- and 13C-NMR results, all the investigated compounds were found as a single enol form in CDCl3 solution. Moreover, their HMBC spectra were applied to identify the observed enol forms and correlations between certain protons and carbon atoms were considered. The dihedral angles of the asymmetric compounds that have aryl units on both sides were calculated by DFT to understand the reason for the observed enol forms. Small dihedral angles caused longer conjugation, resulting in more stable compounds and it was found that the observed enol forms were based on small dihedral angles, namely, resonance is the driving force. Furthermore, the compounds possessing both aryl and alkyl moieties prefer the enol form towards the aromatic ring side due to longer conjugation.

Aromaticity of pyrazolopyridazin(on)es was investigated using NICS(0), NICS(1), NICSzz(1), FIPC-NICS and HOMA aromaticity indexes and it was observed that aromaticity of pyridazin(on)es was amenable to aromaticity of pyrazole and vice versa. Some tautomeric forms of pyridazinone were analyzed and the localized orbital locator maps, electron density maps, Fuzzy, Laplacian, and Mayer bond order methods showed dominant form. Different substituents, amine, chlorine, phenyl, methyl, hydrogen, substituted-phenyl, etc. on both the rings were chosen to search out the substituent effect. Aromaticity of pyrazolopyridazin(on)es was searched out in detail for the first time. Synopsis: Aromaticity of Pyrazolopyridazine was calculated and the effect of bicyclic system on aromaticity was revealed. Furthermore, tautomerization of the same skeleton was investigated and the dominant tautomer was identified by means of aromaticity, bond order, and LOL map.

A number of substituted imidazole-based molecules were synthesized via a two-step one-pot reaction and their UV/vis and fluorescence spectra were analyzed. Emissions of the imidazole-based molecules were attributed to the excited state intramolecular proton transfer (ESIPT) process. Imidazole-based sensor molecules have high Stokes shifts which is good clue for the ESIPT mechanism. Furthermore, the ESIPT mechanism was confirmed by some control experiments in which acceptor and donor groups were functionalized, resulting in hampered ESIPT emission. Time-resolved experiments showed that the skeleton synthesized had different exponential decays depending on the functional groups (OMe and OH). According to the time-resolved experiments, the ESIPT reaction occurred between 1.0 and 3.10 ns. Furthermore, the lifetime of molecules in EtOH increased when the phenyl ring possessed OMe or OH groups. Dihedral angles between the NH and carbonyl groups were calculated and found to be important for a stable configuration. The methyl substituted NH group on the imidazole skeleton in which the ESIPT reaction should be interrupted, revealed a 0.3 ns lifetime in DMSO. Potential energy curves for all compounds were analyzed using TD-DFT. It was seen that there is no barrier for excited state proton transfer resulting in ultrafast ESIPT process.

Mono- or di-substituted imidazole derivatives were synthesized using a one-pot, two-step strategy. All imidazole derivatives were tested for AChE and BChE inhibition and showed nanomolar activity similar to that of the test compound donepezil and higher than that of tacrine. Structure activity relationship studies, docking studies to on X-ray crystal structure of AChE with PDB code 1B41, and adsorption, distribution, metabolism, and excretion (ADME) predictions were performed. The synthesized core skeleton was bound to important regions of the active site of AChE such as the peripheral anionic site (PAS), oxyanion hole (OH), and anionic subsite (AS). Selectivity of the reported test compounds was calculated and enzyme kinetic studies revealed that they behave as competitive inhibitors, while two of the test compounds showed noncompetitive inhibitory behavior. ADME predictions revealed that the synthesized molecules might pass through the blood brain barrier and intestinal epithelial barrier and circulate freely in the blood stream without binding to human serum albumin. While the toxicity of one compound on the WS1 (skin fibroblast) cell line was 1790 µM, its toxicity on the SH-SY5Y (neuroblastoma) cell line was 950 µM.

In this study, 23 different imidazole derivatives were synthesized, and the inhibitory properties of these derivatives against carbonic anhydrase I and II isoenzymes were investigated for the first time. The inhibition concentrations of the imidazole derivatives were found to be in the range of 2.89-115.5 nM. Docking studies examined the binding properties of the imidazole derivatives, and the structure-activity relationship is discussed. Theoretical calculations showed that the binding mode of the imidazole ring was non-zinc binding.

Indole containing dyes were synthesized via a simple method with high yield. These molecules have different colors and UV-vis spectra of them were recorded. Impact of solvents on absorbances was investigated and it was observed that basic solvent such as DMF and pyridine have blue shift. TD-DFT calculations were done and results were compared with experimental data. NMR data of molecules were analyzed and tautomeric forms of colorants and their ratio were determined. It was find out that two tautomers might be formed in solution, called indole and indolenine form. HOMO-LUMO and energy gaps were calculated and plotted. Furthermore, molecular electrostatic potentials were simulated to find out electrophilic and nucleophilic regions. (C) 2016 Elsevier B.V. All rights reserved.

N-Propargyl-2-aroylimidazoles synthesized and converted into the corresponding ketoximes. Under various conditions, several mono- and diketoxime imidazole derivatives were formed by converting the carbonyl or carbonyl and propargyl groups into oxime groups. N-Propargyl monooxime imidazole derivatives were cyclized by treatment with CuI to give various imidazopyrazine N-­oxides. Several copper salts, such as CuOAc, CuSO4, and CuOTf, formed the same cyclization product. This cyclization reaction occurred only in the presence of Cu(I) or Cu(II) salts; other transition metals such as Au, Ag, In, and Fe did not yield cyclic products. The nucleus-independent chemical shift method was used to calculate the aromaticity of the bicyclic rings.

Menges, Nurettin/0000-0002-5990-6275 WOS: 000483709700031 The reaction of pyrrole- and indole-carbaldehydes having a propargyl group attached to the nitrogen atom with various amines was studied. The reaction with ammonia formed pyrrolo[1,2-a]pyrazine and pyrazino[1,2-a]indole while the reaction with alkylamines such as methyl, ethyl, hexyl, and benzylamines formed the corresponding pyrazinone derivatives. Unexpectedly, the reaction with allylamine and propargylamine formed pyrazine derivatives in which the allyl and propargyl groups were removed from the molecule. On the other hand, the reaction of N-propargylated pyrrole-carbaldehyde formed indolizine derivatives upon reaction with sterically bulky adamantyl- and tert-butylamines. To understand the main factors causing these differences in reactivity, the reaction mechanisms were studied by means of computational methods. Our calculations showed that bulky amines tend to attack the central carbon of allene formed by the isomerization of N-propargyl functionality, while the attack on the carbonyl carbon by aliphatic amines is more profound.

We have designed and synthesized an unsymmetrical zinc phthalocyanine (PCA-ZnPc-1) bearing an electron-withdrawing pyrazole-3-carboxylic acid anchoring group and three electron-donating tert-butyl groups as a sensitizer for dye-sensitized solar cells (DSSCs). PCA-ZnPc-1 sensitized solar cell showed a modest power conversion efficiency (1.74%), which may suffer from the flexible and non-conjugated oxygen linker on the sensitizer. However, the obtained efficiency is found to be three to four times higher than that of the unsymmetrical ones bearing only carboxylic acid due to the combination of pyrazole and carboxylic acid moieties within the same anchoring group, which enhances the binding of the dye on the TiO2 surface and results in an increase of electron injection efficiency. Therefore, the pyrazole-3-carboxylic acid is a promising anchoring group for developing new phthalocyanines to build efficient DSSCs.

Imidazo-1,5-alkynyl alcohol derivatives were synthesized, and they were cyclized to imidazo-1,4-oxazines by means of cesium carbonate. Propargyl-allene isomerization was examined, and the reaction mechanism was proposed. Moreover, cytotoxicity of synthesized molecules against LN405 cell lines was investigated by means of structure-activity relationship (SAR). With SAR study, toxicities of some functional groups have been shown. In addition, two lead compounds were tested against DNA damaging.

Novel imidazopyridine derivatives were synthesized according to a very simple protocol and then subjected to cytotoxicity testing against LN-405 cells. Two of the compounds exhibited antiproliferative effects on LN-405 cells at 10 and 75 µM and were selected as lead compounds for further study. Safety experiment for lead compounds on WS1 was carried out and IC50 values were calculated as 480 and 844 µM. LN-405 cell line were incubated with the lead compounds and then tested for DNA damage by comet assay and effects on cell cycle using flow cytometry. The results of these two tests showed that both lead compounds affected the G0/G1 phase and did not allow the cells to reach the synthesis phase. The log BB (blood–brain barrier) and Caco-2 permeability of the synthesized molecules were calculated and it was shown that imidazopyridine derivatives taken orally are likely to pass through gastrointestinal membrane and the blood–brain barrier.

C-acylation of 1,3-diketo compounds has been done successfully employing 1,3 diketo compounds, oxalyl chloride, and phenol derivatives through metal, base, and toxic solvent-free protocol. Dioxinone ring-bearing 1,3,3' tricarbonyl moiety was also obtained in the same conditions using salicyl aldehyde. All reactions were carried out in vegetable oil.

Some new pyrazole-, chromone-, or oxadiazole-substituted 1H-pyrazoles were obtained via 2,3-furandiones. Also, we have presented their plausible mechanisms based on rearrangement; one of these rearrangements is Baker–Venkataraman.

Poly(p-phenylene-1-(2,5-dimethylphenyl)-5-phenyl-1H-pyrazole-3,4-dicarboxy amide) (poly(PDPPD)) was synthesized from reactions of p-phenylene-diamine and 1-(2,5-dimethylphenyl)-5-phenyl-1H-pyrazole-3,4-dicarbonyl dichloride (monomer) by heating under solvent. This newly synthesized poly(PDPPD) was characterized by 1H, 13C-NMR, FT-IR, gel permeation chromatography (GPC). In addition, we investigated optical properties of the poly(PDPPD) containing the substituted pyrazole ring at different molarities. The average transmittance (T avg) values of the poly(PDPPD) in the visible (V) region were higher than the T avg values in the near-ultraviolet (NU) region. The T avg values of the poly(PDPPD) in the NU and visible (V) region decreased with increasing molarity. The absorption band edge (Absbe) value of the poly(PDPPD) decreased with increasing molarity. It was observed that the optical band gap (E g) of the poly(PDPPD) value decreased more with increasing molarity. The refractive index of the poly(PDPPD) decreased with increasing wavelength and decreasing molarity. The structure of the poly(PDPPD) in the lowest energy was optimized by DFT calculation and its HOMO–LUMO orbitals were plotted.

In this work, a new imidazole-based sensitive and selective sensor was synthesized. It was observed that the synthesized new fluorescent sensor had high selectivity and sensitivity to Fe 3+ ions. The association constant of the sensor was found by using Stern Volmer Plot as 14,318 M −1 . Binding stoichiometry between sensor and Fe 3+ ions was found by using Job's plot as 1:1. The synthesized chemical sensor was found to exhibit a large Stokes’ shift (107 nm). The proposed turn-OFF mechanism regarding bonding between sensor and Fe +3 ions was discussed by NMR data and DFT calculations. Furthermore, it was revealed that planarity and functional groups such as methoxy and carbonyl affected the quantum yield. These results were confirmed by plotting of Frontier orbitals and calculated dihedral angles.

Menges, Nurettin/0000-0002-5990-6275 WOS: 000369771800017 PubMed: 26752224 The AgOTf-catalyzed reaction of C-2 substituted pyrrole hydrazones having an N-propargyl group was studied. The selective 6-endo-dig mode of cyclization was observed, giving rise to the formation of pyrrole-fused C,N-cyclic azomethine imine derivatives. The reaction of one azomethine imine derivative with various dipolarophiles resulted in the formation of cycloadducts having a pyrazolopyrrolopyrazine skeleton. The aromaticity of C,N-cyclic azomethine imines as well as that of pyrazolopyrrolopyrazines was determined by calculating of nucleus-independent chemical shifts values. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-112 T360]; Yuzuncu Yil UniversityYuzuncu Yil University [2014-ECZ-B170]; Turkish Academy of Sciences (TUBA)Turkish Academy of Sciences; Middle East Technical University (METU) Financial support from the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TBAG-112 T360), Yuzuncu Yil University (Grant No. 2014-ECZ-B170), the Turkish Academy of Sciences (TUBA), and the Middle East Technical University (METU) is gratefully acknowledged.

Menges, Nurettin/0000-0002-5990-6275 WOS: 000255270500037 Oxalacetic acid and pyruvic acid derivatives have been synthesized efficiently in high yields by the treatment of 4-ethoxycarbonyl-5phenyl-2,3-furandione and 4-benzoyl-5-phenyl-2,3-furandione with 2-phenylindole at room temperature and converted to simple derivatives such as an ester or a hydrazone. (C) 2008 Elsevier Ltd. All rights reserved.

A concise and regioselective approach for the synthesis of 2,3-disubstituted thiophene derivatives is developed.

The synthesis of pyrrole and indole derived oximes and their Au(III)-catalyzed reactions are described.

3,4-Dihydropyrrolo- and indolo-oxazin-1-one derivatives are efficiently obtained by cyclization reactions of corresponding N-propargylpyrrole and -indolecarboxylic acids, respectively.

Kaya, Serdal/0000-0002-0744-8057; Guven, Sinem/0000-0002-1503-3484; Menges, Nurettin/0000-0002-5990-6275 WOS: 000355962200025 PubMed: 25992473 The gold-catalyzed reaction of pyrrole and indole oximes having a propargyl group attached to the nitrogen atom was studied. The selective 6-endo-dig mode of cyclization was observed for the terminal alkynes giving rise to the formation of pyrazine N-oxides in the presence of a gold catalyst. However, the reaction with substituted alkyne transferred the oxime functionality intramolecularly from one carbon atom to another via the 7-endo-dig cyclization process. This transformation is unprecedented in the literature and is named an oximeoxime rearrangement. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-112 T360]; Turkish Academy of Sciences (TUBA)Turkish Academy of Sciences; Middle East Technical University (METU) Financial support from the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TBAG-112 T360), the Turkish Academy of Sciences (TUBA), and Middle East Technical University (METU) is gratefully acknowledged. We also thank Research Assistant Ozlem Sari (METU) for her help with calculations.

WOS: 000362533900004 A concise and regioselective approach for the synthesis of 2,3-disubstituted thiophene derivatives has been developed. The synthetic strategy relies on the reaction of an in situ generated 2-mercaptoacetaldehyde with various alkynones. Furthermore, we calculated the energy gap between the HOMO and the LUMO orbitals of all compounds and observed that the introduction of a strong electron-withdrawing group decreased the HOMO-LUMO energy gap. (C) 2015 Elsevier Ltd. All rights reserved. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-112 T360]; Turkish Academy of Sciences (TUBA)Turkish Academy of Sciences; Yuzuncu Yil UniversityYuzuncu Yil University [YYU-BAP-2014-ECZ-B170]; Middle East Technical University (METU) Financial support from the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TBAG-112 T360), the Turkish Academy of Sciences (TUBA), Middle East Technical University (METU), and Yuzuncu Yil University (Grant No. YYU-BAP-2014-ECZ-B170) are gratefully acknowledged.

A protocol for reduction of C-C double and triple bonds is developed, which relies on the in situ generation of diimide from hydrazine hydrate by oxidation with oxygen.

A series of alkenes and alkynes was subjected to reduction with hydrazine hydrate in ethanol in the presence of oxygen. An efficient method was developed for the reduction of C–C double bonds and C–C triple bonds with diimide, generated in situ from hydrazine hydrate by oxidation with oxygen. The reduction process proceeded for 24–48 hours with high chemoselectivity and excellent yields. This reduction procedure offers synthetic advantages over metal-catalyzed hydrogenation as well as other systems.

WOS: 000320298700006 PubMed ID: 23647431 The pyrrole derivatives having carbonyl groups at the C-2 position were converted to N-propargyl pyrroles. The reaction of those compounds with hydrazine monohydrate resulted in the formation of 5H-pyrrolo[2,1-d][1,2,5]-triazepine derivatives. The synthesis of these compounds was accomplished in three steps starting from pyrrole. On the other hand, attempted cyclization of a pyrrole ester substituted with a propargyl group at the nitrogen atom gave, unexpectedly, the six-membered cyclization product, 2-amino-3-methylpyrrolo[1,2-a]pyrazin-1(2H)-one as the major product. The expected cyclization product with a seven-membered ring, 4-methyl-2,3-dihydro-1H-pyrrolo[2,1-d][1,2,5]-triazepin-1-one was formed as the minor product and was converted quantitatively to the major product. The formation mechanism of the products was investigated, and the results obtained were also supported by theoretical calculations. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [TBAG-112 T36]; Middle East Technical UniversityMiddle East Technical University; Turkish Academy of Sciences (TUBA)Turkish Academy of Sciences; BIDEB-TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) We are indebted to the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TBAG-112 T36), the Middle East Technical University, and the Turkish Academy of Sciences (TUBA) for financial support of this work. Furthermore, N.M. and Y.A. are grateful for a scholarship provided by BIDEB-TUBITAK.