2-acetylfuran Research Articles

Synthesis of palladium complexes containing benzimidazole core and their catalytic activities in direct C[sbnd]H functionalization of five-membered heterocyclic bioactive motifs

Herein, we reported the synthesis of nine new PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-h containing benzimidazole core and examined their catalytic activities in the direct arylation of heteroaromatic species with aryl bromides and arylchlorides. Nine new Pd benzimidazole complexes were synthesized and their structures were elucidated by 1H and 13C NMR spectroscopy, FT-IR spectroscopy, and elemental analysis methods. In the 13C NMR spectra, NCHN peaks of Pd(II) complexes were observed between 159.7–161.5 ppm. Further, direct arylation reaction, using KOAc as base and DMAc as solvent under inert conditions, were carried out with the synthesized complexes in the presence of various aryl bromides and chlorides, and 2-acetyl furan, and furfuryl acetate 2-acetylthiophene and N-methylpyrrole-2- carboxaldehyde. Moreover, moderate to hig yields were obtained in the direct arylation of heteroarenes and aryl bromides under 1 mol% catalyst loading at 150 °C for 2 h loading conditions. The results showed that electron-donating and electron-withdrawing substituents on the aryl halides might produce coupling products in good yields in the presence of complexes 2a-d. Taken together, our findings are expected to contribute to the synthesis and design of palladium complexes containing benzimidazole core structures.

Plausible PEPPSI catalysts for direct C-H functionalization of furans and pyrroles

The worth of bi(hetero)arenes in ongoing medicinal and industrial research fields promotes their efficient synthesis by Pd-PEPPSI-bearing NHC spectator ligands encapsulated as site-selective direct C-H functionalization agents. Eight new asymmetric N-heterocyclic carbenes ligands and their plausible pyridine-assisted Pd (II) complexes are reported in this work. The synthesized compounds were thoroughly characterized by respective spectroscopic techniques, such as 1H, 13C, FTIR and elemental analysis. The structures of synthesized pro-ligand salts and complexes were determined by Single Crystal XRD. The on/off mechanism of pyridine assisted Pd-NHC complexes made them the best C-H functionalized catalysts for regioselective C5 arylated products. Five membered heterocyclic compounds such as 2-acetyl furan, furfuryl acetate and 1-methyl-2-pyrrole-carboxylaldehyde were treated with numerous aryl bromides under optimal catalytic reaction conditions. Furfuryl acetate was used for the first time as a substrate in the present research work. Interestingly, all the prepared catalysts possessed essential structural features that facilitated the formation of desired coupled products in quantitative yield with excellent selectivity.

Volatile Organic Compounds, Total Phenolic Content, Color, and Heating Uniformity of Lemon Peel as Affected by Rotational Speed of Turntable During Microwave Drying

In this study, the effects of rotational speed of microwave turntable (0, 6.5, 9.5, and 12.5 rpm) on surface temperature distribution of lemon peels during drying and, on some quality attributes (color, water activi-ty, total phenolic content (TPC), and volatile organic compounds) of dried lemon peel powders were investigated. The quality analyses were also performed in freeze-dried peels. During microwave drying with rotation, speed of turntable affected the surface temperature values and TPC depending on the power level but did not exert a clear effect on the homogeneity of the surface temperature distribution and the color parameters. The percentage amount of major monoterpene hydrocarbons (limonene, γ-terpinene, myrcene, p-cymene, and α-p-dimethylstyrene) detected in fresh lemon peel decreased after microwave and freeze-drying. At 600W, formation of furan compounds (furfural, furfuryl alcohol, tetrahydrofurfuryl alcohol, 2-acetyl furan, 5-methyl furfural, and HMF) were identified. Microwave drying without rotation (0 rpm) caused uneven heating which led to the production of peel powders with unacceptable dark color especially at 450 and 600W. Drying at 600W-0 rpm gave the darkest color, the highest amount of TPC (1730.7 mg GAE/100g d.b.) and furan compounds. Therefore, microwave drying at low power levels with rotation function preserved the quality of lemon peel powder better.

Cocktail effect and synergistic mechanism of two components of Perilla frutescens essential oil, perillaldehyde and carvone, against Tribolium castaneum

Tribolium castaneum (Herbst) is one of the most harmful insects in stored products. The objective of the current study was to search for active constituents of Perilla frutescens (L.) Britt. essential oils from three localities against T. castaneum, as well as to investigate the optimal formula of active constituents and their synergistic mechanism. A total of 38 constituents were identified from the three essential oils by gas chromatography-mass spectrometry (GC-MS) according to the mass spectra and retention index values, and the relative contents of the individual components were determined by the peak normalization method. The following major compounds were identified: perillaldehyde, (R)-(-)-carvone, 2-furyl methyl ketone, d-limonene, and β-caryophyllene. Contact toxicity was assessed by topical application under room temperature, and the insects were reared in a dark incubator for 24 h at approximately 30 °C and 75 % humidity. Of these compounds, perillaldehyde (LD50 =7.71 μg/adult) and R-(-)-carvone (LD50 =10.93 μg/adult) displayed the most significant contact activities against T. castaneum. Synergistic interactions between perillaldehyde and R-(-)-carvone were evaluated using Wadley's model. All nine tested formulas displayed synergistic effects against T. castaneum, and a 1:4 (v:v) mixture exhibited an intense cocktail effect by dramatically reducing the LD50 to 2.73 μg/adult. The results of the RNA-Seq and qRT-PCR analyses suggested that the synergistic effect could be attributed to a reduced capacity for detoxification and elimination of xenobiotics. Three cytochrome P450 genes (CYP6BQ11, CYP6BQ7, and CYP6BK5) in phase I and two multidrug resistance protein genes (MRP4a and MRPX4) in phase III of the detoxification process may play essential roles. These findings provide a basis for the development of novel natural insecticides for the control of storage pests.

Optimization of Adsorption and Desorption Time in the Extraction of Volatile Compounds in Brewed Java Arabica Coffee Using the HS-SPME/GC-MS Technique

The headspace solid phase microextraction (HS-SPME) technique has been recognized as a reliable technique for characterizing the aroma profile of Arabica coffee beans. The amount and content of the detected volatile compounds depend on the volatile analyte extraction process with HS-SPME, namely the adsorption and desorption processes. However, the optimal extraction time in applying coffee volatile compounds is still limited. This research aimed to obtain the optimum adsorption and desorption time in analyzing volatile compounds in brewed Java Arabica coffee. The adsorption time was optimized for 20 to 60 minutes with 5 minutes desorption time. The desorption time was optimized from 5 to 45 minutes with a 20 minutes of adsorption time. There are 14 volatile compounds with a peak area percentage of more than 2% from adsorption and desorption optimization. The optimal adsorption time was 50 minutes, where there were 5 of 7 compounds with the most significant area, such as 2-furfural (29%), 2-acetyl furan (3%), 2-furfuryl acetate (6%), 5-methyl furfural (12%), and 2-furfuryl alcohol (14%). Meanwhile, the most optimal desorption time was 5 minutes which detected 12 compounds, while the other desorption time only detected eight compounds. Furfuryl formate (2%), pyridine (12%), and 2-furfuryl alcohol (14%) had a higher peak area than the other compounds at a desorption time of 5 minutes. The results showed the same number of volatile compounds at each adsorption time. In conclusion, the adsorption time did not affect the number of compounds detected as in the optimization of desorption time. Adsorption and desorption time is crucial in analyzing volatile compounds from coffee using the HS-SPME/GC-MS technique.

Substituted N-heterocyclic carbene PEPPSI-type palladium complexes with different N-coordinated ligands: Involvement in the direct C[sbnd]H bond activation of heteroarenes derivatives with aryl bromide and their antimicrobial, anti-inflammatory and antioxidant activities

In this study new benzimidazolium salt as N-heterocyclic carbene precursors and their related new PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-e were prepared and caracterized. The structures of all compounds have been characterized by 1H NMR, 13C NMR, and IR spectroscopy, as well as elemental analysis techniques and Direct analysis in real time (DART)–time-of-flight mass spectrometry (TOF-MS), which support the proposed structures. Further confirmations of structural details were provided by a single-crystal X-ray. A single crystal of PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complex 3c shows that the coordination geometry around Pd slightly distorted square-planar geometry. Next, the PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-e were used as catalysts in the direct C5-arylation of 2-acetyl furan and 2-acetylthiophene with various aryl bromides. These complexes exhibited moderate to high catalytic activities and gave CH activation selectively at the C5-position. Further, PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-e have been evaluated for their potential antibacterial properties against a panel of bacterial strains namely, Micrococcus luteus, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus, candida albican and pseudomonas aeruginosa. In addition; these new PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-e were investigated for anti-oxidant activities by super oxide radical; DPPH (2,2-Diphenyl-1-picrylhydrazyl); and hydroxyl radical scavenging assays; in which most of them displayed significant antioxidant activities. Furthermore; PEPPSI-Pd(II)–N-heterocyclic carbene (NHC) complexes 3a-e were evaluated for anti-inflammatory activity by indirect haemolytic and lipoxygenase inhibition assays and revealed good activity.

Changes in harmful Maillard reaction products in low-temperature long-time pasteurization-treated milks reconstituted from whole-milk powders after different storage times

Reconstituted milk treated with low-temperature long-time pasteurization was produced from whole-milk powders stored for 0–18 months. The profiles of initial, intermediate, and advanced stage Maillard reaction products, furosine, furfurals, and advanced glycation end-products in reconstituted milk were investigated. The total lysine content decreased in the reconstituted milk, whereas furosine content increased by 1.8- to 7.4-fold with storage of the corresponding milk powder. 5-(Hydroxymethyl)furfural (HMF) increased by 25–271 % with storage. 2-Furaldehyde (F) and 5-methyl-2-furfural also showed an increasing trend with storage, but 2-furyl methyl ketone (FMC) was detected only in fresh and 4-month-old reconstituted milk powder. The Nε-(carboxymethyl)lysine (CML) content increased by 1.8- to 5.2-fold with storage (from 9.9 ± 1.6 to 28.3 ± 3.3 mg/L). The Nε-(carboxyethyl)lysine content increased by 34–175 %. The increase in the furosine, HMF, F, and CML content in reconstituted milk accelerated between 12 and 18 months of storage. These compounds were more affected by the storage time of the milk powder than other harmful Maillard reaction products.

Synthesis, characterization, DFT, docking studies and molecular dynamics of some 3-phenyl-5-furan isoxazole derivatives as anti-inflammatory and anti-ulcer agents

A vast number of nitrogen heterocyclic derivatives comprising oxygen atom is considered as a valuable combination of therapeutic agents in curative chemistry. In particular, isoxazole, a five-member heterocyclic ring, is detected along with some of the marketed drugs such as danazol, flucloxacillin, dicloxacillin, cloxacillin, and valdecoxib which are known as an anti-inflammatory drug. The incorporation of the isoxazole ring can offer enhanced physical-chemical properties to show a wide scope of targets and diverse biological applications. In this view, the title compounds 5(a-h) were synthesized in good yield starting from different substituted benzaldehydes 1(a-h) and 2-acetyl furan (2) to afford chalcone derivatives 3(a-h). Further, compounds 3(a-h) refluxed with hydroxylamine hydrochloride to afford the title compounds 5(a-h). The purified compounds were explained by spectroscopic procedures (FT-IR, 1H NMR, 13CNMR, and LC-MS), and lastly, the title compounds 5(a-h) were screened for COX-1, COX-2, LOX furthermore, anti-ulcer action. In-vitro, study reveals that compound (5f) is potent with the IC50 values 9.16 ± 0.38 µM (COX-2), 8.15 ± 0.16 µM (15-LOX), and 42.41 0.29 µg mL−1 (anti-ulcer activity against H+/K+ ATPase) which are very close to the standard omeprazole. Besides, in-silico putative binding, possess of compound (5f) was studied by performing molecular docking and molecular dynamic along with ADME/Tox to evaluate its bioavailability and toxicity studies.

A 1D silver(I) coordination polymer of a new hydrozone-hydrazide ligand: Spectral, structural, emission, and anti-bacterial properties and its application as a solid source precursor for silver oxide nanoparticles

A new one-dimensional (1D) coordination polymer of composition [Ag(L)(NO3)]n was synthesized by a reaction of silver(I) nitrate with a new hydrazone-hydrazide ligand (L) derived from 2-acetyl furan and ethyl hydrazine carboxylate. Both the ligand, L, and the silver(I) complex were characterized using elemental analysis, electron impact mass spectrometry (EI-Mass), infrared (IR), proton nuclear magnetic resonance (1H NMR), ultraviolet–visible (UV–Vis) spectroscopy, and emission spectroscopy analyses. Single-crystal X-ray diffraction study shows that the structure of the silver(I) complex consists of 1D polymeric chains in which silver(I) ion is in four coordination complexes arising from one N, O-chelating L and two O, O′-bridging nitrate anions. The complex emitted energy around 360 nm and was used as a single precursor for synthesis of silver oxide nanoparticles (Ag2O NPs). From transmission electron microscopy (TEM) and higher-resolution TEM (HR-TEM) images, the as-prepared Ag2O NPs were nearly spherical in shape with average particle sizes of approximately 22–24 nm. Anti-bacterial properties of both the ligand and the metal complex were studied.

Indoor Air Quality: Assessment of Dangerous Substances in Incense Products.

Indoor air pollution has obtained more attention in a moment where “stay at home” is a maximum repeated for the entire world. It is urgent to know the sources of pollutants indoors, to improve the indoor air quality. This study presents some results obtained for twelve incense products, used indoors, at home, and in temples, but also in spa centers or yoga gymnasiums, where the respiratory intensity is high, and the consequences on health could be more severe. The focus of this study was the gaseous emissions of different types of incense, performing a VOC screening and identifying some specific VOCs different from the usual ones, which are known or suspected to cause severe chronic health effects: carcinogenic, mutagenic, and reprotoxic. Thirteen compounds were selected: benzene, toluene, styrene, naphthalene, furfural, furan, isoprene, 2-butenal, phenol, 2-furyl methyl ketone, formaldehyde, acetaldehyde, and acrolein. The study also indicated that incense cone type shows a higher probability of being more pollutant than incense stick type, as from the 12 products tested, four were cone type, and three of them were in the group of the four higher polluters. Benzene and formaldehyde presented worrying levels in the major part of the products, above guideline values established by the WHO. Unfortunately, there are no limit values established for indoor air for all the compounds studied, but this fact should not exempt us from taking action to alert the population to the potential dangers of using those products. From this study, acetaldehyde, acrolein, furfural, and furan emerge as compounds with levels to deserve attention.

Contents and evolution of potential furfural compounds in milk-based formula, ultra-high temperature milk and pasteurised yoghurt

Potential furfural compounds were detected by reverse phase high performance liquid chromatography (HPLC)-diode array detector (DAD) in milk-based formula (MBF), ultra-high temperature milk (UHT) and pasteurised yoghurt (PY). The content of potential 5-hydroxylmethyl-2-furaldehyde (HMF) and 2-furaldehyde (F) are significantly different in MBF, UHT and PY. 2-Furyl methyl ketone (FMC) and 5-methyl-2-furaldehyde (MF) were not detected in MBF, UHT and PY. Stress testing selected high temperature and high humidity to study the evolution of furfural compounds in MBF, UHT and PY. The contents of potential HMF and F sharply increased under high temperature conditions, while they showed little change under high humidity conditions. Accelerated testing and long-term testing were also conducted. Finally, regression equations of temperature–time-furfural content relationships were derived, by which the contents of furfural compounds in these dairy products stored under certain conditions for a certain time could be predicted.

Synthesis of [PdBr2(benzimidazole-2-ylidene)(pyridine)] complexes and their catalytic activity in the direct C[sbnd]H bond activation of 2-substituted heterocycles

A series of unsymmetrical 1,3-disubstituted benzimidazolium chlorides, 2a-f, having two nitrogen atoms substituted by various alkyl groups were synthesized as N-heterocyclic carbene (NHC) precursors in high yields. The benzimidazolium salts are readily converted into the corresponding PEPPSI-type palladium–NHC complexes 3a-f (PEPPSI = pyridine-enhanced precatalyst preparation, stabilization and initiation). The structures of all the compounds have been characterized by 1H NMR, 13C NMR and IR spectroscopy, as well as the X-ray diffraction technique (3a, 3d and 3e), which support the proposed structures. Next, the palladium-NHC-PEPPSI complexes were used as catalysts in the direct C(5)-arylation of 2-acetyl furan and 2-acetylthiophene with various aryl bromides. These complexes exhibited moderate to high catalytic activities and gave CH activation selectively at the C(5)-position of 2-acetylfuran and 2-acetylthiophene.

N-Heterocyclic carbene-palladium-PEPPSI complexes and their catalytic activity in the direct C–H bond activation of heteroarene derivatives with aryl bromides: synthesis, and antimicrobial and antioxidant activities

The Pd–NHC–PEPPSI complexes were used as catalysts in the direct C5-arylation of 2-acetyl furan, 2-acetylthiophene, and 2n-propylthiazole with different aryl bromides and were evaluated for their potential antibacterial and antioxidant properties.

A novel UHPLC method for determining the degree of coffee roasting by analysis of furans

The aim of this study was to develop a multi-analyte UHPLC method for furans and to apply it to commercial coffee samples as well as commercial roasting trials. Furans, as rising time–temperature indicators (TTIs), promised to be an alternative to unsatisfactory roasting temperature measurements. Consequently, a UHPLC–UV method for the determination of 5-hydroxymethyl-2-furfural (HMF), 5-hydroxymethyl-2-furoic acid (HMFA), 2-furfural (F), 5-methylfurfural (MF), 2-furyl methyl ketone (FMC), 2-furoic acid (FA), and for 3-caffeoylquinic acid (3-CQA) was developed and validated. Commercial roasted coffee beans contained 77.7–322 mg/kg HMF, 73.3–158 mg/kg HMFA, 109–200 mg/kg 2-F, 157–209 mg/kg MF, 12.3–32.8 mg/kg FMC, and 137–205 mg/kg FA. Roasting trial samples showed strong rising HMF contents (max.: Arabica: 769 mg/kg, Robusta: 364 mg/kg) followed by a distinct decline. Only MF and FA appeared as steady rising TTIs in the roasting process in Arabica and Robusta beans. 3-CQA fitted well as a decreasing TTI as expected.

Novel methyl furan based chalcone material for potential nonlinear optical applications

A mixture of 2-acetyl furan and 3, 4, 5-trimethoxybenzaldehyde was used to synthesize and grow the novel methyl furan-based chalcone derivative 1-(furan-2-yl)-3-(3, 4, 5-trimethoxyphenyl) prop-2-en-1-one (FT3MP) crystal. Thermal stability of the crystal was found to be up to its melting point and the second harmonic generation efficiency was found to be 1.5 times higher than KDP crystal. UV–Vis spectrum showed a cut-off wavelength at 442 nm. The UV–Vis absorption spectral studies showed that the crystal has better transparency in the visible region of electromagnetic spectrum.

Synthesis of [PdBr2(Benzimidazole-2-Ylidene)(Pyridine)] Complexes and Their Catalytic Activity in the Direct C-H Bond Activation of 2-Substituted Heterocycles

A series of unsymmetrical 1,3-disubstituted benzimidazolium chlorides 2a-f having two nitrogen atoms substituted by various alkyl groups were synthesized as N-heterocyclic carbene (NHC) precursors in high yields. The benzimidazolium salts readily converted into the corresponding PEPPSI-type palladium–NHC complexes 3a-f (PEPPSI = pyridine-enhanced precatalyst preparation, stabilization, and initiation). The structures of all compounds have been characterized by 1 H NMR, 13 C NMR, and IR spectroscopy, as well as X-rays ( 3a, 3d and 3e ) techniques, which support the proposed structures. Next, the palladium-NHC-PEPPSI complexes were used as catalysts in the direct C(5)-arylation of 2-acetyl furan and 2-acetylthiophene with various aryl bromides. These complexes exhibited moderate to high catalytic activities and gave C-H activation selectively at the C(5)-position of 2-acetylfuran and 2-acetylthiophene.

Contribution of aroma compounds to the antioxidant properties of roasted white yam (Dioscorea rotundata)

BackgroundThe aroma chemistry and the contribution of the aroma compounds to the anti-oxidative properties of roasted yam have yet to be characterized. The growing popularity of roasted yam in regions where they are being consumed calls for a concerted effort to elucidate their aroma chemistry as well as their anti-oxidative properties.ResultsThe aroma compounds in roasted white yam (Dioscorea rotundata) were isolated and identified using static headspace-gas chromatography-mass spectrometry (SH–GC–MS) and gas chromatography–olfactometry (GC–O). In addition, the anti-oxidative activities of the most abundant volatile heterocyclic compounds (2 pyrroles, 4 furans and 3 pyrazines) were evaluated on their inhibitory effect towards the oxidation of hexanal for a period of 30 days. Twenty-nine aroma-active compounds with a flavour dilution (FD) factor range of 2–256 and an array of odour notes were obtained. Among them, the highest odour activities (FD ≥ 128) factors were determined for 2-acetyl furan and 2-acetylpyrrole. Other compounds with significant FD factors ≥ 32 were; 2-methylpyrazine, ethyl furfural, and 5-hydroxy methyl furfural.ConclusionResults of the anti-oxidative activity showed that the pyrroles exhibited the greatest antioxidant activity among all the tested heterocyclic compounds. This was followed by the furans and the pyrazines which had the least antioxidant activity.

Upgrading bio-oil by catalytic fast pyrolysis of acid-washed Saccharina japonica alga in a fluidized-bed reactor

Abstract Macroalgae contain significant amounts of inorganic compounds (K, Na, Mg, and Ca) that cause problems during thermal processing (ash fouling or agglomeration of char and bed material). The macroalga Saccharina japonica (S.J) was demineralized with diluted acid solution to remove inorganic species before using this matter for fast pyrolysis in a bubbling fluidized-bed reactor. The effect of acid washing on the product yield and the quality of bio-oil was systematically investigated. When the pyrolysis temperature increased from 400 to 500 °C, the bio-oil yield was 39.70–45.36 wt%. The major compounds in the bio-oil were levoglucosan and di-anhydromannitol. The fractional catalytic pyrolysis of pre-treated S. japonica using HZSM-5 catalyst (calcined at 550 °C) was investigated in fluidized-bed reactor under the same conditions. Pyrolysis of the pretreated sample with catalyst resulted in 35.37–39.05 wt% liquid yield, which was lower than that from using silica sand. Using HZSM-5 catalytic pyrolysis bio-oil showed a decrease in dianhydromannitol and 2-furyl methyl ketone, and an increase in aromatic compounds such as derivatives of phenol, indole, and naphthalene. The effect of pretreatment by acid washing, and the effect of this catalyst on the pyrolysis product distribution and composition were clarified in relation to previous work.

Characteristics of microbial community and aroma compounds in traditional fermentation of Pixian broad bean paste as compared to industrial fermentation

ABSTRACTTraditionally fermented Pixian broad bean paste (PBP) is a traditional condiment in China and is recognized to have superior quality than the industrially fermented. This work aimed to identify the dominant microbes and unique aroma compounds in traditionally fermented PBP with respect to those in the industrially fermented one. Results showed that several species of lactic acid bacteria, yeasts, Aspergillus, molds, and Staphylococcus were only detected in traditionally fermented PBP, namely, Leuconostoc lactis, Staphylococcus xylosus, S. succinus, Amylomyces rouxii, Mucor genevensis, Absidia corymbifera, Issatchenkia orientalis, basidiomycete yeast sp., and Metschnikowia pulcherrima. Furthermore, the traditionally fermented PBP contained more compounds that contribute to its aroma than those in industrially fermented PBP. A total of 28 aroma substances only were detected in the traditionally fermented PBP. Among these substances, seven were considered aroma-active compounds, namely, ethyl caprylate, hexadecanoic acid methyl ester, 2-methyl-pyrazine, 2,6-dimethyl- pyrazine, 2-pentyl furan, 2-acetyl furan, and hexadecanoic acid. This work provides useful information on the microbial composition and aroma compounds of PBP that can be used to upgrade the quality of industrially fermented PBP.

Synthesis and Photophysical Properties of C 3-Symmetric Star-Shaped Molecules Containing Heterocycles Such as Furan, Thiophene, and Oxazole.

We report simple strategies to synthesize star-shaped molecules containing different heterocycles integrated with a number of variations. Here, cyclotrimerization, Vilsmeier–Haack reaction, Suzuki–Miyaura cross-coupling, and Van Leusen oxazole synthesis have been used as key steps to introduce diverse five-membered heterocycles such as furan, thiophene, and oxazole. More importantly, readily available starting materials such as thiophene, 2-formyl furan, and 2-acetyl furan were utilized. Also, the fluorescent behavior of these π-conjugated systems was studied. C3-Symmetric molecules containing furan moieties show a stronger fluorescence than thiophene-containing star-shaped compounds.