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This article discusses the development of a new method for synthesizing tetrasubstituted pyrroles, which are important in the pharmaceutical industry. The method combines three different components in one step, resulting in a more efficient and selective process with less waste. The researchers used readily available starting materials and performed the reaction without the need for a catalyst or solvent. The optimized conditions produced high yields of the desired product. The method was found to be environmentally friendly and the reaction mechanism involves the formation of new bonds. [Extracted from the article]

An efficient synthesis of highly fluorescent trisubstituted thiophenes was achieved via iodine-catalyzed, base-promoted annulation employing elemental sulfur as a sulfur source. The compounds exhibit excellent photophysical properties like solid-state fluorescence, high quantum yield and solvatochromism. As these thiophene derivatives have potential application in the development of optoelectronic devices, gram-scale synthesis of the desired heterocycles was demonstrated. [ABSTRACT FROM AUTHOR]

A series of self‐assembling gluconamide conjugated naphthalimide amphiphiles (GCNA) was synthesized and the self‐assembly of GCNA into gel rendered an increased electron density in naphthalimide moiety with an overall change in energy of 15.33×10−32 J via J‐type aggregation. SEM analysis and X‐ray diffraction underpinning the nanofibrillar formation, and rheological measurements confirmed the processablity and material fabrication. The enriched electron density in the aggregated GCNA4 via cooperative intermolecular non‐covalent interactions makes it as effective electron donor in the fabrication of triboelectric nanogenerators (TENG). The TENG based on GCNA4‐polydimethylsiloxane (PDMS) triboelectric pair generated an output voltage, current and power density of ∼250 V, 40 μA and ∼622 mW/m2 respectively, which is almost 2.4 times better in performance than the amorphous GCNA4 based TENG. The fabricated TENG can power‐up 240 LEDs, wrist watch, thermometer, calculator and hygrometer. [ABSTRACT FROM AUTHOR]

The inhalation, ingestion, and body absorption of noxious gases lead to severe tissue damage, ophthalmological issues, and neurodegenerative disorders; death may even occur when recognized too late. In particular, methanol gas present in traces can cause blindness, non-reversible organ failure, and even death. Even though ample materials are available for the detection of methanol in other alcoholic analogs at ppm level, their scope is very limited because of the use of either toxic or expensive raw materials or tedious fabrication procedures. In this paper, we report on a simple synthesis of fluorescent amphiphiles achieved using a starting material derived from renewable resources, this material being methyl ricinoleate in good yields. The newly synthesized bio-based amphiphiles were prone to form a gel in a broad range of solvents. The morphology of the gel and the molecular-level interaction involved in the self-assembly process were thoroughly investigated. Rheological studies were carried out to probe the stability, thermal processability, and thixotropic behavior. In order to evaluate the potential application of the self-assembled gel in the field of sensors, we performed sensor measurements. Interestingly, the twisted fibers derived from the molecular assembly could be able to display a stable and selective response towards methanol. We believe that the bottom-up assembled system holds great promise in the environmental, healthcare, medicine, and biological fields. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed, solvent-dependent intramolecular oxypalladation-triggered domino sequences of internal alkynes bearing tethered nucleophilic carboxylic ester and electrophilic enone functionalities were developed for the chemodivergent synthesis of two completely distinct biologically significant complex molecules including isochromenone-fused benzazepines and isobenzofuranone-fused tetrahydroquinolines/chromanes in a single synthetic operation. [ABSTRACT FROM AUTHOR]

A tandem formal [3+3]-cycloaddition/oxidation between chalcones and β-enamine esters, employing iodine as a catalyst, was developed for the construction of various substituted m -terphenyls. A wide range of chalcones and β-enamine esters were tested under metal- and solvent-free conditions for the synthesis of substituted m -terphenyls in good to excellent yields in the presence of sulfur as an oxidant. This reaction proceeds with the formation of four new bonds and one new ring, with a high atom economy. [ABSTRACT FROM AUTHOR]

Using natural processes as a guiding tool, the scientific community is actively involved in achieving substantial advances at the interface of supramolecular chemistry and materials design. In this paper, we have synthesized a series of amphiphilic N-glycosyl naphthalimides using environmentally benign protocols in good yields. For the first time, an exclusive formation of β-anomeric product using ammonium sulfate catalyst, an FDA approved GRAS chemical, has been thoroughly investigated. To explore the potential of N-glycosyl naphthalimides in the field of supramolecular materials, molecular self-assembly studies were systematically performed in a wide range of solvents and they were found to form a hydrogel, organogel and oleogel. The existence of molecular level interactions and assembly pattern were identified using FT-IR, NMR, SAXRD, UV-vis and fluorescence spectral methods and a suitable assembly mechanism was proposed. The morphology of the supramolecular architecture with respect to the molecular structure was identified using optical microscopy and scanning electron microscopy. Rheological studies clearly disclose the strength of soft materials and processability. Conductivity measurements on assembled thin films developed by drop casting of N-glycosyl naphthalimides reveal the semiconducting behaviour. Interestingly, a highly flexible semiconducting material derived by anchoring of a gelator on cotton fabric through hydrogen bonding displayed enhanced conducting properties compared to the assembled thin film. The demonstrated flexible organic semiconducting material obtained via a more sustainable pathway would provide an opportunity to fabricate green electronics. [ABSTRACT FROM AUTHOR]

An efficient ABB’C four-component Strecker reaction between 2-aminopyridines, aromatic aldehydes and trimethylsilyl cyanide (TMSCN) was developed under metal- and solvent-free conditions to access N-arylidene-2-aryl-imidazo[1,2-a]azin-3- amines in high yields. This one-pot reaction was carried out in the presence of elemental sulfur as catalyst using readily available starting material at room temperature. The reaction was tolerant to several substituted 2-aminopyridines and aryl aldehydes and have good green chemistry metrics as compared to the reported methods. [ABSTRACT FROM AUTHOR]

Carbohydrates are versatile materials widely used for several applications including food, pharmaceuticals, cosmetics, and drug delivery systems due to their inherent properties such as non‐toxicity, biodegradability, and bio‐compatibility. Specifically, the urge on carbohydrate research is due to its significance in the biological system, for example, a glycoprotein found in the extracellular matrix, involved in signaling pathways, cell–cell interaction and cell–matrix interaction. Because of the increase in demand of glycolipids for biological applications, in this report, a set of three structurally related gluconamide‐based amphiphiles were synthesized from renewable resources, δ‐gluconolactone and cashew nut shell liquid. The molecular structure of the synthesized glycolipids was characterized by NMR and mass spectral techniques. Molecular self‐assembly of gluconamide‐based amphiphiles was investigated relative to the molecular structure and nature of the solvent used. Interestingly, the nature of the hydrophobic tail present in the glycolipids influences the self‐assembly pattern, which results in a hydrogel, organogel and highly insoluble nanorods. Gelation studies clearly revealed that the involvement of different magnitude of non‐covalent interactions such as hydrogen bonding, π–π stacking and van der Waals interaction. Morphology of self‐assembled architecture was investigated by optical microscopy, FESEM and FETEM analysis. The mechanism involved in the molecular self‐assembly has been deduced by small angle XRD analysis. Thermo reversibility and the thixotropic nature of the derived gels were identified by rheological measurements. Further, antimicrobial and biofilm inhibitory activity of gluconamide‐based amphiphiles were studied against various pathogenic bacterial strains Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, and Pseudomonas aeruginosa, and found effective in inhibition of biofilm and possesses the antibacterial property. Altogether, gluconamide‐based amphiphiles reported in this paper could be potentially used for some of the human problems caused by bacterial biofilms such as infections in the intravascular catheter, burn‐wounds, chronic sinusitis and implanted medical devices. [ABSTRACT FROM AUTHOR]

The efficiency of elemental sulfur for the synthesis of 2H‐pyrido[1,2‐a]pyrimidin‐2‐ones has been demonstrated. This strategy involves coupling of 2‐aminopyridines and β‐oxo esters under neat condition in the absence of external oxidant. The reaction does not require pre‐functionalization of the substrates, thus making it an alternate approach for the synthesis of 2H‐pyrido[1,2‐a]pyrimidin‐2‐ones. The reaction was tolerant to several substituted 2‐aminopyridines and β‐oxo esters. [ABSTRACT FROM AUTHOR]

The implementation of a novel approach in the development of stimuli responsive supramolecular gels is an important objective that challenges material chemists and biologists in order to access an exclusively new category of smart materials. In this report, non-toxic, bio-based amphiphilic glycosylfurans were designed and synthesized using a biocatalyst, Novozyme 435, an immobilized lipase B from Candida antarctica. The self-assembly of these compounds generated oleogels and hydrogels. To our delight, these bio-based amphiphilic glycosylfurans furnished an in situ stimuli responsive hydrogel with simultaneous encapsulation of various biologically relevant molecules and ions. For the first time we are reporting hydrogelation via in situ molecular tuning followed by a self-sorting mechanism. The sol-to-gel transition in the reported smart hydrogel was observed by the addition of acidic buffer of pH 4.0, which could be potentially used for the stimuli responsive delivery of a signalling molecule, H2S and other biomolecules that regulate many physiological and pathological processes. [ABSTRACT FROM AUTHOR]

Owing to the natural abundance, variety of structural features, and highly specific functions, natural monomers render themselves as potential candidates for production of high performance functional polymers. The emerging concept of the biorefinery and development of new biosynthetic routes to synthesize a versatile and broad spectrum of natural monomers and polymers continues to gain momentum. The production of high quality polymers from renewable feedstocks requires innovative chemical modifications and catalytic transformations to achieve higher yields in an efficient manner. A fresh look into monomers available from natural resources such as terpenes, rosin, glycerol, furans, tannins, suberin, their derivatives and miscellaneous monomers may inspire future applications with impactful biobased materials. There are also many areas that require urgent discussion and review pertaining to recent developments in the field; this includes monomer sources that give molecules having special structural features. In particular, cardanol, a naturally occurring low-molecular-weight compound is unique as it contains a phenolic head group and a hydrocarbon chain with different degrees of unsaturation. This molecule possesses functional groups that are amenable for classical chemical modification, which is instrumental in developing a wide range of functional monomers and polymers. A large number of soft and hard materials have been developed from cardanol-based monomers. During the past, a large number of industrial grade materials have been developed from plant-based monomers, including development from microbial and fermentation processes (i.e. lactic acid). This review provides a comprehensive study and survey on recent developments on monomers and polymers derived from urushiol and cardanol based monomers and polymers, vegetable oil-based monomers and polymers, microbially produced monomers and polymers. These all represent emerging fronts giving a vast scope while highlighting important potential material and reagent opportunities. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the synthesis of bio‐based hydrophilic and hydrophobic oligoesters, which in turn are derived from easily accessible monomers from natural resources. In addition to the selection of renewable monomers, Novozyme 435, an immobilized lipase B from Candida antarctica was used for the oligomerization of monomers. The reaction conditions for oligomerization using Novozyme 435 were established to obtain a moderate‐to‐good yield. The average number of repeating units and the molecular weight distribution of hydrophilic and hydrophobic oligoester were identified by using NMR spectroscopy, gel‐permeation chromatography, and MS. The oligoester derived from a hydrophilic monomer self‐assembled to form a viscous solution, which upon further heating resulted in the formation of a polymer by the intermolecular Diels–Alder reaction. The viscosity of the solution and the assembly of oligoester to form a fibrous structure were investigated by using rheological studies, XRD, and SEM. The molecular weight of the cross‐linked polymer was identified by using matrix‐assisted laser desorption/ionization–MS. The thermal properties of the bio‐based polymers were investigated by using thermogravimetric analysis and differential scanning calorimetry. For the first time, the self‐assembly‐assisted polymerization of an oligoester is reported using the intermolecular Diels–Alder reaction, which opens a new avenue in the field of polymer science. [ABSTRACT FROM AUTHOR]

The efficiency of N, N-dimethylformamide (DMF) in the N-heterocyclic carbene-catalyzed Mannich reaction for the synthesis of β-amino ketones has been demonstrated. This strategy involves oxidative coupling of aryl methyl ketones and 2-aminopyridines in the presence of DMF. The reaction does not require pre-functionalization of the substrates, thus making it a practically applicable approach for the generation of β-amino ketones. The reaction requires the use of tin(II) chloride dihydrate (SnCl2⋅2 H2O) as Lewis acid in the presence of tert-butyl hydroperoxide (TBHP) as the oxidant. The reaction was tolerant to several aryl methyl ketones, including 2-acetylnaphthalene and acetylthiophene. Various substituted 2-aminopyridines react with acetophenone to give the desired β-amino ketones in good yields. [ABSTRACT FROM AUTHOR]

Our aim to access a particular chemical functionality on helical tubules has been achieved by the rational molecular design and synthesis of glucono-appended cardanol derivatives. For the first time, we report a chiral molecular packing with α-helical tubules, and chiral symmetry-breaking upon exposure to Cu2+ that generated the final ordered structure via an in situ morphological transition without undergoing any phase change. [ABSTRACT FROM AUTHOR]

An N-heterocyclic carbene catalyzed benzylic Csp³-H bond activation of alkylarenes and N-benzylamines under metal-free conditions was developed. This organocatalyzed oxidative transformation afforded the corresponding carbonyl derivatives in good to excellent yields. A variety of alkylarenes and N-benzylamines were tolerated under the optimized reaction conditions. The established method was further extended to the synthesis of biologically important 3 H-quinazolin-4-ones in good yields. For example, NPS 53574, a potent calcium receptor antagonist, was successfully synthesized by using this oxidative protocol. DFT studies show that the benzylic C-H bond activation proceeds through the nucleophilic attack of the free carbene on the benzylic carbon atom. [ABSTRACT FROM AUTHOR]