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A four-component reaction was developed by taking advantage of the reactivity of propargyl functional groups residing on primarily formed dicyanoaniline products. Various enolizable cyclic ketones were reacted with malononitrile and 4-(prop-2-yn-1-yloxy) benzaldehyde derivatives in an aqueous t-BuOH/NaOH medium, and the resulting dicyanoanilines were subjected to1 a subsequent in situ click reaction to obtain the final dicyanoaniline-anchored triazole products. The enhanced photophysical properties of the novel products are currently under study. Key words: four-component one-pot synthesis, click chemistry, dicyanoanilines, heterocycles. Nous avons mis au point une reaction a quatre composants en exploitant la reactivite des groupes fonctionnels propargyles dont sont pourvus les produits dicyanoaniline initialement formes. Nous avons fait reagir diverses cetones cycliques enolisables avec le malononitrile et des derives 4 (prop-2-yn-1-yloxy)benzaldehyde dans un milieu aqueux contenant du t BuOH et du NaOH. Les dicyanoanilines obtenues ont ete par la suite soumises a une reaction de type << clic >> in situ pour former les triazoles attaches a des dicyanoanilines comme produits finaux. Les proprietes photophysiques ameliorees de ces nouveaux produits sont actuellement a l'etude. [Traduit par la Redaction.] Mots-cles : quatre composants, synthese monotope, chimie clic, dicyanoanilines, heterocycles., Introduction In recent decades, multicomponent reactions (MCRs) have received significant attention from organic chemists due to their facile execution, convenient access to the products of choice, lower costs, and minimized [...]

In recent decades, the frequency and severity of building fires have increased with rapid urbanization, particularly in high-rise buildings and high-building-density areas. Although proactive building fire risk management (PBFRM) can address this issue, significant research gaps exist. This research aims to propose a conceptual framework for understanding the existing condition of integrating proactive building fire risk management in the building construction sector, and the effect on improving building fire safety. It has been performed through a comprehensive review of the relevant literature. This framework identifies five components by answering the following questions: what? (building fire safety), of what? (buildings), to what? (integrate PBFRM in the building construction sector), for what? (ensuring resilience, sustainability and smartness), and how? (through building construction sector governance). According to the proposed conceptual framework, building fire safety can be achieved by integrating the PBFRM measures in different building attributes throughout the building life cycle. At the same time, resilience, sustainability and smartness must be ensured. These can be achieved through governance in the building construction sector. The proposed conceptual framework will contribute to policy and practice by facilitating policymakers and stakeholders in assessing the existing conditions and the efficacy of building fire safety measures, and thereby in devising strategies to further reinforce them. [ABSTRACT FROM AUTHOR]

In this study, the synthesis, surface evaluation, and thermodynamics properties a novel non-ionic glucosamine-based surfactant (2-(dodecyloxy)-N-((2R,3R,4R,5S,6S)-2,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-3-yr)acetamide (NGAS) is carried out and the comparison of the results with N-methylglucamine surfactant is reported. NGAS was synthesized via the facile and straightforward reaction of glucosamine with 2-(dodecyloxy) acetyl chloride in the presence of triethylamine. The surface tension of NGAS was determined by tensiometric methods. The surface properties including Critical Micelle Concentration (CMC), the efficiency of adsorption (pC20), the surface excess (Γmax) and the area occupied by each of the surfactant molecules (Amin) were investigated at 298.15 K in deionized water. The surface tension of water was reduced to about 41 mN.m-1 by using the surfactant at the concentration level of 2.06x10-3 molL-1. The thermodynamic parameters of micellization (ΔG°mic) and surface adsorption (ΔG°ads) were calculated from CMC data. The hydrophilicity and lipophilicity balance parameter (HLB) were obtained from the Griffin equation. According to the results, micellization and surface adsorption of this surfactant is a spontaneous process in aqueous solution. In addition, these results show that NGAS can be used as an emulsifier in oil-in-water emulsions. [ABSTRACT FROM AUTHOR]

Abstract: The first general procedure is described for the synthesis of novel bisarylmethylidenes of 2-methoxy-2-methy[L.sup.-1],3-dioxan-5-one 1. Thus, several derivatives of 3 are obtained rapidly in high yields by reacting 1 [...]

Abstract: A series of new polysubstituted derivatives of 2-tetralones possessing two ester groups were synthesized via a tandem aldol condensation-Diels--Alder-aromatization sequence of reactions. All the three steps took place in [...]

A facile procedure is developed for the three-component Mannich reactions of several heterocyclic, homocyclic, and acyclic ketones by using catalytic quantities of nano Zr[O.sub.2]. As a result, the starting ketones undergo rapid reactions with a variety of aromatic aldehydes and aniline derivatives at room temperature to produce stereoselectively high yields of the corresponding anti p-amino ketones. Interestingly, the catalyst could be recycled for several runs in a row without significant loss of its activity. The structure of the products was assigned based on their spectroscopic data and the anti stereoselectivity was confirmed by X-ray crystallography. Key words: Mannich reaction, multicomponent reaction, nano Zr[O.sub.2] catalyst, diastereoselectivity. On a mis au point une procedure facile pour les reactions de Mannich a trois composantes de plusieurs cetones heterocycliques, homocycliques et acycliques en utilisant des quantites catalytiques de nano Zr[O.sub.2]. Il en resulte que les cetones de depart subissent des reactions rapides avec divers aldehydes aromatiques et derives de l'aniline a temperature ambiante pour produire stereoselectivement avec de hauts rendements les p-amino cetones anti correspondantes. Il est interessant de noter que le catalyseur peut etre recycle plusieurs fois de suite sans perte importante de son activite. Pour attribuer leur structure aux produits, on s'est fonde sur les donnees spectroscopiques et pour confirmer la stereoselectivite anti, on a fait appel a la cristallographie aux rayons X. [Traduit par la Redaction] Mots-cles: reaction de Mannich, reaction a multiples composantes, nano catalyseur Zr[O.sub.2], diastereoselectivite., Introduction Nowadays, multicomponent reactions are among the most frequently adopted strategies in synthetic organic chemistry, since multicomponent reactions can efficiently combine three or more reactants in a single operational process. [...]

A three-component, efficient, and facile procedure has been developed for the synthesis of α-aminonitriles from aldehydes, amines, and trimethylsilyl cyanide using a catalytic amount of magnesium bromide ethyl etherate in the absence of solvent. Rapid formation of products is observed at room temperature in a one-pot procedure under very mild conditions giving excellent yields of the title compounds. Keywords: catalyzed Strecker's reaction, α-aminonitriles, magnesium bromide, solvent-free. On a developpe une methode simple et efficace pour realiser la synthese de α-aminonitriles par reaction monotope d'aldehydes, d'amines et de cyanure de trimethylsilyle, en presence d'une quantite catalytique du complexe bromure de magnesium/etherate d'ethyle, en l'absence de solvant. La formation rapide de produits se produit a la temperature ambiante, duns des conditions tres douces et conduit aux composes mentionnes duns le titre avec d'excellents rendements. Mots cles: reaction de Strecker catalysee, α-aminonitriles, bromure de magnEsium, sans solvant. [Traduit par la REdaction], Introduction A three-component combination of aldehydes, amines, and 'cyanide', known as Strecker's reaction (1), facilitates the formation of α-aminonitriles (2), which are equivalent synthones to imminium moieties (3) and acyl [...]

In this research, La0.8Sr0.2FeO3/cauliflower-like polyaniline (PANi) nanocomposite was architected based on a novel complementary method using dodecylbenzenesulfonic acid as a doping agent. The prepared nanocomposite was characterized using Fourier transform infrared, X-ray powder diffraction, field emission scanning electron microscopy, vibrating sample magnetometer diffuse reflection spectroscopy, and vector network analyzer analyses. All of the used analyses attested that the pure structure of materials has been synthesized. Polarizability, energy bandgap, magnetic property, and microwave absorbing features were tailored by loading the various mass fraction of PANi. Exclusive interactions between the nanoparticles with alkaline property and aniline monomers along the experimental route led to the preparation of nanocomposite with unique morphology. Inserting PANi augmented softness and isotropic magnetic property of the prepared nanocomposite, desirable for microwave absorption. Moreover, polyacrylonitrile (PAN) was applied as a novel microwave absorbing matrix. The maximum reflection loss (RL) of La0.8Sr0.2FeO3/PANi10%/PAN was − 69.24 dB at 12.62 GHz with an efficient bandwidth of 6.47 GHz (RL < − 10 dB) meanwhile the efficient bandwidth was enhanced to 6.97 GHz (RL < − 10 dB) for La0.8Sr0.2FeO3/PANi30%/PAN nanocomposite. [ABSTRACT FROM AUTHOR]