Akynyl ketones were synthesized from tetraalkinylstannanes and both aliphatic and aromatic acyl chlorides under Lewis acid catalisys. The structure of products was confirmed by means of NMR, IR, GC-MS. The method is suitable for the synthesis of long-chain acetylenic ketones.

Abstract: A series of new six novel imidazo[1,2-a]pyridines were synthesized by Groebke-Blackburn-Bienaymé reactions (GBBRs) by employing ammonium chloride (10 mol%) as a catalyst in moderate to good yields (76–44%) using 2-isocyano-1-morpholino-3-phenylpropan- 1-one. This is the first successful use of this type of a-isocyanoacetamide in a GBBR, as these reactive isonitriles readily undergo ring-chain tautomerization, as reported in other IMCR (isonitrile-based multicomponent reactions). The product structures contain a peptidomimetic imidazo[1,2-a]pyridine scaffold linked to an a-aminomorpholide and are of interest to medicinal chemists.

The development of new NIR fluorescent probes is a very important issue due to the wide range of applications. Benzo[a]phenoxazines are molecules with fluorescence at around 600 nm and have been reported also as antifungal agents. Herein, the synthesis of four new Nile Blue derivatives with hydrogen, propyl and/or aminopropyl groups as substituents of the amines of 5- and 9-positions is described. Photophysical properties are evaluated in acidified ethanol and aqueous solution at physiological pH. Antifungal activity is also evaluated through the obtention of MIC values.

Fluorinated nucleosides very important in increased biological and chemical stability of organ fluorine compounds. Synthesis of (1H)-8-trifluloromethyl-2-methyl-4-quinazolinone 3 from 2-amino-3-(trifluoromethyl) benzoic acid 1. Ribosylation of compound 4 with 1-O-acetyl-2,3,5-tri-O-benzoyl-

Herein, zirconium (IV)-based MOF, UiO-66-NH₂ was prepared by a facile solvothermal method. The MOF exhibit small size and large surface area, which can remove cationic dyes from aqueous solution. This adsorption selectivity is due to the favorable electrostatic interactions between the adsorbents and cationic dyes. Furthermore, owing to the individual micro pore structure of UiO-66-NH₂ and its more negative zeta potential resulted from the charge balance for the protonation of –NH₂, UiO-66-NH₂ displays much higher adsorption capacity for cationic dyes and lower adsorption capacity for anionic dyes than UiO-66.

Synthesis of UiO-66-NH₂ was performed by dissolving ZrCl₄ and 2-amino-1,4-benzenedicarboxylic acid in DMF with ultrasonic vibration. The as-obtained mixture was transferred to a Teflon-lined autoclave and then maintained. The resulting solid was filtered, repeatedly washed with CHCl₃ and dried at room temperature.

The most important analysis to confirm the synthesis of a desired MOF is X-ray diffractometry (XRD). XRD patterns of the sample was determined in the range of 2 = 4–50^◦. The MOF pattern has been reported to have unique crystalline phases according to the computational model and synthesized sample, which is confirmed for the synthesis of the desired compound.

For applying UiO-66-NH₂ as adsorbent, it was added into dye solution with continuous stirring in a dark place. Samples were filtrated. The absorbance of filtrate was tested using a UV spectrophotometer. Our Study was about the cationic dye Methylene Blue (MB) and the UV–vis spectra of its solution with UiO-66-NH₂. The absorbtion peaks of MB in UiO-66-NH₂ solution was rapidly descending in 5 hours, indicating that MB molecules were efficiently adsorbed by UiO-66-NH₂. The dye removal efficiency was increased by time.

Organic synthetic research laboratories generate a large amount of waste. Some of the waste is the silica gel used as the stationary phase in column chromatographic separations. Here, the authors discuss the possibility of recycling silica gel wastes thermally at 600 oC, at which temperature the remnant adsorbed organic material combusts. It could be shown that the recycled silica gel maintains its adsorption characteristics. The process could be repeated 10 times with any discernable deterioration of the separation properties of the silica gel. In those cases where triphenyl oxide remained on the silica gel after the separation of the reaction mixture, such as after Wittig olefination and Appel-type reactions, an increase of phosphorus content was noted in the silica gel after thermal treatment. The original and recycled silica gel was partly analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy(EDS) and in inductively coupled plasma - optical emission spectroscopy (ICP-OES). The process significantly reduced waste production in our laboratory and also led to a reduction in costs associated with acquiring new silica gel and with the management and the disposal of spent silica gel. A simple environmental impact assessment has been carried out.

The reduction of functionalized imines to yield amines is many times an intricate task, since most of the methods described in literature to reduce imines to amines do not take into account that many reducing agents have also basic character. In this way, iminic compounds that have phenol functions usually produce the phenolic salt of the precursor when they are treated with a basic reducing agent, but not the desired amine. In this work, we describe an easy way of isolating very pure aminic compounds with alcoholic functions in its structure from the corresponding iminic compounds, by using NaBH₄ as a reducing agent, and avoiding tedious chromatography or multiple solvent extraction steps.

Multicomponent reactions (MCRs) have possessed significant attention since they are performed without the need to isolate any intermediate during their processes; this diminishes the time and saves both energy and raw materials [1-2]. 1-Amidoalkyl-2-naphthol derivatives are of importance as they can be easily converted to biologically active compounds through amide hydrolysis reaction [3]. Recently, various catalysts have been used to prepare these compounds through a multicomponent reaction. In this research, metal-organic frameworks were utilized as heterogeneous catalyst. They are often crystalline solids consisting of metal ions or clusters coordinated to mostly rigid organic linkers such as aromatic polycarboxylates or polyamines to form one-, two-, or three-dimensional porous structures [4]. We reported a green and convenient method for the synthesis of 1-amidoalkyl-2-naphthols from the reaction between β-naphthol, aromatic aldehydes and amide derivatives under microwave irradiation in the presence of Cu₂(NH₂-BDC)₂(DABCO)-Sal-Co(II) as a modified catalyst through post-synthesis method. (Scheme 1). Cu₂(NH₂-BDC)₂(DABCO) was synthesized and then modified with salicylaldehyde and cobalt acetate (II) salt by ball milling technique.

The recognition of metallic ions has been given great attention due to their important roles in many biological and environmental processes. The use of fluorimetry in the qualitative and quantitative determination of such species is considered as one of the most effective analytical method for biomedical and environmental monitoring, allowing fast and sensitive detection, usually with low detection limits which are particularly suitable for dilute media.

In this communication, we report the chemosensory ability study of a benzothiazole unit coupled to an amino acid core. This ensemble can be considered an unnatural amino acid derivative, which can act as building block for intrinsically-labelled fluorescent peptides. Benzothiazoles are known for displaying high relative fluorescence quantum yields and the fine tuning of the optical properties can be achieved by adequate substituent choice at selected positions of the heterocyclic ring.

The evaluation of the unnatural amino acid as a fluorimetric chemosensor was carried out by performing titrations in acetonitrile and acetonitrile/water in the presence of relevant alkaline, alkaline-earth and transition metal cations. It was found that the tested compound had a remarkable fluorimetric response in the presence of Cu²⁺ in acetonitrile and in the presence of Fe³⁺ in acetonitrile/water (9:1).

Acknowledgements: Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (UID/ QUI/0686/2016).

3-Difluoroborodipyrromethene, commonly known as BODIPY has been used in many innovative applications such as biological fluorescent labelling, electroluminescent devices, tunable laser dyes, components for solid state solar cells, photodynamic therapy and optical sensors (fluorimetric or colorimetric). The numerous desirable properties of BODIPY explain its growing success over recent years. It is endowed with chemical, structural and photochemical stability, both in solution and in solid state. Furthermore, it possesses a high coefficient of molar absorptivity, high quantum yield of fluorescence, negligible triplet formation and narrow band emission with high intensity peaks. Furthermore, its photophysical properties can be tuned/improved introducing groups at suitable positions in the BODIPY core.

In continuation of the work developed in our research group, we report in this communication the synthesis, characterization and evaluation of the optical properties of BODIPY derivatives having in mind their potential application as novel chromofluorogenic sensors and/or fluorescent probes for the detection of molecules, cations and anions with biological and medicinal relevance.

Acknowledgements: Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through Centro de Química (UID/ QUI/0686/2016). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT.