Allenes have been demonstrated as synthetically versatile starting materials in organic synthesis. Allenation of terminal alkynes (ATA) reaction produces substituted allenes from terminal alkynes, carbonyl compounds, amines in the presence of Cu, Zn, Cd, Au, Ag and Pd salts. All known ATA reactions, catalyzed by the salts of the above metals, take place at an elevated temperature from 40 °C (in the case of Au, Ag) to 100 °C and higher (in the case of Cu, Zn, Cd). It is suggested that the formation of the allenes happens in a multistep process in which, at first, AТА reaction takes place and, the formed propargylamine then reacts further to generate the allene. Although the ATA reaction in some cases can be carried out at room temperature, not a single example of the conversion of propargylamine to allene at room temperature has been known. We have discovered for the first time that the [CuI – TIBAL], [Ce2(SO4)3 – TIBAL] and [Dy2(SO4)3 – TIBAL] catalytic systems makes it possible to prepare monosubstituted allenes from N,N-diisopropyl substituted propargylamines in dichloromethane or dichloroethane in high yield even at room temperature. Typically we used 0.2 equivalent of metal salt and 1-2 equivalents of TIBAL. This study demonstrates a remarkable activating effect of the TIBAL additive. In addition, the catalytic effect of lanthanide salts (Ce, Dy) on the conversion of propargylamines into monosubstituted allenes was discovered for the first time.

Several computational studies have been published to predict the behaviour of naphthalenediimides (NDI) in the transport of electrons in batteries, as well as their physical properties. This communication compares NDI with their analogues resulting from replacing the nitrogen atom with phosphorus, sulphur, or selenium. The calculations were performed with Gaussian 16 using the theory level B3LYP/6-311++g(d, p) in gas and in DMSO, which allows obtaining values for IP, EA, HOMO, LUMO, Fukui indices, redox potential, and reorganization free energies.

The results achieved indicate that the analogues studied could be an interesting alternative to naphthalenediimides, and that their experimental study may show new tools for lithium batteries.

The synthesis of aryl phosphonates as important pharmaceutical, and pesticide intermediates, catalyst ligands precursors and that of tertiary phosphine oxides is a widely studied area in organophosphorus chemistry. One way of forming P–C bond uses transition metal catalyzed cross coupling reactions. The first examples of the P–C coupling reaction between vinyl- and aryl halides and dialkyl phosphites were carried out in the presence of Pd(PPh₃)₄ catalyst by Hirao et al. To replace the air- and moisture sensitive and rather expensive Pd(PPh₃)₄, different types of Pd-precursors (e.g. Pd(OAc)₂ or PdCl₂) were used together with mono- or bidentate P-ligands. This method was more user friendly, due to the active catalyst was formed in situ. Later on, several cheaper Ni- and Cu-complexes were also applied in the coupling reactions. Eventually, the microwave technology became an attractive method to realize the Hirao reaction. Keglevich and co-workers developed a MW-assisted procedure in the presence of Pd(OAc)₂ or NiCl₂ precursors. These methods were called a “P-ligand free” P–C coupling reactions, as no usual, expensive P-ligands were added, instead, the >P(O)H-reagents were used in an excess. They explored the complete mechanism of the coupling reactions by quantum chemical calculations.

In our latest work, we studied the reactivity of various aryl derivatives (e.g. PhI, PhBr) towards diphenylphosphine oxide and diethyl phosphite in the Pd(OAc)₂-catalyzed, “P-ligand free” P–C coupling reactions under MW condition. Furthermore, we found that there is an inductive period, during which the active catalyst may be formed. After palladium and nickel, the less known copper(I)-promoted reaction was investigated experimentally using iodobenzene and a few secondary phosphine oxides. The mechanism was investigated by quantum chemical calculations.

Cyclic adamantanone ketals have pleasant odors and are of interest in the cosmetic field as fragrances. They are usually prepared by condensation of adamantanone-2 with 1,2-ethanediol and 1,2-propanediol in the presence of catalytic amounts of strong Bronsted or Lewis acids. These reactions are often carried out using Dean-Stark trap and azeotropic removal of water to prevent hydrolysis of the product. Sometimes the reactions require high temperatures, long reaction times, or are difficult to perform. We first developed a CuBr2-catalyzed method for ketalization of adamantanone-2 with 1,2-ethanediol and 1,2-propanediol. The reaction takes place in 1-2 hours at a temperature of 40-100 ^oC, giving the corresponding cyclic ketals in high yields. 4-Мethylspiro[1,3-dioxolane-2,2'-tricyclo[3.3.1.13,7]decane] has a persistent fruit-apple/honey smell and can be used to flavor shampoos, gels, soaps. Spiro[1,3-dioxolane-2,2'-tricyclo[3.3.1.13,7]decane] has a faint note of sage and thyme, as well as a persistent note of freshness, and can be used to flavor toothpaste and mouthwash.

For the first time, regio- and stereoselective synthesis of tetraalkyl-substituted buta-1,3-dienes was carried out using the reaction of dialkyl-substituted alkynes with EtAlCl₂ and metallic magnesium in the presence of catalytic amounts of tantalum (V) chloride in a toluene solution. The effect of the nature of the solvent and temperature on the process of oxidative coupling of molecules of disubstituted alkynes on low-valent tantalum has been studied. A scheme is proposed for the catalytic conversion of disubstituted alkynes to buta-1,3-dienes under the conditions of organoaluminum synthesis. It was found that the reaction of in situ obtained metallocyclopentadienes with methanesulfonyl chloride leads to the selective formation of tetraalkyl-substituted 1,4-dichlorobuta-1,3-dienes.

Pectin is a natural structural polymer that is extensively used in food industry, medicinal and pharmaceutical fields. Considering their potential applications, in this work, microwave-assisted and conventional extraction were evaluated to extract pectin from orange peel by acid hydrolysis using citric acid as extractant. For conventional extraction, temperatures higher than 60°C and long extraction times were necessary to obtained pectin yields of 9.0%. Under convention conditions of extraction, the degree of esterification of pectin was 55.0%. The extraction procedure assisted by microwave was optimized using an experimental design of 3 factors and 2 levels, analyzing the effect of operational variables influence in the pectin yield. The optimization of pectin extraction condition showed that temperature of 55°C, extraction time of 6 min, and solid/liquid ratio of 0.02 mg/mL, are necessary to obtained pectin yields of 25.0%. Under the optimal extraction condition, the degree of esterification of pectin was about 75%. According to the ANOVA analysis, time was the factor that more influence had on yields of pectin. These results showed that microwave-assisted procedure allows obtaining pectin with suitable properties from orange peel over mild operation conditions.

Chiroptical sensing based on circular dichroism (CD) or circularly polarized luminescence (CPL) enables analyses with greater sensitivity and resolution than traditional methods. However, there is not any extensive collection of chromophoric platforms for the synthetic development of chiroptical sensors, their research arousing great interest in recent years. In this sense, synthetically-accessible and conformationally flexible chiral bis(BODIPYs) based on enantiopure C₂-symmetric diamines or diols (helicoBODIPYs) have demonstrated to have appealing chiroptical properties, which significantly depend on the dye preferred helical geometry in solution. Therefore, they could be used as chromophoric platforms for the development of accessible (low cost) chiroptical sensors. In this context, easy at-bridge functionalization in helicoBODIPYs could be used to rapidly develop reactive scaffolds towards sensors. However, knowledge about the influence of this functionalization on the photophysics and chiroptics of the helicoBODIPY is required first. To this end, this communication describes preliminary results concerning the unexpected influence of the at-bridge electronic factors on the photophysics of helicoBODIPYs, mainly due to changes in the probability of undergoing photoinduced intramolecular charge transfer (ICT) processes. These results cast light on the key factors controlling the design of helicoBODIPYs as chiroptical sensors, showing that not only changes in the at-bridge steric factors affect the signalling (e.g., by means of changes in the dye helical geometry by an external stimulus), but also changes in the at-bridge electronic factors.

A rapid, clean and hight efficient one-pot approach to the series of pyrano[3,2-c]chromenes derivatives were synthesized in short time via multicomponent reaction of three components which are aromatic aldehyde, malononitrile, as well as 4-hydroxycoumarin in the presence of a new material MgO/SBA-15 as a catalyst in solvent-free neat conditions is described. The present method has a beneficial effect of mild reaction conditions, at room temperature, easy isolation of product and nanoparticle catalyst with excellent yields

Pristinamycin IIB (PIIB) is a potent antibiotic with limited use due to some structural problems, and also to the bacterial resistance exhibited toward the antibiotic. A thorough study led to the design of novel analogs of PIIB, based on the introduction of a difluorostatone moiety. Herein, we describe the initial in silico studies toward these novel analogs using ADMET modeling predictive models in order to compute the physico-chemistry and estimate the pharmacokinetics, drug-likeness and medicinal chemistry friendliness of these newly designed analogs.

Efficient methods have been developed for synthesizing hither to unknown macrodiolides incorporating 1Z,5Z-diene and 1,3-diyne moieties in 55-79% yields and with >98% stereoselectivity by intermolecular cyclocondesation of (7Z,11Z)-octadeca-7,11-dienedioic acid with α,ω-diols catalyzed by hafnium triflate Hf(OTf)4, as well as by oxidative coupling of α,ω-diynes obtained by esterification of (7Z,11Z)-octadeca-7,11-dienedioic acid with alkynols. The macrodiolides synthesized exhibit in vitro cytotoxic activity toward Jurkat, K562, U937, HL-60, HeLa and Hek293 cell lines.