Oxidation reactions are fundamental and useful chemical transformations, especially for industries. However, the use of heavy metals or stoichiometric organic agents as common oxidants are nowadays rejected, preferring greener and economical procedures. Here, we propose a simple and sustainable method to oxidize aldehydes at room temperature using, in water, hydrogen peroxide as oxidant and PhSe)₂ as catalyst which is a not expensive and commercially available organoselenium reagent. Differently substituted aromatic and aliphatic aldehydes underwent the oxidation in good yields. In the presence of an alcoholic medium, the same substrates can be directly converted into the corresponding esters using the same reaction conditions. In order to avoid the side formation of carboxylic acid the reactions were heated at 50°C in acidic conditions. We also demonstrated that in the same conditions carboxylic acid was not transformed into the corresponding ester. This latter evidences suggest that the oxidation occurred on the hydrated aldehydes or on the hemiacetal in the presence of water and alcohols respectively . Aknowledgment: Technical support of Mr. Lorenzo Bettona from I.T.T.S. "Alessandro Volta", Perugia has been particularly appreciated.

Since 1991, when Arduengo isolated the first free carbene N-heterocyclic (NHC) [1], a wide variety of NHC complexes has been synthesized involving both transition and main group metals [2]. It is possible to modify the properties of these neutral ligands by introducing different substituents, for example, water-soluble functional groups. On the other hand, in the last two decades, the use of gold complexes has increased substantially due to its high efficiency in chemical transformations [3] as well as its proven antimicrobial and antitumor activity [4]. Because water is the biologically most relevant solvent, the synthesis of water-soluble metal-based drugs stable in water or physiological media is a matter of increasing interest. Herein, we report the synthesis and characterization of two water-soluble NHC gold(I) complexes, that is, [1-mesityl-3-(3-sodiumsulfonatopropyl)imidazol-2-ylidene] gold(I) chloro and [1,3-bis(2,6-diisopropyl-4-sodiumsulfonatophenyl)imidazol-2-ylidene] gold(I) chloro. Both were prepared, in high yield, by carbene transmetallation from the appropriate NHC silver complex with chloro tetrahydrothiophene gold ([AuCl(tht)]). The antimicrobial efficacy of both the gold (I) compounds and the respective ligands was assessed by agar diffusion assay and the broth macrodilution method against both gram positive and negative bacteria. MICs values (> 128 ug/ml) were superior to those displayed by the reference antibiotics penicillin G and streptomycin. [1] A.J. Arduengo III, R.L. Harlow, M. Kline, J. Am. Chem. Soc.1991, 113, 361. [2] N-Heterocyclic Carbenes; Diez-Gonzalez, S., Ed.; The Royal Society of Chemistry 2011. [3] a) H. Schmidbaur, A. Schier, Organometallic, 2010, 29, 2. [4] J. Coetzee,S. Cronje,L. Dobrzanska,H.G. Raubenheimer,G. Jooné,M.J. Nell, H.C. Hoppe, Dalton Trans. 2011, 40, 1471–1483.

The selenium catalyzed oxidation by hydrogen peroxides was achieved for the synthesis of epoxides¹. Our group recently developed the stereoselective synthesis of anti-1,2-diols passing through an epoxide intermediate² and involving a perselenenic acid as actual catalyst of the whole process. Here we report the cyclofunctionalization of beta,gamma- and gamma,delta unsaturated acids, and alcohols. The stereoselectivity has been investigated starting from substrates containing additional chiral center in the α position as well as optically pure catalysts. All the reactions were carried out using 4 equivalents of hydrogen peroxides (30%) and diselenides as precatalysts without any organic solvents. High regio- and stereo-selectivity were obtained for almost all the substrates but unfortunately using optically pure diselenides only moderated enantiomeric excesses were obtained. The reaction conditions present important eco-friendly features (on water conditions, room temperature and pressure), generally affording high yields. - References - 1) Garcìa-Marìn,H; van der Toorn, J. C.; Mayoral, J. A.; Garcìa, J. I. J. Mol. Catal 2011, 83-88 2) Santoro, S; Santi, C.; Sabatini, M.; Testaferri, L; Tiecco, M. Adv. Synth. Catal. 2008, 350, 2881-2884

The photochemically generated singlet nitrene insertion into a double bond of an ortho-substituent and C=C bond at a benzene ring was investigated. The insertion into the double bond has to give a condensed heterocycle, but the insertion into a benzolic cycle produces an enlarged cycle up to unstable 1,2-didehydroazepin (DDHA). An addition of a nucleophilic agent required to form stable 3H-azepin, and upon an equilibrium "singlet nitrene -- DDHA" establishment it is shifted to the DDHA formation. It results in decreasing of the condensed heterocycle compound yield and increase of the 3H-azepin yield. To test this assumption we have investigated an addition of water molecules to the reaction system effect upon yields of 3H-azepin-2-one-3-carbonic acid and of 2,1-benzisoxazol-3(1H)-one in the course of the 2-azidobenzoic acid decomposition in aprotic solvents. It was stated that an increase of water amount in the reaction system will produce simultaneous increase both of the heterocycle compound and 3H-azepin. We have proposed that in the absence or small amount of nucleophilic additives 2,1-benzisoxazol-3(1H)-one can react with DDHA to form a complicated mixture of photolysis products, and thus to decrease of the heterocycle compound yields.

Literary data of NMR ¹³C spectra of linear alkanes X-(CH2) _n-Y (I), (X = H; Y - 38 different substituents, including H and CH₃) were considered. The universal way to estimate the chemical shifts of the methylene groups (δ^C_CH2 = δ^C_i, i = 1 ÷ 36) in I was proposed. It is based on the concept that considers changes in the values δ^C_i of each carbon atom in I (called as increments Δδ^C_i) as a result of conversion to I of a hypothetical alkane with an infinitely long chain -(CH₂)_k-(CH₂)_n-(CH₂)_l- (II) by replacing infinitely long fragments -(CH₂)_k- and -(CH₂)_l- of it with the substituents X and Y. The values δ^C_i of each methylene group in II are assumed the same and equal to that of the medium methylene groups in long-chain alkanes (29.75 ppm). Equal to or greater than 0.05 ppm values of Δδ^C_i increments are observed in only r closest to the X and s closest to Y carbon atoms in the H-(CH₂)_r-(CH₂)_t-(CH₂)_s-Y (I). Parameter r = 5 is a constant, but the parameter s = 4 ÷ 9 is variable, depending on the nature of the substituent Y. Value δ^C_t = 29.75 ppm is constant. All Δδ^C_i increments for each substituent Y are calculated using the formula: Δδ^C_i = δ^C_i - 29.75 ppm, and tabulated. Relationship between the parameters r, s and t determines the length of alkyl chain. All compounds I conditionally divided into three groups: long-chain (n> r + s + t), medium-chain (n

In recent years, the synthesis of metal nanoparticles has attracted significant attention because of their unique properties. These nanoparticles are useful for diverse fields including catalysis, electronics, clinical diagnosis, etc. Although many strategies for the preparation of noble- and transition-metal nanoparticles have been published, the synthesis of indium nanoparticles (InNPs) has been scarcely reported. Some top-down methods involve the use of specific equipments and/or high temperatures, and most of the bottom-up methods require the use of indium salts and strong reducing agents such as sodium metal, zinc power, alkalides/electrides, or decomposition of organometallic complexes.¹ Regrettably, some of them provide little control over particle size and size distribution, and generally it is mandatory the presence of stabilizing agents. On the other hand, the reducing systems based on the use of alkali-metals in combination with arenes in aprotic media, with the arene acting as electron carrier have received much attention. Some of us have been working on the preparation of transition metal nanoparticles by fast reduction of the corresponding metal chlorides with lithium and a catalytic amount of an arene [naphthalene, 4,4´-di-tert-butylbiphenyl (DTBB)].² Herein, we report, a simple, mild, and efficient synthesis of very reactive, monodisperse (4.0 ± 1.5 nm) spherical InNPs, using indium(III) chloride in the presence of lithium powder and a catalytic amount of DTBB in THF at room temperature, and in the absence of any anti-agglomeration additive or ligand. Focusing on one of the most studied indium-mediated synthetic transformation, we decided to explore the above-mentioned InNPs-based system for the allylation of a variety of aldehydes and ketones in a one-pot procedure, by adding allyl bromide over a suspension of InNPs followed by the addition of the corresponding carbonyl compound. For most of the tested compounds, the homoallylic alcohol product was obtained in good yields. The InNPs were characterized by transmission electron microscopy (TEM) and UV-Visible spectroscopy. ¹ Estager J., Nockemann P., Seddon K. R., Srinivasan G., y Swadźba-Kwaśny M. ChemSusChem 2012, 5, 117–124 and references therein. ² F. Nador; L. Fortunato; Y. Moglie; C. Vitale and G. Radivoy Synthesis, 2009, 4027-4031 and references therein.

Arylstannanes are valuable reagents for the regiospecific generation of C-C bonds. Recently, we have informed the synthesis of crowded benzophenones by the indium-assisted, solvent free reaction of arylstannanes with bulky benzoyl chlorides.¹ In order to determine the scope of this reaction for the synthesis of benzophenones, we study the reaction, under similar conditions, of arylstannanes with benzoyl chlorides. Experimental results showed that the efficiency of the reaction depends on the electronic nature of the substituents as well as their relative position on the aromatic ring of the benzoyl chloride. A series of reactions carried out with (2,6-dimethylphenyl)trimethylstannane as model, showed that p-nitrobenzoyl chloride did not react and 3,5-dimethoxybenzoyl chloride gave a poor yield of ketone (10%); on the other hand, naphthoyl-, 2,4,6-trimethylbenzoyl- and 2,6-dimethoxybenzoyl chlorides gave the corresponding ketones in 65%, 58% y 55%, respectively. Taking into account that the reactions proceed through a SET from In(0) to the aroyl chloride generating an acyl radical,¹ and with the purpose of explaining experimental results, we performed a theoretical analysis with DFT methods (GAUSSIAN03). Considering that the energy of LUMO is related with electron affinities and that, once the radical anion is formed, the C(O)Cl bond fragments generating the corresponding acyl radical, we thought that the Frontier MO\'s energy, the localization of spin density and the energy (Ea) involved in the fragmentation process would give valuable information about the reactivity observed.² The computational study showed that naphthoyl chloride presents the lower π* MO energy. On the other hand, there is a large difference between the Ea of isomeric dimethoxybenzoyl chlorides. Meanwhile the fragmentation is spontaneous in isomer 2,6-, 7 Kcal/mol are required for the fragmentation of isomer 3,5-. ¹ Lo Fiego, M. J.; Silbestri, G. F.; Lockhart, M. T.; Chopa, A. B. J. Org. Chem. 2011, 76, 1707-1714. ² Dorn, V. B.; Badajoz, M. A.; Lockhart, M. T.; Chopa, A. B.; Pierini, A. B. J. Organomet. Chem. 2008, 693, 2458-62.

Published data of NMR ¹H spectra of linear alkanes X-(CH2)_n-Y (I), (X = H; Y - 38 different substituents, including H and CH₃; n = 1 ÷ 36) were considered. The universal way to estimate the chemical shifts of the methylene groups pronons (δ^H_CH2 = δ^H_i, i = 1 ÷ 36) in I was proposed. It is based on the concept that considers changes in the values δ^H_i of each methylene pronons in I (called as increments Δδ^H_i) as a result of conversion to I of a hypothetical alkane with an infinitely long chain -(CH₂)_k-(CH₂)_n-(CH₂)_l- (II) by replacing infinitely long fragments -(CH₂)_k- and -(CH₂)_l- of it with the substituents X and Y. The values δ^H_i of each methylene group in II are assumed the same and equal to that of the medium methylene groups in long-chain alkanes (1.27 ppm). Equal to or greater than 0.02 ppm values of Δδ^H_i increments are observed in only r closest to the X and s closest to Y methylene pronons in the H-(CH₂)_r-(CH₂)_t-(CH₂)_s-Y (I). Parameter r = 3 is constant as a value δ^H_t = 1.27 ppm, but the parameter s = 2 ÷ 5 is variable, depending on the nature of the substituent Y. All Δδ^H_i increments for each substituent Y are calculated using the formula: Δδ^H_i = δ^H_i – 1.27 ppm, and tabulated. Relationship between the parameters r, s and t determines the length of alkyl chain. All compounds I conditionally divided into three groups: long-chain (n> r + s + t), medium-chain (n

While analyzing the peculiarities of NMR ¹H spectra of different classes of organic compounds we suppose that under recording spectra conditions the intramolecular interactions between unbound fragments of molecule take place through the space. The existence of mentioned interactions leads to the observed changes in spectra compared with expected values of alkoxyl absorbtion in esters of aralkyl acids or acetals of aralkyl aldehydes. The schematic drawing of investigated molecule containing fragments "K-L-M" is represented in Figure. The arbitrary division into the fragments is in accordance with functional principle and depends upon the formulated aim. The aim is the investigation of NMR spectral parameters of the fragment "M" depending upon the structure of the fragment "K" and conversely. The absence of chemical bonds between atoms of the fragments "K" and "M" is an indispensable condition. Both fragments are bound by chemical bonds only with "medium" fragment "L", with its opposite sides. In the linear conformation I the interaction of unbound fragments "K" and "M" is absent. It is possible in the curved conformation II. The analysis of chemical shifts in NMR ¹H spectra of the para-substituted propylbenzens by general formula: p-X-C₆H₄-CRR¹CH₂CH₃ (where R,R¹ = H,CH₃) was made. The alkyl fragment influence on the phenyl ortho-protons absorption was shown earlier. The presence of the aryl fragment influence on the end methyl group was now first shown on the value of the basic spectral parameters - the chemical shifts of methyl protons (δ_СН3^Н) in comparison with analogous data of corresponding alkanes. There were developed and validated specific criteria for identifying such effect. We make the overall conclusion about high probability of the reciprocal intramolecular interactions between unbound fragments of molecule in sec-butylbenzens and sec-butylphenols (R=H; R¹=CH₃) and especially in tert-amylbenzens and tert-amylphenols (R=R¹=CH₃). Due to abovementioned criterion of the presence or absence of intermolecular interaction between unbound fragments it is probable that the interaction between methyl group of propyl fragment and hydrogen atoms of aryl fragment does not exist or has small value in the investigated n-propylcontaining compounds p-X-C₆H₄-CH₂CH₂CH₃ (Y=H or OH).

Molecular self-assembly process of biological building blocks enables the formation of complex architectures and machinery; our interest in studying amphiphilic systems is due to their potential development as supramolecular systems capable of interacting with lipid membranes. Inspired by the pioneering work of Kunitake et. al. and oriented to establish a relationship between structure and morphology of amphiphilic systems, we have started with the synthesis and evaluation of new non-ionic amphiphilic based on azobenzenes. In order to investigate the physicochemical properties of systems with potential application as membrane modulators, it is necessary to evaluate the capability of the system to form liquid crystal mesophases. Both non-ionic amphiphiles presented a liquid crystal behavior. In order, to establish the importance of the connector, compounds with a hydroxi head directed attached to the rigid segment were also studied. Although the structural changes are minor, the position of the hydrophobic tail or the presence of the connector between the polar head and rigid segment led to significantly different stabilities of the mesomorphic transition temperatures observed. Fig1. Non-Ionic Amphiphiles evaluated. Herein, it is presented the thermal and morphological characterization of new non-ionic Azobenzene Amphiphiles evaluated by Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscopy (POM).