Simona Selva

Bio: Simona Selva is an academic researcher from University of Bologna. The author has contributed to research in topics: Reactivity (chemistry) & One-pot synthesis. The author has an hindex of 9, co-authored 15 publications receiving 435 citations.

Sequential One-Pot InBr3-Catalyzed 1,4- then 1,2-Nucleophilic Addition to Enones

Abstract: Low sensitivity toward traces of moisture and high tolerance of different functional groups make indium tribromide suitable for carrying out multistep synthetic sequences. In particular, we have realized a 1,4-conjugated addition of indoles/thiols to α,β-unsaturated ketones mediated by a catalytic amount (10 mol %) of InBr3 obtaining the desired β-substituted ketones in good yields. The Lewis acidity of indium salts was not affected by coordinating and acid nucleophiles; therefore, the subsequent catalytic 1,2-addition of Me3SiCN to carbonyl compounds can be performed in one pot. With the optimized atom-efficient protocol, several polyfunctionalized α-silyloxy cyanohydrins were synthesized in good to excellent yields (up to 97%) and a notable level of simple 1,3-diastereoselection (up to 84:16) was recorded in the case of 2-cyclohexen-1-one 2c.

Reinvestigation of the tautomerism of some substituted 2-hydroxypyridines

Abstract: The tautomerism of some substituted 2-hydroxypyridines is investigated by UV/Vis- and 1 H-, and 13 C- NMR spectroscopic methods, with the aid of the N-Me and O-Me fixed parents. NMR spectroscopic data do not allow discrimination between the two tautomeric forms (with the exception of the unsubstituted 2-hydroxypyridine), while UV/Vis- data permit the quantitative determination, in different solvents, of the amounts of the two forms. The electronic substituent effect and the change of solvent are discussed. An X-Ray diffraction study carried out on a crystal of 2-hydroxy-5-nitropyridine (7) reveals that this compound, in the solid state, is in the oxo-form.

Syntheses and fluxional processes of diphenyl(2-thienyl)phosphane derivatives of triosmium clusters

Abstract: Thermal treatment of [OS3(CO)(12)] with diphenyl(2-thienyl)phosphane, Ph(2)p(C4H3S), results in the formation of [Os-3(CO)(12-x){Ph2P(C4H3S)}(x)] (x = 1-3, 1-3), but no C-H bond activation was observed. Reaction of [H2Os3(CO)(10)] with diphenyl(2-thienyl)phosphane at ambient temperature affords [HOs3(mu-H)(CO)(10){Ph2P(C4H3S}] (4), but when the same reaction is repeated at elevated temperatures, the cyclometallated species [(mu-H)Os-3(CO)(9){mu(3)-Ph(2)p(C4H2S)}] (5) and [mu-H) Os-3(CO)(8){mu 3-Ph2P(C4H2S)}(Ph2P(C4H3S)}] (6) are formed. In addition, two more products, tentatively assigned as [(mu-H)Os-3(CO)(6()mu(3)-Ph2P(C4H2S)}{mu-Ph2P(C4H3S)}{Ph2P-(C4H3S)}] (7) and [(mu-H)Os-3 (CO)(7) {mu-Ph2P(C4H2S)}] (4)tPh(2)P(C(4)H3(S)))(Ph2P(C4H3S))] (8) are obtained. The dynamic behaviours of 2, 5 and 6 have been studied by variable-temperature (VT) and H-1 P-31{H-1} NMR spectroscopy. The VT P-31{H-1} NMR spectra of [Os-3(CO)(10){Ph2P(C4H3S)}(2)] (2) demonstrate that a mixture of two isomers, which are in rapid exchange at room temperature, is present and that the less common cis-trans isomer, whose structure has been determined by X-ray crystallography, is favoured for this cluster. The VT H-1 NMR spectra of 5 indicate the presence of two isomers which are proposed to arise from an oscillation of the sigma,eta(2)-vinyl group of the thienyl moiety between two metal atoms. A similar fluxional process is proposed to occur in 6 and the assignment of the room-temperature structure(s) of this cluster was confirmed by H-1-Os-187 2D HMQC spectroscopy. In addition to 2, the solid-state structures of 3, 5 and 6 have been determined by X-ray crystallography. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.

Catalytic Functionalization of Indoles in a New Dimension

Abstract: 140 years ago Adolf von Baeyer proposed the structure of a heteroaromatic compound which revolutionized organic and medical chemistry: indole. After more than a century, indole itself and the complexity of naturally occurring indole derivatives continue to inspire and influence developments in synthetic chemistry. In particular, the ubiquitous presence of indole rings in pharmaceuticals, agrochemicals, and functional materials are testament to the ever increasing interest in the design of mild and efficient synthetic routes to functionalized indole derivatives. This Review emphasizes the achievements in the selective catalytic functionalization of indoles (C-C bond-forming processes) over the last four years.

In situ hydrothermal synthesis of tetrazole coordination polymers with interesting physical properties

Abstract: Tetrazole compounds have been studied for more than one hundred years and applied in various areas. Several yeas ago Sharpless and his co-workers reported an environmentally friendly process for the preparation of 5-substituted 1H-tetrazoles in water with zinc salt as catalysts. To reveal the exact role of the zinc salt in this reaction, a series of hydrothermal reactions aimed at trapping and characterizing the solid intermediates were investigated. This study allowed us to obtain a myriad interesting metal–organic coordination polymers that not only partially showed the role of the metal species in the synthesis of tetrazole compounds but also provided a class of complexes displaying interesting chemical and physical properties such as second harmonic generation (SHG), fluorescence, ferroelectric and dielectric behaviors. In this tutorial review, we will mainly focus on tetrazole coordination compounds synthesized by in situhydrothermal methods. First, we will discuss the synthesis and crystal structures of these compounds. Their various properties will be mentioned and we will show the applications of tetrazole coordination compounds in organic synthesis. Finally, we will outline some expectations in this area of chemistry. The direct coordination chemistry of tetrazoles to metal ions and in situ synthesis of tetrazole through cycloaddition between organotin azide and organic cyano group will be not discussed in this review.