Laura Aronica | University of Pisa (original) (raw)
Papers by Laura Aronica
Synthetic Communications, 1996
the synthesis of 2-phenylsulphonyltetrahydrofuran (1), 2-phenyl sulphonyl-5-methoxy-2,5-dihydrofu... more the synthesis of 2-phenylsulphonyltetrahydrofuran (1), 2-phenyl sulphonyl-5-methoxy-2,5-dihydrofuran (2) and 2-phenylsulphonylfuran (3) was carried out in very good yields and short reaction times starting from easily available precursors.
Catalysts, 2022
Oxygen and nitrogen heterocycle systems are found in a vast number of natural substrates and biol... more Oxygen and nitrogen heterocycle systems are found in a vast number of natural substrates and biologically active molecules such as antimycotics, antibiotics, antitumors and antioxidants, in addition to pigments and fluorophores [...]
Catalysts, 2021
Supported catalysts are important tools for developing green-economy-based processes. Palladium n... more Supported catalysts are important tools for developing green-economy-based processes. Palladium nanoparticles (NPs) that are immobilized on two fibers developed as metal scavengers (i.e., Smopex®-234 and Smopex®-111, 1% w/w) have been prepared and tested in copper-free cyclocarbonylative Sonogashira reactions. Their catalytic activity has been compared with that of a homogeneous catalyst (i.e., PdCl2(PPh3)2). Pd/Smopex®-234 showed high activity and selectivity in the synthesis of functionalized heterocycles, such as phthalans and isochromans, even when working with a very low amount of palladium (0.2–0.5 mol%). The extension of Pd/Smopex®-234 promoted cyclocarbonylative reactions to propargyl and homopropargyl amides afforded the corresponding isoindoline and dihydrobenzazepine derivatives. A preliminary test on Pd NPs leaching into the solution (1.7 × 10−3 mg) seems to indicate that, at the end of the reaction, almost all of the active metal is present on the fiber surface.
![Research paper thumbnail of Chiroptical response inversion upon sample flipping in thin films of a chiral benzo[1,2-b:4,5-b′]dithiophene-based oligothiophene](https://attachments.academia-assets.com/84701224/thumbnails/1.jpg)
](Materials Chemistry Frontiers, 2017
Our drop-casted films display linear dichroism-linear birefringence interference (LDLB effect) wi... more Our drop-casted films display linear dichroism-linear birefringence interference (LDLB effect) with strong CD signals, which are inverted upon sample flipping.
European Journal of Organic Chemistry, 2017
Applied Catalysis A: General, 2014
Tetrahedron Letters, 1995
a catalytic amount of NidppeCl2 converts an acyl bromide directly into ketones at 0 °C in THF in ... more a catalytic amount of NidppeCl2 converts an acyl bromide directly into ketones at 0 °C in THF in the presence of a Grignard reagent. The described procedure represents a useful way to afford dialkyl, diaryl or alkyl aryl ketones as well as 1,2-diketones. In the adopted reaction conditions double bonds, esters and ketones are unaffected.
Journal of Organometallic Chemistry, 2012
Functionalised b-lactones and b-lactams were prepared starting from propargyl alcohols and propar... more Functionalised b-lactones and b-lactams were prepared starting from propargyl alcohols and propargyl tosyl amides by means of efficient silylcarbocyclisation reactions catalysed by rhodium nanoparticles derived from mesitylene-solvated Rh atoms (Metal Vapour Synthesis technique, MVS) and deposited on inorganic (C, g-Al 2 O 3 Fe 2 O 3) and organic matrices (PBI). All the MVS supported nanoclusters resulted more active than the analogous commercial Rh/C and Rh/g-Al 2 O 3 , as well as homogeneous Rh 4 (CO) 12 used as reference catalyst. In particular, metal vapour derived Rh/C afforded the b-lactones and b-lactams in high yields and chemoselectivity. Preliminary investigations on the nature of the real active metal species involved in the catalytic process showed that rhodium(0) naked nanoparticles are leached by the support. The high catalytic activity encountered with Rh/C could be ascribed to the easy leaching of metal nanoparticles from carbon into solution. Indeed, the presence of a more polar matrix determined a minor catalytic efficiency probably due to a stronger interaction between the metal and the support. Therefore MVS Rh/C species represents a source, stable with ageing at room temperature, of highly active metal nanoparticles.
Catalysts
Oxygen and nitrogen heterocyclic systems are present in a large number of natural and synthetic c... more Oxygen and nitrogen heterocyclic systems are present in a large number of natural and synthetic compounds. In particular, oxa- and aza-silacyclane, tetrahydrofuran, benzofuran, cycloheptadifuranone, cycloheptadipyrrolone, pyrrolidine, lactone, lactam, phthalan, isochromanone, tetrahydroisoquinolinone, benzoindolizidinone, indoline and indolizidine scaffolds are present in many classes of biologically active molecules. Most of these contain a C=O moiety which can be easily introduced using carbonylative reaction conditions. In this field, intramolecular silylformylation and silylcarbocyclization reactions may afford heterocyclic compounds containing a carbonyl functional group together with a vinylsilane moiety which can be further transformed. Considering these two aspects, in this review a detailed analysis of the literature data regarding the application of silylformylation and silylcarbocyclization reactions to the synthesis of several heterocyclic derivatives is reported.
The Journal of Organic Chemistry
Cyclocarbonylative Sonogashira reactions of ortho-ethynylbenzamides have been investigated. The p... more Cyclocarbonylative Sonogashira reactions of ortho-ethynylbenzamides have been investigated. The process is carried out under CO pressure, in the presence of a very small amount of PdCl 2 (PPh 3) 2 (0.4 mol %) as a catalytic precursor and without the need for a Cu salt as the co-catalyst. 2-Ethynylbenzamide reacted successfully with iodoarenes bearing electron-withdrawing and electron-donating groups, giving rise to different classes of compounds depending on the solvent used. On the contrary, N-(4chlorophenyl)-2-ethynylbenzamide afforded exclusively polyfunctionalized isoindolinones with high stereoselectivity toward (E) isomers.
Catalysts
The acyl Sonogashira reaction represents an extension of Sonogashira cross-coupling to acid chlor... more The acyl Sonogashira reaction represents an extension of Sonogashira cross-coupling to acid chlorides which replace aryl or vinyl halides, while terminal acetylenes are used as coupling partners in both reactions. The introduction of a carbonyl functional group on the alkyne backbone determines a radical change in the reactivity of the products. Indeed, α,β-alkynyl ketones can be easily converted into different heterocyclic compounds depending on the experimental conditions employed. Due to its potential, the acyl Sonogashira reaction has been deeply studied with particular attention to the nature of the catalysts and to the structures of both coupling compounds. Considering these two aspects, in this review, a detailed analysis of the literature data regarding the acyl Sonogashira reaction and its role in the synthesis of several heterocyclic derivatives is reported.
![Research paper thumbnail of Synthesis of new bis[1-(thiophenyl)propynones] as potential organic dyes for colorless luminescent solar concentrators (LSCs)](https://attachments.academia-assets.com/66614158/thumbnails/1.jpg)
](Dyes and Pigments
New luminophores having different aryl nuclei and propynones moieties have been obtained via Sono... more New luminophores having different aryl nuclei and propynones moieties have been obtained via Sonogashira reactions. Their optical properties were evaluated and indicated that carbonyl groups are responsible for significant bathochromic effects and high Stokes shifts. The insertion of -OMe groups on the central benzene unit gives to the fluorophore high optical efficiency (7.7%) when homogeneously dispersed in a poly(cyclohexyl methacrylate) (PCMA) film and connected to a PV cell.
ChemNanoMat
Recently we described a chiral benzo [1,2-b:4,5b']dithiophene-based oligothiophene with the very ... more Recently we described a chiral benzo [1,2-b:4,5b']dithiophene-based oligothiophene with the very uncommon chiroptical property of (signal inversion on sample flipping. This is due to the interference between linear dichroism and linear birefringence, called LDLB effect, which is theoretically well understood, but to date very rarely reported in the literature. Samples with very large LDLB effect lead to the unique possibility of discriminating the direction of sample illumination, if from front or back. We present a set of analogue compounds, where we introduce small structural changes aiming to reveal which factors determine very large LDLB effect or true circular dichroism allied to supramolecular chirality. We reveal the primary impact of the deposition technique, where spin coating may exert a primary role, and let us obtain films with outstanding chiroptical features. These features are made even more relevant on account of semiconducting properties of oligothiophenes in view of optical sensing applications.
Synthetic Communications, 1996
the synthesis of 2-phenylsulphonyltetrahydrofuran (1), 2-phenyl sulphonyl-5-methoxy-2,5-dihydrofu... more the synthesis of 2-phenylsulphonyltetrahydrofuran (1), 2-phenyl sulphonyl-5-methoxy-2,5-dihydrofuran (2) and 2-phenylsulphonylfuran (3) was carried out in very good yields and short reaction times starting from easily available precursors.
Catalysts, 2022
Oxygen and nitrogen heterocycle systems are found in a vast number of natural substrates and biol... more Oxygen and nitrogen heterocycle systems are found in a vast number of natural substrates and biologically active molecules such as antimycotics, antibiotics, antitumors and antioxidants, in addition to pigments and fluorophores [...]
Catalysts, 2021
Supported catalysts are important tools for developing green-economy-based processes. Palladium n... more Supported catalysts are important tools for developing green-economy-based processes. Palladium nanoparticles (NPs) that are immobilized on two fibers developed as metal scavengers (i.e., Smopex®-234 and Smopex®-111, 1% w/w) have been prepared and tested in copper-free cyclocarbonylative Sonogashira reactions. Their catalytic activity has been compared with that of a homogeneous catalyst (i.e., PdCl2(PPh3)2). Pd/Smopex®-234 showed high activity and selectivity in the synthesis of functionalized heterocycles, such as phthalans and isochromans, even when working with a very low amount of palladium (0.2–0.5 mol%). The extension of Pd/Smopex®-234 promoted cyclocarbonylative reactions to propargyl and homopropargyl amides afforded the corresponding isoindoline and dihydrobenzazepine derivatives. A preliminary test on Pd NPs leaching into the solution (1.7 × 10−3 mg) seems to indicate that, at the end of the reaction, almost all of the active metal is present on the fiber surface.
Materials Chemistry Frontiers, 2017
Our drop-casted films display linear dichroism-linear birefringence interference (LDLB effect) wi... more Our drop-casted films display linear dichroism-linear birefringence interference (LDLB effect) with strong CD signals, which are inverted upon sample flipping.
European Journal of Organic Chemistry, 2017
Applied Catalysis A: General, 2014
Tetrahedron Letters, 1995
a catalytic amount of NidppeCl2 converts an acyl bromide directly into ketones at 0 °C in THF in ... more a catalytic amount of NidppeCl2 converts an acyl bromide directly into ketones at 0 °C in THF in the presence of a Grignard reagent. The described procedure represents a useful way to afford dialkyl, diaryl or alkyl aryl ketones as well as 1,2-diketones. In the adopted reaction conditions double bonds, esters and ketones are unaffected.
Journal of Organometallic Chemistry, 2012
Functionalised b-lactones and b-lactams were prepared starting from propargyl alcohols and propar... more Functionalised b-lactones and b-lactams were prepared starting from propargyl alcohols and propargyl tosyl amides by means of efficient silylcarbocyclisation reactions catalysed by rhodium nanoparticles derived from mesitylene-solvated Rh atoms (Metal Vapour Synthesis technique, MVS) and deposited on inorganic (C, g-Al 2 O 3 Fe 2 O 3) and organic matrices (PBI). All the MVS supported nanoclusters resulted more active than the analogous commercial Rh/C and Rh/g-Al 2 O 3 , as well as homogeneous Rh 4 (CO) 12 used as reference catalyst. In particular, metal vapour derived Rh/C afforded the b-lactones and b-lactams in high yields and chemoselectivity. Preliminary investigations on the nature of the real active metal species involved in the catalytic process showed that rhodium(0) naked nanoparticles are leached by the support. The high catalytic activity encountered with Rh/C could be ascribed to the easy leaching of metal nanoparticles from carbon into solution. Indeed, the presence of a more polar matrix determined a minor catalytic efficiency probably due to a stronger interaction between the metal and the support. Therefore MVS Rh/C species represents a source, stable with ageing at room temperature, of highly active metal nanoparticles.
Catalysts
Oxygen and nitrogen heterocyclic systems are present in a large number of natural and synthetic c... more Oxygen and nitrogen heterocyclic systems are present in a large number of natural and synthetic compounds. In particular, oxa- and aza-silacyclane, tetrahydrofuran, benzofuran, cycloheptadifuranone, cycloheptadipyrrolone, pyrrolidine, lactone, lactam, phthalan, isochromanone, tetrahydroisoquinolinone, benzoindolizidinone, indoline and indolizidine scaffolds are present in many classes of biologically active molecules. Most of these contain a C=O moiety which can be easily introduced using carbonylative reaction conditions. In this field, intramolecular silylformylation and silylcarbocyclization reactions may afford heterocyclic compounds containing a carbonyl functional group together with a vinylsilane moiety which can be further transformed. Considering these two aspects, in this review a detailed analysis of the literature data regarding the application of silylformylation and silylcarbocyclization reactions to the synthesis of several heterocyclic derivatives is reported.
The Journal of Organic Chemistry
Cyclocarbonylative Sonogashira reactions of ortho-ethynylbenzamides have been investigated. The p... more Cyclocarbonylative Sonogashira reactions of ortho-ethynylbenzamides have been investigated. The process is carried out under CO pressure, in the presence of a very small amount of PdCl 2 (PPh 3) 2 (0.4 mol %) as a catalytic precursor and without the need for a Cu salt as the co-catalyst. 2-Ethynylbenzamide reacted successfully with iodoarenes bearing electron-withdrawing and electron-donating groups, giving rise to different classes of compounds depending on the solvent used. On the contrary, N-(4chlorophenyl)-2-ethynylbenzamide afforded exclusively polyfunctionalized isoindolinones with high stereoselectivity toward (E) isomers.
Catalysts
The acyl Sonogashira reaction represents an extension of Sonogashira cross-coupling to acid chlor... more The acyl Sonogashira reaction represents an extension of Sonogashira cross-coupling to acid chlorides which replace aryl or vinyl halides, while terminal acetylenes are used as coupling partners in both reactions. The introduction of a carbonyl functional group on the alkyne backbone determines a radical change in the reactivity of the products. Indeed, α,β-alkynyl ketones can be easily converted into different heterocyclic compounds depending on the experimental conditions employed. Due to its potential, the acyl Sonogashira reaction has been deeply studied with particular attention to the nature of the catalysts and to the structures of both coupling compounds. Considering these two aspects, in this review, a detailed analysis of the literature data regarding the acyl Sonogashira reaction and its role in the synthesis of several heterocyclic derivatives is reported.
Dyes and Pigments
New luminophores having different aryl nuclei and propynones moieties have been obtained via Sono... more New luminophores having different aryl nuclei and propynones moieties have been obtained via Sonogashira reactions. Their optical properties were evaluated and indicated that carbonyl groups are responsible for significant bathochromic effects and high Stokes shifts. The insertion of -OMe groups on the central benzene unit gives to the fluorophore high optical efficiency (7.7%) when homogeneously dispersed in a poly(cyclohexyl methacrylate) (PCMA) film and connected to a PV cell.
ChemNanoMat
Recently we described a chiral benzo [1,2-b:4,5b']dithiophene-based oligothiophene with the very ... more Recently we described a chiral benzo [1,2-b:4,5b']dithiophene-based oligothiophene with the very uncommon chiroptical property of (signal inversion on sample flipping. This is due to the interference between linear dichroism and linear birefringence, called LDLB effect, which is theoretically well understood, but to date very rarely reported in the literature. Samples with very large LDLB effect lead to the unique possibility of discriminating the direction of sample illumination, if from front or back. We present a set of analogue compounds, where we introduce small structural changes aiming to reveal which factors determine very large LDLB effect or true circular dichroism allied to supramolecular chirality. We reveal the primary impact of the deposition technique, where spin coating may exert a primary role, and let us obtain films with outstanding chiroptical features. These features are made even more relevant on account of semiconducting properties of oligothiophenes in view of optical sensing applications.