The impressive chemico-physical effects observed in sonochemistry are a result of cavitation, as ... more The impressive chemico-physical effects observed in sonochemistry are a result of cavitation, as ultrasonic and hydrodynamic cavitation does not interact with matter at the atomic and molecular levels. Bubble collapse leads to the quasi-adiabatic heating of the vapour inside bubbles, giving rise to local hot spots in the fluid. Cavitation thus transforms a mechanical energy into high kinetic energy, which is released in very short bursts that are exploited for green process intensification. This paper reviews relevant applications of hydrodynamic and acoustic cavitation with the aim of highlighting the particular advantages that these phenomena offer to the intensification of green chemical processes. Emulsification, biodiesel preparation, wastewater decontamination, organic synthesis, enzymatic catalysis and extractions are discussed among others. As a comparison, hydrodynamic cavitation technique is more advantageous in dealing with process intensification at large-scale, as well as the enhancement of mass transfer and heat transfer, while ultrasonic cavitation technique is more convenient to operate, easier to control in the studies at lab-scale, and exhibits more efficient in producing active free radicals and inducing the cleavage of volatile compounds.
Mechanochemically promoted reduction of nitro and azido derivatives may be successfully performed... more Mechanochemically promoted reduction of nitro and azido derivatives may be successfully performed in stainless steel jars without catalyst addition.
A ppm-level Pd/Boemite catalyst has been prepared over 3-mm alumina beads and used for the select... more A ppm-level Pd/Boemite catalyst has been prepared over 3-mm alumina beads and used for the selective hydrogenation of alkynes in a continuous-flow reactor with two modes: closed-loop and flow-through. The...
The development of alternative, green solvents is an important and ongoing challenge. Our latest ... more The development of alternative, green solvents is an important and ongoing challenge. Our latest contribution to the field is the use of γ-valerolactone in aminocarbonylative coupling reactions for the clean synthesis of several 4(3H)-quinazolinones under microwave irradiation. The palladium-catalyzed, four-component carbonylative coupling reactions of o-iodoanilines, trimethyl orthoformate and a variety of amines have been carried out under CO pressure (2.5 bar). This protocol was found to be highly efficient and selective for 4(3H)-quinazolinones, which were isolated in good yields in the presence of two different, recyclable Pd catalysts which were prepared under ultrasound irradiation; a novel lead-free Pd/Boehmite catalyst and a β-cyclodextrin - cross linked Pd catalyst.
The impressive pharmacological properties shown by a number of coumarins have led to extraordinar... more The impressive pharmacological properties shown by a number of coumarins have led to extraordinarily large emphasis being placed on the design of more efficient and greener synthetic procedures to produce them.
ABSTRACTSynthetic chemists are paying ever more attention to enabling technologies as a means to ... more ABSTRACTSynthetic chemists are paying ever more attention to enabling technologies as a means to opening the paths towards the double goal of achieving high efficiency and meeting green criteria. Non-conventional techniques that create unique environments which promote selective modification have been investigated by many as part of the search for more highly efficient synthetic derivatization of cyclodextrins (CD). A few optimized microwave-assisted protocols have so far been developed for the preparation of selective per-alkylated aminocyclodextrin. In this work, a series of β-CD derivatives, whose primary hydroxyls were all replaced by amino groups, has efficiently been synthesized from per-(6-iodo-6-deoxy)-β-CD via nucleophilic substitution with amines under microwave irradiation in closed vessel (N2 pressure). The reduction of per-(6-azido-6-deoxy)-β-CD to per-(6-amino-6-deoxy)-β-CD via catalytic hydrogenation has also been successfully carried out under dielectric heating.
Nowadays the application of cyclodextrin-assisted molecular encapsulation in foods offers many ad... more Nowadays the application of cyclodextrin-assisted molecular encapsulation in foods offers many advantages. Cyclodextrins, their derivatives and their cross-linked polymers can all improve the quality of food in storage, remove specific components and stabilize and increase the presence of components that are important for a healthy diet. The application of cyclodextrins and their complexes in packaging materials can help not only transport of previously nontransportable foods, but may also prevent, or at least decelerate, the spread of microbial infections. The number of publications, particularly analytical papers, on this matter is constantly increasing. Although the application of modern analytical methods and equipment allows for the quantitation of previously subjectively characterized parameters, bio-sensory methods are still important. The application of cyclodextrins in the nutraceutical industry has many advantages; however, some side effects connected with the inclusion complexation ability of these carbohydrates should lead scientists to study cases on an individual basis. Recent developments in the major fields of cyclodextrin related food research are herein summarized.
The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting ... more The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting reactions enables efficient multidecoration in a single step.
The impressive chemico-physical effects observed in sonochemistry are a result of cavitation, as ... more The impressive chemico-physical effects observed in sonochemistry are a result of cavitation, as ultrasonic and hydrodynamic cavitation does not interact with matter at the atomic and molecular levels. Bubble collapse leads to the quasi-adiabatic heating of the vapour inside bubbles, giving rise to local hot spots in the fluid. Cavitation thus transforms a mechanical energy into high kinetic energy, which is released in very short bursts that are exploited for green process intensification. This paper reviews relevant applications of hydrodynamic and acoustic cavitation with the aim of highlighting the particular advantages that these phenomena offer to the intensification of green chemical processes. Emulsification, biodiesel preparation, wastewater decontamination, organic synthesis, enzymatic catalysis and extractions are discussed among others. As a comparison, hydrodynamic cavitation technique is more advantageous in dealing with process intensification at large-scale, as well as the enhancement of mass transfer and heat transfer, while ultrasonic cavitation technique is more convenient to operate, easier to control in the studies at lab-scale, and exhibits more efficient in producing active free radicals and inducing the cleavage of volatile compounds.
Mechanochemically promoted reduction of nitro and azido derivatives may be successfully performed... more Mechanochemically promoted reduction of nitro and azido derivatives may be successfully performed in stainless steel jars without catalyst addition.
A ppm-level Pd/Boemite catalyst has been prepared over 3-mm alumina beads and used for the select... more A ppm-level Pd/Boemite catalyst has been prepared over 3-mm alumina beads and used for the selective hydrogenation of alkynes in a continuous-flow reactor with two modes: closed-loop and flow-through. The...
The development of alternative, green solvents is an important and ongoing challenge. Our latest ... more The development of alternative, green solvents is an important and ongoing challenge. Our latest contribution to the field is the use of γ-valerolactone in aminocarbonylative coupling reactions for the clean synthesis of several 4(3H)-quinazolinones under microwave irradiation. The palladium-catalyzed, four-component carbonylative coupling reactions of o-iodoanilines, trimethyl orthoformate and a variety of amines have been carried out under CO pressure (2.5 bar). This protocol was found to be highly efficient and selective for 4(3H)-quinazolinones, which were isolated in good yields in the presence of two different, recyclable Pd catalysts which were prepared under ultrasound irradiation; a novel lead-free Pd/Boehmite catalyst and a β-cyclodextrin - cross linked Pd catalyst.
The impressive pharmacological properties shown by a number of coumarins have led to extraordinar... more The impressive pharmacological properties shown by a number of coumarins have led to extraordinarily large emphasis being placed on the design of more efficient and greener synthetic procedures to produce them.
ABSTRACTSynthetic chemists are paying ever more attention to enabling technologies as a means to ... more ABSTRACTSynthetic chemists are paying ever more attention to enabling technologies as a means to opening the paths towards the double goal of achieving high efficiency and meeting green criteria. Non-conventional techniques that create unique environments which promote selective modification have been investigated by many as part of the search for more highly efficient synthetic derivatization of cyclodextrins (CD). A few optimized microwave-assisted protocols have so far been developed for the preparation of selective per-alkylated aminocyclodextrin. In this work, a series of β-CD derivatives, whose primary hydroxyls were all replaced by amino groups, has efficiently been synthesized from per-(6-iodo-6-deoxy)-β-CD via nucleophilic substitution with amines under microwave irradiation in closed vessel (N2 pressure). The reduction of per-(6-azido-6-deoxy)-β-CD to per-(6-amino-6-deoxy)-β-CD via catalytic hydrogenation has also been successfully carried out under dielectric heating.
Nowadays the application of cyclodextrin-assisted molecular encapsulation in foods offers many ad... more Nowadays the application of cyclodextrin-assisted molecular encapsulation in foods offers many advantages. Cyclodextrins, their derivatives and their cross-linked polymers can all improve the quality of food in storage, remove specific components and stabilize and increase the presence of components that are important for a healthy diet. The application of cyclodextrins and their complexes in packaging materials can help not only transport of previously nontransportable foods, but may also prevent, or at least decelerate, the spread of microbial infections. The number of publications, particularly analytical papers, on this matter is constantly increasing. Although the application of modern analytical methods and equipment allows for the quantitation of previously subjectively characterized parameters, bio-sensory methods are still important. The application of cyclodextrins in the nutraceutical industry has many advantages; however, some side effects connected with the inclusion complexation ability of these carbohydrates should lead scientists to study cases on an individual basis. Recent developments in the major fields of cyclodextrin related food research are herein summarized.
The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting ... more The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting reactions enables efficient multidecoration in a single step.
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Papers by Katia Martina