Martinelli, Ada
(2021)
Novel catalytic systems and methidologies for organocatalysis and photocatalysis, [Dissertation thesis], Alma Mater Studiorum Università di Bologna.
Dottorato di ricerca in
Chimica, 33 Ciclo. DOI 10.48676/unibo/amsdottorato/9777.
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Abstract
The thesis is divided into two main parts. In the first one organocatalysis is briefly introduced. Then, new enantiopure trityl pyrrolidines modified with an ionic tag are described. All the catalysts are tested in the benchmark Michael addition reaction to prove their activity and stereoselectivity.
In the second part, photocatalysis is first introduced. Then, four different research projects are described.
At first, the construction of a hybrid metal-organo-photoredox catalyst is described. The hybrid photocatalysts obtained were employed in the benchmark photoredox alkylation of aldehydes.
Then, the use of visible light and a photocatalytic system for the cyclization of iodoaryl vinyl derivatives to tetrahydroquinoline structures is described. In addition, the reaction can also be performed using flow-chemistry. Finally, a mechanistic proposal based on some mechanistic studies is described.
Third, a new photoredox catalyzed transformation for the synthesis of 2,3-dihydrofurans is reported. Depending on the involved starting materials, different pathways have arisen. A mechanistic proposal based on reported literatures and experimental data is described.
At last, a new photoredox catalyzed transformation for the synthesis of 2-aminofurans is described. Electrophilic radical addition on allenamides and subsequential intramolecular cyclization are exploited. The reaction proceeds under very mild conditions and in 2-aminofurans are obtained in good to high yield. It represents one of the few applications of allenamides in photoredox catalysis. A mechanistic proposal is described. Finally, preliminary investigations on the applicability of the developed transformation under flow chemistry conditions.
Abstract
The thesis is divided into two main parts. In the first one organocatalysis is briefly introduced. Then, new enantiopure trityl pyrrolidines modified with an ionic tag are described. All the catalysts are tested in the benchmark Michael addition reaction to prove their activity and stereoselectivity.
In the second part, photocatalysis is first introduced. Then, four different research projects are described.
At first, the construction of a hybrid metal-organo-photoredox catalyst is described. The hybrid photocatalysts obtained were employed in the benchmark photoredox alkylation of aldehydes.
Then, the use of visible light and a photocatalytic system for the cyclization of iodoaryl vinyl derivatives to tetrahydroquinoline structures is described. In addition, the reaction can also be performed using flow-chemistry. Finally, a mechanistic proposal based on some mechanistic studies is described.
Third, a new photoredox catalyzed transformation for the synthesis of 2,3-dihydrofurans is reported. Depending on the involved starting materials, different pathways have arisen. A mechanistic proposal based on reported literatures and experimental data is described.
At last, a new photoredox catalyzed transformation for the synthesis of 2-aminofurans is described. Electrophilic radical addition on allenamides and subsequential intramolecular cyclization are exploited. The reaction proceeds under very mild conditions and in 2-aminofurans are obtained in good to high yield. It represents one of the few applications of allenamides in photoredox catalysis. A mechanistic proposal is described. Finally, preliminary investigations on the applicability of the developed transformation under flow chemistry conditions.
Tipologia del documento
Tesi di dottorato
Autore
Martinelli, Ada
Supervisore
Co-supervisore
Dottorato di ricerca
Ciclo
33
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
organocatalysis, photocatalysis, flow chemistry, tetrahydrofurans, furans, tetrahydroquinolines, michael addition, asymmetric synthesis, photoaminocatalyst
URN:NBN
DOI
10.48676/unibo/amsdottorato/9777
Data di discussione
27 Maggio 2021
URI
Altri metadati
Tipologia del documento
Tesi di dottorato
Autore
Martinelli, Ada
Supervisore
Co-supervisore
Dottorato di ricerca
Ciclo
33
Coordinatore
Settore disciplinare
Settore concorsuale
Parole chiave
organocatalysis, photocatalysis, flow chemistry, tetrahydrofurans, furans, tetrahydroquinolines, michael addition, asymmetric synthesis, photoaminocatalyst
URN:NBN
DOI
10.48676/unibo/amsdottorato/9777
Data di discussione
27 Maggio 2021
URI
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