Full text
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| Author(s): |
Hugo dos Santos
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2023-03-29 |
| Examining board members: |
Fernando Antonio Santos Coelho;
Igor Dias Jurberg;
Paulo Cesar Muniz de Lacerda Miranda;
Marcio Weber Paixão;
Marco Antonio Barbosa Ferreira
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| Advisor: | Fernando Antonio Santos Coelho |
| Abstract | |
This doctoral thesis reports catalytic methodologies for the synthesis of heterocyclic compounds, and is divided into two chapters. The main objective of the work developed in the first chapter is to explore Morita–Baylis–Hillman (MBH) reactions between isatins and cycloenones using chiral, bifunctional imidazole organocatalysts containing a hydroxyl group. At first, experiments using chemical kinetics and mass spectrometry combined with theoretical calculations were used to shed light on the reason why these MBH reactions work exceptionally well in aqueous solvent. Several structurally related organocatalysts were synthesized and tested on the MBH reaction, with low but promising enantiomeric excesses obtained. Finally, a new class of nucleophilic components was explored for the reaction of MBH with isatins: the 3-aryl-5-vinyl-1,2,4-oxadiazoles. A series of 3-substituted 3-hydroxy-2-oxindoles containing the oxadiazole nucleus was synthesized in mostly excellent yields (> 90%), and some of these adducts showed significant inhibitory activity against Trypanosoma cruzi or Leishmania infantum. In the second chapter, a simple and efficient synthetic methodology was developed for the synthesis of 1,4-disubstituted and 1,2,4-trisubstituted carbazoles from the benzannulation of indoles and 1,4-diketones as starting materials under ZrCl4 catalysis. The developed protocol proved to be selective when non-symmetric 1,4-diketones were used. The synthetic applicability of the obtained carbazole products was demonstrated using palladium-catalyzed carbon-carbon cross-coupling reactions. Furthermore, the methodology was applied in the synthesis of a tetracyclic 3-deazacanthin-6-one analogue (AU) | |
| FAPESP's process: | 15/09205-0 - New frontiers of the Morita-Baylis-Hillman reaction: 1) New applications of a bifunctional catalyst derived from imidazole. 2) Studies on the asymmetric synthesis of a natural high-potency sweetener |
| Grantee: | Hugo dos Santos |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |