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| Author(s): |
Pablo David Grigol Martinez
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: | 2013-03-15 |
| Examining board members: |
Carlos Roque Duarte Correia;
Silvio do Desterro Cunha;
Ronaldo Aloise Pilli;
Fábio Cesar Gozzo;
Pierre Mothé Esteves
|
| Advisor: | Carlos Roque Duarte Correia |
| Abstract | |
In the first part of this work, the use of endocyclic enecarbamates as substrates in organocatalysis was evaluated. The effect of phosphoric acids as catalysts in promoting Friedel-Crafts reactions involving di and trisubstituted enecarbamates as electrophiles was explored. Different arenes were employed as nucleophiles like indols, furans, naftol and sesamol. It was possible to develop a simple protocol with mild conditions and good yields. The diastereoselectivity observed with trisubstituted enecarbamates favored the trans product in a range of 2.7:1 to 95:5. By using chiral phosphoric acids, the enantioselectivity achieved, so far, was 20% ee, evidencing the potentiality of this methodology. Later, hydrogenolysis reactions over 2-aryl-3-epoxypyrrolidines were performed to prepare aminoalcohols. The key step to synthesize the former pyrrolidines was the Heck-Matsuda reaction of enecarbamates obtained from L-pyroglutamic acid. The stereochemistry of the substituents in the hydrogenolytic step did influence the experimental conditions and yields, allowing in some cases two bonds cleavage in one pot. The aminoalcohols prepared in this methodology were used in a short synthesis of 2-epibulgecinine and in preparation of sphingoid bases exemplified in the synthesis of sphingosine analogue (AU) | |
| FAPESP's process: | 08/00122-0 - Synthetic Applications of the Petasis Reactions of N-acyliminium Ions. Use of enecarbamates in organocatalysis and in the synthesis of sphingosines analogues. |
| Grantee: | Pablo David Grigol Martinez |
| Support Opportunities: | Scholarships in Brazil - Doctorate |