Banca de QUALIFICAÇÃO: LUCIANO PEGUINI DE SOUSA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCIANO PEGUINI DE SOUSA
DATE: 25/08/2022
TIME: 13:30
LOCAL: https://meet.google.com/ngi-ijkv-bqu
TITLE:

ORGANOCATALYSIS AND BIOCATALYSIS APPLIED TO ASYMMETRIC O-MICHAEL-ALDOL REACTIONS USING L-AMINO ACID DERIVATIVES AND ENZYMES

KEY WORDS:

Asymmetric catalysis, Organocatalysis, Biocatalysis, Chromenes.

PAGES: 68
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Síntese Orgânica
SUMMARY:

Asymmetric catalysis is an interesting way to obtain enantiomerically pure or highly pure compounds. Asymmetric catalysis techniques have been modernized and expanded in the last 20 years. Modern synthetic methodologies seek to conciliate agility, low cost and minimal environmental impacts. Asymmetric catalysis is divided into three broad areas: organocatalysis, biocatalysis and organometallic catalysis. This work focused on the synthesis of chromenes (benzopyrans) through the biocatalysis or organocatalysis of the oxa-Michael-aldol reaction of nitrostyrene or cinnamaldehyde with salicylaldehyde. Chromenes are heterocycles with a basic nucleus consisting of a pyran ring fused to a benzene ring (bicyclic). They are important molecules for several industrial branches, but mainly the pharmaceutical. Chiral drugs occupy a prominent place in the industry for their ability to selectively interact with enzymes or with a stereospecific biological receptor (chiral macromolecules), thus provoking a biological response. Through organocatalysis, using thiazolidines (3a and 3b) under different conditions, we sought to synthesize compounds 1a and 1b, with enantiomeric excess. The results showed that for the conditions and compounds tested, it is not possible to synthesize molecules with enantiomeric excess. With the use of enzymes (biocatalysis), CAL-B and α-amylase, an attempt was made to synthesize compounds 1a and 1b, 2a and 2b with enantiomeric excess, again without success. Both in the organocatalysis and in the biocatalysis of the chromene derivatives that were tried to synthesize, there was no success regarding the enantiomeric excess, this may be related to non-activation and/or induced orientation of nitrostyrene during the transition step.

BANKING MEMBERS:
Presidente - 1805937 - JEFFERSON LUIZ PRINCIVAL
Interno - 1222623 - MARCELO SIQUEIRA VALLE