Inser o de catalisador híbrido na síntese de beta-tiocetonas Inser o de catalisador híbrido na síntese de beta-tiocetonas

The Michael reaction (or Michael addition) involves the addition of a nucleophile, called Michael donor, to an electrophile (α,β-unsaturated), called Michael acceptor. Literature reports several types of nucleophiles applied in this reaction. Among them we can mention compounds containing a sulfur atom. When these nucleophiles are applied to this reaction, it is called as thia-Michael reaction. In this study thiophenol, p- chlorothiophenol and p-methoxythiophenol were tested as Michael donors, and several ketones and aldehydes as Michael acceptors, in order to obtain the formation of sigma bonds carbon-sulfur. Compounds that have in their structure the C-S bond are extremely important, because they can present, for example, antibiotic action, antimicrobial analgesic, and anti-HIV. This research proposes, besides the obtainment of many beta-thioketonic compounds, the insertion of a new catalyst in thia-Michael reactions, the bis-L-zinc prolinate. This catalyst provided the obtainment of high yield compounds. The reactions were executed using ultrasound, which caused a significant decrease in the reaction time and an increase in the results obtained when compared with data obtained previously in literature. An important fact in this study is that the catalyst used is not soluble in the reaction media and it can be reused without abrupt loss of yield. A rea o de Michael envolve a adi o de um nucleófilo, denominado doador de Michael, a um eletrófilo (α,β-insaturado), denominado aceptor de Michael. A literatura relata variados tipos de nucleófilos aplicados nesta rea o. Dentre estes podemos citar compostos que contenham o átomo de enxofre. Quando se aplica estes nucleófilos nesta rea o, a mesma é denominada tia-Michael. Neste trabalho foram testados o tiofenol, o p-clorotiofenol, e o p-metoxitiofenol como doadores de Michael e diversas cetonas e aldeídos, como aceptores de Michael, visando à forma o de liga es sigma carbono-enxofre. Compostos que apresentam em sua estrutura a liga o C-S s o de extrema importancia, pois podem apresentar, por exemplo, a o antibiótica, antimicrobiana, analgésica, e anti HIV. Este trabalho prop e, além da obten o de diversos compostos beta-tiocet nicos, a inser o de um novo catalisador nas rea es de tia-Michael, o bis-L-prolinato de zinco. Este catalisador proporcionou a obten o dos compostos com altos rendimentos. As rea es foram executadas utilizando-se o ultrassom, o que proporcionou uma significativa diminui o do tempo reacional juntamente com o aumento dos rendimentos obtidos quando comparados com dados anter