%0 Journal Article
%T Inser  o de catalisador h¨ªbrido na s¨ªntese de beta-tiocetonas Inser  o de catalisador h¨ªbrido na s¨ªntese de beta-tiocetonas
%A Mariana Pompilio Darbem
%A Andrelson Wellington Rinaldi
%A Nelson Luis C. Domingues
%J Orbital : the Electronic Journal of Chemistry
%D 2012
%I Universidade Federal de Mato Grosso do Sul
%X The Michael reaction (or Michael addition) involves the addition of a nucleophile, called Michael donor, to an electrophile (¦Á,¦Â-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 nucle¨®filo, denominado doador de Michael, a um eletr¨®filo (¦Á,¦Â-insaturado), denominado aceptor de Michael. A literatura relata variados tipos de nucle¨®filos aplicados nesta rea  o. Dentre estes podemos citar compostos que contenham o ¨¢tomo de enxofre. Quando se aplica estes nucle¨®filos nesta rea  o, a mesma ¨¦ denominada tia-Michael. Neste trabalho foram testados o tiofenol, o p-clorotiofenol, e o p-metoxitiofenol como doadores de Michael e diversas cetonas e alde¨ªdos, como aceptores de Michael, visando ¨¤ 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 antibi¨®tica, antimicrobiana, analg¨¦sica, e anti HIV. Este trabalho prop e, al¨¦m 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
%K alquila  o
%K sistema de Mitsunobu
%K pirimidina
%K seletividade
%U http://www.orbital.ufms.br/index.php/Chemistry/article/view/334