The ultrasound-assisted oxysulfonylation of different alkenes using sodium salts of organosulfinic acids under air atmosphere is described. The reaction is chemo- and regioselective and the corresponding β-keto-sulfones were obtained in good yields as major products. The use of ultrasound greatly accelerated the formation of products when compared to the conventional methods.

ABSTRACT The present study investigated the antioxidant effect of a new class of quinoline derivatives (a-d) on assays in vitro. Lipid peroxidation, thiol peroxidase-like and free radical scavenging activities were determined to evaluate antioxidant activity of compounds. Thiol oxidase-like and δ-aminolevulinate dehydratase activities were performed as a toxicological parameter. A second objective of this study was to evaluate the in vivo antinociceptive effect of the compound with better antioxidant effect and without toxic effects in a model of nociception induced by formalin in mice. In liver, at 100 µM, compound a reduced the lipid peroxidation to the control levels, while compounds c and d partially reduced it. In brain, only compound d partially reduced the lipid peroxidation at 50 and 100 µM. Compound b did not have an effect on the lipid peroxidation. Thiol peroxidase-like and free radical scavenging activities are not involved in the antioxidant mechanisms of these compounds. Compounds did not present thiol oxidase-like activity and effect on the δ-aminolevulinate dehydratase. In vivo experiments showed that compound a caused an inhibition of licking time in the first and second phases, and edema formation induced by formalin. In conclusion, quinoline derivative without selenium presented better in vitro antioxidant effect and in vivo antinociceptive activity.

Neste trabalho desenvolvemos um método seletivo e eficiente para a síntese de derivados de 3-aril-2-(tiometil)-benzo[b]furanos, via reação de acoplamento com ácidos borônicos, catalisada por paládio. As condições reacionais usadas foram brandas e compatíveis com ácidos borônicos contendo substituintes retiradores, doadores de elétrons ou neutros.

A selective and efficient method for the synthesis of 3-aryl-2-(methylthio)benzo[b]furans derivatives by palladium catalyzed cross-coupling reaction with boronic acids has been developed. The reaction proceeded cleanly under mild conditions and was performed with aryl boronic acids bearing electron-withdrawing, electron donating and neutral substituents.

Apresentamos aqui nossos resultados da adição de tióis, catalisada por PhSeBr, a compostos carbonílicos α,β-insaturados sob condições brandas para obter regiosseletivamente β-mercapto cetonas ou tioacetais com altos rendimentos e seletividade. A reação foi principalmente controlada pela temperatura, na qual os produtos de adição 1,4 foram obtidos à temperatura de -20 ºC. Inversamente quando a reação foi realizada sob refluxo, tioacetais foram obtidos como único produto. O método admite diversos grupos funcionais, como alquilicos, benzilicos e arilicos com substituintes neutros, deficientes e ricos em elétrons no anel aromático.

We present herein results on the PhSeBr-catalyzed addition of thiols to α,β-unsaturated carbonyl compounds under mild conditions to afford regioselectivily β-mercapto ketones or thioacetals in high yields and selectivity. The reaction was highly controlled by the temperature in which, the 1,4-addition products were obtained when the temperature was -20 ºC, conversely when the reaction was carried out at reflux, the thioacetals were obtained as a sole product. The developed protocol stands a wide range of functional groups, in which alkyl, benzyl and aryl with neutral, electron deficient and electron rich substituents on the aromatic ring.