RESUMO
Methods for direct functionalization of C(sp2)-H bonds in pyrrolo[1,2-a]quinoxalines have witnessed emerging development over the last decade. Herein we report a new tactic to afford a selective sulfenylation of 4-aryl pyrrolo[1,2-a]quinoxalines with diaryl disulfides. The reactions proceeded in the presence of a copper catalyst and potassium iodide promoter. Functionalities including nitro, ester, amide, methylthio, and halogen groups were all tolerated. Our method offers a convenient route to obtain highly substituted pyrrolo[1,2-a]quinoxalines-based thioethers in moderate to good yields.
RESUMO
We report a method for addition of α-bromophenylacetic acids to vinyl C[double bond, length as m-dash]C bonds in styrenes to afford γ-lactones. Reactions employed a simple cobalt catalyst Co(NO3)2·6H2O in the presence of dipivaloylmethane (dpm) ligand. Many functionalities including halogen, ester, and nitro groups were compatible with reaction conditions. If α-bromoesters were used, vinylacetates were the major products.
RESUMO
During 2015-2018, seven schools in rural Vietnam experienced diphtheria outbreaks. Multilocus sequence types were the same within schools but differed between schools. Low vaccine coverage and crowded dormitories might have contributed to the outbreaks. Authorities should consider administering routine vaccinations and booster doses for students entering the school system.
Assuntos
Corynebacterium diphtheriae/isolamento & purificação , Difteria/epidemiologia , Surtos de Doenças , Instituições Acadêmicas , Adolescente , Criança , Serviços de Saúde da Criança , Pré-Escolar , Corynebacterium diphtheriae/genética , Demografia , Difteria/etiologia , Difteria/prevenção & controle , Feminino , Humanos , Lactente , Masculino , Tipagem de Sequências Multilocus , Vacinação , Vietnã/epidemiologia , Adulto JovemRESUMO
The findings and conclusions in this article are those of the authors and do not necessarily represent the official positions of the United States Centers for Disease Control and Prevention.