RESUMO
A novel straightforward method for aryl azides having functional groups based on generation and reactions of aryllithiums bearing a triazene group from polybromoarenes using flow microreactor systems was achieved. The present approach will serve as a powerful method in organolithium chemistry and open a new possibility in the synthesis of polyfunctional organic azides.
RESUMO
Generation and reactions of methyl azide (MeN3) were successfully performed by using a flow reactor system, demonstrating that the flow method serves as a safe method for handling hazardous explosive methyl azide. The reaction of NaN3 and Me2SO4 in a flow reactor gave a MeN3 solution, which was used for Huisgen reaction with benzoyl cyanide in a flow reactor after minimal washing. The resulting 1-methyl-5-benzoyltetrazole serves as a key intermediate of picarbutrazox (IX), a new potent pesticide.
Assuntos
Azidas/química , Substâncias Perigosas/química , Praguicidas/química , Tetrazóis/química , Praguicidas/síntese química , Azida Sódica/química , Temperatura , Tetrazóis/síntese químicaRESUMO
A flow microreactor method for three-component coupling of benzyne was developed based on flash chemistry. o-Bromophenyllithium generated from 1-bromo-2-iodobenzene and a functionalized aryllithium generated from the corresponding aryl halide were mixed at -70 °C. In the subsequent reactor o-bromophenyllithium is decomposed to generate benzyne without affecting the functionalized aryllithium at -30 °C, and carbolithiation of benzyne with the aryllithium took place spontaneously. The resulting functionalized biaryllithium was reacted with an electrophile in the subsequent reactor to give the corresponding three-component coupling product. The precise optimization of reaction conditions using the temperature-residence time mapping is responsible for the success of the present transformation. The present method has been successfully applied to the synthesis of boscalid.
RESUMO
Reactions of functionalized aryllithiums with dialkyl oxalates were achieved using a flow microreactor to obtain α-keto esters with high selectivity by virtue of fast 1 : 1 micromixing.