Nitration of phenylpropiolic acid derivatives ArC≡CX (X=CN, CO2Me) in HSO3F at −75...−50°C afforded mononitro compounds, for instance, m-O2NC6H4C≡CX. Vinyl type cations generated in HSO3F from methyl 3-arylpropiolates ArC+=CHCO2Me react along two pathways. The first among them results in formation of fluorosulfonates ArC(OSO2F)=CHCO2Me, and the second one after the attack of vinyl cation on the aryl moiety of the substrate affords a dimer that on nitration is converted into a nitro product with conserved triple bond.
苯基
丙炔酸衍
生物 ArC≡CX (X=CN、CO2Me)在 -75...-50°C 下于 HSO3F 中发生硝化反应,生成单
硝基化合物,例如 m-O2NC6H4C≡CX。在 HSO3F 中,3-芳基
丙炔酸甲酯 ArC+=CHCO2Me 生成的
乙烯基阳离子会沿着两条途径发生反应。第一种途径是形成
氟磺酸盐 ArC(OSO2F)=CHCO2Me,第二种途径是
乙烯基阳离子攻击底物的芳基后产生二聚体,二聚体在硝化时转化为带有保留三键的硝基产物。