Syntheses with organoboranes. XIII. Synthesis of ω-(4-bromophenyl)alkanoic acids and their borylation
作者:Marek Zaidlewicz、Andrzej Wolan
DOI:10.1016/s0022-328x(02)01383-9
日期:2002.9
ω-(4-Bromophenyl)alkanoic acids 2c–e were obtained from 1-bromo-4-alkenylbenzenes 5c–e by hydroboration–thermal isomerization–oxidation. Their esters 11c–e were transformed in good yields into the corresponding boronates 12c–e by the cross-coupling reaction with 4,4,5,5,4′,4′,5′,5′-octamethyl[2,2′]bi[[1,3,2]dioxaborolanyl] (10) in an ionic liquid, [bmim][BF4]. The use of pinacolborane for the coupling
通过氢硼化-热异构化-氧化,从1-溴-4-烯基苯5c - e获得ω-(4-溴苯基)链烷酸2c - e。通过与4,4,5,5,4',4',5',5'-八甲基[2.2'] bi的交叉偶联反应,将它们的酯11c - e转化为相应的硼酸酯12c - e的高收率。离子液体[bmim] [BF 4 ]中的[[1,3,2]二恶硼硼烷基](10)。使用频哪醇硼烷在离子液体中进行偶联反应可得到脱溴产物,并降低了12c - e的收率。3-(4-溴苯基)丙酸乙酯(通过与[2,2']双[[1,3,2]二氧杂硼烷基]交叉偶联,将7c)转化成3-(4- [1,3,2]二恶硼硼烷基)丙酸乙酯(9c)。