作者:Ulf Wellmar、Anna-Britta Hörnfeldt、Salo Gronowitz
DOI:10.1002/jhet.5570320410
日期:1995.7
for regioselective preparation of 5-(2′-bromo-5′-furyl)-, 5-(2′-bromo-4′-furyl)-, 5-(2′-bromo-5′-thienyl)-, 5-(2′-bromo-4′-thienyl)-, 5-(4′-bromo-2′-thiazolyl)-, 5-(3′-bromophenyl)-, 5-(6′-bromo-2′-pyridyl)- and 5-(4′-bromo-2′-pyrimidyl)-substituted 2,4-di-t-butoxypyrimidines. In the coupling between 2,4-di-t-butoxy-5-pyrimidineboronic acid and the nine different aryl dibromides that were tried as
我们先前进一步开发的Suzuki Pd(0)催化的弱碱性介质中的芳基硼酸与芳基溴化物或碘化物之间的偶联已用于区域选择性制备5-(2'-溴-5'-呋喃基)-, 5-(2'-溴-4'-呋喃基)-,5-(2'-溴-5'-噻吩基)-,5-(2'-溴-4'-噻吩基)-,5-(4' -溴-2'-噻唑基),5-(3'-溴苯基)-,5-(6'-溴-2'-吡啶基)-和5-(4'-溴-2'-嘧啶基)-取代2,4-二-吨-butoxypyrimidines。在这两者之间2,4-二-耦合吨丁氧基-5-嘧啶硼酸和被尝试作为偶联的九个不同的芳基二溴化物,只有2,4-和2,5- dibromothiazoles没有给出令人满意的产率,15 %和0%。其他七个芳基二溴化物可提供所需的5-(溴芳基)-2,4-二-t-丁氧基嘧啶的产率为58-89%。尝试来合成2,4-二-吨-丁氧基-5-(2'-溴-4'-噻吩基)嘧啶从2-溴