Regioselective Metalation and Functionalization of the Pyrazolo[1,5-<i>a</i>]pyridine Scaffold Using Mg- and Zn-TMP Bases
作者:Moritz Balkenhohl、Bruno Salgues、Takahiro Hirai、Konstantin Karaghiosoff、Paul Knochel
DOI:10.1021/acs.orglett.8b01204
日期:2018.5.18
A regioselective functionalization of the pyrazolo[1,5-a]pyridine scaffold using Mg- and Zn-TMP bases (TMP = 2,2,6,6-tetramethylpiperidyl) in the presence or absence of BF3·OEt2 is described. Also, various functionalized pyrazolo[1,5-a]pyridines bearing an ester function (and an NHBoc or ethyl group) are magnesiated and functionalized, leading to polysubstituted heterocycles. Additionally, a sulfoxide
描述了在存在或不存在BF 3 ·OEt 2的情况下,使用Mg-和Zn-TMP碱基(TMP = 2,2,6,6-四甲基哌啶基)对吡唑并[1,5- a ]吡啶骨架进行的区域选择性官能化。另外,将具有酯官能团(和NHBoc或乙基)的各种官能化的吡唑并[1,5- a ]吡啶进行镁化和官能化,从而形成多取代的杂环。另外,据报道使用亚硫酸镁直接进行亚金属的邻位金属化,然后进行吡唑并[1,5- a ]吡啶亚砜的无过渡金属的胺化。