Derailed
<i>Ohira‐Bestmann</i>
Reaction of
<i>γ</i>
,
<i>δ</i>
‐Unsaturated Aldehydes for the Stereoselective Synthesis of Cyclopenta[
<i>c</i>
]pyrazoles
作者:Tobias Sandmeier、Niels Sievertsen、Erick M. Carreira
DOI:10.1002/hlca.202000058
日期:2020.6
The synthesis of cyclopenta[c]pyrazoles from γ,δ‐unsaturated aldehydes by a domino sequence involving one‐carbon homologation and intramolecular azomethine imine 1,3‐dipolarcycloaddition is disclosed. The fused pyrazoles bearing aromatic and aliphatic substituents are obtained in good yields and excellent diastereomeric purity. Additionally, the synthetic utility of the pyrazole products generated
公开了通过涉及一个碳同系物和分子内偶氮甲亚胺亚胺1,3-偶极环加成反应的多米诺序列,由γ,δ-不饱和醛合成环戊[ c ]吡唑。获得具有芳族和脂族取代基的稠合吡唑,具有良好的产率和优异的非对映体纯度。另外,通过该方法产生的吡唑产物的合成效用已经在一系列官能化反应中得到强调。提出的方法为合成含吡唑的生物活性化合物提供了战略机遇。