SmI2-Promoted novel tandem elimination and coupling reactions of aliphatic imides with carbonyl compounds: application to the synthesis of dl-isoretronecanol
Treatment of α-hetero-substituted cyclic imides with carbonylcompounds mediated by samarium(II) diiodide in the presence of HMPA was found to undergo novel tandem elimination and reductive coupling reactions to generate α-hydroxyalkylated imides in good to high yields. Stereochemistry of the coupling products was researched and the result that increasing the steric bulkiness of the N-substituents
<scp>
γ‐Al
<sub>2</sub>
O
<sub>3</sub>
</scp>
/triflic acid as cooperative catalysts for the tandem Michael addition/carbocyclization: An easy access to 2‐substituted pyrrolo[2,1‐
<i>a</i>
]isoquinolines and 3‐substituted pyrrolidine‐2,5‐diones
tandem Michael addition/carbocyclization of 3,4-dimethoxyphenethyl maleimide with carbon and sulfur nucleophiles is accomplished via a relay catalysis using γ-Al2O3/TfOH binary system. The X-ray Photoelectron Spectroscopy (XPS) analysis of binary system indicates the presence of AlF3, AlO(OH) species. This approach provides an easy access to 2-aryl or 2-thio aryl pyrrolo[2,1-a]isoquinolines in good yields
3,4-二甲氧基苯乙基马来酰亚胺与碳和硫亲核试剂的串联迈克尔加成/碳环化是通过使用γ-Al 2 O 3 /TfOH二元体系的中继催化完成的。二元系统的 X 射线光电子能谱 (XPS) 分析表明存在 AlF 3、AlO(OH) 物质。该方法提供了以串联方式以良好产率容易地获得2-芳基或2-硫代芳基吡咯并[2,1- a ]异喹啉。在γ-Al 2 O 3 /TfOH二元体系比例合适的情况下,还实现了N/C/S亲核试剂与N-苄基马来酰亚胺的迈克尔加成。这些反应成功的关键是产生 AlF图 3 中,来自 γ-Al 2 O 3和 TfOH 的AlO(OH) 物质可能描绘了通常由强布朗斯台德酸(如 TfOH)显示的不利背景反应。