Lewis acidic ionic liquids for the synthesis of electrophilic alkenes via the Knoevenagel condensation
作者:Jitendra R Harjani、Susheel J Nara、Manikrao M Salunkhe
DOI:10.1016/s0040-4039(01)02341-3
日期:2002.2
[bpy]Cl·AlCl3, N=0.67 ionic liquids were found to work well as the Lewis acid catalyst and solvent in the Knoevenagelcondensations of benzaldehyde and substituted benzaldehydes with diethylmalonate to give benzylidene malonates. The benzylidene malonates subsequently underwent Michael additions with diethylmalonate. The extent of Michael product formed during the reaction was found to vary with the Lewis acidity
A convenient one-pot synthesis, theoretical studies, and NMR-based conformational analysis of nitroarylidene dimalonates
作者:Leman Alkan、Özgür Alver、Stephen T. Astley、Eralp Kulan、Cemal Parlak
DOI:10.1016/j.molstruc.2022.133848
日期:2022.12
Tandem Knoevenagel-Michael addition of diethyl malonate to nitro-substituted benzaldehydes was found to proceed in a mild and convenient process. The 1H NMR spectra of the products showed significant changes according to the position of the nitro group. Conformational analysis calculations confirmed that in all cases, a structure containing a mirror plane occurred at energies near the ground state
发现丙二酸二乙酯与硝基取代的苯甲醛的串联 Knoevenagel-Michael 加成过程温和且方便。产物的1 H NMR 光谱显示出根据硝基位置的显着变化。构象分析计算证实,在所有情况下,包含镜面的结构出现在接近基态的能量处。然而,对于间位和邻位取代的产物,增加的空间拥挤导致乙基取代基的旋转自由度降低。与空间应力增加的观察结果一致,分子轨道计算预测邻硝基取代产物的亲电反应性更高。