Correlations between carbon-13 nuclear magnetic resonance chemical shifts and reactivities of siloxybutadienes and siloxyazabutadienes in the Diels-Alder reaction with dimethyl acetylenedicarboxylate.
摘要:
在硅烷化丁二烯衍生物 (1) 与乙炔二甲酸二甲酯(DMAD)的反应中,建议根据二烯末端亚甲基碳(δ13C-4)的碳-13 核磁共振化学位移,按照以下线性关系预测二烯的反应活性:a) 总电子密度与δ13C-4 的关系;b) ln k 对 1/[ELUMO(DMAD)-EHOMO(二烯)]; c) ln k 对 δ13C-4。二烯的总电子密度以及最高占位分子轨道(HOMOs)和最低未占位分子轨道(LUMOs)的能级是通过修正的忽略二原子重叠(MNDO)法计算得出的。
:The reaction of N-silylated iminoethers with 2-substituted acetyl chlorides yields activated 2-azadienes. These were shown to react with electron-deficient acetylenic dienophiles to yield pyridones. They also react with quinones to give the corresponding aromatized cycloadducts in good yields. The reaction of a-azadienes with activated nitriles provided a very practical route towards polysubstituted pyrimidones. A multicomponent protocol is reported which combines a N-t-butyldimethylsilyl iminoether, an acetyl chloride derivative and a dienophile in the presence of triethylamine without isolation of any intermediate. This provides an extremely practical and versatile route to various mono- and polycyclic azaaromatics with a predictable substitution pattern. Yields ranged from 43 % to 94 % for the complete sequence. (C) 1999 Elsevier Science Ltd. All rights reserved.
A Diels-Alder route to pyridone and piperidone derivatives
作者:Francy Sainte、Beatrice Serckx-Poncin、Anne Marie Hesbain-Frisque、Leon Ghosez
DOI:10.1021/ja00369a049
日期:1982.3
SAINTE, F.;SERCKS-PONCIN, B.;HESBAIN-FRISQUE, A. -M.;GHOSEZ, L., J. AMER. CHEM. SOC., 1982, 104, N 5, 1428-1430
作者:SAINTE, F.、SERCKS-PONCIN, B.、HESBAIN-FRISQUE, A. -M.、GHOSEZ, L.