作者:A. V. Vasilyev、S. Walspurger、M. Haouas、J. Sommer、P. Pale、A. P. Rudenko
DOI:10.1039/b412323a
日期:——
In superacids with H0
=
−14 to −20, it has been found that 1,3-diarylpropynones ArCCCOAr′ are either protonated on oxygen of carbonyl groups with the formation of stable ions ArCCC(O+H)Ar′ or undergo further transformations when the highly conjugated system is electron-rich enough. In the latter case, 3-arylindenones are produced very rapidly and with high efficiency (up to 95% yield in less than 30 min). The influence of the substituents Ar, Ar′ and of the reaction conditions on the behavior of 1,3-diarylpropynones and on the intramolecular cyclisation have been studied. From the collected data, a mechanism has been proposed involving vinyl cations ArC+=CHCOAr′ and/or dications ArC+=CHC(O+H)Ar′.
在pH值为−14至−20的超酸中,发现1,3-二芳基丙炔酮ArCCCOAr′可以通过羰基氧的质子化形成稳定的离子ArCCC(O+H)Ar′,或者当高度共轭体系的电子丰富时发生进一步转化。在后者的情况下,3-芳基茚酮非常迅速且高效地生成(在不到30分钟内产率可达95%)。对取代基Ar、Ar′和反应条件对1,3-二芳基丙炔酮行为以及分子内环化的影响进行了研究。根据收集的数据,提出了一种机制,涉及乙烯基阳离子ArC+=CHCOAr′和/或二阳离子ArC+=CHC(O+H)Ar′。