Vasilyev A V, Walspurger S, Haouas M, Sommer J, Pale P, Rudenko A P
Saint-Petersburg Forest Technical Academy, Institutsky per.5, Saint-Petersburg, 194021, Russia.
Org Biomol Chem. 2004 Dec 7;2(23):3483-9. doi: 10.1039/b412323a. Epub 2004 Nov 2.
In superacids with H0=-14 to -20, it has been found that 1,3-diarylpropynones ArC triple bond CCOAr' are either protonated on oxygen of carbonyl groups with the formation of stable ions ArC triple bond CC(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'.
在哈米特酸度函数H0为-14至-20的超强酸中，已发现1,3-二芳基丙炔酮ArC≡CCOAr' 要么在羰基的氧上质子化，形成稳定离子ArC≡CC(OH+)Ar'，要么在高度共轭体系电子足够丰富时发生进一步转化。在后一种情况下，3-芳基茚酮能非常快速且高效地生成（在不到30分钟内产率高达95%）。已研究了取代基Ar、Ar' 以及反应条件对1,3-二芳基丙炔酮行为和分子内环化的影响。根据收集到的数据，提出了一种涉及乙烯基阳离子ArC+=CHCOAr' 和/或双阳离子ArC+=CHC(OH+)Ar' 的机理。
