A range of 2-substituted 2,3-dihydro-1H-quinolin-4-ones have been synthesized from anilines by a two-step process involving Sonogashira coupling with a propargyl alcohol then acid-catalyzed cyclization of the resulting 2-(3′-hydroxypropynyl)anilines. The cyclization reaction appears to proceed via regioselective rearrangement of the propargyl alcohol to an α,β-unsaturated ketone (Rupe rearrangement) and then 6-endo-trig ring closure (Donnelly-Farrell cyclization). The isolation of the α,β-unsaturated ketone intermediate in one example supports this pathway.
一系列2-取代的
2,3-二氢-1H-喹啉-4-酮是通过两步反应从
苯胺合成的,首先是与
丙炔醇进行Sonogashira偶联,然后是对得到的2-(3′-羟基
丙炔基)
苯胺进行酸催化环化。环化反应似乎通过
丙炔醇的区域选择性重排形成α,β-不饱和酮(Rupe重排),然后是6-端环关闭(Donnelly-Farrell环化)。在一个例子中,α,β-不饱和酮中间体的分离支持了该路径。