Reactions of 3,3,3-Trihalogeno-1-nitropropenes with Arenes in the Superacid CF<sub>3</sub>SO<sub>3</sub>H: Synthesis of (<i>Z</i>)-3,3,3-Trihalogeno-1,2-diarylpropan-1-one Oximes and Study on the Reaction Mechanism
作者:Andrei A. Golushko、Maria A. Sandzhieva、Alexander Yu. Ivanov、Irina A. Boyarskaya、Olesya V. Khoroshilova、Alexey Yu. Barkov、Aleksander V. Vasilyev
DOI:10.1021/acs.joc.8b01406
日期:2018.9.7
3-trihalogeno-1,2-diarylpropan-1-one oximes C(Hal3)CH(Ar)–C(Ar)═NOH (CHal3-oximes) in yields of 23–99%. Such CHal3-oximes having one ortho-substituent in the aryl ring exist as atropoisomers in solutions at room temperature. Several cationic intermediates of this reaction were studied by means of NMR and DFT calculations, which proves the detailed reaction mechanism of the formation of CHal3-oximes in
3,3,3-三卤代-1-硝基丙烯C(Hal 3)CH═CH(NO 2)(Hal = F,Cl,Br)在室温下与CF 3 SO 3 H(TfOH)中的芳烃反应在1小时内提供3,3,3-三卤代-1,2-二芳基丙-1-酮肟C(Hal 3)CH(Ar)–C(Ar)═NOH(CHal 3-肟)的产率为23–99 %。这种在芳基环上具有一个邻取代基的CHal 3-肟在室温下以非对映异构体的形式存在于溶液中。通过NMR和DFT计算研究了该反应的几种阳离子中间体,证明了在TfOH中形成CHal 3-肟的详细反应机理。查尔3在微波或热活化条件下,在DMF中将DBU中的D-肟(对于Hal = Cl,Br)进行环化成5卤代3,4-二芳基异恶唑,收率为37–59%。在贝克曼重排条件下,在室温下于24小时内将PCl 5在苯中的CHal 3-肟首先转化为亚氨基酰氯(收率94–96%),然后转化为相应的苯甲酰胺PhCONHCHPh(CHal