Isoindoloisoquinalinone, pyrroloisoquinolinone and benzo[a]quinolizinone units are constructed via intramolecular cyclization of the methoxy substituted N-phenethylimides using BBr3.
Activation of imide carbonyl group with trifluoromethanesulfonic acid facilitates the intramolecular cyclization of phenethylphthalimides to give a fused isoindoloisoquinolinone skeleton. The first one pot regioselective synthesis of isoindoloisoquinolinone alkaloid (±)-nuevamine has been successfully executed using this methodology.
Syntheses of fused tetrahydro-β-carboline analogues through imide carbonyl activation using BBr3: Evidence for the involvement of fused cyclic N-acyliminium ion intermediate
The fused cyclic N-acyliminium ion generated during the imide carbonyl activation reaction of phenethylphthalimide was confirmed by single crystal X-ray diffraction. The Lewis acid assisted imide carbonyl activation methodology was successfully extended to synthesize fused tetrahydro-β-carboline units from the corresponding N-indolylethylimides.
单晶 X 射线衍射证实了在苯乙基邻苯二甲酰亚胺的亚胺羰基活化反应中生成的融合环 N-酰亚胺离子。路易斯酸辅助亚胺羰基活化方法被成功地扩展到从相应的 N-吲哚乙亚胺合成融合的四氢-β-咔啉单元。