在各种反应条件下,由3-苯甲基苯并咪唑鎓溴化物生成的苯并咪唑鎓烷基化物的1,3-偶极环加成反应与非对称活化偶极亲和剂导致吡咯并[1,2- a ]苯并咪唑和吡咯并[1,2- a的复杂混合物]喹喔啉衍生物。为了解释所有实验结果,研究了反应条件对反应产物的影响。首次出现4-羟基-4,5-二氢吡咯并[1,2 - a ]喹喔啉衍生物6,吡咯并[1,2- a ]喹喔啉季盐8以及4-甲氧基-4,5-二氢吡咯并酮[1,2- a ]喹喔啉9被分离出来,被充分表征,并提出它们的相互转化,以及提出的反应机理。
Molecular Diversity of the Three-Component Reactions of N-Benzylbenzimidazolium Salts, Aromatic Aldehydes, and Active Methylene Compounds
作者:Li Hui、Yu-Xiu Jin、Jin-Xiu Wang、Chao-Guo Yan
DOI:10.1002/ejoc.201101199
日期:2011.12
The three-componentreactions of in-situ-formed N-benzylbenzimidazoliumsalts, aromaticaldehydes, and activemethylenecompounds in the presence of triethylamine showed very interesting moleculardiversity. The reactions with Meldrum's acid or barbiturate in acetonitrile gave a series of the novel zwitterionic salts in high yields. Under similar reaction conditions, the reactions with malononitrile
Oxidant promoted 1,3-dipolar cycloaddition of benzimidazolium ylides to alkenes for preparation of 4<i>H</i>-pyrrolo[1,2-<i>a</i>]benzimidazole
作者:Bingxiang Wang、Jiaxin Hu、Xuechun Zhang、Yuefei Hu、Hongwen Hu
DOI:10.1002/jhet.5570370620
日期:2000.11
An oxidantpromoted1,3-dipolarcycloaddition of benzimidazoliumylides to alkenes was developed for the preparation of 4H-pyrrolo[1,2-a]benzimidazole derivatives in moderate yields under mild conditions. In the presence of a suitable oxidant, the most commercially available “normal” alkenes, instead of alkynes or “abnormal” alkenes, could be used as dipolarophiles successfully. Moreover, CrO3/Et3N
开发了一种氧化剂促进苯并咪唑鎓烷基化物与烯烃的1,3-偶极环加成反应,用于在温和条件下以中等收率制备4 H-吡咯并[1,2- a ]苯并咪唑衍生物。在合适的氧化剂存在下,最商业上可买到的“正构”烯烃,而不是炔烃或“反常”烯烃,可以成功地用作双极性亲和剂。此外,在该程序中,已证明CrO 3 / Et 3 N是比MnO 2或重铬酸四基吡啶钴(II)更为有效的脱氢剂。
A new approach to pyrrolo[1,2-a]quinoxaline derivatives
作者:Xue-chun Zhang、Wei-yuan Huang
DOI:10.1016/s0040-4039(97)01021-6
日期:1997.7
2-dihydropoly(per)fluoroalkanoate(2) reacted with N-phenacyl benzimidazole bromide(1a–1b),N-acetonyl benzimidazole bromide(1c) and N-ethoxycarbonylmethyl benzimidazole bromide(1d) in DMF to give pyrrolo[1,2-a]quinoxaline derivatives(3ae-3dg) respectively.
Synthesis of Fluorinated Indolizines and 4<i>H</i>-Pyrrolo[1,2-<i>a</i>]benzimidazoles via 1,3-Dipolar Cycloaddition of Fluoroalkenes to<i>N</i>-Ylides
作者:Qing-Yun Chen、Kai Wu
DOI:10.1055/s-2003-36246
日期:——
In the presence of K2CO3 and Et3N, pyridinium, quinolinium, isoquinolinium and benzimidazolinium N-ylides, generated in situ from their halides, react with gaseous flouroalkenes [CF2=CFX (1), X = Cl (a), Br (b), CF3 (d)] in DMF under atmospheric pressure in normal glassware at 70 °C to give the corresponding fluorinated indolizines or H-pyrrolo[1,2-a]benzimidazoles via 1,3-dipolar [3+2] cycloaddition. Similar results are obtained with tetrafluoroethene in an autoclave.
Construction of dispirocyclohexyl-3,3′-bisoxindole and dispirocyclopentyl-3,3′-bisoxindole via domino cycloaddition reactions of N-benzylbenzimidazolium salts with 2-(2-oxoindolin-3-ylidene)acetates
作者:Guo-Liang Shen、Jing Sun、Chao-Guo Yan
DOI:10.1039/c4ra13760d
日期:——
Two kinds of spirocyclic oxindoles were selectively synthesized from cycloaddition of N-benzyl-N-phenacylbenzimidazolium salts with two molecules of 2-(2-oxoindolin-3-ylidene)acetates.