开发了在亚磷酸二乙酯存在下吡啶鎓盐和三甲基硅烷基氰化物 (TMSCN) 的铜催化反应。该反应首次实现了从容易获得的起始材料一步构建生物学上重要的2-氰基咪唑并[1,2- a ]吡啶的反应,并且在克级是可行的。该协议的范围通过 27 个示例进行了演示。在这一一锅法中可以实现连续的双氰化和环化。TMSCN 发挥双重作用,不仅作为“CN”源,而且作为咪唑并[1,2- a ]吡啶环化的偶联伙伴。
Reactions of N-benzyl-pyridinium or -isoquinolinium ylides with ethyl 3-fluoro-3-(fluoroalkyl)acrylates to give fluoroalkyl-substituted indolizine and pyrrolo[2,1-a]isoquinoline derivatives
作者:Weimin Peng、Shizheng Zhu
DOI:10.1039/b103586j
日期:2001.11.29
In the presence of base, N-benzylpyridinium and N-benzylisoquinolinium ylides generated in situ from the N-benzyl-pyridinium or -isoquinolinium bromides react with ethyl 3-fluoro-3-fluoroalkyl(except bromodifluoromethyl)acrylates to give one or two fluoroalkylated indolizine and pyrrolo[2,1-a]isoquinoline derivatives through 1,3-dipolar cycloaddition followed by an oxidative aromatization or 1,3-H-shift aromatization process. While ethyl 3-bromodifluoromethyl-3-fluoroacrylate reacts with 4-nitrobenzylpyridinium ylide, a trifluoromethylated indolizine derivative was obtained unexpectedly. It is more remarkable that the reaction of ethyl 3-bromodifluoromethyl-3-fluoroacrylate with N-benzylisoquinolinium ylide produces a fluorocarbonyl-substituted pyrrolo[2,1-a]isoquinoline
derivative, which is fully characterized by spectroscopic methods and X-ray diffraction analysis, in addition to the 1,3-H-shift aromatization product.
Transition-Metal-Free Synthesis of Indolizines from Electron-Deficient Alkenes via One-Pot Reaction Using TEMPO as an Oxidant
作者:Yu Zhang、Huayou Hu、Fei Shi、Zhaole Lu、Xiaolei Zhu、Weiqiu Kan、Xiang Wang
DOI:10.1055/s-0035-1560973
日期:——
Abstract A one-pot method for the synthesis of multisubstituted indolizines from α-halo carbonyl compounds, pyridines, and electron-deficient alkenes is reported. The oxidative dehydrogenation reaction takes place under transition-metal-free conditions using TEMPO as an oxidant. This protocol uses ready available starting materials in a convenientprocedure under mild reaction conditions. A one-pot method
Application of primary halogenated hydrocarbons for the synthesis of 3-aryl and 3-alkyl indolizines
作者:Yan Liu、Huayou Hu、Junyu Zhou、Wenhui Wang、Youliang He、Chao Wang
DOI:10.1039/c7ob00980a
日期:——
properties that make it suitable for numerous applications in many fields, such as biology, medicine and materials. However, the synthesis of 3-alkyl indolizines from bulky primary halogenated alkanes has not yet been reported. Herein, a transition-metal-free synthetic route to 3-aryl and 3-alkyl indolizines from electron-deficient alkenes, pyridines and primary halogenated hydrocarbons has been reported
3-Arylindolizines were prepared by one-pot domino reactions from benzyl halides with pyridine (or isoquinoline) and cyclic or acyclic dihalide-substituted electron-deficient alkenes in the presence of potassium carbonate via in situ generated N-ylide intermediate. Both electron-donating and electron-withdrawing groups are tolerated in the aryl ring of benzyl halides. The yields range from moderate to high.
One-pot synthesis of indolizine via 1,3-dipolar cycloaddition using a sub-equivalent amount of K<sub>2</sub>Cr<sub>2</sub>O<sub>7</sub> as an efficient oxidant under base free conditions
作者:Chao Wang、Huayou Hu、Juanfang Xu、Weiqiu Kan
DOI:10.1039/c5ra06019b
日期:——
X = Cl or Br; EWG1, EWG2 = electron withdrow group, one-pot reaction, 29 examples, yields from moderate to high, gram scale-up potential confirmed.
X = 氯或溴;EWG1,EWG2 = 电子吸引基团,一锅法反应,29个例子,产率从中等到高,克级放大潜力得到确认。