14142-15-5Relevant academic research and scientific papers
Synthesis of Eight-Membered Nitrogen Heterocycles via a Heterogeneous PtI2-Catalyzed Cascade Cycloaddition Reaction of δ-Aminoalkynes with Electron-Deficient Alkynes
Li, Xinhong,Wang, Songmeng,Wang, Hongkai,Wang, Weilin,Liu, Lingyan,Chang, Weixing,Li, Jing
, p. 1525 - 1531 (2020/03/23)
A novel heterogeneous PtI2-catalyzed cascade reaction of δ-aminoalkynes was developed for the synthesis of various eight-membered nitrogen heterocycles in excellent yields. The reaction proceeds via a hydration of δ-aminoalkynes and subsequent intramolecular cyclization and intermolecular addition as well as ring-expansion cascade reaction with another electron-deficient alkynes. This method has the advantages of simple operation and mild reaction conditions. And the simple PtI2 with no any supports could be readily recycled through simple centrifugation without substantial loss of activity in 1,2-dichloroethane (DCE). The recyclability of PtI2 may be ascribed to its insolubility in DCE. The reaction constitutes a formal [6+2]-cycloaddition. (Figure presented.).
Ring Chain Isomerism of Substituted Tetrahydropyridines
Moehrle, Hans,Dwuletzki, Heinz
, p. 1323 - 1328 (2007/10/02)
The reactions of δ-bromoketones 1 with amines lead to cyclic enamines 6 or secondary δ-aminoketones 3 depending on the nature of the amine used.Amino substituents which increase the nucleophilicity forces the course of the reaction towards cyclisation to 6, which in turn yields the corresponding iminium salts 5.This pathway can be suppressed by large substituents leading to the formation of ammonium salts 4. δ-Anilinoketones 3 represent borderline cases because they cyclise only in acidic media. - Keywords: Ring Chain Isomerism, Tetrahydropyridines, δ-Aminoketones, Cyclic Iminium Salts
