Further Synthetic Applications of Functionalized 1,3-Dipoles

Abstract

Reactions of nitrile imines, azomethine imines, and ethyl diazoacetate (as representatives of functionalized 1,3-dipoles) with reactive olefins lead to a series of novel fused heterocycles after suitable ring closure. The influence of the nature of the heterocyclic leaving group and the substituents in the phenacyl residue in a group of phenacylimidazolium salts on the course of their reaction to produce 1,2-dihydrofurans and perhydropyrazolopyrroles is investigated.

Michael Adducts-Source for Biologically Potent Heterocycles

“…The starting compounds (E)-1,4-diarylbut-2-ene-1,4-dione (1) was prepared by the literature procedure. 23) General Procedure of Synthesis of Dimethyl 2-(1,2-diaroylethyl)malonate (2a-f) A mixture of dimethyl malonate (15 mmol), …”

Reactions of heterocyclic compounds with nitrilimines and their precursors

“…42 Photolysis of 6 leads to the corresponding nitrilimines 1.43-50 N-(a-Arylhydrazoacyl)pyridinium bromides 9 are usually prepared by the azo coupling of N-(acylmethyl)pyridinium bromides with diazotized anilines57 or iV-nitrosoacetanilides.58 Thermolysis of the pyridinium betaines, generated by the action of bases on 9, leads to the corresponding nitrilimines lf,g. 59 The thermal decomposition of 5-aryl-4-arylazoisoxazoles 10 leads to two competitive reactions. 33 The cleavage of the N-0 bond gives a triazole derivative via So far only one report has dealt with the behavior of three-membered heterocycles toward nitrilimines.…”