Recent developments in chemical reactivity of N,N-dimethylenamino ketones as synthons for various heterocycles

Abstract

This review demonstrates the high number of synthetic applications of enaminones in the preparation of acyclic, carbocyclic, heterocyclic and fused heterocyclic compounds.

2,3‐Dichloro‐5,6‐Dicyano‐1,4‐Benzoquinone (DDQ)‐Mediated Tandem Oxidative Coupling/Intramolecular Annulation/Dehydro‐Aromatization for the Synthesis of Polysubstituted and Fused Pyridines

“…[12] Recently, by utilizing pushpull enamines as the substrates, our group has developed some new methods for constructing diverse compounds via oxidative reaction in the presence of DDQ or I 2 /benzoyl peroxide. [12] Recently, by utilizing pushpull enamines as the substrates, our group has developed some new methods for constructing diverse compounds via oxidative reaction in the presence of DDQ or I 2 /benzoyl peroxide.…”

“…Push-pull enamine is a class of versatile synthetic building blocks and has been widely applied in the synthesis of N-heterocycles such as pyridines, pyrazoles, and chromones. [12] Recently, by utilizing pushpull enamines as the substrates, our group has developed some new methods for constructing diverse compounds via oxidative reaction in the presence of DDQ or I 2 /benzoyl peroxide. [13] In aim of further expanding the application of enamines for the synthesis of N-heterocycles and our longstanding research interest in the oxidative reaction of 1, 3diarylpropenes, [13a,c-d,14] herein we wish to report a tandem reaction of β-enaminoesters and 1,3-diarylpropenes mediated by DDQ via oxidative coupling/ intramolecular annulation/dehydro-aromatization, which gives the polysubstituted pyridines under metalfree condition.…”

“…With the optimal reaction conditions in hand, various β-enaminoesters were investigated by new developed method ( Table 2). β-Enaminoesters 1 b-1 s, which contained electron-donating or electron-withdrawing group on the benzene ring, could react with 1,3-diphenylpropene 2 a smoothly (entries [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The corresponding polysubstituted pyridines 3 b-3 s were obtained in 60-90% yields.…”

Iron‐Promoted Reductive Ring‐Opening and Isomerization Reactions of C4‐Alkynylisoxazoles Leading to 2‐Alkynylenaminones and Polysubstituted Furans

“…[16] Enaminones have recently been recognized as versatile and valuable intermediates because of the enamine ambident nucleophilic and enone electrophilic characters, which has been used by many researchers for accessing biologically important heterocycles. [17] Herein, we report a new iron(III)-promoted reductive ring-opening and isomerization reactions of C4-alkynylisoxazoles, which yields 2-alkynylenaminone and polysubstituted furan products.…”

Convenient Synthesis of Polyaza‐2‐(heteroaryl)pyridine Derivatives

“…Some 2-pyridine derivatives are considered as cardiotonic agents such as milrinone and as potential human immunodeficiency virus 1-specific transcriptase inhibitors [3,4]. Moreover, it has been reported that there are many review articles that deal with the synthesis of pyridine derivatives from enaminones [5][6][7][8][9].…”