In the search for experimental and quantumchemical evidence for zwitterionic nature of (2 E )-3-[4-(dimethylamino)phenyl]-2-nitroprop-2-enenitrile – An extreme example of donor–π–acceptor push–pull molecule

Unexpected course of reaction between (E)-2-aryl-1-cyano-1-nitroethenes and diazafluorene: why is there no 1,3-dipolar cycloaddition?

“…At present, several compounds from this group are known [8–11]. However, their chemical properties are not well known.…”

Chemistry of 2-aryl-1-cyano-1-nitroethenes. Part I. Synthesis and physical properties

“…These issues are the subject of the next part of our study. ) 328(4.23) [12], [17], [18], [20], [23], [32], [34], [36] 2 ) [12], [17], [18], [25], [30], [32], [33] 4 [12], [17], [18], [20], [23], [31], [32], [36] 8 ) 371(4.33)EtOH [12], [20], [23], [27], [30], [32] 25…”

“…This process proceeds via a reaction involving thionyl chloride in a dry diethyl ether solution. Under these conditions, the final product may be synthesized with yields up to 47% [12,[14][15][16][17][18]. After purification using column chromatography (SiO 2 /benzene) NAN of a purity suitable for use in Knoevenagel condensation is obtained.…”

“…An analogous methodology was also applied later in the case of ACNs 2, 7, 10, 14, 15, 23 and 25 [21][22][23][24]. Later [18,[25][26][27]28], other aliphatic and alicyclic amines (n-propylamine, n-pentylamine, morpholine, ethylenediamine, β-alanine) were also tested as catalysts in similar syntheses. In these syntheses several new compounds were prepared.…”

Chemistry of 2-aryl-1-cyano-1-nitroethenes. Part II. Chemical transformations

“…ACNs have been known since the first half of the twentieth century [2]. Currently, several compounds of this group are known; nonetheless, their chemical properties are not well recognized [3][4][5][6]. The chemical transformations of these compounds include [2+3] cycloaddition to nitrogen-containing Three-Atoms-Components (TACs), which occupies an important place among the synthetic tools of organic chemistry [7].…”