Nitrile∁ketenimine tautomerism in substituted alkylidene malononitriles and alkylidene cyanoacetates

Determination of Heats of Tautomerization of Nitrile—Ketenimine by Mass Spectrometry

“…From the analysis of the UV spectra in ethanol and in ethanol/sodium hydroxide solution, the observed hyperchromic effect on the band around 355 nm (detectable only in polar hydroxylic solvents) was assigned to the ocurrence of a ketenimine structure. 3 Contrarily, the long wavelength UV absorption was kept at 230°c for most determinations. temperature effects at the ion source were assayed at 185°c.…”

“…A few studies where enolization of nitriles is proposed to take place have been found in the recent literature. [1][2][3] Most of nitriles appear to favour strongly the cyano form in this equilibrium. Kasturi et al have carried out the study of the UV absorption spectra of a number of 1,2-dicyano esters and 1,1,2tricyano compounds demonstrating the presence of nitrile-ketenimine tautomerism.…”

Determination of thermodynamic parameters of tautomerization in gas phase by mass spectrometry and DFT calculations: Keto-enol versus nitrile–ketenimine equilibria

“…While keto-enol tautomeric equilibria of carbonylic compounds have been studied extensively [1,2], there are few reports on the occurrence of nitrile-ketenimine tautomerism [3][4][5].…”

A Versatile Hexadiene Synthesis by Decarboxylative sp3–sp3 Coupling/Cope Rearrangement

“…As nitrile groups are expected to stabilize the incipient charge during decarboxylation and can be further manipulated by reduction or hydrolysis, alkylidene malononitriles 4 were chosen as promising substrates. Moreover, the starting materials are easily prepared by a simple Knoevenagel condensation of malononitrile [12] with readily available allylic b-keto esters. [13] To test the feasibility of the proposed reaction, 4 a was allowed to react with 5 mol % [Pd(PPh 3 ) 4 ] in CH 2 Cl 2 (Scheme 4).…”