Novel stilbene‐based Fischer base analog of leuco‐TAM – (2E,2′Z)‐{2‐(4‐(E)‐styrylphenyl)propane‐1,3‐diylidene}bis(1,3,3‐trimethylindoline) – derivatives: synthesis and structural consideration by 1D NMR and 2D NMR spectroscopy

Abstract

We report the synthesis of a series of novel stilbene-based (St) Fischer base analogs of leuco-triarylmethane (LTAM) dyes by treating Fischer base with (E)-4-styrylbenzaldehyde derivatives. All St-LTAM molecules examined herein are characterized by 1D and 2D NMR. They were found to exhibit ZE configuration and isomerize to their diastereomers EE and ZZ in 2-3 h. They exhibit type I behavior of diastereomeric isomerization.

Study of E/Z isomerization of (arylamino)methylidenefuran‐2(3H)‐ones by 1H, 13C, 15N spectroscopy and DFT calculations in different solvents

“…[27] The methods were also applied for the elucidation of structural details of relatively small organic compounds [28] as well as their complexes with metals, [29] and for the more complex compounds such as stilbene-based Fischer base analog of leuco-TAM. [30] Thus, the NMR technique allows one to determine and make an assignment of the signals from E-and Z-isomers.…”

“…Recently, different nuclear magnetic resonance (NMR) methods including, generally, 1 H and 13 C NMR spectroscopy as well as COSY, HMBC, and nuclear Overhauser spectroscopy (NOESY) experiments were successfully applied for the studying of the conformational and configurational peculiarities of some heterocyclic compounds and their derivatives from various series including benzoquinonimines, pyrroles, 1 H –imidazoles, morphinan‐6‐one, 2 H ‐pyran‐2‐ones, hydroquinolinones, and spirocyclopropyloxindoles . The methods were also applied for the elucidation of structural details of relatively small organic compounds as well as their complexes with metals, and for the more complex compounds such as stilbene‐based Fischer base analog of leuco‐TAM . Thus, the NMR technique allows one to determine and make an assignment of the signals from E‐ and Z‐ isomers.…”