TY  - JOUR
AU  - Rašović, Aleksandar
AU  - Blagojević, Vladimir A.
AU  - Baranac Stojanović, Marija
AU  - Kleinpeter, Erich
AU  - Marković, Rade
AU  - Minić, Dragica M.
PY  - 2016
UR  - https://dais.sanu.ac.rs/123456789/2324
AB  - Information about the strength of donor–acceptor interactions in push–pull alkenes is valuable, as this so-called “push–pull effect” influences their chemical reactivity and dynamic behaviour. In this paper, we discuss the applicability of NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C double bond to quantify the push–pull effect in biologically important 2-alkylidene-4-oxothiazolidines. While olefinic proton chemical shifts and differences in 13C NMR chemical shifts of the two carbons constituting the C[double bond, length as m-dash]C double bond fail to give the correct trend in the electron withdrawing ability of the substituents attached to the exocyclic carbon of the double bond, barriers to rotation prove to be a reliable quantity in providing information about the extent of donor–acceptor interactions in the push–pull systems studied. In particular all relevant kinetic data, that is the Arrhenius parameters (apparent activation energy Ea and frequency factor A) and activation parameters (ΔS‡, ΔH‡ and ΔG‡), were determined from the data of the experimentally studied configurational isomerization of (E)-9a. These results were compared to previously published related data for other two compounds, (Z)-1b and (2E,5Z)-7, showing that experimentally determined ΔG‡ values are a good indicator of the strength of push–pull character. Theoretical calculations of the rotational barriers of eight selected derivatives excellently correlate with the calculated C[double bond, length as m-dash]C bond lengths and corroborate the applicability of ΔG‡ for estimation of the strength of the push–pull effect in these and related systems.
PB  - Royal Society of Chemistry
T2  - New Journal of Chemistry
T1  - Quantification of the push–pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C bond
SP  - 6364
EP  - 6373
VL  - 40
DO  - 10.1039/c6nj00901h
UR  - https://hdl.handle.net/21.15107/rcub_dais_2324
ER  - 

@article{
author = "Rašović, Aleksandar and Blagojević, Vladimir A. and Baranac Stojanović, Marija and Kleinpeter, Erich and Marković, Rade and Minić, Dragica M.",
year = "2016",
abstract = "Information about the strength of donor–acceptor interactions in push–pull alkenes is valuable, as this so-called “push–pull effect” influences their chemical reactivity and dynamic behaviour. In this paper, we discuss the applicability of NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C double bond to quantify the push–pull effect in biologically important 2-alkylidene-4-oxothiazolidines. While olefinic proton chemical shifts and differences in 13C NMR chemical shifts of the two carbons constituting the C[double bond, length as m-dash]C double bond fail to give the correct trend in the electron withdrawing ability of the substituents attached to the exocyclic carbon of the double bond, barriers to rotation prove to be a reliable quantity in providing information about the extent of donor–acceptor interactions in the push–pull systems studied. In particular all relevant kinetic data, that is the Arrhenius parameters (apparent activation energy Ea and frequency factor A) and activation parameters (ΔS‡, ΔH‡ and ΔG‡), were determined from the data of the experimentally studied configurational isomerization of (E)-9a. These results were compared to previously published related data for other two compounds, (Z)-1b and (2E,5Z)-7, showing that experimentally determined ΔG‡ values are a good indicator of the strength of push–pull character. Theoretical calculations of the rotational barriers of eight selected derivatives excellently correlate with the calculated C[double bond, length as m-dash]C bond lengths and corroborate the applicability of ΔG‡ for estimation of the strength of the push–pull effect in these and related systems.",
publisher = "Royal Society of Chemistry",
journal = "New Journal of Chemistry",
title = "Quantification of the push–pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C bond",
pages = "6364-6373",
volume = "40",
doi = "10.1039/c6nj00901h",
url = "https://hdl.handle.net/21.15107/rcub_dais_2324"
}

Rašović, A., Blagojević, V. A., Baranac Stojanović, M., Kleinpeter, E., Marković, R.,& Minić, D. M.. (2016). Quantification of the push–pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C bond. in New Journal of Chemistry
Royal Society of Chemistry., 40, 6364-6373.
https://doi.org/10.1039/c6nj00901h
https://hdl.handle.net/21.15107/rcub_dais_2324

Rašović A, Blagojević VA, Baranac Stojanović M, Kleinpeter E, Marković R, Minić DM. Quantification of the push–pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C bond. in New Journal of Chemistry. 2016;40:6364-6373.
doi:10.1039/c6nj00901h
https://hdl.handle.net/21.15107/rcub_dais_2324 .

Rašović, Aleksandar, Blagojević, Vladimir A., Baranac Stojanović, Marija, Kleinpeter, Erich, Marković, Rade, Minić, Dragica M., "Quantification of the push–pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C[double bond, length as m-dash]C bond" in New Journal of Chemistry, 40 (2016):6364-6373,
https://doi.org/10.1039/c6nj00901h .,
https://hdl.handle.net/21.15107/rcub_dais_2324 .