Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines
Authorized Users Only
2014
Authors
Rančić, Milica
Trišović, Nemanja

Milčić, Miloš

Jovanović, Maja

Jovanović, Bratislav Ž.
Marinković, Aleksandar

Article (Published version)

Metadata
Show full item recordAbstract
Two series of 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines have been synthesized using different methods of conventional and microwave-assisted synthesis, and linear free-energy relationships have been applied to the C-13 NMR chemical shifts of the carbon atoms of interest. The substituent-induced chemical shifts have been analyzed using single substituent parameter and dual substituent parameter methods. The presented correlations describe satisfactorily the field and resonance substituent effects having similar contributions for C1 and the azomethine carbon, with exception of the carbon atom in para position to the substituent X. In both series, negative values have been found for C1 atom (reverse substituent effect). Quantum chemical calculations of the optimized geometries at MP2/6-31G++(d,p) level, together with C-13 NMR chemical shifts, give a better insight into the influence of the molecular conformation on the transmission of electronic substituent effects. Th...e comparison of correlation results for different series of imines with phenyl, 4-nitrophenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl group attached at the azomethine carbon with the results for 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines for the same substituent set (X) indicates that a combination of the influences of electronic effects of the substituent X and the (1)-unit can be described as a sensitive balance of different resonance structures.
Source:
Journal of Heterocyclic Chemistry, 2014, 51, 5, 1442-1451Publisher:
- Wiley-Blackwell, Hoboken
Funding / projects:
- Study of the Synthesis, Structure and Activity of Natural and Synthetic Organic Compounds (RS-172013)
DOI: 10.1002/jhet.1752
ISSN: 0022-152X
WoS: 000342746900035
Scopus: 2-s2.0-85028227018
Institution/Community
Tehnološko-metalurški fakultetTY - JOUR AU - Rančić, Milica AU - Trišović, Nemanja AU - Milčić, Miloš AU - Jovanović, Maja AU - Jovanović, Bratislav Ž. AU - Marinković, Aleksandar PY - 2014 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2732 AB - Two series of 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines have been synthesized using different methods of conventional and microwave-assisted synthesis, and linear free-energy relationships have been applied to the C-13 NMR chemical shifts of the carbon atoms of interest. The substituent-induced chemical shifts have been analyzed using single substituent parameter and dual substituent parameter methods. The presented correlations describe satisfactorily the field and resonance substituent effects having similar contributions for C1 and the azomethine carbon, with exception of the carbon atom in para position to the substituent X. In both series, negative values have been found for C1 atom (reverse substituent effect). Quantum chemical calculations of the optimized geometries at MP2/6-31G++(d,p) level, together with C-13 NMR chemical shifts, give a better insight into the influence of the molecular conformation on the transmission of electronic substituent effects. The comparison of correlation results for different series of imines with phenyl, 4-nitrophenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl group attached at the azomethine carbon with the results for 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines for the same substituent set (X) indicates that a combination of the influences of electronic effects of the substituent X and the (1)-unit can be described as a sensitive balance of different resonance structures. PB - Wiley-Blackwell, Hoboken T2 - Journal of Heterocyclic Chemistry T1 - Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines EP - 1451 IS - 5 SP - 1442 VL - 51 DO - 10.1002/jhet.1752 ER -
@article{ author = "Rančić, Milica and Trišović, Nemanja and Milčić, Miloš and Jovanović, Maja and Jovanović, Bratislav Ž. and Marinković, Aleksandar", year = "2014", abstract = "Two series of 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines have been synthesized using different methods of conventional and microwave-assisted synthesis, and linear free-energy relationships have been applied to the C-13 NMR chemical shifts of the carbon atoms of interest. The substituent-induced chemical shifts have been analyzed using single substituent parameter and dual substituent parameter methods. The presented correlations describe satisfactorily the field and resonance substituent effects having similar contributions for C1 and the azomethine carbon, with exception of the carbon atom in para position to the substituent X. In both series, negative values have been found for C1 atom (reverse substituent effect). Quantum chemical calculations of the optimized geometries at MP2/6-31G++(d,p) level, together with C-13 NMR chemical shifts, give a better insight into the influence of the molecular conformation on the transmission of electronic substituent effects. The comparison of correlation results for different series of imines with phenyl, 4-nitrophenyl, 2-pyridyl, 3-pyridyl, 4-pyridyl group attached at the azomethine carbon with the results for 4-substituted N-[1-(pyridine-3- and -4-yl)ethylidene]anilines for the same substituent set (X) indicates that a combination of the influences of electronic effects of the substituent X and the (1)-unit can be described as a sensitive balance of different resonance structures.", publisher = "Wiley-Blackwell, Hoboken", journal = "Journal of Heterocyclic Chemistry", title = "Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines", pages = "1451-1442", number = "5", volume = "51", doi = "10.1002/jhet.1752" }
Rančić, M., Trišović, N., Milčić, M., Jovanović, M., Jovanović, B. Ž.,& Marinković, A.. (2014). Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines. in Journal of Heterocyclic Chemistry Wiley-Blackwell, Hoboken., 51(5), 1442-1451. https://doi.org/10.1002/jhet.1752
Rančić M, Trišović N, Milčić M, Jovanović M, Jovanović BŽ, Marinković A. Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines. in Journal of Heterocyclic Chemistry. 2014;51(5):1442-1451. doi:10.1002/jhet.1752 .
Rančić, Milica, Trišović, Nemanja, Milčić, Miloš, Jovanović, Maja, Jovanović, Bratislav Ž., Marinković, Aleksandar, "Linear Free-Energy Relationships Applied to the C-13 NMR Chemical Shifts in 4-Substituted N-[1-(Pyridine-3-and-4-yl)ethylidene]anilines" in Journal of Heterocyclic Chemistry, 51, no. 5 (2014):1442-1451, https://doi.org/10.1002/jhet.1752 . .