AI Article Synopsis
- The study examines one- to three-bond 13C, 13C scalar couplings in pyrimidine derivatives using both experimental data and DFT calculations, focusing on four key contributions.
- It discusses the significance of non-contact terms and how substituent effects in pyrimidines compare to those in benzene and pyridine, with a dominance of the Fermi contact term in overall trends.
- Furthermore, while the inductive effect primarily influences 1J(C,C) couplings in benzene derivatives, this research highlights unique differences in pyrimidines, suggesting that nitrogen lone pair orientation can modify the impact of substituents on these couplings.
Article Abstract
One- two- and three 13C, 13C (n = 1, 2, 3) scalar couplings, (n)J(C,C) in a set of pyrimidine derivatives were studied both experimentally at natural abundance and theoretically by their DFT calculation of all four contributions. Trends of non-contact terms are discussed and substituent effects are rationalized, comparing some of them with the corresponding values in benzene and pyridine. Although substituent effects on non-contact terms are relatively important, the whole trend is dominated by the Fermi contact term. According to the current literature, substituent effects on 1J(C,C) couplings in benzene derivatives are dominated by the inductive effect, which, apparently, is also the case in nitrogen heteroaromatic compounds. However, some differences observed in this work for substituent effects on 1J(C,C) couplings in pyrimidine derivatives suggest that in the latter type of compounds substituent effects can be affected by the orientation of the ring nitrogen lone pairs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/mrc.1426 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!