Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State
The conformation of the title compounds was determined in solution by <sup>1</sup>H-NMR spectroscopy and in solid state by single-crystal X-ray diffraction (XRD) complemented with density functional theory. The compounds were found to exist exclusively in solution and solid state as <...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-05-01
|
| Series: | Crystals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4352/9/6/277 |
| _version_ | 1797999599089090560 |
|---|---|
| author | Malose J. Mphahlele Marole M. Maluleka Richard M. Mampa |
| author_facet | Malose J. Mphahlele Marole M. Maluleka Richard M. Mampa |
| author_sort | Malose J. Mphahlele |
| collection | DOAJ |
| description | The conformation of the title compounds was determined in solution by <sup>1</sup>H-NMR spectroscopy and in solid state by single-crystal X-ray diffraction (XRD) complemented with density functional theory. The compounds were found to exist exclusively in solution and solid state as <i>trans</i>-2-aminochalcone epoxides with strong intramolecular hydrogen bonding interaction between the amino and carbonyl groups. These 2-aminochalcone epoxides experienced a solvent effect in DMSO-<i>d</i><sub>6</sub>, which resulted in an anomalous chemical shift for the α-hydrogen signal, presumably due to complexation of solute molecules with DMSO. The solute−solvent interaction would probably fix the <i>trans</i> conformation of epoxyketone such that α-H is more accessible to both aryl rings, and in turn, experience their combined anisotropic effect. Intermolecular interactions in the crystal structures were confirmed and quantified using the Hirshfeld surface analysis. Moreover, the <i>trans</i> stereochemistry of the α-epoxyketones facilitated direct one-pot sequential sulfuric acid-mediated ring opening and aryl migration to afford the corresponding 3-arylquinolin-4(1<i>H</i>)-ones (azaisoflavones). |
| first_indexed | 2024-04-11T11:07:16Z |
| format | Article |
| id | doaj.art-40f0251b10df4d96ba99574ad9610202 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-11T11:07:16Z |
| publishDate | 2019-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-40f0251b10df4d96ba99574ad96102022022-12-22T04:28:16ZengMDPI AGCrystals2073-43522019-05-019627710.3390/cryst9060277cryst9060277Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid StateMalose J. Mphahlele0Marole M. Maluleka1Richard M. Mampa2Department of Chemistry, College of Science, Engineering and Technology, University of South Africa, Private Bag X06, Florida 1710, South AfricaDepartment of Chemistry, College of Science, Engineering and Technology, University of South Africa, Private Bag X06, Florida 1710, South AfricaDepartment of Chemistry, University of Limpopo, Private Bag X1106, Sovenga 0727, South AfricaThe conformation of the title compounds was determined in solution by <sup>1</sup>H-NMR spectroscopy and in solid state by single-crystal X-ray diffraction (XRD) complemented with density functional theory. The compounds were found to exist exclusively in solution and solid state as <i>trans</i>-2-aminochalcone epoxides with strong intramolecular hydrogen bonding interaction between the amino and carbonyl groups. These 2-aminochalcone epoxides experienced a solvent effect in DMSO-<i>d</i><sub>6</sub>, which resulted in an anomalous chemical shift for the α-hydrogen signal, presumably due to complexation of solute molecules with DMSO. The solute−solvent interaction would probably fix the <i>trans</i> conformation of epoxyketone such that α-H is more accessible to both aryl rings, and in turn, experience their combined anisotropic effect. Intermolecular interactions in the crystal structures were confirmed and quantified using the Hirshfeld surface analysis. Moreover, the <i>trans</i> stereochemistry of the α-epoxyketones facilitated direct one-pot sequential sulfuric acid-mediated ring opening and aryl migration to afford the corresponding 3-arylquinolin-4(1<i>H</i>)-ones (azaisoflavones).https://www.mdpi.com/2073-4352/9/6/277<i>trans-</i>2-amino-3,5-dibromochalcone epoxidesNMR spectroscopyXRDDFT3-arylquinolin-4(1<i>H</i>)-ones |
| spellingShingle | Malose J. Mphahlele Marole M. Maluleka Richard M. Mampa Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State Crystals <i>trans-</i>2-amino-3,5-dibromochalcone epoxides NMR spectroscopy XRD DFT 3-arylquinolin-4(1<i>H</i>)-ones |
| title | Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State |
| title_full | Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State |
| title_fullStr | Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State |
| title_full_unstemmed | Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State |
| title_short | Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State |
| title_sort | elucidation of the structure of the 2 amino 3 5 dibromochalcone epoxides in solution and solid state |
| topic | <i>trans-</i>2-amino-3,5-dibromochalcone epoxides NMR spectroscopy XRD DFT 3-arylquinolin-4(1<i>H</i>)-ones |
| url | https://www.mdpi.com/2073-4352/9/6/277 |
| work_keys_str_mv | AT malosejmphahlele elucidationofthestructureofthe2amino35dibromochalconeepoxidesinsolutionandsolidstate AT marolemmaluleka elucidationofthestructureofthe2amino35dibromochalconeepoxidesinsolutionandsolidstate AT richardmmampa elucidationofthestructureofthe2amino35dibromochalconeepoxidesinsolutionandsolidstate |