Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9
Seven new 1,2,3,4,5-pentathiepino[6,7-<i>a</i>]indolizines were synthesized in which the pentathiepine moieties bear an indolizine backbone that is derivatized from C–H to F-, Cl-, Br-, I-, NO<sub>2</sub>-, and CH<sub>3</sub>-substitutions, respectively, in a meta...
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MDPI AG
2023-12-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/29/1/216 |
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| author | Roberto Tallarita Lukas Manuel Jacobsen Benedict J. Elvers Stefan Richter Siva S. M. Bandaru Jevy V. Correia Carola Schulzke |
| author_facet | Roberto Tallarita Lukas Manuel Jacobsen Benedict J. Elvers Stefan Richter Siva S. M. Bandaru Jevy V. Correia Carola Schulzke |
| author_sort | Roberto Tallarita |
| collection | DOAJ |
| description | Seven new 1,2,3,4,5-pentathiepino[6,7-<i>a</i>]indolizines were synthesized in which the pentathiepine moieties bear an indolizine backbone that is derivatized from C–H to F-, Cl-, Br-, I-, NO<sub>2</sub>-, and CH<sub>3</sub>-substitutions, respectively, in a meta position relative to the aza group on the pyridine moiety. Their preparation took place via two common steps: (i) a Sonogashira coupling between (4-substituted) 2-bromo- or 2-chloropyridines and propynyl 3,3-diethylacetal, and (ii) a ring closing reaction mediated by a molybdenum oxo-bistetrasulfido complex and elemental sulfur. The latter simultaneously facilitates the 1,2,3,4,5-pentathiepino chain/ring- and indolizine ring-formations. The fluoro derivative was addressed with 2-bromo-5-aminopyridine as the starting material via a Sandmeyer reaction. The iodo derivative was obtained from 5-bromo-2-alkynylpiridine using a metal-assisted variation of the Finkelstein reaction. The requirement to explore different reaction conditions and the varied respective yields of the final products are discussed. The influence of the distinct substitutions on the pyridine moieties, their electronic structures, and respective chemical properties was investigated through a set of spectroscopic/analytical characterizations. Intriguingly, in all cases, the nitro-substituted derivative exhibited a distinct behavior compared to the six other investigated derivatives, which was also addressed computationally. All seven new pentathiepines were crystallized, and their respective molecular structures were determined using single crystal X-ray diffraction. These structures are compared and discussed as are their respective packing patterns. |
| first_indexed | 2024-03-08T15:01:15Z |
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| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-08T15:01:15Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-50f93001b1af4e49bef89a435e5131742024-01-10T15:04:32ZengMDPI AGMolecules1420-30492023-12-0129121610.3390/molecules29010216Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9Roberto Tallarita0Lukas Manuel Jacobsen1Benedict J. Elvers2Stefan Richter3Siva S. M. Bandaru4Jevy V. Correia5Carola Schulzke6Bioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanyBioinorganic Chemistry, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489 Greifswald, GermanySeven new 1,2,3,4,5-pentathiepino[6,7-<i>a</i>]indolizines were synthesized in which the pentathiepine moieties bear an indolizine backbone that is derivatized from C–H to F-, Cl-, Br-, I-, NO<sub>2</sub>-, and CH<sub>3</sub>-substitutions, respectively, in a meta position relative to the aza group on the pyridine moiety. Their preparation took place via two common steps: (i) a Sonogashira coupling between (4-substituted) 2-bromo- or 2-chloropyridines and propynyl 3,3-diethylacetal, and (ii) a ring closing reaction mediated by a molybdenum oxo-bistetrasulfido complex and elemental sulfur. The latter simultaneously facilitates the 1,2,3,4,5-pentathiepino chain/ring- and indolizine ring-formations. The fluoro derivative was addressed with 2-bromo-5-aminopyridine as the starting material via a Sandmeyer reaction. The iodo derivative was obtained from 5-bromo-2-alkynylpiridine using a metal-assisted variation of the Finkelstein reaction. The requirement to explore different reaction conditions and the varied respective yields of the final products are discussed. The influence of the distinct substitutions on the pyridine moieties, their electronic structures, and respective chemical properties was investigated through a set of spectroscopic/analytical characterizations. Intriguingly, in all cases, the nitro-substituted derivative exhibited a distinct behavior compared to the six other investigated derivatives, which was also addressed computationally. All seven new pentathiepines were crystallized, and their respective molecular structures were determined using single crystal X-ray diffraction. These structures are compared and discussed as are their respective packing patterns.https://www.mdpi.com/1420-3049/29/1/216pentathiepinesmolybdenumpolysulfides<i>N</i>-heterocycles<i>S</i>-heterocyclesindolizine |
| spellingShingle | Roberto Tallarita Lukas Manuel Jacobsen Benedict J. Elvers Stefan Richter Siva S. M. Bandaru Jevy V. Correia Carola Schulzke Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 Molecules pentathiepines molybdenum polysulfides <i>N</i>-heterocycles <i>S</i>-heterocycles indolizine |
| title | Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 |
| title_full | Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 |
| title_fullStr | Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 |
| title_full_unstemmed | Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 |
| title_short | Synthesis of Seven Indolizine-Derived Pentathiepines: Strong Electronic Structure Response to Nitro Substitution in Position C-9 |
| title_sort | synthesis of seven indolizine derived pentathiepines strong electronic structure response to nitro substitution in position c 9 |
| topic | pentathiepines molybdenum polysulfides <i>N</i>-heterocycles <i>S</i>-heterocycles indolizine |
| url | https://www.mdpi.com/1420-3049/29/1/216 |
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