On the imidazole-2-thione-based route to tricyclic 1,4-diphosphinines: synthesis, structures and reactions
On the imidazole-2-thione-based route to tricyclic 1,4-diphosphinines: synthesis, structures and reactions
dc.contributor.advisor | Streubel, Rainer | |
dc.contributor.author | Koner, Abhishek | |
dc.date.accessioned | 2020-04-24T23:43:39Z | |
dc.date.available | 2020-04-24T23:43:39Z | |
dc.date.issued | 15.02.2018 | |
dc.identifier.uri | https://hdl.handle.net/20.500.11811/7505 | |
dc.description.abstract | The PhD Thesis “On the imidazole-2-thione-based route to tricyclic 1,4-diphosphinines: synthesis, structures and reactions” describes the synthetic concept to and first studies on the chemistry of novel tricyclic 1,4-dihydro-1,4-diphosphinines and 1,4-diphosphinines. In the first part, synthesis of the major starting material, the (Et2N)2P- and Et2N(Cl)P-substituted imidazole-2-thiones is described. The latter was converted into tricyclic 1,4-dihydro-1,4-diphosphinines via an LDA-induced double salt metathesis. Further studies on Et2N(Cl)P-substituted imidazole-2-thiones focused on backbone phosphaalkenyl substituted imidazole-2-thiones and/or imidazole-2-ylidenes. The chemistry of tricyclic 1,4-dihydro-1,4-diphosphinines were explored in various directions ranging from P-oxidation to P-functionalization and competing P/S-centered reactions with electrophiles; the latter was accompanied by theoretical studies (A. Frontera). Furthermore, reduction of 1,4-dichloro-1,4-dihydro-1,4-diphosphinines with a mild reducing agent enabled access to first examples of isolated stable, red 1,4-diphos-phinines which are very sensible towards moist air. The 1,4-diphosphinines were fully characterized including cyclic voltammetry (CV) and UV/vis measurements as well as theoretical bonding analysis (L. Nyulaszi). Among the remarkable results are a reversible 3e-reduction (CV) and that the LUMO is largely concentrated on the phosphorus centers. The latter explains why anionic nucleophiles add to the phosphorus centers in a 1,4-fashion to produce anionic phosphanido centers which can be quenched with electrophiles. Further investigations revealed that 1,4-diphosphinines are excellent dienophiles in [4+2] reactions including a wide variety of C-C and N-N p-systems, but also s-bonds as in diphenyl dichalcogenides (E = S, Se). The latter reactions led exclusively to trans products which was explained on the basis of DFT calculations as a sequence of 1,4-addition followed by P-inversion (L. Nyulaszi). | |
dc.language.iso | eng | |
dc.rights | In Copyright | |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | |
dc.subject | imidazole-2-thiones | |
dc.subject | 1,4-diphosphinine | |
dc.subject | Diels-Alder reaction | |
dc.subject | Backbone phosphanylation | |
dc.subject.ddc | 540 Chemie | |
dc.title | On the imidazole-2-thione-based route to tricyclic 1,4-diphosphinines: synthesis, structures and reactions | |
dc.type | Dissertation oder Habilitation | |
dc.publisher.name | Universitäts- und Landesbibliothek Bonn | |
dc.publisher.location | Bonn | |
dc.rights.accessRights | openAccess | |
dc.identifier.urn | https://nbn-resolving.org/urn:nbn:de:hbz:5n-49824 | |
ulbbn.pubtype | Erstveröffentlichung | |
ulbbnediss.affiliation.name | Rheinische Friedrich-Wilhelms-Universität Bonn | |
ulbbnediss.affiliation.location | Bonn | |
ulbbnediss.thesis.level | Dissertation | |
ulbbnediss.dissID | 4982 | |
ulbbnediss.date.accepted | 13.12.2017 | |
ulbbnediss.institute | Mathematisch-Naturwissenschaftliche Fakultät : Fachgruppe Chemie / Institut für Anorganische Chemie | |
ulbbnediss.fakultaet | Mathematisch-Naturwissenschaftliche Fakultät | |
dc.contributor.coReferee | Beck, Johannes |
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