dc.contributor.advisor | Palomo Nicolau, Claudio | |
dc.contributor.advisor | Landa Alvarez, Aitor | |
dc.contributor.author | Izquierdo Arruferia, Joseba | |
dc.date.accessioned | 2018-09-25T06:31:37Z | |
dc.date.available | 2018-09-25T06:31:37Z | |
dc.date.issued | 2018-06-14 | |
dc.date.submitted | 2018-06-14 | |
dc.identifier.uri | http://hdl.handle.net/10810/28824 | |
dc.description | 562 p. | es_ES |
dc.description.abstract | The aim of this thesis has been the development of new pronucleophiles for organocatalytic reactions,leading to 2-tert-alkyl azaaryl adducts and 5,5-disubstituted hydatoins, products that are of interest inbiological and medicinal chemistry. To this end, we have developed for the first time 2-(cyanomethyl)azaarene N-oxides and 1H-imidazol-4(5H)-ones and 1H-imidazol-5(4H)-ones (Figure 1) aseasily enolizable pronucleophiles .Figure 1On one hand, 2-(cyanomethyl)azaarene N-oxides were tested in the addition to ¿-oxyenones (whose utilitywas first recognized by this group, JACS 2014, 136, 17869¿17881) using a new family ofmultifunctional squaramide-Brønsted base catalysts bearing a bulky silyl group. Reactions performedwith these catalysts gave the addition products (with quaternary stereocenters) with high yields andexcellent enantiolectivities (up to 93 % yield; up to 94% ee) (JACS 2016, 138, 3282¿3285).Scheme 2On the other hand, 1H-imidazol-4(5H)-ones and 1H-imidazol-5(4H)-ones were synthesized and evaluatedas new pronucleophiles in conjugated reactions. After acidic or basic hydrolysis, these compounds allowhighly efficient construction of 5,5-disubstituted hydantoins. Their addition to nitroolefins and vinylketones carried out with squaramide type bifunctional catalysts proceed in general with excellentstereoselectivities (up to >98:2 dr; up to >99% ee) (doi:10.1002/chem.201800506) (Scheme 3).Scheme 3In conclusion, three new pronucleophiles and two new bifunctional catalysts have been described forthe organocatalytic asymmetric formation of quaternary stereocentres. 2-Cyanomethylazaarene Noxideshave demonstrated their utility as efficient reagents for the asymmetric synthesis of ¿-quaternary o-substituted alkylazaarenes via soft enolization conditions. 1H-Imidazol-4(5H)-ones I and1H-Imidazol-5(4H)-ones II have proved to be excellent substrates for the organocatalytic Michaelreaction of enantiomerically enriched 5,5-disubstituted hydantoins. | es_ES |
dc.language.iso | eng | es_ES |
dc.rights | info:eu-repo/semantics/openAccess | es_ES |
dc.subject | heterocyclic compounds | es_ES |
dc.subject | organosilicon chemistry | es_ES |
dc.subject | stereochemistry and conformational analysis | es_ES |
dc.subject | compuestos heterocíclicos | es_ES |
dc.subject | química de organosilicicos | es_ES |
dc.subject | estereoquímica y análisis conformacional | es_ES |
dc.title | New approaches to optically active 2-tert-alkyl azaaryl compounds and 5,5-disubstituted hydantoins | es_ES |
dc.type | info:eu-repo/semantics/doctoralThesis | es_ES |
dc.rights.holder | (c)2018 JOSEBA IZQUIERDO ARRUFERIA | |
dc.identifier.studentID | 545810 | es_ES |
dc.identifier.projectID | 19552 | es_ES |
dc.departamentoes | Química orgánica I | es_ES |
dc.departamentoeu | Kimika organikoa I | es_ES |