Harnessing Noncovalent π‑Type Interactions in Thiourea-Chloride Supramolecular Complexes: Toward the Asymmetric Dearomatization of Diazaheterocycles
Enantioselective dearomatization of diazaheterocycles through anion-binding catalysis has been developed. The process involves the nucleophilic addition of phosphorus nucleophiles to in situ generated N-benzoyliminium chlorides, using a tert-leucine-derived thiourea as an H-bond donor catalyst, ther...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/404438 |
| Acceso en línea: | http://hdl.handle.net/10261/404438 https://api.elsevier.com/content/abstract/scopus_id/105014166298 |
| Access Level: | acceso abierto |
| Palabra clave: | Anion-binding catalysis Cyclic hydrazino phosphonates Dearomatization Diazaheterocycle Mechanism Noncovalent interactions Supramolecular complex Thiourea |
| Sumario: | Enantioselective dearomatization of diazaheterocycles through anion-binding catalysis has been developed. The process involves the nucleophilic addition of phosphorus nucleophiles to in situ generated N-benzoyliminium chlorides, using a tert-leucine-derived thiourea as an H-bond donor catalyst, thereby providing access to appealing cyclic hydrazino phosphonates and their derivatives. Mechanistic investigations suggest that the low solubility of these salts might favor the formation of a supramolecular thiourea-chloride-iminium 2:1:1 complex, which is proposed as the catalytically relevant species accounting for the observed nonlinear effect. Experimental and computational data support a 4H-activation model via this highly ordered ion pair, in which two thiourea molecules are arranged in an antiparallel orientation around the chloride, generating a C 2-symmetric groove. Hence, stereodefined insertion of the N-benzoyliminium is ensured by key noncovalent π-type interactions, thereby maximizing the enantioinduction event. |
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