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Iterative arylation of itaconimides with diazonium salts through electrophilic palladium catalysis

  • N-Arylitaconimides, accessible from maleic anhydride, anilines, and paraformaldehyde, react with arene diazonium salts in Pd-catalyzed Matsuda-Heck arylation to the pharmacologically relevant E-configured 3-arylmethylidene pyrrolidine-2,5-diones (also known as arylmethylidene succinimides) through exo-selective beta-H-elimination. The coupling proceeds at ambient temperature with the simple and easy-to-handle precatalyst Pd-II-acetate under ligandand base-free conditions. Notable features are high isolated yields, regio- and stereoselectivities, and short reaction times. In a comparative investigation, aryl iodides, bromides, and triflates were shown to be inferior coupling reagents in this reaction. The 3-arylmethylidene pyrrolidine-2,5-diones undergo second Matsuda-Heck coupling, which proceeds via endo-selective beta-H-elimination to give diarylmethyl-substituted maleimides as coupling products. These products can also be accessed in one flask by sequential addition of different arene diazonium salts to the starting itaconimide.N-Arylitaconimides, accessible from maleic anhydride, anilines, and paraformaldehyde, react with arene diazonium salts in Pd-catalyzed Matsuda-Heck arylation to the pharmacologically relevant E-configured 3-arylmethylidene pyrrolidine-2,5-diones (also known as arylmethylidene succinimides) through exo-selective beta-H-elimination. The coupling proceeds at ambient temperature with the simple and easy-to-handle precatalyst Pd-II-acetate under ligandand base-free conditions. Notable features are high isolated yields, regio- and stereoselectivities, and short reaction times. In a comparative investigation, aryl iodides, bromides, and triflates were shown to be inferior coupling reagents in this reaction. The 3-arylmethylidene pyrrolidine-2,5-diones undergo second Matsuda-Heck coupling, which proceeds via endo-selective beta-H-elimination to give diarylmethyl-substituted maleimides as coupling products. These products can also be accessed in one flask by sequential addition of different arene diazonium salts to the starting itaconimide. The potential of 3-arylmethylidene succinimides as photoswitches was tested. Upon irradiation of the E-isomer at 300 nm, partial isomerization to the Z-isomer (E/Z = 65:35 in the photostationary state) was observed. The isomerization was found to be nearly completely reversible by irradiating the mixture at 400 nm.zeige mehrzeige weniger

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Metadaten
Verfasserangaben:Nastja RiemerGND, Michael ShipmanORCiD, Pablo WessigORCiDGND, Bernd SchmidtORCiDGND
DOI:https://doi.org/10.1021/acs.joc.9b00627
ISSN:0022-3263
Pubmed ID:https://pubmed.ncbi.nlm.nih.gov/30990318
Titel des übergeordneten Werks (Englisch):The journal of organic chemistry
Untertitel (Englisch):divergent beta-H-Elimination pathways in repetitive Matsuda-Heck reactions
Verlag:American Chemical Society
Verlagsort:Washington
Publikationstyp:Wissenschaftlicher Artikel
Sprache:Englisch
Datum der Erstveröffentlichung:16.04.2019
Erscheinungsjahr:2019
Datum der Freischaltung:11.02.2021
Band:84
Ausgabe:9
Seitenanzahl:15
Erste Seite:5732
Letzte Seite:5746
Organisationseinheiten:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie
DDC-Klassifikation:5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften
Peer Review:Referiert
Publikationsweg:Open Access / Green Open-Access
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