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.…
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 |