191031-91-1Relevant articles and documents
Palladium-catalyzed heteroaryl thioethers synthesis overcoming palladium dithiolate resting states inertness: Practical road to sulfones and NH-sulfoximines
Guilbaud, Johan,Labonde, Marine,Selmi, Awatef,Kammoun, Majed,Cattey, Hélène,Pirio, Nadine,Roger, Julien,Hierso, Jean-Cyrille
, p. 52 - 58 (2018/04/11)
We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium–1,1′-bis[(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance. In the palladium-catalyzed C–S coupling of heteroaromatic thiols, reactivity limitation is attached with electron-deficient thiols. We show that this limitation can be resolved by the successful use of 2-bromoheteroarenes in the C–S coupling. We established herein that this choice of heteroaryl electrophilic reagent in palladium-catalyzed C–S bond formation allows overcoming palladium dithiolate out-of-cycle resting state inertness. This was illustrated in the stoichiometric reactivity study of the palladium dithiolate formed from 4-trifluoromethylbenzen-1-thiol –isolated and characterized by multinuclear NMR and XRD– with both 2-chloropyridine and 2-bromopyridine.
