- Base-Activated Latent Heteroaromatic Sulfinates as Nucleophilic Coupling Partners in Palladium-Catalyzed Cross-Coupling Reactions
-
Heteroaromatic sulfinates are effective nucleophilic reagents in Pd0-catalyzed cross-coupling reactions with aryl halides. However, metal sulfinate salts can be challenging to purify, solubilize in reaction media, and are not tolerant to multi-step transformations. Here we introduce base-activated, latent sulfinate reagents: β-nitrile and β-ester sulfones. We show that under the cross-coupling conditions, these species generate the sulfinate salt in situ, which then undergo efficient palladium-catalyzed desulfinative cross-coupling with (hetero)aryl bromides to deliver a broad range of biaryls. These latent sulfinate reagents have proven to be stable through multi-step substrate elaboration, and amenable to scale-up.
- Cook, Xinlan A. F.,Pantaine, Lo?c R. E.,Blakemore, David C.,Moses, Ian B.,Sach, Neal W.,Shavnya, Andre,Willis, Michael C.
-
supporting information
p. 22461 - 22468
(2021/09/09)
-
- Synthetic Applications of N-N Linked Heterocycles. Part 12. The Preparation of 4-Alkylthio- and 4-Arylthio-pyridines by Regiospecific Attack of Thioalkoxide Ions on N-(4-Oxopyridin-1-yl)pyridinium Salts
-
Thiolate ions add regiospecifically to N-(4-oxopyridin-1-yl)pyridinium salts (2)-(7) to give in good to excellent yields only the 1,4-dihydropyridine adducts (8)-(13), regardless of whether or not the pyridone moiety carries substituents for sterically shielding the 2- and 6-positions of the pyridinium ring.The addition is believed to be thermodynamically controlled.Decomposition of the dihydro-adducts under free-radical conditions, or by pyrolysis, gives good yields of pyridin-4-yl thioethers (14) and (16) though the reaction failed with the 2-methyl adducts (9).An improved synthesis of 6-methyl-4-oxopyran-2-carboxylic acid is also described.
- Sammes, Michael P.,Leung, Christopher W. F.,Mak, Chi Keung,Katritzky, Alan R.
-
p. 1585 - 1590
(2007/10/02)
-