- Regioselective differentiation of vicinal methylene C-H bonds enabled by silver-catalysed nitrene transfer
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Silver-catalyzed nitrene insertion enables the formation of benzosultams in good yield and with regioselectivity complementary to other transition metal nitrene-transfer catalysts. Preferential formation of six-membered benzosultam rings predominates for alkyl-substituted benzenesulphonamide precursors. Ligand-controlled tunability is also achieved for benzenesulphonamides with γ-branched alkyl substituents. Mechanistic probes suggest that the reaction pathway differs depending on whether a α (benzylic) or β (homobenzylic) C-H bond undergoes amidation, as well as the catalyst identity.
- Scamp, Ryan J.,Scheffer, Bradley,Schomaker, Jennifer M.
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supporting information
p. 7362 - 7365
(2019/06/27)
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- Highly Chemoselective NH- and O-Transfer to Thiols Using Hypervalent Iodine Reagents: Synthesis of Sulfonimidates and Sulfonamides
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Aryl thiols can be selectively converted to sulfonimidates or sulfonamides with three new S-X connections being made selectively in one pot. Using hypervalent iodine reagents in the presence of ammonium carbamate, NH- and O-groups are transferred under mild and practical conditions. Reducing the loading of ammonium carbamate changed the product distribution, converting the sulfonimidate to the sulfonamide. Studies into the possible intermediate species are presented, suggesting that multiple pathways may be possible via sulfinate esters, or related intermediates, with each species forming the same products.
- Tota, Arianna,St John-Campbell, Sahra,Briggs, Edward L.,Estévez, Gala Ogalla,Afonso, Michelle,Degennaro, Leonardo,Luisi, Renzo,Bull, James A.
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supporting information
p. 2599 - 2602
(2018/05/22)
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