56692-06-9Relevant articles and documents
Catalytic Chemoselective Sulfimidation with an Electrophilic [CoIII(TAML)]?-Nitrene Radical Complex**
van Leest, Nicolaas P.,van der Vlugt, Jarl Ivar,de Bruin, Bas
supporting information, p. 371 - 378 (2020/12/01)
The cobalt species PPh4[CoIII(TAMLred)] is a competent and stable catalyst for the sulfimidation of (aryl)(alkyl)-substituted sulfides with iminoiodinanes, reaching turnover numbers up to 900 and turnover frequencies of 640 min?1 under mild and aerobic conditions. The sulfimidation proceeds in a highly chemoselective manner, even in the presence of alkenes or weak C?H bonds, as supported by inter- and intramolecular competition experiments. Functionalization of the sulfide substituent with various electron-donating and electron-withdrawing arenes and several alkyl, benzyl and vinyl fragments is tolerated, with up to quantitative product yields. Sulfimidation of phenyl allyl sulfide led to [2,3]-sigmatropic rearrangement of the initially formed sulfimide species to afford the corresponding N-allyl-S-phenyl-thiohydroxylamines as attractive products. Mechanistic studies suggest that the actual nitrene transfer to the sulfide proceeds via (previously characterized) electrophilic nitrene radical intermediates that afford the sulfimide products via electronically asynchronous transition states, in which SET from the sulfide to the nitrene radical complex precedes N?S bond formation in a single concerted process.
Palladium-catalyzed direct β-arylation of ketones with diaryliodonium salts: A stoichiometric heavy metal-free and user-friendly approach
Huang, Zhongxing,Sam, Quynh P.,Dong, Guangbin
, p. 5491 - 5498 (2015/09/28)
We herein report a new protocol for the Pd-catalyzed β-arylation of ketones without stoichiometric heavy metals. Widely accessible diaryliodonium salts are used as both the oxidant and aryl source. This tandem redox catalysis merges ketone dehydrogenation and conjugate addition without an additional oxidant or reductant. This transformation features the use of a unique bis-N-tosylsulfilimine ligand and the combination of potassium trifluoroacetate/trifluoroacetic acid to maintain an appropriate acidity of the reaction medium. The reaction tolerates both air and moisture, and shows a broad substrate scope. Kinetics studies, along with filtration and poisoning tests, support the involvement of palladium nanoparticles in the catalysis.
