71426-20-5Relevant articles and documents
Synthesis of: N -alkylated 2-pyridones through Pummerer type reactions of activated sulfoxides and 2-fluoropyridine derivatives
Hu, Gang,Xu, Jiaxi,Li, Pingfan
, p. 4151 - 4158 (2018/06/12)
N-Alkylated 2-pyridone products were obtained in good to excellent yields through a one-pot procedure involving either normal or interrupted Pummerer reactions between triflic anhydride activated sulfoxides and 2-fluoropyridine derivatives, followed by hydrolysis. This is a rare case that uses 2-fluoropyridine as a nucleophile in Pummerer type reactions.
Tetrabutylammonium tribromide impregnated MCM-48 as a heterogeneous catalyst for selective oxidation of sulfides
Gogoi, Prasanta,Hazarika, Sukanya,Barman, Pranjit
, p. 38044 - 38047 (2015/06/30)
We report here tetrabutylammonium tribromide supported on MCM-48 as a highly efficient heterogeneous catalyst for the selective oxidation of sulfides, in ethanolic medium using hydrogen peroxide as an oxidant. The aforementioned oxidation reactions were found to proceed rapidly (20 min) and in good yield (85-99%) (17 examples). The oxidation products were characterized by 1H NMR, 13C NMR and elemental analysis. The catalytic properties were analysed by TEM, XRD and BET-surface area measurement. No over-oxidation of the substrates was observed (analysed by GC), and the catalyst was effectively recycled for five consecutive cycles without any significant loss in its catalytic activity.
Competitive and selective Csp3-Br versus Csp2-Br bond activation in palladium-catalysed Suzuki cross-coupling: An experimental and theoretical study of the role of phosphine ligands
Mollar, Cristian,Besora, Maria,Maseras, Feliu,Asensio, Gregorio,Medio-Simon, Mercedes
supporting information; experimental part, p. 13390 - 13397 (2011/02/24)
Phosphine ligands have been demonstrated to have an effect on reactivity and selectivity in the competitive intramolecular palladium-catalysed Suzuki-Miyaura coupling of dibromo sulfoxide 1a possessing two different hybridised electrophilic carbons. It was found that the bromine bond to the sp3-hybridised carbon is selectively replaced in the presence of unhindered phosphines such as PPh3 or xantphos. The use of hindered phosphine ligands such as P(o-tol)3 and P(1-naphthyl)3 reversed the selectivity, conducting the cross-coupling at the Csp 2-Br. Identical trends were observed in external competition experiments carried out with bromomethyl sulfoxide and different substituted bromoarenes. DFT and DFT/MM calculations showed that the selectivity observed is mainly due to the different facility of the ligands to dissociate. Bisphosphine catalysts favour coupling at the sp3 carbon, whereas monophosphine catalysts prefer the sp2 carbon. Customised catalysts: Proper selection of the phosphine ligand in the palladium catalyst enables a highly intra- and intermolecular selective Suzuki-Miyaura coupling at either Csp 3-Br or Csp2-Br (see figure). DFT and DFT/MM calculations show that the selectivity observed is mainly due to the different facilities of the ligands for dissociation. Copyright
