1818-07-1Relevant articles and documents
Polyether-based triphase catalysts. A synthetic comparison
Fukunishi, Koji,Czech, Bronislaw,Regen, Steven L.
, p. 1218 - 1221 (1981)
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The Co-operative Effect in the Activation of the Phenoxide Anion with Oligo(oxyethylenes) containing Quaternary Ammonium Groups
Janout, Vaclav,Masar, Bohumil,Hrudkova, Hana,Cefelin, Pavel
, p. 213 - 214 (1989)
An unusual increase in activity accompanying the catalysis of a model substitution reaction between sodium phenoxide and 1-bromo-octane with oligo(oxyethylenes), linear or bound to the polymer, was observed after the introduction of quaternary ammonium gr
Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
, (2022/01/08)
Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.
Base-Free Palladium-Catalyzed Borylation of Aryl Chlorides with Diborons
Yamamoto, Yutaro,Matsubara, Hiroshi,Yorimitsu, Hideki,Osuka, Atsuhiro
, p. 2317 - 2320 (2016/07/28)
The base-free palladium-catalyzed borylation of aryl chlorides with diborons was achieved. The base-free conditions offered acceptable functional group compatibility. Based on experimental and computational studies, it was shown that smooth boryl transfer from the diborons to the arylpalladium chloride was promoted by strong interaction between the Lewis acidic boron and the chlorine atom on palladium.
