25674-55-9Relevant academic research and scientific papers
Application of directed metalation in synthesis. Part 6: A novel anionic rearrangement under directed metalation conditions leading to heteroannulation
Pradhan, Tarun Kanti,Mukherjee, Chandrani,Kamila, Sukanta,De, Asish
, p. 5215 - 5224 (2007/10/03)
A short and efficient synthesis of condensed 1,4-oxathiin-2-ones from easily available phenols is described. The key step in this synthesis is a hitherto unreported anionic rearrangement under directed metalation conditions. The rearrangement occurs after
Synthetic routes to polyheteroacenes: Characterization of a heterocyclic ladder polymer containing phenoxathiinium-type building blocks
Oyaizu, Kenichi,Mikami, Takefumi,Mitsuhashi, Fumio,Tsuchida, Eishun
, p. 67 - 78 (2007/10/03)
The synthetic routes to ladder polymers that consist of benzenetetrayl subunits with oxo and methylsulfonio linkages are described. As the key intermediate, poly(phenylene oxide)s having pendant methylsulfenyl groups are prepared by copper-catalyzed oxidative polymerization of the corresponding phenols with O2. The oxidation of the polymer with an equimolar amount of H2O2 in the presence of acetic acid effects the high-yielding conversion of methylsulfenyl to methylsulfinyl groups without the formation of the undesired methylsulfonyl groups. The superacidified condensation of the resulting polymer (Swern reaction of aryl sulfoxides) under dilution conditions induces the polymer-analogous intramolecular electrophilic ring-closing reaction of the hydroxymethylphenylsulfonium cation onto the adjacent benzene ring to yield the required ladder polymer, which has proved to be a semiconductor with an intrinsic electric conductivity of 2 × 10-5 S/cm. A comparison of the spectroscopic properties of the ladder polymer with those of the model compounds such as 5-methylphenoxathiinium triflate and phenoxathiin discloses π-electron delocalization over the methylsulfonio linkages, demonstrating the efficacy of the ladderization for p-π/d-π interactions in arylsulfonium moieties. This synthetic approach permits the thio and alkylsulfonio ladder linkages for a variety of phenyl ethers to form in high yields.
