Bromomethyl (E)-2-phenylethenyl and bromomethyl (Z)-1-bromo-2-phenylethenyl sulfones undergo condensation with enolates generated from malononitrile, dimethyl malonate, methyl and ethyl acetoacetate using NaH in THF to give tetrahydrothiophene S,S-dioxides. Methyl (E)-1-bromo-2-phenylethenyl and methyl (E)-2-bromo-2-phenylethenyl sulfones react with sodium malononitrile to give 2-[2-(methylsulfonyl)-1-phenylethylidene]malononitrile. The bromomethyl-(E)-2-bromo-2-phenyl ethenyl sulfone reacts with sodium malononitrile to give 2-[2-(bromomethylsulfonyl)-1-phenylethylidene]malononitrile exclusively.
Aerobic copper-catalyzed synthesis of (E)-alkenyl sulfones and (E)-β-halo-alkenyl sulfones via addition of sodium sulfinates to alkynes
作者:Nobukazu Taniguchi
DOI:10.1016/j.tet.2014.01.071
日期:2014.3
(E)-alkenyl sulfones. When a CuCl catalyst was employed, the hydrosulfonylation proceeded syn-selectively, and (E)-alkenyl sulfones were synthesized in excellent yields. In contrast, the reaction using CuI catalyst produced (E)-β-haloalkenyl sulfones anti-selectively in the presence of potassium halides. Furthermore, the (E)-β-bromoalkenyl sulfones are possible to convert into various alkenyl sulfones by Suzuki–Miyaura
Stereoselective Synthesis of (E)-Alkenyl Sulfones from Alkenes or Alkynes via Copper-Catalyzed Oxidation of Sodium Sulfinates
作者:Nobukazu Taniguchi
DOI:10.1055/s-0030-1260544
日期:2011.6
Alkenyl sulfones can be stereoselectively synthesized from alkenes or alkynes using sodium sulfinates. The reaction can be performed by a copper-catalyzedoxidation of sodium sulfinates in air. The reaction of alkenes gives (E)-alkenyl sulfones via anti addition of sulfonyl cation and elimination process. Furthermore, the employment of alkynes produces (E)-β-haloalkenyl sulfones in the presence of