Authors:Alastair Baker, Michael Graz, Robert Saunders, Gareth J. S. Evans, Ilaria Pitotti, and Thomas Wirth
Rapid alkylations of thiols are performed in a packed-bed flow reactor where potassium carbonate acts as a heterogeneous base in anhydrous solvents at ambient temperature. The reaction also has a high efficiency as the removal of the solvent is the only work up required to isolate the product. The products can be used in a subsequent oxidation which was performed sequentially in semibatch mode. The alkylations of phenol and benzyl amine have been demonstrated on an array of bases, but higher temperatures and longer reaction times are required than with thiols.
Authors:Alastair Baker, Michael Graz, Robert Saunders, Gareth J. S. Evans, Sandra Kaul, and Thomas Wirth
Using mild conditions and short reaction times, symmetrical disulfides have been synthesized in flow chemistry using phase transfer catalysts to facilitate the substitution of organohalides with disodium disulfide. Also, the synthesis of symmetrical trisulfides was possible using this procedure with an additional equivalent of sulfur.