Hg cathode-free electrochemical detosylation of N,N-disubstituted p-toluenesulfonamides was successfully carried out by a constant Current electrolysis using an undivided cell equipped with a platinum cathode and a magnesium anode in the presence of an arene mediator. The deprotection proceeded efficiently and selectively under neutral and mild conditions with a stoichiometric amount of electricity without the use of an Hg cathode to obtain the corresponding secondary amines in good to excellent yields. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of Aromatic Sulfonamides through a Copper-Catalyzed Coupling of Aryldiazonium Tetrafluoroborates, DABCO·(SO<sub>2</sub>)<sub>2</sub>, and <i>N</i>-Chloroamines
A copper-catalyzed aminosulfonylation of aryldiazonium tetrafluoroborates, DABCO·(SO2)2, and N-chloroamines is described. This coupling reaction provides an efficient and simple approach to a wide range of sulfonamides in moderate to good yields under mild conditions. Mechanistic investigation suggests that a radical process and transition-metal catalysis are merged in this tandem reaction.
A novel nucleophilicsubstitutionreaction at the nitrogen of arylsulfonamides by means of phosphide anions has been described. This reaction allows for the efficient transformation of arylsulfonamides into synthetically valuable phosphamides, amines, and a variety of protected amines.