RESUMEN
Thirteen bridged triazolium and imidazolium dicationic salts, which uniquely pair closo-icosahedral perfluoroborane [B(12)F(12)](2-), borane [B(12)H(12)](2-), or carborane [CB(11)H(12)](-) anionic species with unsaturated bridged heterocyclium dications, were synthesized using an aqueous benchtop method. This considerably extends the scope of a reported aqueous synthesis of binary [heterocyclium](2)[B(12)H(12)] and [heterocyclium][CB(11)H(12)] salts. Also, the one-step preparation of five new precursor bridged heterocyclium dicationic dihalide salts using conventional procedures and in one case a microwave-assisted method is described.
RESUMEN
Ten new salts that pair triazolium and imidazolium cations with closo-icosahedral anions [B(12)H(12)](2-) and [CB(11)H(12)](-) were synthesized in water solvent using an open-air, benchtop method. These unreported [Heterocyclium](2)[B(12)H(12)] and [Heterocyclium][CB(11)H(12)] salts extend reports of [Imidazolium][CB(11)H(12)] and [Pyridinium][CB(11)H(12)] salts that were synthesized in anhydrous organic solvents under an inert atmosphere with glovebox or Schlenk techniques. Spectroscopic data, melting points, and densities are reported for each salt. Single-crystal X-ray structures are provided for the five new [B(12)H(12)](2-) salts.
RESUMEN
A new one-pot nitration employing tetramethylammonium nitrate and trifluoromethanesulfonic anhydride in dichloromethane to provide a ready source of the nitronium triflate nitrating agent is presented. Rapid and selective nitration with a variety of aromatic and heteroaromatic substrates is achieved resulting in the synthesis of several novel organic compounds. A distinct advantage is the removal of undesired byproducts by aqueous workup. This very mild nitration permits large-scale syntheses and gives high isolated product yields that often require no further purification. This tetramethylammonium nitrate-based nitration also has been applied to microwave-assisted conditions, and the results with several compounds are outlined.