Improved methods for the synthesis and isolation of imidazolium based ionic salts

Air stable pincer (CNC) N-heterocyclic carbene–cobalt complexes and their application as catalysts for C–N coupling reactions

“…The ligand precursor (1a: R=Me) was first reported by Hermann et al [25] and later by others [7a,26] and recently we have reported a quick throughput solvent free method for the synthesis and isolation of imidazolium salts that include 1a and 1b [27]. Our procedure alleviated all the limitations associated with the purification and isolation of imidazolium salts using previously reported methods [26a,28].…”

“…ThermoScientific Flash2000 Elemental Analyser respectively. Pincer imidazolium salts 1a and 1b; were synthesised and isolated in excellent yield using improved solvent free technique [27].…”

Sterically Hindered N‐Heterocyclic Salts Utilized as Antimicrobial Agents

“…For the preparation of the salts ( 6a – 9b ), we applied a solvent‐free technique we reported earlier, which is based on the neat alkylation of neutral imidazoles, in this instance 6 – 9 by each of the two alkyl halides . Although no products were isolated in the attempted synthesis of salts 7b , 8a , and 8b , which we believe is mainly due to steric constraints associated with, especially, the bulkier 4,5‐phenanthro derivatives ( 8a and 8b ) and added flexibility of propyl iodide ( 7b ), the yields were low to moderate, and 1 H‐NMR was used to confirm identities of the new compounds.…”

“…Combined organic layers were dried over a bed of anhydrous MgSO 4 and filtered. All volatiles were removed under reduced pressure, and the crude product was purified by column chromatography, where elution with MeOH afforded pure products .…”

“…A solvent‐free method we reported was used for the synthesis of the ferrocenylmethylimidazolium iodides 6a – 9b . Typically, the corresponding N ‐ferrocenylmethyl‐4,5‐arylimidazoles 6 – 9 (1 equiv) and excess alkyl iodide were mixed neat under a nitrogen atmosphere and heated at 50°C for 24 h. The resulting mixture was allowed to cool to room temperature, and a minimal amount of diethyl ether was added to precipitate out the salt, which was then filtered, further washed with diethyl ether (5 × 10 mL), and dried in vacuo .…”