Synthesis and Antimicrobial Activity of Imidazolium and Triazolium Chiral Ionic Liquids

A simple and efficient procedure for the synthesis of new optically active imidazolium and triazolium ionic liquids in a three step reaction sequence is described. In the first step, the ring opening of 1,2-butylene oxide by imidazole or 1,2,4-triazole resulted in the formation of N-2-hydroxybutylimidazole and N-2-hydroxybutyl-1,2,4-triazole, respectively. In the second step, racemic mixtures of the secondary alcohols were resolved with good enantioselectivity by a lipase-catalyzed transesterification with enol esters (vinyl acetate and 1-acetoxy-2-methylcyclohexene). In the final step, the optically active intermediates were alkylated with several haloalkanes to yield optically active ionic liquids. The inhibitory activity of the synthesized ionic liquids was tested towards gramnegative and gram-positive bacteria and fungi.