Low toxicity imidazolium & pyridinium ionic liquids: synthesis, antimicrobial toxicity, biodegradation studies and applications in tsuji-trost reactions

Abstract

A series of seventy achiral and chiral ionic liquids was designed, synthesized and characterized. Out of these seventy ILs, fifteen are achiral, twenty one lactic acid based and rest are mandelic acid based ILs. All compounds were characterized by a number of techniques including: 1H, 13C, 19F NMR, IR, MS and specific rotation. Antimicrobial and antifungal toxicity studies were carried out using the representative examples chosen from these ILs. Lactic and mandelic acid based ILs and ester based achiral ILs were found to be non toxic towards eight strains of bacteria and twelve strains of fungi. Antifungal toxicity was performed on two monoester and two diester CILs. Twenty one ILs were screened for biodegradation studies out of which the ILs with diester functionality were found to be readily biodegradable. Six achiral ester and amide based ILs were chosen to employ in Tsuji-Trost reactions as reaction media. Reactions were performed using two methods consisting use of two different bases. Chiral catalysts (S,S)-iPr-phosferrox, mandyphos and R-BINAP were used for chiral induction. Excellent enantioselectivities with moderate yields were obtained in these reactions.