Ionic liquids containing plant derived benzoate as anions, exhibiting supramolecular polymeric aggregation: Impact of the aggregation on organic catalysis in aqueous medium

Naturally occurring benzoic acid (BA) derived anions have been used to prepare halogen free hydrophilic ionic liquids (ILs 1-4). The supramolecular polymeric aggregation behaviour of these ILs has been studied through high-resolution electron spray ionization mass spectrometry (HR-ESI-MS). Furthermore, these ILs were applied as catalyst/phase transfer catalyst in the synthesis of tetrahydrobenzo[b]pyran and its derivatives. These reactions were conducted in aqueous medium under ultrasound assistance. The results suggested that 1-ethyl-3-methylimidazolium 2-hydroxybenzoate (IL-1) was a highly efficient catalyst yielding 86.9% product in 30 min. In addition, the impact of aggregation behaviour of ILs on their catalytic activity was also investigated. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Naturally occurring benzoic acid derived anions have been used to prepare halogen-free hydrophilic ionic liquids, which were further studied for their supramolecular polymeric aggregation behavior. Among them, IL-1 showed highly efficient catalytic performance, yielding 86.9% product in 30 minutes.