Imidazolium and Benzimidazolium Salts: A Veritable Playground for Organic and Supramolecular Chemists

摘要

Over the past few years, we have undertaken a multidisciplinary research effort to show that it is possible not only to study imidazolium cations at the molecular level, but also to tune the macroscopic properties of the supramolecular systems they form. The study of functional imidazolium-based supramolecular architectures gives rise to emerging opportunities in chemistry, and bridges the gap between organic and supramolecular systems in an effort to fully understand the driving forces behind the assembly of these units in different hierarchies. Imidazolium and benzimidazolium cations are important building blocks common to the different projects described in this account, where we show and discuss how our research group has exploited imidazolium salts and their supramolecular assistance in catalysis, and more particularly, what we learned from each step and how this information guided us in the design of new strategies. 1 Introduction 2 Development of a One-Pot, Two-Step Biphasic Catalytic Sequence 3 Incorporation of Imidazolium Cations into Different Catalytic Scaffolds for Reactions Performed in Neat Water 3.1 -Cyclodextrin-Functionalized Imidazolium Salts: A Bimodal Ligand Precursor for Aqueous Catalysis 3.2 Functionalized Benzimidazolium Salts as N-Heterocyclic Carbene Precursors 4 Chiral Imidazolium-Functionalized Catalysts 4.1 Early Studies 4.2 Optimization Studies 4.3 Recyclability 5 Imidazolium Cations Bearing Chiral Catalytic Anions 5.1 Aldol Reaction 5.2 Michael Addition 6 Development of Supramolecular Bio-Hybrid Catalysts 6.1 First Generation Catalyst 6.2Second Generation Catalyst 6.3Third Generation Catalyst 7 Conclusion