A convergent synthesis of imidazoles and their use in task specific ionic liquids for carbon capture

As a method driven organic chemistry group, we strive to resolve problems not only within the realm of academia, but those facing all of humanity. Recently, the pollution of the planet with greenhouse gases has become an ever pressing global challenge to overcome. While there has been a strong push towards alternative forms of energy to combustion of coal and fossil fuels, other chemicals are even more damaging than CO2 emissions, such as those used as refrigerants. Our group envisioned that the use of ionic liquids (ILs) could potentially replace these compounds, using the ability of these ILs to selectively and reversibly absorb CO2 over other gases like N2 and O2. In order to do this efficiently, we developed a new method for synthesizing aprotic heterocyclic anionic ILs (AHA-ILs), allowing for a much cheaper, more time efficient route towards these compounds; both requirements necessary to make large scale application a viable possibility. While doing so, we began to focus on the imidazole ring, an important moiety that can act both as the anionic and cationic component in an AHAIL. What we required was a quick and efficient route towards these structures.;To achieve this, we developed a method using the bimetallic combination of Au(I) and Ag(I) co-catalysis for the convergent assembly of propargyl bromides and amidines towards the construction of highly substituted imidazoles. This mild and efficient process provided a convergent route towards these heterocycles, alleviating the necessity for a linear construction as well as harsh reagents, conditions, and generating and isolating unstable intermediates. From this research we have been able to make site-specific modifications to the imidazole core, as well as assembling both highly functionalized and unsubstituted imidazoles. Development of this method would assist us in fine-tuning ILs and their chemical and physical properties by making sitespecific modifications prior to generating the desired ILs, allowing us to easily access ILs with desirable properties for reversible CO2 capture.