Several ionic liquids (ILs) were prepared in order to study the susceptibility of various cores and substituents to biodegradability using the ‘CO2 headspace’ test (ISO 14593). Several of the ILs contained tertiary amine substituents and were tested as solvents and reagents for several base mediated processes including Suzuki–Miyaura, Sonogashira, Knoevenagel, and Morita–Baylis–Hilman reactions. It was found that although these ILs contain basic functionality, they do not promote base mediated reactions. Density functional theory molecular calculations confirmed that the protonation of these ILs is energetically unfavourable.