Solvents from nature

In this perspective, a personal journey from solvent to solvent is presented to demonstrate how environmentally friendly solvents can be part of the solution of various chemical challenges. Solvents are important components of Nature to provide one or more liquid phases for chemical reactions and processes. While some solvents are available from Nature even in large quantities, most of the solvents are man-made. Historically, solvents were developed and/or selected to help the chemical or physical objectives of the user(s) only. With the increasing importance of local and global health and environmental issues, including the introduction of green chemistry and the molecular approach for pollution prevention, the potential impacts of solvents became important selection tools. One of the key principles of green chemistry is the elimination of solvents in chemical processes or the replacement of hazardous solvents with environmentally benign solvents. The development of solvent-free alternative processes is the best solution, especially when either one of the substrates or the product is a liquid and can be used as the solvent of the reaction. However, if solvents are crucial to a process we should select from solvents that will have no or limited impact on health and the environment.