Environmentally benign solvent systems: Toward a greener [4+2] cycloaddition process

Green chemistry is a field that encompasses a wide range of environmentally benign technologies. This review discusses the principles of green chemistry, as well as recent applications of these principles to the Diels-Alder reaction, with a focus on benign solvent systems. Specifically, Diels-Alder reactions in water, ionic liquids, supercritical carbon dioxide, and solvent-free systems will be reviewed up to February 2006.