Cyrene: A bio-based sustainable solvent for organic synthesis

Cyrene (dihydrolevoglucosenone) is a green dipolar aprotic solvent prepared by pyrolysis of cellulose-containing biomass. Cyrene possesses a beneficial occupational health and safety profile combined with good biodegradability without NO_x or SO_x production. Since 2014, when Cyrene was for the first time introduced as a green solvent, it has attracted much attention in different fields. In this review, we discuss organic reactions, for which Cyrene was employed to play the role of medium. Significant progress was achieved in the replacement of conventional aprotic solvents by Cyrene as a safe and sustainable alternative. Cyrene demonstrated to be an effective medium for diverse chemical transformations, from carbon-carbon coupling reactions to bio-catalyzed processes and polymerization. The applications of Cyrene as a co-solvent (e.g. in form of aqueous solutions) for organic synthesis are also discussed.