An expeditious and greener synthesis of functionalized cyclopentenones in deep eutectic solvents

In recent years, cyclopentenones have been the target of various synthetic efforts because their five member-ring structure is a characteristic of many compounds with a broad range of biological properties.1 Conventionally, the cyclopentenone unit has been synthesized starting from furaldehyde and primary and secondary amines but most of the reported methods suffer of some disadvantages, such as use of toxic solvents or catalysts, harsh reaction conditions, environmental problems, undesirable wastes, unsatisfactory yield, and tedious work-up procedures. Therefore, the potential important biological activity of compounds related to bifunctionalized cyclopentenones derivatives has demanded alternative, environmentally friendly strategies to synthesize bifunctionalized cyclopentenones.In recent years much attention has been devoted to deep eutectic solvents (DESs) as new sustainable alternatives to traditional solvents and ionic liquids. Compared to ionic liquids, DESs are generally cheaper to make, are less toxic and are often biodegradable. Thus, DESs can be used as low–cost, safe and efficient solvents. We report here a practical, inexpensive, rapid and green method for the preparation of cyclopentenones derivatives in deep eutectic solvents.