Catalysis with deep eutectic solvents: challenges and opportunities

Abstract

Deep eutectic solvents (DESs) have emerged as a transformative class of green solvents, offering unique advantages in catalysis due to their tunable physico-chemical properties, low toxicity, and biodegradability. This review explores the dual role of DESs as both solvents and catalytic media, highlighting their impact on diverse catalytic processes, including organic transformations, biomass valorization, and environmental remediation. DESs exhibit remarkable solvation properties that enhance reaction selectivity, yield, and efficiency, often surpassing traditional organic solvents. Their versatility extends to homogeneous and heterogeneous catalysis, where they not only facilitate reactions but also stabilize catalytic species, thereby prolonging catalyst life. In addition, task-specific DESs have demonstrated enhanced catalytic activity in key reactions such as esterification, condensation, oxidation, and carbon-carbon bond formation. Despite these advantages, challenges such as high viscosity and water sensitivity remain areas of active research. Further exploration of DES structural modifications and mechanistic insights will drive their wider adoption in sustainable chemistry. This review provides a comprehensive overview of recent advances in DES-based catalysis, highlighting their role in promoting greener and more efficient chemical processes.