Deep eutectic solvents as sustainable media for multicomponent sulfonylation: an efficient strategy to synthesize (hetero)aryl sulfones

The synthesis of valuable sulfone compounds by direct insertion of SO2 is an area of great interest in chemical research. However, the preparation of functional sulfones from transition-metal catalysis currently relies on precious metal catalysts, organic solvents and stepwise procedures that result in resource depletion, significant environmental pollution and poor atom economy. We herein describe an efficient approach toward (hetero)aryl sulfones using a deep eutectic solvent (DES) as a sustainable medium. This practical protocol tolerates a wide range of substrates without additional metal catalysts and volatile organic compounds (VOCs) as solvents and offers several advantages, including recyclability, biodegradability and low cost of components. A green and sustainable multicomponent sulfonylation starting from boronic acids, K2S2O5 and halides has been developed using a deep eutectic solvent (DES) as a reaction medium.