Switchable aqueous catalytic systems for organic transformations

In living organisms, enzyme catalysis takes place in aqueous media with extraordinary spatiotemporal control and precision. The mechanistic knowledge of enzyme catalysis and related approaches of creating a suitable microenvironment for efficient chemical transformations have been an important source of inspiration for the design of biomimetic artificial catalysts. However, in nature-like environments, it has proven difficult for artificial catalysts to promote effective chemical transformations. Besides, control over reaction rate and selectivity are important for smart application purposes. These can be achieved via incorporation of stimuli-responsive features into the structure of smart catalytic systems. Here, we summarize such catalytic systems whose activity can be switched 'on' or 'off' by the application of stimuli in aqueous environments. We describe the switchable catalytic systems capable of performing organic transformations with classification in accordance to the stimulating agent. Switchable catalytic activity in aqueous environments provides new possibilities for the development of smart materials for biomedicine and chemical biology. Moreover, engineering of aqueous catalytic systems can be expected to grow in the coming years with a further broadening of its application to diverse fields. Control over chemical transformations in aqueous environments employing catalytic systems whose activity can be switched on/off is challenging. Here, the authors review the switchable catalytic systems that operate in aqueous environments in response to external stimuli, such as pH, temperature, light, small molecules, electric field, magnetic field and mechanical energy.

Automated summary

In living organisms, enzyme catalysis in aqueous media has precise spatiotemporal control. This knowledge has inspired the design of biomimetic artificial catalysts. However, it is challenging for these catalysts to be effective in natural-like environments. Control over reaction rate and selectivity can be achieved by incorporating stimuli-responsive features into smart catalytic systems. This review summarizes switchable catalytic systems that operate in aqueous environments in response to external stimuli, providing new opportunities for the development of smart materials for biomedicine and chemical biology.