Salt Metathesis: An Ultimate Click Reaction

In this Comment, we suggest salt metathesis (or ion exchange) as an ultimate click reaction, extending click chemistry principles beyond covalent bonds to ionic interactions. These universal and robust reactions, which nature utilizes in marine organisms' biomineralization processes, proceed spontaneously under mild conditions with minimal waste, embodying the core principles of click philosophy. This perspective expands the traditional scope of click chemistry and opens new opportunities in synthetic accessibility across organic, inorganic, and materials science spaces.