superacidpromoted

Superacid-promoted refers to chemical transformations that are accelerated or enabled by the use of a superacid. Superacids are acids whose acidity exceeds that of 100% sulfuric acid, typically produced by combining strong Brønsted acids with Lewis acids or by using highly fluorinated sulfonic acids. Classic examples include mixtures known as magic acid and other systems that generate extremely strong protonating power. These systems enable formation of highly reactive carbocation-like intermediates that are difficult to access with ordinary acids.

In this context, substrates such as hydrocarbons can undergo rearrangements, isomerizations, or electrophilic functionalization under conditions not possible with conventional acids. Reactions include alkylations, cyclizations, and selective activations that rely on stabilization of carbocationic species by the acid medium.

Applications span organic synthesis, catalysis, and materials chemistry. The term emphasizes the promotional role of the acid in enabling transformations, sometimes used with co-catalysts or Lewis acids in dual-acid systems.

Safety and practicality are important considerations: superacids are highly corrosive and moisture sensitive, requiring specialized equipment and containment. Substrate scope, chemoselectivity, and environmental impact vary widely among systems, and many protocols are restricted to controlled laboratory settings.

Origin and development of superacid chemistry are attributed to researchers such as George A. Olah, who demonstrated that superacids can stabilize unusual intermediates and open new reaction pathways.