IDPi Catalysis

High acidity and structural confinement are pivotal elements in asymmetric acid catalysis. The recently introduced imidodiphosphorimidate (IDPi) Brønsted acids have met with remarkable success in combining those features, acting as powerful Brønsted acid catalysts and “silylium” Lewis acid precatalysts in numerous thus far inaccessible transformations. Substrates as challenging to activate as simple olefins were readily transformed, ketones were employed as acceptors in aldolizations allowing sub‐ppm level catalysis, whereas enolates of the smallest donor aldehyde, acetaldehyde, did not polymerize but selectively added a single time to a variety of acceptor aldehydes. The development and application of imidodiphosphorimidates (IDPis) as powerful Brønsted acid catalysts and “silylium” Lewis acid precatalysts are discussed in this Minireview. Due to their extraordinarily high acidity and confined chiral microenvironment, IDPis outperformed all previously reported chiral Brønsted acids in a number of challenging C−C and C−O bond‐forming transformations.