Imidodiphosphorimidates (IDPis): Catalyst Motifs with Unprecedented Reactivity and Selectivity

The conceptually designed imidodiphosphorimidates (IDPis) have emerged as one of the most potent classes of chiral acid catalysts. They are characterized by enzyme-like, highly confined active site and high acidity, which underlie their wide-reaching applications as Bronsted acid catalysts and as precatalysts for silylium Lewis acids. Many carbon-carbon and carbon-heteroatom bond formation reactions that were deemed intractable could now be attained with spectacular reactivity and selectivity. Substrates that are small, unbiased and/or possess insufficient reactivity such as simple alkenes could now be engaged. The high structural confinement is particularly invaluable to control stereo- and chemoselectivity. The well-defined steric environment offers unique opportunity to control high-energy but structurally unbiased cation intermediates such as the norbonyl cations. Beyond practical appeals such as good scalability as well as ease and modularity of preparation, the extremely low pre-catalyst loadings required to achieve high turnover and stereoselectivity have also come to define a new frontier in organocatalysis.