Axially Chiral Bronsted Acid Catalyzed Transformations of Electrophilic Imines

Conformationally rigid phosphoric acids derived from suitably substituted axially dissymmetric 1,1'-bi-2,2'-naphthol (BI-NOL) find wide application in organic synthesis. These chiral Bronsted acids are able to catalyze enantioselective transformations of electrophilic imines with both carbon-centered and other hetero nucleophiles to generate enantioenriched products of academic, industrial and biological significance. Selected examples of this transformation as well as catalytic action and stereochemical features of plausible transition state intermediates are discussed in the present review.