Chiral Pyrophosphoric Acid Catalysts for the para -Selective and Enantioselective Aza-Friedel-Crafts Reaction of Phenols

Chiral BINOL-derived pyrophosphoric acid catalysts were developed and used for the regio-and enantioselective aza-Friedel-Crafts reaction of phenols with aldimines. ortho/para-Directing phenols could react at the para-position selectively with moderate to good enantioselectivities. Moreover, the gram-scale transformation of a product into the key intermediate for the antifungal agent (R)-bifonazole was demonstrated.