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.
Key words
Brønsted acid - phosphoric acid - pyrophosphoric acid - organocatalyst - aza-Friedel–Crafts
reaction - phenol - regio-selectivity