Enantioselective Mannich Reaction of 2‐Aminochromones With Isatin‐Derived N ‐Boc Ketimines

ABSTRACT

Chiral 3,3‐disubstituted oxindoles and chromone derivatives exhibit a wide range of physiological activities. Herein, we demonstrate a chiral phosphoric acid catalytic enantioselective Mannich reaction of 2‐aminochromones with isatin‐derived N ‐Boc ketimines, providing a series of novel 3‐chromone‐3‐amino‐oxindoles with moderate to good yields (up to 98%) in moderate to good enantioselectivities (up to 93%). The absolute configuration of one product was assigned by an x‐ray crystal structural analysis. In addition, several products were found to exhibit promising antifungal activity against the plant pathogen Botrytis cinerea .