Journal of the American Chemical Society, Vol.131, No.21, 7242-7242, 2009
Chiral Arylaminophosphonium Barfates as a New Class of Charged Bronsted Acid for the Enantioselective Activation of Nonionic Lewis Bases
Heterochiral [7.7]-P-spirocyclic arylaminophosphonium barfates have been designed as a novel charged, cationic Bronsted acid catalyst, and their catalytic and stereocontrolting abilities have been clearly demonstrated in the development of the unprecedented, highly enantioselective conjugate addition of arylamines to nitroolefins. This study uncovers a new function of chiral tetraaminophosphonium cations and its potential synthetic utility, thereby providing a new avenue to the molecular design of chiral charged Bronsted acid catalysts and their applications.