Aromatic amination/imination approach to chiral benzimidazoles.
The powerful Buchwald-Hartwig amination was utilized for the construction of the benzimidazole nucleus with the substituted nitrogen atom bearing a chiral substituent. A successive amination/imination was followed by an acid-catalyzed ring closure step to give the benzimidazole ring. The products were deprotonated and acylated at the C2 position and could be alkylated on nitrogen to give chiral benzimidazolium salts.
Rivas
Felix M
FM
Department of Chemistry, University at Buffalo, the State University of New York, Buffalo, New York 14260-3000, USA.
Giessert
Anthony J
AJ
Diver
Steven T
ST