A versatile catalyst for asymmetric reactions of carbonyl groups working purely by activation through hydrogen bonding: Mukaiyama-aldol, hetero Diels-Alder and Friedel-Crafts reactions.
Bis-sulfonamides are demonstrated to be promising candidates for the efficient activation of carbonyl compounds through hydrogen bonding. Exemplified by three carbonyl addition reactions: Mukaiyama-aldol, hetero Diels-Alder and Friedel-Crafts reactions we show that bis-triflamides or bis-nonaflamides of commercially available chiral diamines act as chiral Brønsted-acid catalysts, leading to the optically active products in moderate to excellent yields and with enantioselectivities up to 73% ee.
Zhuang
Wei
W
Danish National Research Foundation: Center for Catalysis, Department of Chemistry, Aarhus University, DK-8000, Aarhus C, Denmark.
Poulsen
Thomas B
TB
Jørgensen
Karl Anker
KA