Datensatz

Zusammenfassung

This work describes studies on asymmetric counteranion-directed Lewis acid organocatalysis. In the first part, the development of a catalytic asymmetric Hosomi–Sakurai reaction using BINOL-derived disulfonimides is described. Good to excellent yields and enantioselectivities were achieved in the methallylation of aromatic aldehydes. In order to enable the enantioselective reaction of less reactive substrates, studies towards the development of novel, more active catalysts were conducted in the second part. Disulfonimides bearing hydrogen bond donors for internal activation were studied both experimentally and by quantum chemical calcualtions in order to rationalize and exploit their exceptional catalytic activity. These studies enabled us to conduct non-enantioselective organocatalysis with catalyst loadings as low as 10 ppm. In the last part of this dissertation, studies towards chiral, enantiopure catalysts bearing C–H-acidic moieties are described. These studies resulted in the development of a new type of chiral acid catalyst, namely binaphthyl-allyl-tetrasulfones (BALTs).