title: Synthesis and application of the first planar chiral strong Brønsted acid organocatalysts.
abstract: The synthesis of planar chiral strong Brønsted acid organocatalysts derived from [2.2]paracyclophane is described. Resolution was accomplished according to a modified protocol involving pseudo-ortho-substituted [2.2]paracyclophane-based sulfoxides for the synthesis of three new sulfonic acids. The first planar chiral phosphoric acid diester was obtained from the corresponding phenyl-substituted diol derived from enantiopure 4-bromo-12-hydroxy [2.2]paracyclophane. These new classes of catalysts were tested in an enantioselective Friedel-Crafts reaction as well as in a direct asymmetric Mannich reaction and gave yields of up to 93% and ee-values of up to 38%.
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany. enders@rwth-aachen.de
authors.forename: Dieter
authors.initials: D
authors.lastname: Enders
authors.forename: Monika
authors.initials: M
authors.lastname: Ludwig
authors.forename: Gerhard
authors.initials: G
authors.lastname: Raabe