Synthesis of an advanced precursor of Rivastigmine: Cinchona-derived quaternary ammonium salts as organocatalysts for stereoselective imine reductions

Enantioselectivities up to 93% were obtained in the trichlorosilane addition to differently functionalized imines with novel picolinamide-Cinchona derivatives. The new catalyst has been applied in the synthesis of an advanced precursor of Rivastigmine.130