SYNTHESIS OF AXIALLY DISSYMMETRIC CHIRAL AMMONIUM-SALTS BY QUATERNIZATION OF SECONDARY-AMINES WITH (R)-(+)-2,2'-BIS(BROMOMETHYL)-6,6'-DINITROBIPHENYL AND (R)-(+)-2,2'-BIS(BROMOMETHYL)-1,1'-BINAPHTHYL AND AN EXAMINATION OF THEIR ABILITIES AS CHIRAL PHASE-TRANSFER CATALYSTS
Chiral quaternary ammonium salts were prepared from the reaction of (R)-(+)-2,2'-bis(bromomethyl)-6,6'-dinitrobiphenyl and (R)-(+)-2,2'-bis(bromomethyl)-1,1'-binaphthyl with some secondary amines and observed to exhibit activity in chiral induction in the epoxidation of chalcone (e.e. = 1.3-7.5%) and the Darzens condensation of benzaldehyde and phenacyl chloride (e.e. = 1.6-2.0%) under phase-transfer conditions.