Author/Authors :
Park، نويسنده , , Hyeung-geun and Jeong، نويسنده , , Byeong-seon and Yoo، نويسنده , , Mi-Sook and Lee، نويسنده , , Jeong-Hee and Park، نويسنده , , Boon-saeng and Kim، نويسنده , , Myoung Goo and Jew، نويسنده , , Sang-sup، نويسنده ,
Abstract :
A series of cinchona alkaloid-derived dimeric quaternary ammonium salts were prepared as chiral phase-transfer catalysts by the introduction of various functional groups on the phenyl ligand. Among them, the 2-F-substituted derivative 21 showed the highest enantioselectivity in the alkylation of the glycine anion equivalent 1 (97 to >99% ee).