Reversal of Asymmetric Induction in Arenetricarbonyl-chromium(0) Complexes via Dilithiation with the (-)-Sparteine/BuLi System and Enantioselective Quench
27 September 2001 (online)
Dilithiation of methoxymethoxyarenetricarbonylchromium complexes by 2.5 equivalents of BuLi and 6 equivalents of (-)-sparteine followed by enantioselective electrophilic quench gave the planar chiral (R)-enantiomers in up to 95% enantiomeric excess. This was the opposite enantiomer obtained under conditions for enantioselective monolithiation with (-)-sparteine/BuLi.
arenetricarbonylchromium(0) complexes - dilithiation - (-)-sparteine - enantioselective deprotonation - enantioselective quench