Design, synthesis, and evaluation of a novel class of enantioselective electrophilic fluorinating agents:: N-fluoro ammonium salts of cinchona alkaloids (F-CA-BF4)

[GRAPHICS] The first enantiopure N-fluoro quaternary ammonium salts of cinchona alkaloids as enantioselective fluorinating agents are reported. A one step transfer-fluorination on the naturally occurring cinchona alkaloids gave the fluorinating agents F-CA BF4. This new generation of fluorinating agents exhibited asymmetric induction up to 61% on fluorination of enolates and silyl enol ethers of 2-methyl-1-tetralone.