Enantioselective fluorination mediated by cinchona alkaloids/selectfluor combinations: A catalytic approach

A novel catalytic approach related to the enantioselective fluorination reaction using N-fluoroammonium salts of cinchona alkaloids which produces non-racemic alpha-fluoroketones is described. Acyl enol ethers of ketones 1 are enantioselectively fluorinated with Selectfluor(R) in the presence of a catalytic amount of cinchona alkaloid and 1.2 equivalents of sodium acetate at room temperature for 1-3 days to famish alpha-fluoroketones 2 in good yields and moderate enantioselectivity (up to 54% ee). (C) 2006 Elsevier B.V. All rights reserved.