Asymmetric -alkylation of cyclic -keto esters and -keto amides by phase-transfer catalysis

Without employing any transition metal, a highly enantioselective -alkylation of cyclic -keto esters and -keto amides has been realized by phase-transfer catalysis. This improved procedure is applicable to different kinds of halides with cinchona derivatives and gives the corresponding products in excellent enantiopurities (up to 98% ee) and good yields (up to 98%). Moreover, the reaction was scalable and the phase-transfer catalyst was recyclable. This provided an alternative and competitive method to the asymmetric -alkylation of -dicarbonyl compounds.