Dichloromalonate ester

An enantioselective halogenation reaction of silyl enolates mediated by ZrCU with chiral halogen source was reported (Equation 14) [19]. Dichloromalonate ester (43) was employed for the reaction as a halogen source. 

Yamamoto and co-workers have demonstrated the highly enantioselective stoichiometric chlorination of silyl enol ethers using a,a-dichloromalonic ester X8 as the halogen source in the presence of ZrCLt (Table 43.5 entry 1). Coordination of the Lewis acid (Z1CI4) to reagent X8 was crucial to generate a C2-symmetric environment where the selective chlorination occurs. Hajra et al. have reported on a similar stoichiometric enantioselective chlorination of... 

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