The remarkably high reactivity of α-cyano-α-fluorophenylacetyl chloride (CFPA–Cl) towards hindered nucleophiles in enantiomeric excess determination

Abstract
The reaction of PhCF(CN)COCl 2b with 3,3-dimethylbutan-2-ol 5 was found to proceed more than 500 times faster than that of PhCCF3(OMe)COCl (MTPA–Cl)1b, suggesting that the CFPA method should potentially lead to much less kinetic resolution than the currently much-used MTPA method in enantiometric excess determinations.