Enantioselective organocatalytic route to trifluoromethyl-β-amino acids using chiral bases

Herein are studied new aspects of enantioselective (1,3) proton transfer of ethyl-4,4,4-trifluoroacetoacetate (ETFAA) amino derivatives. When catalyzed by an appropriate chiral base, ee's as high as 71% are observed. Special emphasis is given to mechanistic insights of the reaction by use of deuterated derivative. All results converge on a deprotonation as both rate and asymmetric determining step. This study opens a new route to trifluoromethylated chiral building blocks.