There is scarcity of approaches for the enantioselective generation of trifluoromethyl-substituted cyclopropanes. We have been interested in the discovery and identification of catalysts that are compatible with conditions necessary to generate reactive intermediates in situ in order to access new building blocks for drug discovery. Towards that aim, we have documented reaction processes involving diazotization of 2,2,2-trifluoroethylamine in the presence of Fe-porphyrin or [{Rh(esp)}2] (esp=a,a,a’,a’-tetramethyl-1,3-benzenedipropionate) catalysts as ways of accessing trifluoromethylsubstituted cyclopropanes and cyclopropenes, respectively. The generation of the reactive intermediate and concomitant cyclopropanation in water comprise a tandem sequence that avoids preparation, purification, and handling of the diazoalkane. Herein, we report an enantioselective cobaltcatalyzed process that furnishes trifluoromethyl-substituted cyclopropanes in high ee, d.r. and yield [Eq. (1)]. The reaction proceeds smoothly in aqueous media with the alkene as limiting reagent and in situ generation of the reactive F3CCHN2 from 2,2,2-trifluoroethylamine hydrochloride. [7,8]