Trifluoromethyl-stabilized optically active oxiranyl and aziridinyl anions for stereospecific syntheses of trifluoromethylated compounds

Asymmetric Syntheses with Aziridinecarboxylate and Aziridinephosphonate Building Blocks

“…Recently, Uneyama reported that treatment of (R)-1-tosyl-2-trifluoromethylaziridine 76 (Scheme 3.24) with n-BuLi at -100°C and subsequent trapping of the anion with electrophiles such as chloroformates produced aziridine-2-carboxylates 77 in good to excellent yields [71]. The retention of the configuration of the trifluoromethylated quaternary carbon center in the course of the reaction was confirmed by derivatization of the product and by X-ray studies.…”

1,1,1-Trifluoro-2,3-epoxypropane

“…The Electrophilic Reaction via Oxiranyl Anion of TFPO. 40,50 The oxiranyl anion prepared from TFPO reacts with various electrophiles stereospecifically. The reaction gives optically active 2-substituted-2-trifluoromethyl oxiranes, the chirality as well as optical purity are retained through the reactions.…”

Stereoselective Functionalization of 2‐(1‐Aminoalkyl)aziridines via Lithiation of Aziridine–Borane Complexes

“…In contrast, the chemistry of lithiated aziridines (aziridinyl anions) produced by direct lithiation/deprotonation has received much less attention. [5] Most diastereoselective lithiated aziridines have been generated from N-toluenesulfonyl aziridines [4c, 6] or from aziridines bearing an anion stabilising group such as acyl, [7] alkenyl, [8] oxazolinyl, [9] benzotriazoyl, [10] sulfonyl [11] or trifluoromethyl [12] attached directly. Few methods to prepare aziridinyl anions without a stabilising substituent are known.…”