The first example of organocatalytic aziridination reaction of α-substituted-α,β-unsaturated ketones is presented. The reaction was found to be highly enantio- and diastereoselective, yielding N-tosylated aziridines. Low-temperature nuclear magnetic resonance (NMR) spectra allowed for the determination of the N-inversion barrier, that was found to be quite lower with respect to unsubstituted aziridines. A thorough conformational analysis supported by low-temperature NMR data allowed for the determination of the absolute configuration of the main stereoisomer by means of time-dependent Density Functional Theory simulation of the electronic circular dichroism spectra.
Keywords: DFT calculations; absolute configuration; aziridines; dynamic-NMR; organocatalysis.
© 2015 Wiley Periodicals, Inc.