Asymmetric aziridination of chalcones catalyzed by a novel backbone 1,8-bisoxazolinylanthracene (AnBOX)-copper complexElectronic supplementary information (ESI) available: characterization data, 1H NMR and 13C NMR spectra for the ligand AnBOX 1 and all unknown compounds 3, and HPLC chromatograms for the determination of the ee values of all the aziridine derivatives 3. See http://www.rsc.org/suppdata/cc/b4/b404134h/