Sk. Bertilsson et al., Chiral N,N '- and N,O-bidentate anionic ligands. Preparation, metal complexation, and evaluation in the asymmetric aziridination of olefins, ORGANOMETAL, 18(7), 1999, pp. 1281-1286
The chiral ligands 1-phenyl-2-[(4S)-phenyl-4,5-dihydrooxazol-2-yl]propen-2-
ol (1a) and [1-phenyl-2-((4S)-phenyl-4,5-dihydrooxazol-2-yl)vinyl]-p-tolyla
mine (2a) were prepared, together with some structural analogues (1b-e, 2b)
in two steps from optically pure phenylglycinol or phenylalaninol. Transit
ion-metal-ligand complexes were isolated from the ligand la and Cu(II), Pd(
II), and Co(II). The copper complexes of la and 2a were found to be highly
active catalysts for the asymmetric aziridination of styrene, giving the co
rresponding N-tosylaziridine in excellent yields and with enantiomeric exce
ss in the range of 15-34%.