Asymmetric Ring Opening of meso-Epoxides with Aromatic Amines Using (R)-(+)-BINOL-Sc(OTf)3-NMM Complex as an Efficient Catalyst

This work reports the asymmetric ring-opening reaction of meso-epoxides with aromatic amines by using the highly efficient in situ generated (R)-(+)-BINOL-Sc(OTf)(3)-N-methylmorpholine complex. The asymmetric ring opening of cis-stilbene oxide with various substituted aromatic amines gave enantioenriched beta-amino alcohols in good yields and with excellent enantioselectivities when the reaction was conducted at 0 degrees C for 12 h. The reaction proceeded under mild conditions using simple and inexpensive starting materials such as (R)-(+)-1,1'-bi-2-naphthol [(R)-(+)-BINOL], meso-stilbene oxide, aniline derivatives, and 4 angstrom molecular sieves. This new and versatile catalytic system has competitive advantages such as short reaction times, no additives, and no expensive chiral ligands that require a multistep synthesis under harsh reaction conditions.