Asymmetric Reactions of Enamines with Methyl (E)-4-Oxo-4-(2-oxo-1,3-oxazolidin-3-yl)-2-butenoate by Use of a Chiral Titanium Reagent

Article abstract of DOI:10.1246/bcsj.64.2122

Asymmetric Michael and <2+2> cycloaddition reactions between enamines and methyl (E)-4-oxo-4-(2-oxo-1,3-oxazolidin-3-yl)-2-butenoate proceed with a chiral titanium reagent generated in situ from dichlorodiisopropoxytitanium and a tartrate-derived chiral 1,4-diol.In the presence of excess amounts of the chiral titanium reagent, good to moderate enantioselectivity is attained.The reactions are also well catalyzed even with a catalytic amount of the titanium reagent.