Assembled catalysts of titanium and non-cross-linked chiral copolymers for an enantioselective carbonyl-ene reaction

New insoluble chiral catalysts were prepared from a self-assembly of Ti(O-i-Pr)4 and non-cross-linked copolymers with (R)-binaphthol (BINOL) pendant groups. In the presence of one of the chiral catalysts, an enantioselective carbonyl-ene reaction proceeded at room temperature to give an adduct in 85% yield with 88% ee. This insoluble assembled catalyst was easily prepared and reusable.