Asymmetric anionic polymerization of 7-cyano-7-phenyl-1,4-benzoquinone methide

Asymmetric anionic polymerizations of a prochiral monomer, 7-cyano-7-phenyl-1,4-benzoquinone methide (3), using chiral initiators were performed under various conditions, and optically active polymers having configurational chirality in the main chain were obtained though their specific rotation values are quite small. The optically active polymer with a negative specific rotation value of -4.4A degrees was obtained by polymerization of 3 with a lithium isopropylphenoxide ((PrPhOLi)-Pr-i)/(-)-sparteine ((-)-Sp) in a mixture solution of dichloromethane/toluene ratio of 30/70 (in vol%) at -40 A degrees C. Stereostructures of 1-mer, 2-mer, and oligomers obtained by asymmetric anionic oligomerization of 3 with (PrPhOLi)-Pr-i/(-)-Sp were examined in detail. It was found that the stereoselectivity turned out to be the opposite between the initiation reaction and the propagation one.