Asymmetric anionic polymerization of 2,6-dimethyl-7-phenyl-1,4-benzoquinone methide

Asymmetric anionic polymerizations of 2,6-dimethyl-7-phenyl-1,4-benzoquinone methide (1) were performed with various chiral anionic initiators, and the specific rotations of the obtained polymers were investigated. Optically active poly(1)s with configurational chirality were obtained with all the initiators, and a complex of fluorenyllithium (FlLi) with (-)-sparteine [(-)-Sp] produced poly(1) with the largest negative specific rotation ([alpha](435) = -26.8degrees). The specific rotations of poly(l)s obtained with FlLi/(-)-Sp depended on the initiator concentration and the solvent polarity. The maximum specific rotations were obtained at an almost constant initiator concentration (ca. 0.03 mol/L), regardless of the monomer concentration, in toluene, whereas a higher initiator concentration was required in more polar solvents. These results suggested that the aggregation state of the propagating chain end significantly affected the specific rotation of poly(1). (C) 2004 Wiley Periodicals, Inc.