Chemistry Letters, Vol.42, No.4, 366-368, 2013
Asymmetric Coupling Polymerizations of 2,3-Dihalido-N-substituted Maleimide Derivatives in the Presence of Chiral Bisoxazolines
Yamamoto coupling polymerizations of 2,3-dihalido-N-substituted maleimides (DXRMI) were carried out using nickel catalysts. In addition, coupling reactions of 2,3-dihalido-N-cyclohexylmaleimide (DXCHMI) were performed with nickel complexes in the presence of directly coupled chiral bisoxazolines (R'box) to give optically active poly(N-substituted maleimide-2,3-diyl)s [poly(RMI)s] (specific rotation [alpha](435) = +6.0 to -34.6 degrees). Polymers with number-average molecular weights (M-n) ranging from 270 to 36200 were obtained in 17% to quantitative yields. Poly(N-cyclohexylmaleimide-2,3-diyl) [poly(CHMI)] formed with [Ni(cod)(2)]-R'box exhibited the largest absolute value, [alpha](435) = 34.6 degrees.