Anionic polymerization of 3,5-(2,4-)dimethoxystyrene and 2,4,6-trimethoxystyrene and functionalization of the resulting polymers by lithiation

Anionic polymerizations of 3,5-dimethoxystyrene (1), 2,4-dimethoxystyrene (2), and 2,4,6-trimethoxystyrene (3) were studied in THF at 195 K using sec-butyllithium as an initiator. Initiation reactions proceeded immediately upon addition of initiator for all monomers, but the propagation rates decreased in the order of 1 2 3. Both the monomers 1 and 2 gave the corresponding polymers having predictable molecular weights and narrow molecular weight distributions. However, the monomer 3 gave no polymer. It was confirmed that lithiation reaction of poly(1) and poly(2) by n-butyllithium in THF at 238 K proceeded with ease at the 4− and 3-positions of phenyl ring, respectively. Lithiated poly(1) and poly(2) are expected to be novel functional polymers for various applications.