Stereochemistry in Anionic Polymerization of Styrene Derivatives Bearing Optically Active Amino Groups at ortho-Position

Three ortho-substituted styrenes, 2-[(S)-2-(1-pyrrolidinylmethyl)-1-pyrrolidinylmethyl]styrene (1), 2-[(S)-2-(methoxymethyl)-1-pyrrolidinylmethyl]styrene (2), and 2-[(S)-2-(N,N-diethylaminomethyl)-1-pyrrolidinylmethyl]styrene (3), were synthesized, and the effects of the ortho-substituents on polymerizability and the stereoregularity and chiroptical property of the polymers obtained by anionic method were examined. The anionic polymerization of 1–3 with n-BuLi in toluene at 0°C gave optically active polymers in good yields. Although the polymer obtained from 2 with n-BuLi at 0°C showed a low stereoregularity, the anionic polymerization of 1 and 3 gave the polymers with a high stereoregularity, which was supported by 13C NMR analysis. The poly(1) and poly(3) are likely to have regular conformation. Enantioselective oxidative coupling of a naphthol derivative was carried out using poly(1)s as a chiral ligand to obtain a corresponding 2,2’-binaphthol derivative.