Asymmetric radical polymerization and copolymerization of N-(1-phenyldibenzosuberyl)methacrylamide and its derivative leading to optically active helical polymers

N-(1-Phenyldibenzosuberyl)methaerylamide (PDBSMAM) and its derivative N-[(4-butylphenyl)dibenzosuberyl]methaerylamide (BuPDBSMAM) were synthesized and polymerized in the presence of (+)- and (-)-menthols at different temperatures. The tacticity of the polymers was estimated to be nearly 100% isotactic from the H-1 NMR spectra of polymethacrylamides derived in D2SO4. Poly(PDBSMAM) was not soluble in the common organic solvents, and its circular dichroism spectrum in the solid state was similar to that of the optically active poly(1-phenyldibenzosubery] methacrylate) (poly(PDBSMA)) with a prevailing one-handed helicity, indicating that the poly(PDBSMAM) also has a similar helicity. Poly(BuPDBSMAM) was optically active and soluble in THF and chloroform. Its optical activity was much higher than that of the poly[N-(triphenylmethayl)methacrylamidel, suggesting that one-handed helicity may be more efficiently induced on the poly(BuPDBSMAM). The copolymerization of BuPDBSMAM with a small amount of optically active N-[(R)-(+)-1-(1-naphthyl)ethyl]methacrylamide, particularly in the presence of (-)-menthol, produced a polymer with a high optical activity. The prevailing helicity may also be efficiently induced. The chiroptical properties of the obtained polymers were studied in detail. The chiral recognition by the polymers was also evaluated. (c) 2007 Wiley Periodicals, Inc.