Convenient synthesis of polymers containing terminal aldehyde and ketone moieties by selective oxidation of polymeric terminal diols with an oxoaminium salt

Abstract

AbstractSynthesis of polymers with aldehyde or ketone groups at both chain ends was carried out by oxidation of polymeric terminal diols with an oxoaminium salt (OAS), the oxidized form of 2,2,6,6‐tetramethylpiperidine‐1‐oxyl. Terminal diols of polyethers, polyesters, polycarbonates, polybutadiene, and hydrogenated polybutadiene were oxidized with 2,0 equiv. of OAS in dichloromethane at room temperature in the dark. The corresponding aldehyde‐and/or ketoneterminated polymers were obtained in high yields with high conversion of OH group and little change in molecular weight. Poly(ethylene glycol) and poly(ethylene adipate) terminal diols were oxidized with low efficiency. Especially, in the case of poly(ethylene glycol), intermolecular reactions occurred to afford high molecular weight polymer. The ratio of aldehyde (CHO) to ketone (CO) groups in the oxidized polymer originating from the hydrogenated polybutadiene terminal diol was calculated to be 37/63.