Synthetic transformation of d-xylose into a four-membered cyclic ether allows for reactions with CO2 leading to linear polycarbonates by either ring-opening copolymerisation directly or by isolation of a six-membered cyclic carbonate followed by ring-opening polymerisation.

The copolymerization of CO 2 and epoxides in the presence of chain-transfer agents (CTAs) has provided a well-controlled route to polycarbonate polyols. Upon employing dicarboxylic acid CTAs which contain discrete metalbinding sites, it is possible to synthesize polycarbonates with a single-metal complex present in the main chain, either during the copolymerization process or in a postpolymerization procedure. In these ways, the (bipy)Re(CO) 3 Br complex has been incorporated into the polycarbonate backbone. Furthermore, in a one-pot, two-step synthesis, a second epoxide containing a vinyl substituent can be introduced to afford a triblock ABA polycarbonate, where the metal is contained in the B block. Subsequent to the thiol−ene click chemistry of HS ∧ COOH and deprotonation, the resulting anionic polymer is shown to self-assemble in deionized water to provide rather uniform, spherical micelles. Since this procedure is modular, it is applicable to a wide variety of CTAs containing metal complexes or metal-binding sites, thereby providing a pathway to synthesize a wide range of micellar catalysts for pursuing organometallic transformations in water.

We have designed and synthesized poly­(monothiocarbonate)­s containing a single well-defined metal complex in the polymers’ backbone via the immortal copolymerization of carbonyl sulfide and propylene oxide in the presence of chain transfer agents (CTAs). Our initial studies in this area have involved the utilization of metal carbonyl diols, which serve as CTAs. Included in this investigation are the metal complexes ()­Cr­(CO)3 and ()­Re­(CO)3Br. Because of the electron-withdrawing abilities of the metal carbonyl fragments, the CTA afforded catalyst-alkoxide bonds are not sufficiently nucleophilic to react with CO2; hence, the more reactive carbonyl sulfide analog was employed. As anticipated, the molecular weights of the resulting copolymers decreased with increasing quantities of added metal complexes. The incorporation of the metal complexes directly into the polymers’ backbone was noted by νco infrared and 1H NMR spectroscopies. Estimates of metal loading were obtained using calibration curves of the pure metal complexes based on νco infrared or electronic spectra. Thermal decomposition of the copolymers occurred above 180 °C.

Carbon dioxide based polymers synthesized from the metal-catalysed copolymeriation of epoxides and CO2 containing the terpyridine ligand as an end group are reported. The strategy used was to carry out...