Anionic Alternating Copolymerization of Ketene and Aldehyde:  Control of Enantioselectivity by Bisoxazoline-Type Ligand for Synthesis of Optically Active Polyesters

Polyester Obtained by Anionic Polymerization of Ethylketene

“…[44] Copolymers based on ethylphenylketene and benzaldehyde were also mentioned. [45] To our knowledge, aldoketenes polymerizations have never been reported. Probably, this may be assigned to the fact that aldoketenes are very unstable products: indeed, while ketoketenes are relatively stable compounds (especially diarylketenes and, to a lower extent arylalkylketenes then dialkylketenes [46] ), aldoketenes form dimers very easily.…”

An energy efficient and facile synthesis of high molecular weight polyesters using ketenes

“…While well-established in small molecule organic chemistry, 7 ketenes have been exploited sparingly in polymer synthesis. Examples include the synthesis of polyesters through the anionic polymerization of a ketene and an aldehyde, [8][9][10] and the chain extension of low molecular weight polyesters by coupling with ketenes. 11 Similarly, Garner has described the copolymerization of sebacyl bisketene and bisphenol-A 12 which involves the generation of the reactive bisketene by reaction of an acid chloride with base at low temperature (À78 1C), under inert conditions and at high dilution.…”

Asymmetric Polymerization

“…Asymmetric alternating copolymerization of ketenes and aromatic aldehydes has been reported [91] . The catalyst with initiator consisting of Et 2 Zn and i -Pr -Pybox ( 36 ) effi ciently promoted enantioselective alternating copolymerization of ethylphenylketene and benzaldehyde in CH 2 Cl 2 to give optically active copolymers ( 37 ) with [ α ] D up to − 158 ° (Scheme 13.7 ).…”