Cationic Co–Salphen Complexes Bisligated by DMAP as Catalysts for the Copolymerization of Cyclohexene Oxide with Phthalic Anhydride or Carbon Dioxide

Abstract

For the copolymerization of cyclohexene oxide (CHO) with phthalic anhydride (PA), cationic complex [Co­(III)­(dmap)2–Salphen]­[BF4] (3) showed higher activity than a combination of Co–Salphen–Cl (2) with 1 equiv of DMAP. The catalytic activity was further improved by using a bimetallic complex 5 in which the Co­(III)­(dmap)2–Salphen moiety was bridged by a 1,2,5,6-substituted naphthalene linker. A similar trend of catalytic activity was detected for the copolymerization of CHO with CO2.

A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde‐Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides

“…Alternatively, two extensively studied atom‐economical and chain‐growth methods for producing aliphatic polyesters include ring‐opening polymerization (ROP) of lactones [13–18] and copolymerization of epoxides with cyclic anhydrides, [19] which can yield polyesters with controlled structures under mild conditions. Advances have enabled the copolymerization route to produce structurally diverse polyesters using two distinct and commercially available monomers (Scheme 1A) [20–31] . More than 400 polyesters made from more than 20 anhydrides and 20 epoxides have been reported to date [32] .…”

A Facile and Unprecedented Route to a Library of Thermostable Formaldehyde‐Derived Polyesters: Highly Active and Selective Copolymerization of Cyclic Acetals and Anhydrides

“…Advances have enabled the copolymerization route to produce structurally diverse polyesters using two distinct and commercially available monomers (Scheme 1A). [20][21][22][23][24][25][26][27][28][29][30][31] More than 400 polyesters made from more than 20 anhydrides and 20 epoxides have been reported to date. [32] The development of novel and efficient methods for producing aliphatic polyesters is at the forefront of sustainability efforts.…”

Heterodinuclear catalysts Zn(ii)/M and Mg(ii)/M, where M = Na(i), Ca(ii) or Cd(ii), for phthalic anhydride/cyclohexene oxide ring opening copolymerisation

“…5,15,[24][25][26][27][28] Amongst the leading PA/CHO ROCOP catalysts are bicomponent metal catalyst + ionic co-catalyst systems (PPNCl), commonly featuring Al(III), Co(III) or Cr(III) coordinated by salen, salophen, triphenolate or porphyrin ligands. 25,[29][30][31][32] For example, one of the more active systems is Cr(III)-salen/PPNCl, which showed a turn-over-frequency (TOF) of approx. 60 h −1 (k obs = 12.0 × 10…”

“…5,15,[24][25][26][27][28] Amongst the leading PA/CHO ROCOP catalysts are bicomponent metal catalyst + ionic co-catalyst systems (PPNCl), commonly featuring Al(III), Co(III) or Cr(III) coordinated by salen, salophen, triphenolate or porphyrin ligands. 25,[29][30][31][32] For example, one of the more active systems is Cr(III)-salen/PPNCl, which showed a turn-over-frequency (TOF) of approx. 24 Several adaptations have been reported to improve activity, notably by the groups of Lee and Coates, in which the nucleophilic co-catalyst is appended to the phenol or diamine backbone moieties, respectively (Fig.…”