Carbonylative Polymerization of Oxetanes Initiated by Acetyl Cobalt Complexes

Abstract

Four acetyl cobalt complexes, [AcCo(CO)(3)P(p-tolyl)(3)] (1; p-tolyl=4-Me-C(6)H(4)), [AcCo(CO)(3)P(OPh)(3)] (2), [AcCo(CO)(3)P(NMe(2))(3)] (3), and [AcCo(CO)(2)(dppp)] (4; dppp=1,3-bis(diphenylphosphanyl)propane), were synthesized, characterized, and examined as catalysts for the unprecedented carbonylative polymerization of oxetanes. Copolymers containing ester (4-hydroxyalkanoate) and/or ether units were obtained with complexes 1 and 2, but not with complexes 3 and 4 either in the presence or absence of additional phosphorus ligands. The ester unit/ether unit ratio varied in the range 21:79-63:37, and the highest ester/ether ratio of 63:37 was achieved by using complex 1 in the presence of a further 5 equivalents of P(OPh)(3). Although direct carbonylative polymerization is possible, preformation and ring opening of the gamma-lactone is also suggested as an alternative pathway.

The role of the deformational entropy in the miscibility of polymer blends investigated using a hybrid statistical mechanics and molecular dynamics model

“…In nature, these polyesters such as poly(hydroxyalkanoates) are produced by microorganisms. 6 However, recently they were synthetically prepared by ring opening polymerization of lactones 7 or the carbonylative polymerization of cyclic ethers, 8 the monomers of which are petroleum-based chemicals. The carbonylative polymerization of oxetanes, catalyzed by a series of well-isolated acylcobalt complexes, to afford biodegradable poly(4-hydroxybutyrates) was also reported.…”

“…The carbonylative polymerization of oxetanes, catalyzed by a series of well-isolated acylcobalt complexes, to afford biodegradable poly(4-hydroxybutyrates) was also reported. 8,9 Carbon monoxide, which works as the carbonyl moiety source in the polymerization, recently has also become a valuable C1 resource in various organic syntheses and polymerization reactions of poly(glycolic acid). 10 Copolymers of carbon monoxide and formaldehyde are a very interesting class of copolymers with a wide range of industrial applications depending on the CO/CH 2 O ratio in the copolymer, resulting in polymeric materials with a wide array of chemical and physical properties.…”

Zwitterionic Design Principle of Nickel(II) Catalysts for Carbonylative Polymerization of Cyclic Ethers

“…[1] Since it can be easily obtained by CO 2 reduction, CO is ar aw materials with low carbon footprint. [9][10][11][12][13][14][15][16] Cobalt was the metal of choice to catalyze the COPs of, for example,e poxides,a ziridines and imines. [2] Among the COPs,C O-olefin copolymerization is well-studied, [3][4][5][6][7][8] while the COPs of heteroatom-containing comonomers (for example,e poxides, aziridines,imines,etc.)…”

“…Among the products,p olyketones are photodegradable,a nd polyesters are hydrolytically degradable.T hese features make COP an attractive platform for producing sustainable polymers for av ariety of applications. [11][12][13][14][15][16] Acyl-Co-(CO) 4 is likely ubiquitously involved as the catalytically active species.The mechanisms for the enchainment of the polar comonomers have much commonalities among themselves but are different from the coordinative insertion mechanism of olefin enchainment. only experienced amodest amount of research interest.…”

Zwitterionic Design Principle of Nickel(II) Catalysts for Carbonylative Polymerization of Cyclic Ethers

“…[9][10][11][12][13][14][15][16] Cobalt was the metal of choice to catalyze the COPs of, for example,e poxides,a ziridines and imines. [11][12][13][14][15][16] Acyl-Co-(CO) 4 is likely ubiquitously involved as the catalytically active species.The mechanisms for the enchainment of the polar comonomers have much commonalities among themselves but are different from the coordinative insertion mechanism of olefin enchainment. Thee lectrophilic acyl group is the reactive site for the nucleophilic co-monomers instead of the Co center.T he COPs of cyclic amines and imines,w hich are good nucleophiles,a re relatively fast, give polyamides in high yields,a nd often display living characters.…”