Metal-Catalyzed Copolymerization of Imines and CO: A Non-Amino Acid Route to Polypeptides

Metal‐Catalyzed Synthesis of Alternating Copolymers

“…In 2007, Sun et al reported the first copolymerization of imines with CO using a Co catalyst (Scheme 8). [83] The authors found that a simple acylcobalt complex can effectively catalyze this reaction to produce polypeptides of high molecular weights with low polydispersity. Copolymerization was performed in dioxane under 55 bar of CO pressure at 50 8C for 6 h to obtain the alternating copolymer with M n ¼ 1 900-4 100 g Á mol À1 in 73% yield.…”

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.…”

“…[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.) [11,16] Cyclic ethers,primarily epoxides,require the presence of apyridine derivative as the co-catalyst to undergo COP. [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.…”

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.…”