Synthesis of a polyester macromonomer via the cobalt‐catalyzed alternating copolymerization of propylene oxide and carbon monoxide

Nakano, Koji; Kondo, Fumiyoshi; Nozaki, Kyoko

doi:10.1002/pola.20383

Cited by 24 publications

(17 citation statements)

References 20 publications

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“…Although the copolymerization proposed by Sen and Arndtsen has yet to be realized, they demonstrated the first example of stoichiometric imine insertion into metal-acyl bonds, a necessary reaction for the copolymerization to occur. Several groups have noted that the Co 2 (CO) 8 /3-hydroxypyridine catalyst system produces polyester as the major product in contrary to the patent report that b-lactones were the major products [7] and have subsequently studied the binary catalyst systems based on Co 2 (CO) 8 [40][41][42][43][44][45]. We have been interested in the design and development of carbonylative polymerization of COPH using the de novo approach based on welldefined single-site molecular catalysts.…”

Section: Introductionmentioning

confidence: 99%

The role of phosphine in cobalt-catalyzed carbonylative polymerization of N-alkylaziridine

LeGall

et al. 2005

Journal of Organometallic Chemistry

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Section: Introductionmentioning

confidence: 99%

The role of phosphine in cobalt-catalyzed carbonylative polymerization of N-alkylaziridine

LeGall

et al. 2005

Journal of Organometallic Chemistry

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“…Alternating copolymerization has attracted much attention, because a polymer obtained by alternating copolymerization of two monomers A and B has a uniform A–B sequence to exhibit totally different chemical and physical properties from those of other types of copolymers, random and block ones 1–15. In addition to this aspect of formation of new main chain structure, such a unique manner of copolymerization allows construction of an alternating array of two different side chains R A and R B , which are inherited from the corresponding monomers A and B, respectively.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of polyester having sequentially ordered two orthogonal reactive groups by anionic alternating copolymerization of epoxide and bislactone

Uenishi

Sudo

Endō

2009

J. Polym. Sci. A Polym. Chem.

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This article presents a route to a novel polyester having sequentially ordered two orthogonal reactive groups. The polyester was given by the imidazoleinitiated alternating copolymerization of allyl glycidyl ether (AGE) and a bislactone 1. This copolymerization system is characterized by the following three reaction behaviors: (1) the selective participation of only one of the two lactone moieties of 1 to the copolymerization to give a linear polyester, and the consequent introduction of the second lactone into the side chain of the polyester, (2) the participation of the epoxy moiety in AGE to the copolymerization, and the consequent introduction of the carbon-carbon double bond into the side chain of the polyester, and (3) arrangement of the sequentially ordered two orthogonal reactive groups according to the alternating manner. The introduction of the two reactive groups to the side chain of the alternating copolymer allowed two routes of sequential chemoselective reactions: (A) The ring-opening reaction of the lactone moiety with n-propylamine and the following Pt-catalyzed hydrosilylation of the carbon-carbon double bond with dimethylphenylsilane and (B) the sequential reactions of the reverse order. V V C 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6750-6757, 2009

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“…[7c] For the sterically bulkier and less nucleophilic 3, selective carbonylative enchainment occurred, as assessed by NMR spectroscopy (entries [3][4][5][6][7][8]. [11] Somewhat surprisingly, carbonylative enchainment of THF also took place and resulted in d-oxyvaleroyl ester units in the polymer products.…”

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confidence: 99%

“…The polymerization has a living character, as evidenced by the narrow polydispersity (Table 1, entries 3-8) and the linear increase of molecular weight (M n ) with increasing monomer conversion, [11] and hence the ester units must populate the polymer chain in a gradient fashion that increases from the head to the tail. The gradient ester distribution and the variation in the ester abundance can likely be attributed to competition for the acyl site by THF, azetidine, and [Co(CO) 4 ]…”

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Cobalt‐Catalyzed Carbonylative Copolymerization of N‐Alkylazetidines and Tetrahydrofuran

Liu

2005

Angew Chem Int Ed

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The metal-catalyzed carbonylative polymerization of heterocycles (COPH) has received much attention in the last few years as a novel method for the synthesis of polyamides and polyesters. [1][2][3][4][5][6][7] Motivation for these research activities is the practical demand for polymers with heteroatom-containing backbones that are susceptible to hydrolytic and/or enzymatic attack in biological or ecological environments. [8,9] We are interested in the development of COPH using an approach based on single-site catalysts, under the idea that well-defined molecular catalysts would allow rational design and control of the chemical composition, molecular weight, and microstructure of the polymer product.Herein, we report the carbonylative polymerization of azetidines catalyzed by [Co(CH 3 CO)(CO) 3 P(o-tol) 3 ] (1; tol = tolyl), and the participation of the tetrahydrofuran (THF) solvent in the polymerization to give ester units in the polymer products. The use of LiI as a cocatalyst eliminates the g-lactam by-product and influences both the amount and distribution of the ester units in the polymer backbone. The well-controlled distribution of the ester units and the living character of the polymerization have allowed the synthesis of polymers with alternating amide blocks and ester segments, which undergo two-stage degradation. [10] Herein, N-n-butylazetidine (2) and Nisobutylazetidine (3) are used as representative monomers. The polymerization was carried out in THF under CO (1000 psi) at 60-80 8C (Table 1). For 2, in addition to the major carbonylative enchainment that resulted in the amide units, a simple ring-opening enchainment without carbonylation was also observed, which resulted in amine units in the polymer chain (entries 1 and 2).[7c] For the sterically bulkier and less nucleophilic 3, selective carbonylative enchainment occurred, as assessed by NMR spectroscopy (entries 3-8).[11] Somewhat surprisingly, carbonylative enchainment of THF also took place and resulted in d-oxyvaleroyl ester units in the polymer products.[12] Thus, the reactions of 2 and 3 in THF produced poly(amide-co-amine-co-ester)s (PAAEs) and poly(amideco-ester)s (PAEs), respectively [Table 1, Eqs. (1) and (2)].The extent of THF carbonylative enchainment differed when 2 and 3 were used as the monomer: twofold as many ester units were incorporated with 3 than with 2 (entries 1 vs. 3, and 2 vs. 4).The ester abundance, which is defined as the number of ester units divided by the total number of all monomer units, was also a function of the initial monomer-to-catalyst ratio. Higher monomer loadings resulted in a lower degree of ester incorporation (entries 3-8), which suggests that the reaction of THF was favored when the azetidine concentration was low. Directly monitoring the amide and ester growth by in situ IR spectroscopy confirmed that the ester abundance in the Table 1: Carbonylative polymerization of azetidine and THF (CO pressure 1000 psi). [a] Entry THF[mL]Azetidine Azetidine/1 (molar ratio)Cocatalyst Selectivity [b] Ester abun...

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Synthesis of a polyester macromonomer via the cobalt‐catalyzed alternating copolymerization of propylene oxide and carbon monoxide

Cited by 24 publications

References 20 publications

The role of phosphine in cobalt-catalyzed carbonylative polymerization of N-alkylaziridine

The role of phosphine in cobalt-catalyzed carbonylative polymerization of N-alkylaziridine

Synthesis of polyester having sequentially ordered two orthogonal reactive groups by anionic alternating copolymerization of epoxide and bislactone

Cobalt‐Catalyzed Carbonylative Copolymerization of N‐Alkylazetidines and Tetrahydrofuran

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