Stereoselective Epoxide Polymerization and Copolymerization

Childers, M. Ian; Longo, Julie M.; Zee, Nathan J. Van; LaPointe, Anne M.; Coates, Geoffrey W.

doi:10.1021/cr400725x

Cited by 422 publications

(351 citation statements)

References 183 publications

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“…A variety of comprehensive reviews on catalytic synthesis of organic molecules from CO2 have emerged in recent years, including metalbased and organic catalysis. 4,5,6,11,18,19,20,21,22,23,24,25,26,27,28 There are two catalytic approaches that have found widespread use for activation of the rather inert CO2 molecule (Scheme 1); both approaches involve incorporation of the entire CO2 molecule, which is our main focus here. In the first approach (Scheme 1a), C-CO2 bonds are primarily formed through insertion of CO2 into reactive metal-carbon bonds; in these reactions CO2 acts as an electrophile.…”

Section: Strategies For Bond Formation To Co2mentioning

confidence: 99%

“…methanol 3 ), as a sustainable carbon source. The number of efficient protocols for incorporation of CO2 is steadily growing, 4,5,6,7,8 however, little work has been devoted to making enantioselective reactions with CO2 [a general review of this area has been provided by Kleij and coworkers (2013) 9 and Lu (2016) 10 , and a specific review of stereoselective polymerization by Coates and coworkers (2014) 11 ]. It can be noted that both the carbon and the oxygen atoms of CO2 can be involved in the generation of novel chiral centres.…”

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confidence: 99%

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Enantioselective Incorporation of CO₂: Status and Potential

et al. 2017

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CO2 is a promising and sustainable carbon feedstock for organic synthesis. New catalytic protocols for efficient incorporation of CO2 into organic molecules are continuously reported. However, little progress has been made in the enantioselective conversion of CO2 to form enantioenriched molecules. In order to allow CO2 to become a versatile carbon source in academia, and in the fine chemical and pharmaceutical industries, the development of enantioselective approaches is essential. Here we discuss general strategies for CO2 activation and for generation of enantioenriched molecules, alongside selected examples of reactions involving asymmetric incorporation of CO2. Main product classes considered are carboxylic acids and derivatives (C-2 CO2 bonds), and carbonates, carbamates, and polycarbonates (C-OCO bonds). Similarities to asymmetric hydrogenation are discussed, and some strategies for developing novel enantioselective CO2 reactions are outlined.

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Section: Strategies For Bond Formation To Co2mentioning

confidence: 99%

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confidence: 99%

Enantioselective Incorporation of CO₂: Status and Potential

et al. 2017

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“…Metal alkoxide species, M-OR, have been shown to be the true active species in numerous ROP processes. [1][2][3][4][5][6][7][8][9][10][11][12][13][18][19][20][21][22][23][24] For example, in 2004, Lewiński and co-workers reported the first structurally characterized aluminum ε-caprolactone complex, indicating that the Al-Me group has poor reactivity with CL. 77 Thus, in most ROP cases, an alcohol is used as an initiator and is essential in order to start the polymerization.…”

Section: Introductionmentioning

confidence: 99%

A Comparison of Gallium and Indium Alkoxide Complexes as Catalysts for Ring-Opening Polymerization of Lactide

et al. 2017

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ABSTRACT:The synthesis, characterization, and reactivity of an aluminum alkoxide complex supported by a ferrocene-based ligand, (thiolfan*)Al(O t Bu) (1 red , thiolfan* = 1,1'-di(2,4-di-tert-butyl-6-thiophenoxy)ferrocene), are reported. The homopolymers of L-lactide (LA), ε-caprolactone (CL), δ-valerolactone (VL), cyclohexene oxide (CHO), trimethylene carbonate (TMC), and their copolymers were obtained in a controlled manner by using redox reagents. Detailed DFT calculations and experimental studies were performed to investigate the mechanism. Mechanistic studies show that after the insertion of the first monomer, the coordination effect of the carbonyl group, which has usually been ignored in previous reports, can significantly change the energy barrier of the propagation steps, thus playing an important role in polymerization and copolymerization processes.

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“…1), which exhibited excellent activity, unprecedented enantioselectivity and molecular-weight control for the alternating copolymerization of CO 2 with mesoepoxides such as CPO under mild reaction conditions 25 . Previously, Coates and co-workers [26][27][28] have demonstrated that the dinuclear cobalt complexes based on binaphthol linker were highly active and enantioselective for homopolymerization of terminal epoxides. As a consequence, the same enantiopure biphenol-linked dinuclear Co(III) complex was employed as catalyst for enantioselective copolymerization of CO 2 with COPO.…”

Section: Resultsmentioning

confidence: 99%

Crystalline-gradient polycarbonates prepared from enantioselective terpolymerization of meso-epoxides with CO2

Liu

Ren

et al. 2014

Nat Commun

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The development of efficient processes for CO 2 transformation into useful products is a long-standing goal for chemists, since CO 2 is an abundant, inexpensive and non-toxic renewable C1 resource. Here we describe the enantioselective copolymerization of 3,4-epoxytetrahydrofuran with CO 2 mediated by biphenol-linked dinuclear cobalt complex, affording the corresponding polycarbonate with 499% carbonate linkages and excellent enantioselectivity (up to 99% enantiomeric excess). Notably, the resultant isotactic polycarbonate is a typical semicrystalline polymer, possessing a melting point of 271°C. Furthermore, the enantioselective terpolymerization of 3,4-epoxytetrahydrofuran, cyclopentene oxide and CO 2 mediated by this dinuclear cobalt complex gives novel gradient polycarbonates, in which the decrement of one component and the increment of the other component occur sequentially from one chain end to the other end. The resultant terpolymers show perfectly isotactic structure and have unique crystalline-gradient nature, in which the crystallinity continuously varies along the main chain.

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Stereoselective Epoxide Polymerization and Copolymerization

Cited by 422 publications

References 183 publications

Enantioselective Incorporation of CO₂: Status and Potential

Enantioselective Incorporation of CO₂: Status and Potential

A Comparison of Gallium and Indium Alkoxide Complexes as Catalysts for Ring-Opening Polymerization of Lactide

Crystalline-gradient polycarbonates prepared from enantioselective terpolymerization of meso-epoxides with CO2

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Stereoselective Epoxide Polymerization and Copolymerization

Cited by 422 publications

References 183 publications

Enantioselective Incorporation of CO2: Status and Potential

Enantioselective Incorporation of CO2: Status and Potential

A Comparison of Gallium and Indium Alkoxide Complexes as Catalysts for Ring-Opening Polymerization of Lactide

Crystalline-gradient polycarbonates prepared from enantioselective terpolymerization of meso-epoxides with CO2

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Enantioselective Incorporation of CO₂: Status and Potential

Enantioselective Incorporation of CO₂: Status and Potential