Advancements in oxazolidinone synthesis utilizing carbon dioxide as a C1 source

Polymer‐supported pyridinium salts, prepared by quaternarization of crosslinked poly(4‐vinylpyridine) with alkyl halides, effectively catalyze the reaction of carbon dioxide (1 atm) and glycidyl phenyl ether (GPE) to afford the corresponding five‐membered cyclic carbonate (4‐phenoxymethyl‐1,3‐dioxolan‐2‐one). Poly(4‐vinylpyridine) quarternarized with alkyl bromides show high catalytic activities, and the reaction of carbon dioxide (1 atm) and GPE at 100 °C affords 4‐phenoxymethyl‐1,3‐dioxolan‐2‐one quantitatively in 6 h. The rate constant in the reaction of GPE and carbon dioxide in N‐methyl pyrrolidinone using poly(4‐vinylpyridine) quarternarized with n‐butyl bromide (kobs = 102 min−1) is almost comparable with those for homogeneous catalysts with good activities (e.g., LiI), and the rate of the reaction obeys the first‐order kinetics. A used catalyst may be recovered by centrifugation, and the recycled catalyst also promotes the reaction of GPE and carbon dioxide. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5673–5678, 2007

Enzymes are biocatalysts constructed of a folded chain of amino acids. They may be used under mild conditions for specific and selective reactions. While many enzymes have been found to be catalytically active in both aqueous and organic solutions, it was not until quite recently that enzymes were used to catalyze reactions in carbon dioxide when Randolph et al. (1985) performed the enzyme-catalyzed hydrolysis of disodium p-nitrophenol using alkaline phosphatase and Hammond et al. (1985) used polyphenol oxidase to catalyze the oxidation of p-cresol and p-chlorophenol. Since that time, more than 80 papers have been published concerning reactions in this medium. Enzymes can be 10–15 times more active in carbon dioxide than in organic solvents (Mori and Okahata, 1998). Reactions include hydrolysis, esterification, transesterification, and oxidation. Reactor configurations for these reactions were batch, semibatch, and continuous. There are many factors that influence the outcome of enzymatic reactions in carbon dioxide. These include enzyme activity, enzyme stability, temperature, pH, pressure, diffusional limitations of a two-phase heterogeneous mixture, solubility of enzyme and/or substrates, water content of the reaction system, and flow rate of carbon dioxide (continuous and semibatch reactions). It is important to understand the aspects that control and limit biocatalysis in carbon dioxide if one wants to improve upon the process. This chapter serves as a brief introduction to enzyme chemistry in carbon dioxide. The advantages and disadvantages of running reactions in this medium, as well as the factors that influence reactions, are all presented. Many of the reactions studied in this area are summarized in a manner that is easy to read and referenced in Table 6.1. Carbon dioxide is cited as a good choice of solvents for a number of reasons. Some of the advantages of running reactions in carbon dioxide instead of the more traditional organic solvents include the low viscosity of the solvent, the convenient recovery of the products and non-reacted components, abundant availability, low cost, no solvent contamination of products, full miscibility with other gases, non-existent toxicity, low surface tension, non-flammability, and recyclability. The low mass-transfer limitations are an advantage because of the large diffusivity of reactants.

Carbon Dioxide as Chemical Feedstock

: The electron rich polyhydride complex molybdenum Mo(dmpe)2H4, formed by reduction of Mo(dmpe)2Cl2 under H2, reacts with CO2 to give a complex manifold of products containing formate, carbon dioxide and carbonate ligands. The final product of the reaction is Mo(dmpe)2(CO3)H2, in which reductive disproportionation of CO2 has led to a formation of a carbonate ligand. Two other products have been identified in which only two of the initial hydrides have been retained, one of which is the crystallographically characterized bis-formate Mo(dmpe)2(OCHO)2. The complex crystallizes in the monoclinic space group P and has an octahedral geometry with trans Eta 1-formate ligands. A precursor to 3 containing an Eta 2-CO2 ligand has been spectroscopically characterized as MKo(dmpe)2(CO2)(OCHO)H. Two complexes formed early in the reaction sequence, before elimination of H2, have been spectroscopically identified as Mo(dmpe)2(CO2)(OCHO)H3 and Mo(dmpe)2(OCHO)2H2. The characteristic absorptions between 1600 and 2800 cm-1 of the formate, carbonate, hydride, and carbon dioxide ligands in these molecules have been assigned on the basis of Carbon 13 and deuterium labelling studies.

Reactions of carbon dioxide on pyrophoric nickel-on-silica surfaces

Chemical reactions involving carbon dioxide are prominent in a variety of environments and, therefore, important for modeling reaction pathways and quantifying molecular abundances. In atmospheres and in outer solar system ices, for example, radiation induced degradation of abundant chemical species like ozone, oxygen, carbon dioxide, or molecular nitrogen can liberate high energy oxygen or nitrogen atoms that may react with carbon dioxide. This work presents a study of these reactions where in the carbon dioxide — oxygen atom reaction, two carbon trioxide isomers (C2v and D3h symmetry) were found to form. In the carbon dioxide — nitrogen atom system, the bent OCNO radical was formed. Rate constants have been derived for these reaction pathways and the dynamics of the reactions are investigated.

Carboxylation of olefins/alkynes with CO2 to industrially relevant acrylic acid derivatives

Arylcarbamic esters were synthesized directly from carbon dioxide and an aromatic amine via a zinc carbamate. The alkylation of the reaction mixture of carbon dioxide, an aromatic amine, and diethylzinc with dialkyl sulfate formed alkyl arylcarbamate in a high yield. Also, 2-hydroxycyclohexyl diphenylcarbamate was obtained selectively in a good yield by the reaction of carbon dioxide, epoxycyclohexane, and ethylzinc diphenylamide. Other arylcarbamates of 1,2-cyclohexanediol were obtained by the reactions of carbon dioxide, an aromatic amine, diethylzinc, and epoxycyclohexane.

Polymeric epoxides can be converted to corresponding five-membered cyclic carbonates effectively by the reaction with carbon dioxide. For instance, poly(glycidyl methacrylate) (PGMA) was quantitatively converted to a polymethacrylate bearing a five-membered cyclic carbonate group (PDOMA) by the polymer reaction with carbon dioxide using alkali metal or quaternary ammonium halide salt as a catalyst. The salts having more Lewis acidic cation and more nucleophilic anion acted as more effective catalysts. Kinetic analyses of the polymer reaction show that the reaction rate can be expressed by the empirical equation : -d[epoxide]/dt = k[epoxide][catalyst] m , where m depends on the Lewis acidity of the catalyst and molecular weight of the epoxide. The rate of the reaction is independent of the pressure of carbon dioxide. Further, various polymeric epoxides such as GMA copolymers, poly(glycidyl acrylate), and poly(vinylbenzyl glycidyl ether) could be converted to the corresponding polymers bearing five-membered cyclic carbonate moieties by the reaction with carbon dioxide, whereas the presence of an aromatic group in the structure of the polymer could retard the reaction with carbon dioxide.

PHOTOSYNTHESIS, PHOTOREDUCTION AND DARK REDUCTION OF CARBON DIOXIDE IN CERTAIN ALGAE

Carbon dioxide and N-phenylethylenimine were allowed to copolymerize using a Bronsted acid such as phenol or acetic acid to give a white powder, melting at 160–270°C, with a carbon dioxide content of 2.90–20.5 mol %. The content of carbon dioxide in the copolymer increased with carbon dioxide in the feed, while the melting point decreased. The infrared spectrum of the copolymer showed the characteristic peak of urethane linkage. 3-Phenyl-oxazolidone-2, which might be produced by the reaction of carbon dioxide and N-phenylethylenimine, did not react with carbon dioxide or N-phenylethylenimine and was not contained in the copolymer. Carbon dioxide did not react with poly(N-phenylethylenimine) or phenol. From the facts mentioned above, it was concluded that the formation of urethane linkage was due to the copolymerization of carbon dioxide and N-phenylethylenimine. From ultraviolet spectroscopic analysis of the mixture of carbon dioxide and N-phenylethylenimine, an appreciable interaction between two monomers was observed. From the experimental data on the monomer composition in the feed and copolymer, the apparent monomer reactivity ratios were evaluated. On the basis of these results, the probable mechanism of the copolymerization via a complex of carbon dioxide and N-phenylethylenimine was proposed.

Oxazolidinone synthesis through the coupling of carbon dioxide and aziridines was catalysed by an aluminium(salphen) complex at 50-100 °C and 1-10 bar pressure under solvent-free conditions. The process was applicable to a variety of substituted aziridines, giving products with high regioselectivity. It involved the use of a sustainable and reusable aluminium-based catalyst, used carbon dioxide as a C1 source and provided access to pharmaceutically important oxazolidinones as illustrated by a total synthesis of toloxatone. This protocol was scalable, and the catalyst could be recovered and reused. A catalytic cycle was proposed based on stereochemical, kinetic and Hammett studies.

Extrapolation of world energy consumption between 1990 and 2007 to the future reveals the complete exhaustion of petroleum, natural gas, uranium and coal reserves on Earth in 2040, 2044, 2049 and 2054, respectively. We are proposing global carbon dioxide recycling to use renewable energy so that all people in the whole world can survive. The electricity will be generated by solar cell in deserts and used to produce hydrogen by seawater electrolysis at t nearby desert coasts. Hydrogen, for which no infrastructures of transportation and combustion exist, will be converted to methane at desert coasts by the reaction with carbon dioxide captured by energy consumers. Among systems in global carbon dioxide recycling, seawater electrolysis and carbon dioxide methanation have not been performed industrially. We created energy-saving cathodes for hydrogen production and anodes for oxygen evolution without chlorine formation in seawater electrolysis, and ideal catalysts for methane formation by the reaction of carbon dioxide with hydrogen. Prototype plant and industrial scale pilot plant have been built.

Managing impure carbon dioxide produced by fossil fuel-based generation of electricity is required for successful implementation of carbon capture, utilization, and storage. Impurities in carbon dioxide, particularly [Formula: see text] and [Formula: see text], are geochemically more reactive than the carbon dioxide and may adversely impact a carbon dioxide storage reservoir by generating additional acidity. Hydrothermal experiments are performed to evaluate geochemical and mineralogic effects of injecting [Formula: see text]-[Formula: see text] fluid into a carbonate reservoir. The experimental design is based on a natural carbon dioxide reservoir, the Madison Limestone on the Moxa Arch of Southwest Wyoming, which serves as a natural analog for geologic cosequestration of sulfur dioxide and carbon dioxide. Idealized Madison Limestone ([Formula: see text]) and [Formula: see text] brine ([Formula: see text], initial [Formula: see text]) reacted at reservoir conditions (110°C and 25 MPa) for approximately 165 days (3960 h). Carbon dioxide fluid containing 500 ppmv sulfur dioxide was injected and the experiment continued for approximately 55 days (1326 h). Sulfur dioxide partitions out of the supercritical carbon dioxide phase and dissolves into coexisting brine on the time scale of the experiments (55 days). Injecting supercritical [Formula: see text]-[Formula: see text] or pure supercritical carbon dioxide into a brine-limestone system produces the same in situ pH (4.6) and ex situ pH (6.4–6.5), as measured 28 h after injection because dissolution of calcite buffers in situ pH. Precipitation of anhydrite sequesters injected sulfur and, coupled with dissolution of calcite, effectively buffers the amount of dissolved calcium to the same concentrations measured in limestone-brine experiments injected with pure carbon dioxide. Supercritical [Formula: see text]-[Formula: see text] does not enhance the sequestration potential of a carbonate reservoir relative to pure supercritical carbon dioxide. Our results substantiate predictions from natural analog studies of the Madison Limestone that anhydrite traps sulfur and carbonate minerals ultimately reprecipitate and mineralize carbon in carbonate reservoirs.

Liquid ventilation