Ethylene oxide reaction with carbon dioxide

The Grignard reagent from 2-thenyl chloride can be obtained by the use of the "cyclic reactor.However, rearrangement occurs in its reaction with carbon dioxide, ethyl chlorocarbonate, acetyl chloride, formaldehyde, and ethylene oxide to 3-substituted 2-methylthio-phenes, Only in the case of carbon dioxide has the normal product also been isolated. 

Telechelic polymers, containing one or more end groups with the capacity to react with other molecules, are useful for synthesizing block and other copolymers [Fontanille, 1989 Hsieh and Quirk, 1996 Nuyken and Pask, 1989 Pantazis et al., 2003 Patil et al., 1998 Quirk et al., 1989, 1996 Rempp et al., 1988]. Living anionic polymers can be terminated with a variety of electrophilic reagents to yield telechelic polymers. For example, reaction with carbon dioxide, ethylene oxide, and allyl bromide yield polymers terminated with carboxyl, hydroxyl, and allyl groups, respectively. Functionalization with hydroxyl or carboxyl groups can also be achieved by reaction with a lactone or anhydride, respectively. Polymers with amine end... 

Carboxylation has also been seldom used especially for the constmction of various spiro-8-lactones. Rieke et al. have developed a direct synthesis of spiro-8-lactones from conjugated dienes and epoxides [114,115] (Scheme 67). Treatment of 1,2-bis (methylene)-cyclohexane-magnesium reagent derived from diene 306, with an excess of ethylene oxide, gave intermediate 307, which upon reaction with carbon dioxide and hydrolysis afforded the spiro-8-lactone 308. 

Ethylene glycol can be manufactured by the reaction of ethylene oxide with carbon dioxide to form ethylene carbonate (eq. 17) which can be hydroly2ed to ethylene glycol (eq. 18). 

In the 1940s and 1950s, a considerable amount of research was funded to find and develop the chemists impossible dream a process for the direct oxidation of ethylene to EO, without any by-products. Finally, Union Carbide found the silver bullet that did the joE)—a catalyst made of silver oxide. Silver oxide is the only substance found having sufficient activity and selectivity. (Activity relates to the amount of conversion, selectivity relates to the right yield.) Moreover, ethylene is the only olefin affected in this way. The others, propylene, butylene, etc., tend to oxidize completely, forming carbon dioxide and water. But when silver oxide is used as a catalyst with ethylene, the dominant reaction is the formation of EO. Some ethylene still ends up being further oxidized, as much as 25% in some processes, as shown in Figure 10—2. 

A method of considerable industrial importance for the large-scale preparation of ethylene oxide is direct oxidation of ethylene at elevated temperatures over a suitably prepared metallic silver catalyst. Although the reaction may be written aa indicated in Eq. (09), in actual practice only about half the ethylene is converted into ethylene oxide, the remainder being oxidized further to carbon dioxide and water. In spite of this seeming disadvantage, catalytic oxidation appears at present to bo economically competitive with chlorohydrin formation aa a means for the commercial production of ethylene oxide.MM Unfortunately, other olefins, such as propylene and mo-butylene for example, apparently give only carbon dioxide and water under the usual oxidation conditions,1310 so that until now the patent hu balance ethylene oxide has been the only representative accessible by tins route. 

In all experiments, the major products were ethane and carbon dioxide. Under some conditions, ethylene and carbon monoxide were also observed. In the following, Rj is the C] products (CO2 and CO) formation rate, and R2 is the C2 products (C2H6 and C2H4) formation rate. The methane conversion is defined as (Rj+2R2)/CH4 in feed. The selectivity to C2 products is defined as 2R2/(Ri+2R2), while the C2 yield is defined as the product of conversion and selectivity. Our experimental results indicate that methane does react with carbon dioxide to produce carbon monoxide and either hydrogen or water under reaction conditions, but if oxygen is present, most of the carbon monoxide will be further oxidized to... 

Ethylene carbonate is produced industrially by the reaction of carbon dioxide with ethylene oxide (reaction 8.36), in the presence of a catalyst, such as tetrabutyl-ammonium bromide. 

When ethylene is oxidized over Ag, carbon dioxide may be formed either directly from ethylene, bypassing ethylene oxide, or by stepwise oxidation of ethylene oxide. To obtain confirmation for the occurrence of these reactions Margolis and Roginskii (118) carried out investigations with a mixture of C14-labeled ethylene, ethylene oxide, and oxygen. Variations in concentrations of initial compounds and reaction products as a function of the contact time were determined, as well as the activity distribution. 

The reaction of carbon dioxide with epoxides affords ethylene carbonates. Recent examples include the use of Ni(cyclam)Br2 and Ti(0-i-Pr)4. From propylene oxide 78 and carbon dioxide at room temperature and atmospheric pressure, in the presence of MoCls/PPhs as the catalyst, 78 % of the cyclic carbonate 79 is obtained. ... 

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