Ethene Ethers

Relative acidity at175 C Si02 [%] Na20 [%] Conversion [%] Selectivities Ethene Ether [%] [%] C(coke) [%]... 

Alcohols undergo dehydration in supercritical and hot water (41). Tertiary alcohols require no catalyst, but secondary and primary alcohols require an acid catalyst. With 0.01 MH2SO4 as a catalyst, ethanol eliminates water at 385°C and 34.5 MPa to form ethene. Reaction occurs in tens of seconds. Only a small amount of diethyl ether forms as a side reaction. 

For example, carbon dioxide from air or ethene nitrogen oxides from nitrogen methanol from diethyl ether. In general, carbon dioxide, carbon monoxide, ammonia, hydrogen sulfide, mercaptans, ethane, ethene, acetylene (ethyne), propane and propylene are readily removed at 25°. In mixtures of gases, the more polar ones are preferentially adsorbed). 

Athen, n. ethene (ethylene), -yl, n. ethenyl. Ather, m. ether (in older names frequently equivalent to ester). atberilhnlich, a. ether-Uke, ethereal. 

Therapeutic Function Inhalation anesthetic Chemical Name (2,2,2-trlfluoroethoxy)ethene Common Name 2,2,2-trifluoroethyl vinyl ether Structural Formula CF3CH20CH=CH2 Chemical Abstracts Registry No. 406-90-6... 

An alternative synthesis of 9//-tribenz.[/ >,ia, /]azepine (65, R = H) involves cycloaddition of 10,1 l-dehydro-5i/-dibenz[/t,/]azepine (66), generated from 5-acetyl-10-bromo-5//-dibcnz[/ ,/]azepine, with cyclohexa-1,3-diene.8 The cycloadduct 67, so-formed, with potassium rm-butoxide in refluxing bis(2-methoxyethyl) ether (diglyme) undergoes hydrolysis and loss of ethene to give the tribenzazepine in 39% yield. 

Catalyst performance was far superior to the corresponding BINAP or Me-Du-Phos systems, with both conversions and selectivities being higher. The hydrogenation of enol ethers using Rh-PennPhos catalysts has been reported in a patent by Zhang [67d]. Under mild conditions, high enantioselectivities were obtained (73-94% ee) for 1-aryl-l-methoxy-ethene derivatives 121, compared to Me-DuPhos (40-73% ee) and BINAP (46-48% ee). 

Water and carbon monoxide can produce dihydrogen in situ (shift reaction), as has been shown in the synthesis of diethylketone (pentan-3-one) from ethene, CO and water in the presence of palladium(II) salts, triphenylphosphine and acids [37], Ether chain ends have been observed in some polymerization reactions [40] and low molecular weight products can also contain an ether moiety as an end group. Most likely ether chain ends are not formed by attack of alcohol at coordinated ethene in a Wacker type reaction, since this is usually followed by fast (3-hydride elimination. Instead we propose that a palladium-... 

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