Furan with ethylene carbonate

Furans have also been incorporated (76USP3979367) into the main chains of polymers by modification of ethylene-carbon monoxide interpolymers in analogous fashion to the pyrroles (Section 1.11.4.1.1). The interpolymer was simply treated with acid in a solvent, and magnesium sulfate was added to react with the water formed in the cyclization. As with the pyrroles, the furan units were introduced to improve thermal processing. 

On the other hand, ethylene-TPD on p UO3 indicated the desorption of acetaldehyde (490 K). In addition, an unexpected product was also observed. This product was identified as furan (C4H4O, m/e 68, 39) which desorbed at ca. 550 K with a carbon selectivity of ca. 40 %. Furan formation from ethylene on UO3 requiring the formation of one carbon-carbon bond and of one carbon-oxygen bond, is most likely accompanied by oxygen depletion from the UO3 surfaces and subsequent reduction of U cations into lower oxidation states. The observation of furan from ethylene shows that one may obtain oxygenated products with a high carbon number from ethylene (a relatively abundant feed stock) via one single step. 

The irradiation of the thiophene in gas phase yields ethylene, allene, methyl-acetylene, carbon disulfide, and vinylacetylene. No Dewar thiophene or cyclo-propene derivatives were isolated (69CJC2965). The irradiation in liquid phase gave the Dewar thiophene which can be trapped as a Diels-Alder adduct with furan (85JA723). The Dewar thiophene and cyclopropene-3-thiocarbaldehyde can be obtained by irradiation in argon matrices at 10 K (86JA1691). 

The generation of the carbcxi-carbon double bond of unsaturated nitrogen heterocycles by the rDA reaction of cycloadducts that act as protected ethylenes has been accomplished. Azetines have been prepared by this method. Another example is the synthesis of l-methyl-3-pyrroline (201). By protecting the ethylene of N-methylmaleimide (199) with furan and then reducing with lithium aluminum hydride, adduct (200) was obtained (equation 86). Pyrolysis of adduct (200) at 250-300 C gave l-methyl-3-pyrroline (201) in 60% isolated yield. The ethylene moiety of N-substituted maleimides can also be generated via rDA reactions. Examples include the generation of N-phenylmaleimide (equation 87) and of N-acetoxymaleimide (equation 88). ... 

In model studies of the naphthalene-sodium-tetrahydro-furan system, tetrahydrofuran was found to decompose to ethylene and the sodium enolate of acetaldehyde, with the ethylene alkylating the naphthalene in both reductive and nonreductive modes. The initial step of this decomposition, proton abstraction from the alpha carbon of tetrahydrofuran, led to formation of a hydride of unknown form. 

As all pyrolysis reactions, the decomposition of furfural to furan and carbon monoxide is accompanied by other minor reactions. Of the gases formed, only 80 percent is carbon monoxide, other gases identified being 10 percent hydrogen as well as small quantities of carbon dioxide, butadiene, propadiene, ethylene, propylene, acetylene, methylacetylene, and cyclopropene. As the quantities of carbon dioxide and butadiene are roughly equal on a molar basis, it is believed that a part of the furfural reacts with pyrolytically liberated hydrogen ... 

Recently, Gunnoe and co-workers showed in several detailed studies that TpRu (Me)(CO)(NCMe) is a very reactive compound with respect to C-H activation processes giving rise to several unusual transformations of organic substrates. For instance, TpRu(Me)(CO)(NCMe) was found to polymerize styrene and methyl methacrylate in benzene at 90 Furthermore, TpRu(Me)(CO)(NCMe) initiates carbon-hydrogen bond activation of benzene and at the 2-position of furan and thiophene to produce methane and TpRu(aryl)(CO)(NCMe) (aryl = phenyl, 2-furyl, 2-thienyl) (Scheme 24). The solid-state structure has been determined for TpRu(2-thienyl)(CO)(NCMe). The complexes TpRu(aryl)(CO)(NCMe) also serve as catalysts for the formation of ethylbenzene, 2-ethylfuran and 2-ethylthiophene from ethylene and benzene, furan, and thiophene, respectively (vide infra). DFT/B3LYP... 

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