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Addition and cyclization reactions in the thermal conversion of hydrocarbons with enyne structure, 3 A mechanistic study of the thermal cycloisomerization of 1,4-diphenyl-1-buten-3-yne

✍ Scribed by Hofmann, Jörg ;Zimmermann, Gerhard ;Homann, Klaus-Heinrich

Publisher
John Wiley and Sons
Year
1995
Tongue
English
Weight
784 KB
Volume
1995
Category
Article
ISSN
0947-3440

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✦ Synopsis

The gas-phase pyrolysis of 1,4-diphenyl-l-buten-3-yne (1) was investigated in the temperature range between 600 and 800°C and in the presence of different carrier gases (N2, N2/ toluene, H2). By a detailed analysis (GC, GC/MS, GC/FTIR) all volatile reaction products were identified and quantitatively determined. Besides several fragmentation products (substituted benzenes C7-Cl0) and some carbon-rich deposits the main products are benzene (4), naphthalene (5) as well as 1-( 2) and 2-phenylnaphthalene (3). Under similar conditions 4-(4-fluorophenyl)-l-phenyl-1-buten-3-yne (1 a) furnished mainly fluorobenzene (4a), naphthalene ( 5 ) , 1-(2a) and 2-(4-fluorophenyl)naphthalene (3a).

-If sufficient H atoms are available in the reactive gas phase the conversion of l / l a is predominantly controlled by radical processes.

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