Hydrodimerization, benzene

Zeolite catalysts in many forms are used for important commercial processes. The studies were extended to L zeolites, mordenite, erionite, and dealuminated faujasites and mordenites. More attention is paid now to zeolites with univalent and multivalent cations and to multicomponent catalysts. Among these some important examples are the tellurium-containing catalyst for hydrocarbon dehydrocyclization (42), the difunctional Ni- and Pd-zeolite catalysts for benzene hydrodimerization to phenylcyclohexane (42), the catalyst for the hydrogenation of phenol cyclohexanol (44), the 4% Ni/NaY which forms butanol, 2-ethylhexanol, 2-ethylhexanal, and 2-ethylhexanol from a mixture of n-butyraldehyde and hydrogen. 

A similar acid catalyzed reaction (equation 41), called hydrodimerization, was found for benzene and alkylbenzenes, which are converted over polyfunctional zeolite catalysts to phenylcyclohexane derivatives89. 

The hydrodimerization is also a useful method in the preparation of heterocycles [7,8], 6>-Bis(yS-bicarbethoxyvinylamino)benzene (III) thus yields by intramolecular reductive coupling 2,3-bis(dicarbethoxymethyl)-l,2,3,4-tetrahydroquinoxaline (IV), which on heating gives quinoxaline [7], as in Eq. (2). Compound IV may be anodically oxidized to the substituted quinoxaline [9],... 

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