Hydrocarbons aralkyl

Dialkyl peroxides have the stmctural formula R—OO—R/ where R and R are the same or different primary, secondary, or tertiary alkyl, cycloalkyl, and aralkyl hydrocarbon or hetero-substituted hydrocarbon radicals. Organomineral peroxides have the formulas R Q(OOR) and R QOOQR, where at least one of the peroxygens is bonded directly to the organo-substituted metal or metalloid, Q. Dialkyl peroxides include cyclic and bicycflc peroxides where the R and R groups are linked, eg, endoperoxides and derivatives of 1,2-dioxane. Also included are polymeric peroxides, which usually are called poly(alkylene peroxides) or alkylene—oxygen copolymers, and poly(organomineral peroxides) (44), where Q = As or Sb. 

Butadiene has been co-oxidized with a number of aralkyl hydrocarbons and cyclic olefins. The order of increasing reactivity toward butadieneperoxy radicals (X—02—C H602) is cumene, sec-butylbenzene < cyclooctene < cyclohexene... 

The reactivities in abstraction toward the ROo radicals correlate poorly with the methyl data. For example, toward R02 radicals the cyclic olefins and Tetralin are as reactive as cumene (within a factor of about 2), while toward CH3 , Tetralin and cumene are at least 10 times more reactive than the cyclic olefins. This apparent lack of selectivity in abstraction by the peroxy radical is no doubt related to the factors controlling the selectivity in addition but to some degree is a function of the reactants. The peroxy radical appears to show a somewhat more typical selectivity (8, 18) toward a broad selection of aralkyl hydrocarbons, although the changes in exothermicity are more significant in this series. 

Aromatic and Aralkyl Hydrocarbons An aromatic ring in a molecule stabilizes the molecular ion peak (rule 4, Section 2.7), which is usually sufficiently large that accurate intensity measurements can be made on the M + 1 and M + 2 peaks. 

Substitutive thiocyanation in the 7-position of cholesterol and its benzoate have been reported.80 The same position attacked in halo-genation.282 233 Ready substitutive thiocyanation occurs9 in the side chains of aralkyl hydrocarbons, e.g., thiocyanation of the isopropyl group of retene.79 Ultraviolet irradiation is necessary and the substrate... 

Thiocyanation can be directed, by choice of suitable reaction conditions, to the nucleus or side chain of most aralkyl hydrocarbons. For example 1-methylnaphthalene gives exclusively l-methyI-4-cyanato-naphthalene in acetic acid in darkness but gives exclusively 1-thio-cyanatomethylnaphthalene on irradiated carbon tetrachloride solution. Mixtures of the two, in varying proportions, are obtained from solutions allowed to stand in ordinary sunlight. 

Russell GA (1957) Deuterium-isotope effects in the autoxidation of aralkyl hydrocarbons. Mechanism of the interaction of peroxy radicals. J Am Chem Soc 79 3871-3877... 

Russel GA. The rate of oxidation of aralkyl hydrocarbons. Polar effects in free radical reactions. J Am Chem Soc 1956 78 1047-1054. 

Small but significant effects of solvent polarity were found in the autoxidation of a variety of alkenes and aralkyl hydrocarbons [216-220] (styrene [216, 218, 219], ethyl methyl ketone [217], cyclohexene [218], cumene [218, 219], tetralin [219], etc.). An extensive study on solvent effects in the azobisisobutyronitrile (AIBN)-initiated oxidation of tetralin in a great variety of solvents and binary solvent mixtures was made by Kamiya et al. [220],... 

Russell, G. A. Deuterium-isotope Effects in the Autoxidation of Aralkyl Hydrocarbons. Mechanisms of the Interaction of Peroxy Radicals. /. Am. Chem. Soc. 79 3871, 1957. 

Fig. 1. Oxidation of mixtures of cumene and aralkyl hydrocarbons at 90°C, 0.02 M f-butyl perbenzoate. A, Dibenzyl ether B, indan C, diphenylmethane D, ethylbenzene E, theoretical for an inert diluent. Reprinted with permission from ref. 139. Copyright by the American Chemical Society.

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