Cycloalkanes alkylation with

Cycloalkanes possessing a tertiary carbon atom may be alkylated under conditions similar to those applied for the alkylation of isoalkanes. Methylcyclopentane and methylcyclohexane were studied most.5 Methylcyclopentane reacts with propylene and isobutylene in the presence of HF (23-25°C), and methylcyclohexane can also be reacted with isobutylene and 2-butene under the same conditions.20 Methylcyclopentane is alkylated with propylene in the presence of HBr—AlBr3 (—42°C) to produce l-ethyl-2-methylcyclohexane.21 C12H22 bicyclic compounds are also formed under alkylation conditions.21 22 Cyclohexane, in contrast, requires elevated temperature, and only strong catalysts are effective. HC1—AICI3 catalyzes the cyclohexane-ethylene reaction at 50-60°C to yield mainly dimethyl- and tetra-methylcyclohexanes (rather than mono- and diethylcyclohexanes). The relatively weak boron trifluoride, in turn, is not active in the alkylation of cyclohexane.23... 

Though FAME has limited oxidation stability, they remain a valid alternative for diesel. Conventional diesel fuel has a boiling range of 180-340 °C, with a composition of n-alkanes, cycloalkanes, alkyl benzenes, and polyaromatic compounds. Fossil diesels have a CN in the range 40-100. FAME has properties that are close to all these basic diesel properties. FAME can also easily blend with fossil diesel at any level due to their similar solvent behavior the viscosity of fossil diesel and biodiesel are also in the same range. 

The name naphthenic acid is derived from the early discovery of monobasic carboxyUc acids in petroleum, with these acids being based on a saturated single-ring stmcture. The low molecular weight naphthenic acids contain alkylated cyclopentane carboxyUc acids, with smaller amounts of cyclohexane derivatives occurring. The carboxyl group is usually attached to a side chain rather than direcdy attached to the cycloalkane. The simplest naphthenic acid is cyclopentane acetic acid [1123-00-8] (1, n = 1). 

Fluonnation and skeletal transformation of fluorinated cycloalkanes occurs in the reaction with antimony pentafluoride at high temperature [777] In the case of perfluorinated benzocyclobutanes, an unexpected alicyclic ring cleavage has been observed Perfluorinated alkyl benzocyclobutanes, when treated with antimony pentafluoride, ean be converted to perfluorinated styrenes and then transformed to perfluorinated indans [77S, 779]... 

The results of the calculation of the activation energies and the rate constants of peroxyl, alkoxyl, and alkyl radicals with alkanes and cycloalkanes are presented in Table 6.3-Table 6.5. 

The petroleum-based oils contain hundreds to thousands of hydrocarbon compounds, including a substantial fraction of nitrogen- and sulfur-containing compounds. The hydrocarbons are mainly mixtures of snaight- and branched-chain hydrocarbons (alkanes), cycloalkanes, and aromatic hydrocarbons. Polynuclear aromatic hydrocarbons, alkyl polynuclear aromatic hydrocarbons, and metals are important components of motor oils and crankcase oils, with the used oils... 

Few examples of preparatively useful intermolecular C-H insertions of electrophilic carbene complexes have been reported. Because of the high reactivity of complexes capable of inserting into C-H bonds, the intermolecular reaction is limited to simple substrates (Table 4.9). From the results reported to date it seems that cycloalkanes and electron-rich heteroaromatics are suitable substrates for intermolecular alkylation by carbene complexes [1165]. The examples in Table 4.9 show that intermolecular C-H insertion enables highly convergent syntheses. Elaborate structures can be constructed in a single step from readily available starting materials. Enantioselective, intermolecular C-H insertions with simple cycloalkenes can be realized with up to 93% ee by use of enantiomerically pure rhodium(II) carboxylates [1093]. 

Products of ethylation and methylation of enolates of cycloalkane-1,3-diones with ring sizes 7-10 have been studied under a variety of alkylating reagent-solvent systems. Decrease in the 0 C alkylation ratios with increase in ring size is believed to be a consequence of greater steric strain in the conjugated enolate resonance contributor and consequent diminution in the proportion of D-attack. 

Cycloalkenes such as cyclohexene, 1-methylcyclohexene, cyclopentene, and nor-bornene are hydrosilylated with triethylsilane in the presence of aluminum chloride catalyst in methylene chloride at 0 °C or below to afford the corresponding hydrosilylated (triethylsilyl)cycloalkanes in 65-82% yields [Eq. (23)]. The reaction of 1-methylcyclohexene with triethylsilane at —20 °C occurs regio- and stereoselectively to give c/i-l-triethylsilyl-2-methylcyclohexane via a tra x-hydrosilylation pathway. Cycloalkenes having an alkyl group at the double-bonded carbon are more reactive than non-substituted compounds in Lewis acid-catalyzed hydrosilylations. ... 

Arylalkenes [23] and alkenes with electron withdrawing substituents [24] can be bis-alkylated across the alkene bond by electrochemical reaction with dflialoal-kanes giving 3- to 6-membered carbocyclic products in good yields. ITie best reaction conditions use an undivided cell with a nickel cathode and a sacrificial aluminium anode in dimethylformamide or N-methylpyrrolidone containing a tetraalkylammonium salt. Anodically generated aluminium ions are essential for the reaction. 1,2-Disubstituted alkenes, regardless of their stereochemistry, are converted to the tranj-substituted cycloalkane. 

Yttrium-catalyzed enyne cyclization/hydrosilylation was proposed to occur via cr-bond metathesis of the Y-G bond of pre-catalyst Cp 2YMe(THF) with the Si-H bond of the silane to form the yttrium hydride complex Ig (Scheme 8). Hydrometallation of the C=G bond of the enyne coupled with complexation of the pendant G=G bond could form the alkenylyttrium alkyl complex Ilg. Subsequent / -migratory insertion of the alkene moiety into the Y-C bond of Ilg could form cyclopentylmethyl complex Illg. Silylation of the resulting Y-C bond via cr-bond metathesis could release the silylated cycloalkane and regenerate the active yttrium hydride catalyst. Predominant formation of the /ra //j--cyclopentane presumably results from preferential orientation of the allylic substituent in a pseudo-equatorial position in a chairlike transition state for intramolecular carbometallation (Ilg —IHg). 

The influence of the length of fhe alkyl chain of fhe imidazolium IL s cation on the solubility in n-alkanes or cycloalkanes, and the interaction with a solvent has already been discussed for different ILs by the comparison of... 

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