Alkanes olefination

Since it is well known that chloroalkenes are often much less stable than the corresponding alkanes, olefinic unsaturation may be an important source of thermal instability in PVC. Chain-end unsaturation could arise by disproportionation during bimolecular reaction of polymer radicals Eq. (2). 

Synthetic fibers washing (Alkylphenol ethoxylates,) fatty alcohol ethoxylates, alkane (olefine)-sulfonates, fatty alcohol (ether) sulfates, end-group-blocked fatty alcohol ethoxylates... 

The reaction selectivity is better under these conditions at steady state, because an equihbrated ratio is observed between the resulting higher and lower homolog alkanes. In addition, dynamic conditions allow us to vary the contact time to obtain information about primary products and then about the mechanism. It appears that, in the case of propane metathesis in a stationary regime, conversion increases Hnearly with contact time, which shows that the reaction is under dynamic control with no diffusion Hmitation. Under these conditions, decreasing contact time results in an increase of the selectivity for hydrogen and olefin whereas that of alkanes decreases. Similarly, the alkanes/olefins ratio tends to zero as the contact... 

The hydrocarbons in cmde oil are alkanes, olefins, aromatics, polyaromatics, and organic compounds containing S, N, 0, and heavy metals. Since there are many isomers of aU of these types of molecules, the reactions implied by the preceding equations rapidly approach infinity. A representative reaction of these might be the cracking of hexadecane (number 3 heating oil) into octane and octette (components in gasoline). 

Type II (slow homodimerization) Styrene, allylstannanes" Styrene, 2° allylic alcohols, vinyl dioxolanes, vinyl boronates Styrenes (large ortho substit.) " " 2° allylic alcohols, vinyl epoxides, unprotected 3° allylic alcohols, acrylates, acrylamides, acrylic acid, acrolein, vinyl ketones, vinyl boronates perfluorinated alkane olefins ... 

Type IV (spectators to CM) 1,1-Disubstituted olefms " 1,1-Disubstituted olefms, disub. o ,/ -unsaturated carbonyls, 4° allylic carbon-containing olefins, perfluorinated alkane olefins, 3° allylamines (protected)" Vinyl nitro olefins, protected trisubstituted allyl alcohols, a,/ -olefin of 2-subst. 1.3- butadienes, a,/ -olefm of electronically deactivated 1.3- butadienes ... 

The underlying cause of isomerism was disclosed only after the structure theory was produced. Owing to the work of Butlerov and his followers the isomers of various classes of organic compounds, alkanes, olefins, alcohols, etc., were investigated. In 1867 the German chemist W. Korner, a student of A. Kekule, introduced the terms ortho-, meta-, and para-isomer for disubstituted derivatives of benzene. 

Wagenknecht [17] found that the reduction of 1-bromobutane at graphite in carbon dioxide-saturated DMF containing TEABr is a two-electron process, and that the generated butyl carbanions lead to the formation of butane, 1-butene, octane, butyl valerate, butyl-A,A-dimethyloxamate, and dibutyl-2-methylmalonate. Earlier work by Kaabak and CO workers [26], dealing with the reduction of iodoethane and 1-bromobutane at graphite in DMF, revealed that alkanes, olefins, dimers, and solvent-derived species are produced. 

Iron porphyrins have been studied extensively over the past 30 + years as model systems of cytochrome P450.13 Biomimetic model studies included variants in axial ligands (thiolate and other bases), the oxidation of alkanes, olefins, sulfides, and amines, and utilization of several oxidants such as hypochlorite (bleach), iodoso-benzene (ArlO), hydrogen peroxide, and organic peroxides (ROOH). The first-generation models employed the mevo-tetraary I porphyrins (Figure 3.5). These were... 

Traditionally, the exact same basis set will be used to define atoms in varying chemical environments. The 6-310 carbon basis set is the same regardless of the nature of the carbon (alkane, olefin, alcohol, carbanion, ketone, carboxylic acid, etc.). The three-dimensional space of the carbon atom must be different in these molecules, yet the Mulliken procedure sums up the occupancy of identically defined orbitals in all these different chemical environments. The natural population analysis (NPA), developed by Reed, Weinstock, and Weinhold,i0 > 8 attempts to define atomic orbitals based on the molecular wavefunction, thereby obtaining different atomic orbitals depending on the chemical environment. 

In homogeneous catalytic chlorination in the liquid phase, a chloride of I, P, S, Sb, Fe, or Sn (for patent literature see reference 324a), or radical-formers such as tetraethyllead,325 are added to the liquid or CC14 solution of the alkane. Olefins which may be present also act as catalysts.326,327... 

The exhaust gas of spark ignited engines contains a hydrocarbon mixture of complex composition ranging from Ci to C9 molecules including alkanes, olefins, diolefins, alkynes and aromatics. 

Skeletal rearrangement of alkanes, olefins, and functionalized compounds pinacolone rearrangement Wagner-Meerwein rearrangement epoxide rearrangement rearrangement of cyclic acetals... 

Another recent finding is that NOx can be selectively reduced by a variety of organic compounds (e.g., alkanes, olefins, alcohols) over several different catalysts under excess O2 ("lean") conditions. This reaction is referred to as hydrocarbon-SCR (HC-SCR). HC-SCR was first independently reported by Held [31] and by Iwamoto [32] and their co-workers. Both groups concluded that Cu-ZSM5 was the most effective catalyst for this reaction. Unlike NO decomposition, however, the Cu-ZSM5 HC-SCR catalyst is not completely poisoned by S02[33]. Follow-up studies have now demonstrated that various other hydrogen- [34] and metal-exchanged zeolites [35-37], as well as non-zeolitic materials [38-40] are HC-SCR catalysts under a variety of reaction conditions. 

The acronym FIONA, which is often used, means Paraffins (n-alkanes). Isoparaffins (iso-alkanes). Olefins (alkenes), Naphtenes (cyclanes). Aromatics. 

The composition of coke formed during the transformation of alkanes, olefins and monoaromatics on various zeolites was established within a large range of temperatures (100-450°C). The main conclusions drawn from this study are ... 

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