Olefin derivatives

Opposing reactions. Consider the kinetics of the N02-catalyzed isomerization of olefins. Derive the expression shown for kCV]. where KTC = k,mns/kCiS, in experiments starting only with m-olefin,11... 

LAB is derived exclusively from petroleum- or natural gas-based feedstocks. Thus, it is referred to as a petrochemical (or synthetic) surfactant intermediate. Feedstocks for LAB production are generally paraffins (carbon chain length in the range of C8-C14) derived from kerosene and benzene. Internal olefins derived from ethylene are sometimes used in place of paraffins. 

Here R is a methyl or ethyl group, R is C4 including branched all l, R is the olefin derived from dehydration of R OH, and R ° is an oligomer of R ". It is demonstrated here that these pathways can be controlled by the properties of the acid catalyst utilized,... 

Reaction pathways apparently analogous to d and f of Eq. (26) yield a mixture of propylene and cyclopropane. Only when photochemical activation was employed were the major products olefins derived from metathesis-decomposition of the metallocycle. The failure to form metathesis olefins under moderate conditions is significant. It may be that either unimolecular dissociation of the olefin from the complex (in the absence of excess olefin to restabilize the carbene) is energetically unfavored, or the metallocyclobutane structure in the equilibrium given by steps a and b in Eq. (26) is highly stabilized and favored. These results... 

Another area of high research intensity is the catalytic dehydrogenation of alkanes to yield industrially important olefin derivatives by a formally endothermic (ca. 35 kcal mol-1) loss of H2. Recent results have concentrated on pincer iridium complexes, which catalytically dehydrogenate cycloalkanes, in the presence of a hydrogen accepting (sacrificial) olefin, with turnover numbers (TONs) of >1000 (Equation (23)) (see, e.g., Ref 33,... 

In 2008, Chakraborty el al. reported that Michael addition of nitromethane to the sugar olefinic derivative 36 provided the sugar-based (I-nitro acid ester 37 (Scheme 14), which was used as starting material for the preparation of a novel type of cyclohexyl amines.36... 

This condensation is completely analogous to that of ethyl diazoacetate, mentioned on p. 281, and, in general, azides and aliphatic diazo-compounds are strikingly similar in the manner in which they react with unsaturated substances like acetylenes, olefine derivatives, and hydrogen cyanide to yield heterocyclic compounds. 

It is particularly interesting, that some titanium and tantalum carbene complexes olefinate derivatives of carboxylic acids. These reagents are, moreover, much less basic than phosphorus ylides, and thus enable the olefination of strongly C-H acidic carbonyl compounds. 

The reduction of simple trisubstituted olefins derived from 25d has found use in the enantioselective total synthesis of pseudopteroxazole 31c, demethyl methoxy-calamenene 32c, and both enantiomers of mutisianthol 33c (Scheme 4) [41,46,47]. 

Chiral l,T-diphosphetanylferrocene Et-FerroTANE serves as an effective ligand for the rhodium-catalyzed hydrogenation of y9-aryl- and /9-alkyl-substituted monoamido ita-conates (Eqs. 19 and 20) [54]. The Et-DuPhos-Rh catalyst was utihzed for the asymmetric hydrogenation of the trisubstituted olefin derivative in the preparation of an important intermediate for the drug candoxatril (>99% ee) [110]. 

Generally, nitrosamides I undergo irreversible thermal rearrangements (at temperatures ranging from ambient to ca.lOO ) to diazo esters III which themselves decompose even faster under these conditions to give the carboxylic esters or acids and the olefins derived from the R group (1,2). The stability of nitrosamides and the final products from III are very much dependent on the nature of the R group (primary, secondary, tertiary... 

Racemic aldehyde 2 under similar reaction conditions yielded two diastereo-meric pinacols the configuration of all the products was assigned by X-ray diffraction. On the basis of these results a mechanistic scheme could be proposed to explain the stereochemical course of the coupling reactions [19]. It is assumed that the reaction proceeds via an intermediate titanaoxirane by insertion of a molecule of aldehyde 2 into the Ti—C bond - a proposal that has been put forward recently on the basis of DFT calculations [20]. The pinacol-type coupling products could be employed as bidentate P,P chelate ligands to Mo(CO)4 fragments however analogous experiments carried out with the olefinic derivatives 18 were unsuccessful [19]. 

Similar it - metal interactions have been suggested for the intramolecular interaction of an olefin with aluminum in terminal olefin derivatives of the type AI[(CH2) CH=CH2]3, which have been shown to be monomeric in solution even though the corresponding AL[(CH2) +1CHs]3 alkyl derivatives are predominantly dimeric with bridging alkyl groups under similar conditions (37). 

A great number of olefinic compounds are known to photodimerize in the crystalline state (1,2). Formation of a-truxillic and / -truxinic acids from two types of cinnamic acid crystals was interpreted by Bernstein and Quimby in 1943 to be a crystal lattice controlled reaction (5). In 1964 their hypothesis on cinnamic acid crystals was visualized by Schmidt and co-workers, who correlated the crystal structure of several olefin derivatives with photoreactivity and configuration of the products (4). In these olefinic crystals the potentially reactive double bonds are oriented in parallel to each other and are separated by approximately 4 A, favorable for [2+2] cycloaddition with minimal atomic and molecular motion. In general, the environment of olefinic double bonds in these crystals conforms to one of three principal types (a) the -type crystal, in which the double bonds of neighboring molecules make contact at a distance of -3.7 A across a center of symmetry to give a centrosymmetric dimer (1-dimer) (b) the / -type crystal, characterized by a lattice having one axial length of... 

The boiling point, refractive index, and density of the olefin derivative of any paraffin were shown, by use of Table III, to stand in the onier of their olefin type. Table X contains the engine data of the olefin derivatives of 2-methylpentane and 3-methylpentane, recorded in the order of their olefin type. No consistent relations between octane numbers or critical compression ratios are obvious—but the blending octane numbers of these branched olefins, as measured by both the research and Motor methods, do generally stand in the order of their type. Two olefins of type III form exceptions, the exceptions being in one case too high and in the other case too low. 

Another very important property of plasticizers for PVC resins is the ability to act as a dispersing medium for polyvinyl chloride plastisols. The performance of the particular plasticizer in a plastisol application depends to a great extent on a property known as its viscosity stability. The stability of the plastisol to viscosity build up is the manifestation of the solvating effects of the plasticizer, and thus, those materials with higher solvating efficiency tend to display an increase in plastisol viscosity on standing. Figure 3 is the plot of the viscosity stability of PVC o-phthalate ester plastisol compositions and, in essence, compares the alcohol-derived plasticizers with that of the olefin-derived plasticizer. The data show that... 

The degradation of a 20-ketopregnane to a 17-ketoandrostane by ozonolysis first requires conversion of the 20-ketone to a A17(20)-olefinic derivative. This can be accomplished by ... 

Reaction XL. (6) Action of Carbon Monoxide on Alcohols under pressure in Presence of Catalysis. (J. C. S., 1936, 358.)—Acetic acid and higher acids can be formed by the action of carbon monoxide on the alcohol at 330° and 200 atm. in presence of phosphoric acid catalysts. Branched chain acids may be formed from normal alcohols, through the intermediary of the olefines derived from the alcohols by dehydration. 

The mass spectra of monometallic olefin derivatives of metal carbonyls of the following types have been investigated ... 

Aside from regioisomers, exojendo diastereoisomers are formed when substituted olefinic derivatives are transformed. The exojendo ratio is manly determined on the stage of the exciplex when secondary orbital interactions occur. These interactions may be compared to those which influences... 

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