Vinylic 1-hexene

As in the Negishi reaction, various alkylboron reagents have also been successfully coupled with electrophile partners. Suzuki et al. coupled 1-bromo-l-phenylthioethene with 9-[2-(3-cyclohexenyl)ethyl]-9-BBN (27), prepared by a simple addition of 9-borabicyclo[3.3.1]nonane (9-BBN) to 4-vinyl-1-hexene (26), to furnish 4-(3-cyclohexenyl)-2-phenylthio-1-butene (28) in good yield [36],... 

C-H vinyl C-H, associated with (CH2=CH-) C-H, vinyl (hexene), CH2=CH- Hydrocarbons, aliphatic... 

Reactions of 3- and 4-piperidone-derived enamines with a dienester gave intermediates which could be dehydrogenated to tetrahydroquinolines and tetrahydroisoquinolines (678). The methyl vinyl ketone annelation of pyrrolines was extended to an erythrinan synthesis (679). Perhydrophenan-threnones were obtained from 1-acetylcyclohexene and pyrrolidinocyclo-hexene (680) or alternatively from Birch reduction and cyclization of a 2-pyridyl ethyl ketone intermediate, which was formed by alkylation of an enamine with a 2-vinylpyridine (681). 

Table 12.3 Claisen rearangement of allyl vinyl ether to form 5-hexenal ...

Look at the IR spectra of hexane, 1-hexene, and 1-hexyne in Figure 12.14 to see an example of how IR spectroscopy can be used. Although all three IR spectra contain many peaks, there are characteristic absorptions of the C=C and C=C functional groups that allow the three compounds to be distinguished. Thus, 1-hexene shows a characteristic C=C absorption at 1660 cm"1 and a vinylic =C—H absorption at 3100 cm"1, whereas 1-hexyne has a C=C absorption at 2100 cm"1 and a terminal alkyne =C-H absorption at 3300 cm"1. 

Alkenes show several characteristic stretching absorptions. Vinylic =C—H bonds absorb from 3020 to 3100 cm-1, and alkene C=C bonds usually absorb near 1650 cm-1, although in some cases the peaks can be rather small and difficult to see clearly. Both absorptions are visible in the 1-hexene spectrum in Figure 12.14b. 

Der Bis-[2-phenyl-2-cyan-vinyl]-ather (1) wird iiberwiegend zum 2,5-Diphenyl-hexen-(2)-disdure-nitril (III) reduziert. Je nach Kathodenpotential wird zusatzlich 2,5-Diphe-nyl-hexadien-(2,4)-disaure-dinitril (II) bzw. bei 2 V das 2,5-Diphenyl-hexandisaure-dinitril (IV) erhalten. Da es sich hier primar um die Rekombination zweier radikalischer Spaltprodukte des Athers I handelt, ist cine hohe Depolarisator-Konzentration vorteil-haft2 ... 

The reactivity of T8[OSiMe2H]g is dominated by its capacity to undergo hydrosilylation reactions with a wide variety of vinyl and allyl derivatives (Figure 30) that have subsequently mainly been used as precursors to polymers and nanocomposites by the introduction of reactive terminating functions as shown in Table 19. For example, T8[OSiMe2H]g has been modified with allyglycidyl ether, epoxy-5-hexene, and 1,2-cyclohexene-epoxide to give epoxy-terminated FOSS. These have then been treated with m-phenylenediamine, with polyamic acids or... 

In contrast to the behavior of 3-hexyne in trifluoroacetic acid, addition of HCl in acetic acid yields essentially rra s-3-chloro-3-hexene (48%) and 3-hexanone (52%) as products, with less than 1% of the cis chloride (31,42,43). The 3-hexanone has been shown to arise from an intermediate vinyl acetate. The kinetics are complicated, but they seem to be of first order in substrate and second order in HCl. Added tetramethylammonium chloride increases the rate of product formation and changes the product composition to >95% trans-3-chloro-3-hexene and <5% 3-hexanone. A termolecular electrophilic addition via an intermediate such as 14 has been proposed (31,42) to account for these data. 

The monomers used to make an addition polymer need not be identical. When two or more different monomers are polymerized into the same chain, the product is a copolymer. For instance, we routinely copolymerize ethylene with small percentages of other monomers such as a-olefins (e.g., 1-butene and 1-hexene) and vinyl acetate. We call the products of these reactions linear low density polyethylenes and ethylene-vinyl acetate copolymer, respectively. We encounter these copolymers in such diverse applications as cling film, food storage containers, natural gas distribution pipes, and shoe insoles. 

We can incorporate short chain branches into polymers by copolymerizing two or more comonomers. When we apply this method to addition copolymers, the branch is derived from a monomer that contains a terminal vinyl group that can be incorporated into the growing chain. The most common family of this type is the linear low density polyethylenes, which incorporate 1-butene, 1-hexene, or 1-octene to yield ethyl, butyl, or hexyl branches, respectively. Other common examples include ethylene-vinyl acetate and ethylene-acrylic acid copolymers. Figure 5.10 shows examples of these branches. 

Since vinyl anions generally retain configuration 39> while isomeric vinyl radicals rapidly interconvert 40) these results constitute evidence that reductions of alkyl iodides do proceed via radical intermediates. Isomerization of stereoisomeric vinyl anions is ruled out by the lack of effect of phenol on the stereochemistry of the products (Scheme III). Since cis and trans-3-hexene are formed in differing proportions from the two halides, it may be concluded that the stereoisomeric vinyl radicals are being intercepted by electron trans-... 

The partial loss of configuration often observed during reduction of cyclopropyl halides may actually occur via the corresponding cyclopropyl radicals, which lose configuration rapidly °>. In that event, their behavior would resemble that of vinyl halides, as exemplified by the 3-iodo-3-hexenes 16>. Occasional cases of partial inversion could be associated with shielding of the cyclopropyl carbanion by the electrode surface, with concomitant protonation on the other face of the carbanion S8>. 

For the addition of ethylene, EtOAc as solvent was particularly advantageous and gave 418 in 60% yield (Scheme 6.86). The monosubstituted ethylenes 1-hexene, vinylcyclohexane, allyltrimethylsilane, allyl alcohol, ethyl vinyl ether, vinyl acetate and N-vinyl-2-pyrrolidone furnished [2 + 2]-cycloadducts of the type 419 in yields of 54—100%. Mixtures of [2 + 2]-cycloadducts of the types 419 and 420 were formed with vinylcyclopropane, styrene and derivatives substituted at the phenyl group, acrylonitrile, methyl acrylate and phenyl vinyl thioether (yields of 56-76%), in which the diastereomers 419 predominated up to a ratio of 2.5 1 except in the case of the styrenes, where this ratio was 1 1. The Hammett p value for the addition of the styrenes to 417 turned out to be -0.54, suggesting that there is little charge separation in the transition state [155]. In the case of 6, the p value was determined as +0.79 (see Section 6.3.1) and indicates a slight polarization in the opposite direction. This astounding variety of substrates for 417 is contrasted by only a few monosubstituted ethylenes whose addition products with 417 could not be observed or were formed in only small amounts phenyl vinyl ether, vinyl bromide, (perfluorobutyl)-ethylene, phenyl vinyl sulfoxide and sulfone, methyl vinyl ketone and the vinylpyri-dines. 

Vinyl halides, such as ds- and trans- i-iodo-3-hexene [33], undergo a one-electron reduction with expulsion of a hahde ion to give a vinyl radical that is further reduced and protonated. When vinyl halides are electrolyzed in the presence of trimethylchlorosilane, sdylated products are obtained [34]. 

In the tetrabromide of 4-vinyl-l-cyclo-hexene, the higher alkylated double bond could be selectively deprotected by cpe [177]. 

Use of aryl, vinyl and alkynyl iodides as electrophiles is possible using Pd° catalysis. Dieter and Li have evaluated the reaction between Al-Boc-pyrrolidine and Af-Boc-piperidine with several aryl and heteroaryl iodides, 1- and 2-iodo-l-hexene, and 1-iodohexyne. The yields range from about 10-80%, with typical yields in the 40-60% range (Scheme 32). 

Poly(propylene-co-1 -hexene) Poly(ethylene-co-vinyl acetate) Styrene-ethylene-butylene-styrene - - oil Styrene-butadiene-styrene -I- oil Nitrile rubber Nitrile rubber -I- diluent ... 

In addition, phenylsufonylallene (110), a,(3-unsaturated phosphonates (111), and alkenes with perfluorinated substituents (112) are all useful dipolarophiles. The yields observed with methyl 2-propenoate are significantly lower than those with the corresponding acrylate (entries 7 and 9), because of the additional substituent. On the other hand, the dipolar cycloadditions with either ethyl vinyl ether, 1-hexene, cyclohexene, or a trisubstituted dipolarophile provide the corresponding isoxazolidines in either low yields or not at all (18). 

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