Pent-l-ene

Olefin Metathesis and Metathesis Polymerization 5.5 Pent-l-ene and its derivatives 

The behaviour of pent-l-ene is typical of that of terminal olefins. Its metathesis to form oct-4-ene and ethene, reaction (9), is most readily achieved with high 

Catalysts based on M0CI5, WClg, or ReCls generally lead to extensive alkylation (Graham 1971 Uchida, A. 1971) or isomerization (Uchida, Y. 1972 Uchida, A. 1977), with little or no apparent metathesis. Some exceptions to this rule are the 

Catalyst system Solvent Typical yield Reference 

MoCl2(PPh3)2(NO)2/Me3Al2Cl3 PhCl/5 C 48%/50min Zuech 1968, 1970 Hughes 1974 

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When quinalbarbitone (secobarbital, 296) was irradiated in acid solution (pH 2) at 254 nm, it underwent photodealkylation to give (297), (298), pent-l-ene and pent-2-ene. These four compounds were also obtained at pH 10, but in addition there were the ring-opened materials (299) to (301), Scheme 2.7 [ 176],... 

Synonyms Amylene a-/3-Amylene BRN 1731269 EINECS 203-694-5 Pent-l-ene 1-Pentylene Propylethylene, UN 1108. 

The elimination of hydrogen halides from some monohaloalkanes can result in the formation of two alkenes. Consider 2-bromopentane, for example. You can see from its structure that the elimination of HBr will produce both pent-l-ene and pent-2-ene. 

FIGURE 5. Reduction in linewidth in the Li solid state NMR spectrum of the dimer of ( )-2-lithio-l-phenyl-1-(o-hthiophenyl)pent-l-ene (90% Li) by various techniques (a) static Li H spectmm, halfwidth 6.3 kHz (b) Li H CP/MAS spectmm, rotational frequency 3 kHz (c) central transition in the Li H CP/MAS spectmm, halfwidth 130 Hz (d) central transition in the Li H CP/MAS spectmm with additional Li decouphng. The two Li resonances are separated by 1.25 ppm hneshape analysis yields half-widths of 92 and 81 Hz, respectively ... 

Monomer CH3CH2CH2CH=CH2 Preferred lUPAC name pent-l-ene... 

Structure-based name poly(l-propylethane-l,2-diyl). Source-based name poly(pent-l-ene)... 

Comparison of the results for catalytic isomerization of pent-l-ene to trans-pent-2-ene with the basic and one-electron donating properties of the catalysts led to the conclusion that two different reaction mechanisms operate in double bond isomerization reactions (a) an ionic mechanism which involves proton abstraction from the alkene molecule by the super base site (pAia = 37 for pentenes) and (b) a free radical mechanism which involves the abstraction of a hydrogen atom from the alkene by the one-electron donor center (Scheme 39). 

Cycloalkenes undergo ring-opening polymerization in the presence of coordination initiators based on transition metals to yield polymers containing a double bond, for instance, cyclo-pentene yields polypentenamer [IUPAC poly(pent-l-ene-l,5-diyl)] [Amass, 1989 Cazalis et al., 2000, 2002a,b Claverie and Soula, 2003 Doherty et al., 1986 Ivin, 1984, 1987 Ivin and Mol, 1997 Ofstead, 1988 Schrock, 1990, 1994 Tmka and Gmbbs, 2001], The... 

Ethene and 1-hexene do not react with hydrosilane under GO pressure in the presence of an Rh catalyst. Any product is obtained under the conditions similar to the reaction of 1-alkynes. Thus, the alkynyl moiety in pent-l-ene-4-yne 48, 4-oxahept-l-en-6-yne 50, and 4-oxa-2-methylhept-l-en-6-yne 52 is solely silylformylated to give 49, 51, and 53, respectively (Equations (12)-(14)). 

Solvent Conversion (%) pent-l-ene Yield (%) pentane Yield (%) pent-2-ene TOF (min )... 

BMrSbFe was used in the catalytic hydrogenation of pent-l-ene the rates were nearly five tunes higher than for the comparable homogeneous reaction in acetone (see table 6.6). 

In marked contrast to that of cyclobutanes, the cycloreversion of cyclobutanones to ethene and ketene88 is most probably a concerted process.89-94 For example, the fact that the pyrolysis of 2-propylcyclobutanone (13) at 350 °C gives ethene and pent-l-ene in the ratio of 3.8 1 is not easily explained by a diradical mechanism.90 This transformation presumably involves two competing cycloreversion reactions. As expected for a concerted process, the conversion through the less sterically congested transition structure is favored. For this reason, ethene is generated as the major alkene.90... 

L = CO, ethylene, propene, pent-l-ene, butadiene, H2S, THF, acetone, acetonitrile, nitromethane). The moiety [Re(CO)5] + can also be added to a nucleophilic atom of a coordinated ligand, which provides a systematic way to prepare ligand-bridged complexes,12 for example,... 

Other alkene complexes [Re(CO)5(alkene)] [BF4] (alkene = propene, pent-l-ene, buta-1,3-diene) can also be obtained from Re(CO)5(FBF3) and alkene.13... 

Sc (ri -C5Me4)Si(Me)2NBu (PMe3)(p.-H)]2 was a catalyst for the oligomerisation of propene, but-l-ene or pent-l-ene and polymerisation of Using stoichiometric... 

Friedel-Crafts alkylation of benzo[6]thiophene has received little attention. The published results, which deserve reexamination, indicate that exclusive 3-substitution occurs in some cases, whereas in others, 2-substitution predominates. Benzo[6]thiophene is alkylated with isopropyl chloride, isopropanol, or propene in the presence of various acid catalysts under a variety of reaction conditions to give a mixture of 2- and 3-isopropylbenzo[6]thiophene in which the 2-isomer predominates (78-92%).358 410 In contrast, alkylation with isobutene in the presence of either 80% sulfuric acid415 or 100% phosphoric acid416 is said to afford exclusively 3-/er<-butylbenzo[6]thiophene in yields of 100 and 75%, respectively. In neither case was the structure of the product rigorously confirmed. Likewise, 3-Jeri-amylbenzo [63-thiophene is the exclusive product of alkylation with tert-amyl alcohol in the presence of stannic chloride414 alkylation with pent-l-ene, hex-l-ene, and a Ci8 propylene polymer is also claimed to give... 

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