Acyclic monoalkenes

Berndt, T., and O. Boge, Products and Mechanism of the Reaction of NO, with Selected Acyclic Monoalkenes, J. Atmos. Chem., 21, 275-291 (1995). 

Consider a telomer being formed from a cyclopentenyl polymer growing under the pairwise mechanism (Scheme 12.14) with growth being curtailed by cross-metathesis under two extreme conditions (i) with only pent-2-ene present (C4 C5 C6 = 0 100 0) and (ii) with a fully equilibrated mixture of acyclic monoalkenes (C4 C5 C6 = 1 2 1). Under condition (i), one would expect the formation of only hierarchical telomers (n = 1,2,3,4,5, etc.) of the type (C2)-[(cyc-C5) ]-(C3) as the pent-2-ene is split into a C2 and a C3 unit across the growing cyclo polyene. In contrast, under condition (ii), one would expect each hierarchical telomer to be formed in a 1 2 1 ratio of (C2)-[(cyc-C5)n]-(C2) (C2)-[(cyc-C5) ]-(C3) (C3)-[(cyc-Q)n]-(C3)> depending on whether there is cross-metathesis with C4, C5 or C6 (ratio = 1 2 1). The outcome will thus depend on how quickly the pent-2-ene is equilibrated by homo-metathesis to yield the C4, C5 and C6 mixture. Analysis of the rate of pent-2-ene homo-metathesis showed that it was not fast. Indeed, it proceeded at approximately the same rate as the telomerisation reaction. One would thus expect the telomer product early in the reaction to be essentially pure (C2)-[(cyc-C5) ]-(C3) species. Then, as C4 and C6 increase in concentration relative to C5, formation of the (C2)-[(cyc-C5) ]-(C2) and (C3)-[(cyc-C5) ]-(C3) telomers should increase proportionally. This was not found to be the case. 

Sensitized intramolecular reaction of two 1,3-dienes (86) (Sch. 17) yields predominantly the [2+2] adduct 87, with small amounts of [4+4] adduct 89 and little, if any, [4+2] product 88 [58,59], consistent with Hammond results for intermolecular reactions of acyclic dienes (Sch. 4). Benzophenone-sensitized reaction yields a mixture of two isomers of 87. Heating this mixture to 200 °C converts both isomers of 87 to cyclo-octadiene 89 [58]. Unsensitized photoreaction of 86 in the presence of copper(I) triflate gives a significant amount of [4+2] adduct 88. Extended irradiation time converts much of 87 and 89 into 88, as well as producing secondary products [59]. Copper triflate-mediated photocycloaddition of a related tethered diene-monoalkene, gave only the [2+2] adduct [59]. 

Endoperoxides from acylic 1,3-dienes. 1,4-Endoperoxides have been obtained in the photooxygenation of acyclic 1,3-dienes (5, 488). These are the usual products of oxygenation of cyclic 1,3-dienes. In fact, it was originally suggested that an acyclic 1,3-diene is more reactive to than an isolated double bond. However, more recent results suggest the following order of reactivity of carbon—carbon double bonds toward Oj trisubstituted mono-alkene > 1,3-diene > 1,1-disubstituted monoalkene. ... 

This survey of the 2000 literature relating to rr-hydrocarbon complexes of the transition elements other than p-CsHs and r -arene complexes is similar in nature to previous reports. This chapter is sub-divided into the following sections dealing with reviews complexes containing allyls or monoalkenes unconjugated alkenes conjugated alkenes acyclic alkenes alkynes and polymetallic complexes. 

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