Olefinic and Allenic Hydrocarbons

Areas of acetylenic chemistry reviewed recently include the base-catalysed isomerization of acetylenes, nucleophilic additions to acetylenes, additions to activated triple bonds, synthetic and naturally occurring acetylene compounds as drugs, allenic and acetylenic carotenoids, linear polymers from acetylenes, carbonylation of mono-olefinic and monoacetylenic hydrocarbons, and the combustion and oxidation of acetylene. Several books have also appeared. ... 

In addition, saturated tertiary hydrocarbons [108] also act as a chiral source of asymmetric autocatalysis to give the pyrimidyl alkanol, with the absolute configurations corresponding to that of the chiral alkanes (Scheme 21). The correlation between the absolute configuration of the hydrocarbon and that of the obtained alkanol is reproducible. Therefore, the asymmetric autocatalysis is sufficiently applicable as a chiral sensor for saturated tertiary hydrocarbons. Various chiral hydrocarbons with zr-electrons such as 1,1 -binaphthyls [110], helicenes [82], olefins [83], allenes [111], and [2.2]paracy-clophanes [112,113] serve as chiral initiators in this asymmetric autocatalysis. 

Two separate studies on photocyclization of allenes include examples of how Lewis acids and the polarity of the solvent affect the regioselectivity of the addition of activated olefins and 1,1-dicyclopropylallene, and provide details of the intramolecular photoaddition of allenes to a,p-cyclohexenones. Copper(i) trifluoromethanesulphonate has been found to catalyse the intramolecular photocyclization of several monocyclic (3- and Y"(pent-4-enyl)allyl alcohols for instance, the allyl alcohol (19) forms the tricyclic hydrocarbon (20), which is an... 

This chapter comprises organotin derivatives of unsubstituted acetylenic hydrocarbons and their tautomeric allenic forms. Compounds with olefinic and acetylenic groups follow the principle of the next neighbors, i.e., ccmipounds with the olefinic group nearer to tin shall be found in Chapter 2.. The derivatives listed in Tables 106 and 107 are prepared by methods from the following scheme. 

Dioxiranes are three-membered cyclic ring peroxides that are expected to be very unstable owing to ring strain. They are effective oxygenating agents for epoxidations of olefins, allenes, polycyclic aromatic hydrocarbons, enols. and a, /i-unsaturated ketones for insertions of oxygen into X—H... 

Coordination polymerisation via re complexes comprises polymerisation and copolymerisation processes with transition metal-based catalysts of unsaturated hydrocarbon monomers such as olefins [11-19], vinylaromatic monomers such as styrene [13, 20, 21], conjugated dienes [22-29], cycloolefins [30-39] and alkynes [39-45]. The coordination polymerisation of olefins concerns mostly ethylene, propylene and higher a-olefins [46], although polymerisation of cumulated diolefins (allenes) [47, 48], isomerisation 2, co-polymerisation of a-olefins [49], isomerisation 1,2-polymerisation of /i-olcfins [50, 51] and cyclopolymerisation of non-conjugated a, eo-diolefins [52, 53] are also included among coordination polymerisations involving re complex formation. 

Recently, we reported an entirely new and efficient formal [3 + 2] cycloaddition based on the hydrocarbonation reaction of allenes. The palladium-catalyzed reaction of the activated olefins 4 with allenes 26, bearing an acti-... 

Product distributions are plotted in Figures 7 to 12. These data suggest that the primary products are ethylene, methane, hydrogen, butenes, butadiene, methylcyclopentene, hexadienes, acetylene, and ethane, and the secondary products are cyclopentene, cyclopentadiene, benzene, toluene, and polycyclic aromatics. All C4 olefins were present, with 1-butene the major component. Isobutylene, trans- and cis-2-butene were also identified. Selectivity of polycyclic aromatic hydrocarbon formation was calculated in terms of naphthalene because the main part of these aromatics was found to be naphthalene. Trace amounts of propane, allene, methylacetylene, cyclohexane, cyclohexadiene, 4-methylcyclohex-ene, xylenes, and styrene were also identified. The amount of carbon deposit on the reactor wall was very small and was neglected. 

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