Norbomene and norbomadiene

Butoxynorbomadiene provides a convenient route to 7-sub-stituted norbomenes and norbomadienes including anti-7-nor-bomenol,2 7-norbomadienyl acetate,2 7-norbomadienol,2 7-chloro-norbomadiene, 7-methylnorbomadiene, and 7-phenylnorbor-... 

Although the gem-dihalocyclopropanes are fairly stable compounds, they can participate — as has been shown in the above sections — in quite a number of chemical transformations. Several reactions between dihalocarbenes and alkenes have been described in which no dihalocyclopropane formation could be observed that these intermediates might have been produced was only inferred from the type of products finally isolated. A typical process of this type is the e/ufo-addition of dihalocarbenes to norbomene and norbomadiene as discussed above. Comparable rearrangements have been observed, when dichlorocarbene additions either lead to aromatic products or when they cycloadd to rather inert aromatic systems. In the latter case a ring-enlargement takes place. A reaction related to the concerted opening of two cyclopropane rings in a bicyclopropyl system as discussed above takes place when dichlorocarbene is added to spiro[2.4]hepta-4,6-diene [227]. 

Bomane Group (BicycloQ2.2.IQ heptane Type). Name the bomane-type bicyclic terpene hydrocarbons (bicycleheptane type) as norbomanes, norbomenes, and norbomadienes and base these names on systematic bicyclo numbering and rules (Formula 73, Chart 9). For those derivatives which have a carbon skeleton identical to bomane, use the bomane, bomene, and bornadiene names, and base these names on the recommended fixed numbering of the bomane carbon skeleton (Formula 75, Chart 8). See Chart 14. 

Olefinic dipolarophiles, such as dimethyl fumarate, fumaronitrile, ethyl vinyl ether, AT-phenylmaleimide, norbomene, and norbomadiene, react with... 

Hydrocyanation is also catalyzed by [Pd(PPh3)4] (103) and [Pd P(OPh), 4] (132), again in both cases in the presence of excess ligand. Complex (132) is an effective catalyst for the addition of hydrogen cyanide to cyclic monoenes and dienes such as norbomene and norbomadiene ethylene also reacted readily. The product obtained from norbomene was the exo isomer (equation 165). When norbomadiene was the substrate, some of the endo product was formed. ... 

Asymmetric hydrocyanation has now been achieved using norbomene and norbomadiene as substrates. The reduction of either [PdCl2(+)-DIOP] or PdCl2 in presence of (-I )-DIOP led to a palladium(O) species formulated simply as [Pd(-l-)-DIOP]. This gave, in reaction (164), an optical yield of 30% for the 2-cxo-cyanonorbornane formed. Norbomadiene with the same catalyst gave 2-cxo-cyanonorborn-5-ene with an optical purity of 17%. When the ligand CHIRAPHOS (51) was used, the catalytic activity was greatly diminished. In addition to the review of the early work already mentioned, two more recent reviews of hydrocyanation have appeared. ... 

Rhj(OAc)4 catalyzes the transfer of S and SO from more readily available episulfides and episulfoxides to norbomene and norbomadiene, albeit in modest yields."... 

In their recent landmark femtosecond-resolved mass spectrometry studies, Zewail and coworkers have used mass spectrometry for monitoring the time-resolved unimolecular fragmentation of neutral norbomene and norbomadiene. In both cases, the RDA reactions occurred, but only in the norbomadiene case was the well-known H loss giving rise to C7H7+ ions found to compete. Still, non-concertedness and biradicaloid character of the intermediates is being addressed by femtosecond dynamic studies. In this context, Kompa and coworkers" have compared the expulsion of H+ from femtosecond-laser-irradiated... 

Cycloadditions. Norbomene and norbomadiene undergo cycloaddition with alkynes from the exo-face. 2,6-Diisopropylphenyl isocyanide is provided as a ligand for the Re catalyst. ... 

The strained double bond in 27 reacts with benzyne (from benzenediazonium carboxylate) to give the exo-[2+2] adduct 346. Analogous cycloadditions to norbomene and norbomadiene are knownh It was recently reported that 7- -butoxynorbornadiene gives both [2+2] regioisomers 348 and 349, as well as the homo[4+2] cycloadduct 350. The predominance of syn (348) over anti (349) adduct is thought to be a consequence of stabilization of the diradical intermediate by the r-butoxy oxygen atom. 

Besides norbomene and norbomadiene, 1,3-dioxolenes are possible partners in these ternary couplings. Hence, starting from unsubstituted or 2-substituted 1,3-dioxolene, tri-butylphenyltin, and various bromoarenes, ci5-4,5-disubstituted 1,3-dioxolanes are obtained in good yields (Scheme 7). ... 

Mo(OBu )(N(C 3PrV2>6)(=CHCMe2R) (R= Me. Ph) polymerise 7-oxabenzonorbomadiene and 2,3-endb-cu-diacetoxy-7-oxonorbaniene into polymers that have a narrow molecular weight distribution. Other norbomene and norbomadiene derivatives form stable metallacycles instead.3 >... 

Abstract The presented paper is a summary of our results on synthesis and polymerization of silyl-containing norbomenes and norbomadienes via ring-opening metathesis polymerization (ROMP) and addition processes as well as ring-opening polymerization (ROP) of silacyclobutanes and disilacyclobutanes. The synthesis of heterochain and carbochain polymer families with regularly varied substituents at Si atom and various number and location Si(CH3)3-substituents has been realized. Systematic study of gas transport parameters of polycarbosilanes series of different classes allowed us to find out real eorrelations between features of chemical polymer structure and its gas separation eharacteristics. 

Norbomenes and norbomadienes derivatives were S5mthesized by Diels-Alder condensation of cyclopentadiene and corresponding dienophile as a key reaction [3-6] ... 

Czelusniak I, Szymanska-Buzar T. Ring-opening metathesis polymerization of norbomene and norbomadiene by tungsten(n) and molybdenum(II) complexes. J Mol Catal A Chem 2002 190 131-143. 

The exact control of polymer microstructures (e.g., tacticity and double-bond configuration) resulting from the ROMP of substituted norbomenes and norbomadienes is essential for the development of polymers with well-defined physical properties. Norbomene and norbomadiene-derived polymers could be accessed with... 

In this area, the complex Cp RuCl(cod) has shown to be an excellent catalyst for the [2+2] cycloaddition of various internal alkynes with a variety of substituted norbomenes and norbomadienes [69-83]. A number of aspects of this reaction have been studied, notably the reactivity, the chemo- and regioselectivity of tmsymmet-rical substrates [69-73] and the asymmetric induction with chiral auxiliaries on the alkyne partner [74—77] [Eq. (31)]. 

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