Formation of Cyclododecatriene

Butadiene reacts with cyclododecatriene-nickel or bis(cyclooctadiene)-nickel at 20° C, replacing the olefinic ligands and forming a new molecule of cyclododecatriene (99), In this reaction atomic nickel must be the catalyst, as it is in some reactions of bis(acrylonitrile)-nickel. Most of the catalytically formed cyclododecatriene has the trans-trans-cis configuration, but, small amounts of the trans-cis-cis isomer have also been detected. When the reaction between (LIV) and butadiene was carried out at — 40°C. Wilke et al. were able to isolate an intermediate (LVI) the nature of which was of great importance in elucidating reaction mechanism. Complex (LVI) is actually a bis(7r-allyl)-nickel type of compound involving a twelve-carbon-atom chain, formed by condensation of three molecules of butadiene. Ally  

The conversion of the C12 chain in (LVI) to cyclododecatriene can also be achieved by treating (LVI) with electron donors such as carbon monoxide, phosphines, or even butadiene. With phosphines under mild conditions the ring closure to cyclododecatriene takes place without decomposition of the complex and cyclododecatriene-nickel-phosphine adducts are isolated (99). With carbon monoxide at — 60° C (LVI) affords a vinylcycloundecadienone (LVII) (99). 

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The next step was to investigate the reaction of the centro-nickel compound wdth butadiene. When a solution of this compound is saturated with butadiene at room temperature, we observe that after a certain period the excess of butadiene has reacted with formation of cyclododecatriene and a new complex which can be isolated by removing the cyclododecatriene under high vacuum. The same catalytic reaction can be carried out by using bis (1,5-cyclo-octadiene) nickel as a catalyst. Cyclododecatriene synthesized in this way consists of three isomers. The main product is trans,trans,trans-cyc ododecdAx ene and the isolated by-products are transytrans,cis- and cis,cis,trans-cyc ododec3itnene. The latter compound is a new isomer, previously imknown (b.p.14 110° C., 1.5129). The synthesis of... 

Finally, the addition of one molecule of P(C2H5)3 induces an electron miration with formation of cyclododecatriene. No displacement occurs and the prodfuct obtained is identical to that prepared from the cyclododecatriene-centro-nickel complex itself ... 

In the catalytic formation of cyclododecatriene, the open chain species is cy-clized and displaced by entering butadiene with simultaneous reformation of the open chain species. When carbon monoxide is added to the complex, coupling takes place with incorporation of carbon monoxide to form cyclic ketone, namely 11-vinyl-3,7-cycloundecadien-l-one 128>. Isocyanide is isoelectronic with carbon monoxide, as described before thus isocyanide effects similar in-... 

The formation of cyclododecatriene nickel from nickel(II) chloride and butadiene in the presence of trialkylaluminium compounds is an example of the oligomerization of a ligand during complex formation. Fiirther examples of this will be found on pp 239-241. 

BH3 itself. One example is the formation of 9-BBN, shown above. Another is conversion of 1,5,9-cyclododecatriene to perhydro-9(i -boraphenalene ... 

Among transition metal complexes used as catalysts for reactions of the above-mentioned types b and c, the most versatile are nickel complexes. The characteristic reactions of butadiene catalyzed by nickel complexes are cyclizations. Formations of 1,5-cyclooctadiene (COD) (1) and 1,5,9-cyclododecatriene (CDT) (2) are typical reactions (2-9). In addition, other cyclic compounds (3-6) shown below are formed by nickel catalysts. Considerable selectivity to form one of these cyclic oligomers as a main product by modification of the catalytic species with different phosphine or phosphite as ligands has been observed (3, 4). 

Rings of five, six, or seven members can be formed in this way. Similar cyclization can also be accomplished with other monoalkylboranes and, in some instances, with BH3 itself.384 One example is the formation of 9-BBN, shown above. Another is conversion of 1,5,9-cyclododecatriene to perhydro-9b-boraphenalene 385... 

Several cyclic oligomers 1-5 are prepared from butadiene using transition metal catalysts. The preparation of 1,5-cyclooctadiene (3 1,5-COD) by a catalyst prepared from Ni(CO)4 and phosphine is the first report on cyclooligomerzation of butadiene [1], However, the activity of this catalyst is low due to strong coordination of CO. Catalyst prepared from TiCU and EtjAl has higher catalytic activity for the formation of 1,5-COD and 1,5,9-cyclododecatriene (1,5,9-CDT 4). Also Ni(0) catalysts are active for the preparation of COD and CDT. In addition to COD and CDT, the cyclic... 

Two isomeric 1,5,9-cyclododecatrienes, namely, trans,trans,cis-CijH 18 (XLVI) and trans,trans,trans-CuHis (XLVII), are formed in good yield by the cyclic trimerization of butadiene using certain Ziegler-type catalysts 247, 250, 251, 252). The formation of these 12-membered ring hydrocarbons probably proceeds via metal 7r-complexed intermediates. When the cyclic triene (XLVII) is treated with nickel acetylacetonate and... 

C-C linking with formation of, for instance, cyclododecatriene which still remains on the transition metal in the form of a new 7r-complex. 

Ozonolysis as used below is the oxidation process involving addition of ozone to an alkene to form an ozonide intermediate which eventually leads to the final product. Beyond the initial reaction of ozone to form ozonides and other subsequent intermediates, it is important to recall that the reaction can be carried out under reductive and oxidative conditions. In a general sense, early use of ozonolysis in the oxidation of dienes and polyenes was as an aid for structural determination wherein partial oxidation was avoided. In further work both oxidative and reductive conditions have been applied . The use of such methods will be reviewed elsewhere in this book. Based on this analytical use it was often assumed that partial ozonolysis could only be carried out in conjugated dienes such as 1,3-cyclohexadiene, where the formation of the first ozonide inhibited reaction at the second double bond. Indeed, much of the more recent work in the ozonolysis of dienes has been on conjugated dienes such as 2,3-di-r-butyl-l,3-butadiene, 2,3-diphenyl-l,3-butadiene, cyclopentadiene and others. Polyethylene could be used as a support to allow ozonolysis for substrates that ordinarily failed, such as 2,3,4,5-tetramethyl-2,4-hexadiene, and allowed in addition isolation of the ozonide. Oxidation of nonconjugated substrates, such as 1,4-cyclohexadiene and 1,5,9-cyclododecatriene, gave only low yields of unsaturated dicarboxylic acids. In a recent specific example... 

Unlike nickel catalysts which form cyclic dimers and trimers (1,5-cyclooctadiene and 1,5,9-cyclododecatriene), palladium compounds catalyze linear dimerization of conjugated dienes. 1,3-Butadiene itself is converted to 1,3,7-octatriene. The reaction most characteristic of palladium is the formation of various telomers. 1,3-Buta-diene dimerizes with incorporation of various nucleophiles to form telomers of the following type ... 

Co2(CO)s reacts with propargyl alcohols giving benzenic cyclotrimers and dehydrated oligomers.By contrast, (CDT)Ni (CDT = cyclododecatriene) reacts with alkynes to give homoleptic trinuclear clusters. No dehydration occurs during the formation of these complexes it is worthy of note that diols do not react with nickel. 

Nickel is a further transition metal of high importance in CO2 activation. Ethene and carbon dioxide react in the presence of nickel-(1,5,9-cyclododecatriene) and a chelating ligand such as dcpe or 2,2 bipyridyl (bipy) yielding an oxanickelacyclopentanone which can be decomposed to propionic acid, methyl propionate or - via succeeding reaction with carbon monoxide - to succinic anhydride [4,5]. Another catalyst leads to the formation of products with an ethene/ C02-ratio of 2 1 (Figure 4). By using nickelbis(cyclooctadiene) and... 

Diene oligomerization reactions may also lead to the formation of allyl compounds. During reduction of Ni(acac)2 in the presence of tram, tram, trani-cyclododecatriene,... 

Highly unsaturated cyclic compounds likewise do not react to give di-or tricarboxylic acids, but tertiary monocarboxylic acids are obtained with CO/HgO by a transannular reaction with hydride transfer and formation of bi- or tricyclic systems at the bridgehead. Thus, cyclodecadiene-1,5 reacts to give a mixture of cis- and trans decalin carboxylic acid [624] and cyclododecatriene-1,5,9 reacts to give a mixture of isomeric tertiary per-hydroacenaphthene carboxylic acids. 

The C—C bond formation in these complexes is reversible. Treatment of the butadiene or isoprene derivatives with molten triphenylphosphine leads to diene evolution, in moderate yields, but reductive coupling of the M—C bonds occurs when the complexes are reacted with CO at low T since 4-vinylcyclohexene is formed . An unstable olefin complex can be formed from divinylcyclobutane and (cyclododecatriene)Ni(tricyclohexylphosphine) that liberates divinylcyclobutane when... 

Hoecker and Musch [32] elaborated in more detail the methods of chromatographic and spectrometric analysis of these macrocyclic compounds and studied the influence of the reaction parameters on their formation. Interestingly, through metathesis reaction of some cyclic polyenes such as 1,5-cyclooctadiene and 1,5,9-cyclododecatriene, Scott and Calderon [29] obtained macrocycles with similar structures. It is noteworthy that the higher degree of unsaturation led in this case to a greater fragmentation of the reaction products. 

Formation. Although a peroxy radical cyclization mechanism was proposed (ly 2 ) for prostaglandin biosynthesis, this mode of reaction had received little chemical attention. Early reports suggested that peroxy radical cyclization was an important variant in the autoxidation of polyunsaturated materials such as squalene ( ) and cyclododecatriene ( ). Products were not fully characterized in these studies, however, due to the difficulties of peroxide isolation and purification. 

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