Trimerization 1,3-butadiene

Some insight into the nature of the coordination and addition steps can be deduced from the cyclo-oligomerization work reported by Wilke (316). Butadiene can be converted into several isomers of cyclododeca-triene using (C2H5)aAlCl/TiCl4, AlEta/Cr02Cl2 and AlEta/nickel acetyl-acetonate catalysts. With the nickel catalysts, open chain, jr-complexed intermediates have been isolated for both the butadiene trimer and the dimer. The open chain dimer structure is shown below, where Do = a bulky Lewis base and the nickel is apparently zero valent. 

Figure 7.6 Industrial use of (from the top) propylene dimerization, butadiene dimerization, butadiene trimer-ization, and butadiene plus ethylene codimerization. In EPDM rubber, the terminal double bond of 1,4-hexadiene takes part in polymer formation. The internal double bond is used during curing.

G. Wilke and his group. For instance in the presence of [Ni(rj -C3Hs)2] (or [Ni(acac)2l3 + Al2Et6), butadiene trimerizes, probably via the catalytic cycle ... 

Cooligomerization (hetero-oligomerization) of olefins and acetylenes with butadiene in the presence of nickel complexes prevents the formation of butadiene trimers. During hetero-oligomerization chain and cyclic compounds may be formed see equations (13.87) and (13.88). Dodeca-2,6,10-triene-l,12-diylnickel reacts with allene to give various products. Reaction (13.89) is an example. 

Nylon 6 (poly (e-caproamide), polycaprolactam) can be made by anionic polymerization of caprolactam using strong bases, e.g. NaOH. This technique is mainly confined to RIM (section 1.4). Nylon 6 is made commercially by the ring-opening polymerization of caprolactam in the presence of water (via the intermediate H2N(CH2)sCOOH). Nylon 12 is made by the ring opening of lauryllactam which is obtained from the butadiene trimer, cyclododecatriene (CDT). It has a very low water absorption and is used for oil-resistant tubing. 

TT-f f f-Cyclododecatrienenickel reacts with 3 moles of butadiene at — 40°C, and the cyclododecatriene ligand is replaced by a newly formed linear butadiene-trimer, equation (6-62). When this reaction is carried out in... 

When research into ROMP began at Hiils around 1969, the company had been operating a butadiene trimerization plant to produce CDDT for 4 years, and though butadiene dimerization to cydooctadiene COD was known, at the time there were no dedicated commerdal sources for this feedstock. Accordingly, the cydo-C12 feedstock was readily available and the cydo-C8 feedstock was only available as a by-product from the Hiils trimer plant. This supply chain imbalance favored the development of the polydodecenamer. ... 

Dimerization is the main path. However, trimerization to form 1.3,6,10-dodecatetraene (15) takes place with certain Pd complexes in the absence of a phosphine ligand. The reaction in benzene at 50 C using 7r-allylpalladium acetate as a catalyst yielded 1,3,6,10-dodecatetraene (15) with a selectivity of 79% at a conversion of 30% based on butadiene in 22 h[ 19,20]. 1,3,7-Octatriene (7) is dimerized to 1,5,7,10.15-hexadecapentaene (16) with 70% selectivity by using bis-rr-allylpalladium. On the other hand. 9-allyl-l,4,6.12-tridecatetraene (17) is formed as the main product when PI13P is added in a 1 1. ratio[21]. 

The by-product of this process, pelargonic acid [112-05-0] is also an item of commerce. The usual source of sebacic acid [111-20-6] for nylon-6,10 [9008-66-6] is also from a natural product, ticinoleic acid [141-22-0] (12-hydroxyoleic acid), isolated from castor oil [8001-79-4]. The acid reacts with excess sodium or potassium hydroxide at high temperatures (250—275°C) to produce sebacic acid and 2-octanol [123-96-6] (166) by cleavage at the 9,10-unsaturated position. The manufacture of dodecanedioic acid [693-23-2] for nylon-6,12 begins with the catalytic trimerization of butadiene to make cyclododecatriene [4904-61-4] followed by reduction to cyclododecane [294-62-2] (see Butadiene). The cyclododecane is oxidatively cleaved to dodecanedioic acid in a process similar to that used in adipic acid production. 

Reaction between butadiene and CO2 has been extensively studied (171) since the reaction was first demonstrated (167—170). This reaction has been shown to be catalyzed by Pd (172,173), Ni (174), Ru (175), Pt (178), and Rh (172,173) catalysts. Products include gamma (5) and delta lactones (6), acids (7,8), and esters (9). Mechanistic studies have shown that butadiene initially forms a dimer (Pd, Ru, Ni) or trimer (Rh) intermediate followed by CO2 insertion (171). The fate of these intermediates depends on the metal, the ligands, and the reaction conditions. 

Nylon 12 first beeame available on a semieommercial scale in 1963. The monomer, dodecanelactam, is prepared from butadiene by a multistaged reaction. In one proeess butadiene is treated with a Ziegler-type eatalyst system to yield the cyclic trimer, cyclododeca-1, 5, 9-triene. This may then be hydrogenated to give cyelododeeane, which is then subjeeted to direct air oxidation to give a mixture of cyclododecanol and cyclododecanone. Treatment of the mixture with... 

Other isomers of cdt are also obtained and, if a coordination site on the nickel is blocked by the addition of a ligand such as a tertiary phosphine, dimerization of the butadiene, rather than trimerization, occurs. 

A Diels-Alder type [4+2] cycloadditions of 4,5-dihydropyridazine, prepared in situ from its trimer, with 2-methyl- and 2,3-dimethyl-1,3-butadienes (65, R = H, Me R = Me) afforded a complex reaction mixture, from which 6-methyl- and 6,7-dimethyl-3,4,4n,5-tetrahydro-8//-pyrido[l,2-ftjpyridazines (66, R = H, Me R =Me) could be isolated (97CEJ1588). With 1,3-butadiene (65, R = R =H) only a mixture of endo and exo isomers 67 and 68 (R = R =H) was obtained. 

Conjugated dienes can be dimerized or trimerized at their 1,4 positions (formally, [4 4- 4] and [4 4-4 4-4] cycloadditions) by treatment with certain complexes or other transition metal compounds. " Thus butadiene gives 1,5-cyclooctadiene and 1,5,9-cyclododecatriene. " The relative amount of each product can be controlled by use of the proper catalyst. For example, Ni P(OC6H4—o-Ph)3 gives predominant dimerization, while Ni(cyclooctadiene)2 gives mostly trimerization. The products arise, not by direct 1,4 to 1,4 attack, but by stepwise mechanisms involving metal-alkene complexes. " ... 

On the other hand, numerous examples are already known in which monomeric metaphosphoric esters are generated by thermolysis reactions. Most worthy of mention in this context is the gas phase pyrolysis of the cyclic phosphonate 150 which leads via a retro-Diels-Alder reaction to butadiene and monomeric methyl metaphosphate (151) 108,109, no). While most of the phosphorus appears as pyrophosphate and trimeric and polymeric metaphosphate, a low percentage (<5%) of products 152 and 153 is also found on condensation of the pyrolyzate in a cold trap containing diethylaniline or N,N,N, N,-tetraethyl-m-phenylene-diamine. The... 

The products of electrochemical oxidation of conjugated dienes are considerably affected by the reaction conditions such as the material of the electrode, the supporting electrolyte and the solvent. The oxidation of butadiene with a graphite or carbon-cloth anode in 0.5 M methanolic solution of NaClCU mainly yields dimerized products along with small amounts of monomeric and trimeric compounds (equation 5)1. The use of platinum or glassy carbon mainly gives monomeric products. Other dienes such as isoprene, 1,3-cyclohexadiene, 2,4-hexadiene, 1,3-pentadiene and 2,3-dimethyl-l,3-butadiene yield complex mixtures of isomers of monomeric, dimeric and trimeric compounds, in which the dimeric products are the main products. 

The nickel-catalyzed [4 + 4]-cycloaddition of butadiene to form cyclooctadiene was first reported by Reed in 1954.90 Pioneering mechanistic and synthetic studies largely derived from the Wilke group advanced this process to an industrially important route to cyclodimers, trimers, and other molecules of interest.91-94,943 95,96 While successful with simple dienes, this process is not useful thus far with substitutionally complex dienes as needed in complex molecule synthesis. In 1986, Wender and Ihle reported the first intramolecular nickel-catalyzed [4 + 4]-reaction of... 

Among the recently published works, the one which showed that the cyclic structures of water clusters open up to form a linear structure above a certain threshold electric field value a was a systematic ab initio study on the effect of electric field on structure, energetics, and transition states of trimer, tetramer, and pentamer water clusters (both cyclic and acyclic) [36], Considering c/.v-butadiene as a model system, the strength and the direction of a static electric field has been used to examine the delocalization energy, the probabilities of some local electronic structures, the behavior of electron pairs, and the electronic fluctuations [37]. Another recent work performed by Rai et al. focused on the studies using the DFT and its time-dependent counterpart of effects of uniform static electric field on aromatic and aliphatic hydrocarbons [38],... 

Another potential use of homogeneous hydrogenation catalysts is the hydrogenation of dienes and trienes to monoolefins, where they display high specificity. Such an example is the conversion of the easily available butadiene dimers and trimers to polymer intermediates6. 

The procedure described is based on the selective reduction with diimide described by Ohno and Okamoto and by Nozaki and Noyori. It illustrates the generation of diimide from the air oxidation of hydrazine and the use of diimide for the selective reduction of the trans double bond in cis,trans,trans-, S,9-cyc o-dodecatriene, the product of trimerization of butadiene. ... 

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