Cyclododecatriene nickel

C2aH5oLi2N, Ni, (Dilithium trans-1,5,9-cyclododecatriene)nickel bis(N,N,N ,N -tetramethylethylene-diamine), 45B, 928 C2 5H1gBr2Fe03, 1-Bromo-2-(bromomethyl)naphthalene enneacarbonyldi-iron reaction product, 40B, 799 C2 5HieFe03, Iron 7r-complex, 35B, 582... 

With ttt-l,5,9-cyclododecatriene-nickel a novel bimetallic nickel sandwich is formed ... 

Nickel(O) reacts with the olefin to form a nickel(0)-olefin complex, which can also coordinate the alkyl aluminum compound via a multicenter bond between the nickel, the aluminum and the a carbon atom of the trialkylaluminum. In a concerted reaction the aluminum and the hydride are transferred to the olefin. In this mechanistic hypothesis the nickel thus mostly serves as a template to bring the olefin and the aluminum compound into close proximity. No free Al-H or Ni-H species is ever formed in the course of the reaction. The adduct of an amine-stabihzed dimethylaluminum hydride and (cyclododecatriene)nickel, whose structure was determined by X-ray crystallography, was considered to serve as a model for this type of mechanism since it shows the hydride bridging the aluminum and alkene-coordinated nickel center [31]. 

Significant advances in organonickel chemistry followed the discovery of frtzws,fraws,fraws-(l,5,9-cyclododecatriene)nickel, Ni(cdt), and bis(l,5-cycloocta-diene)nickel Ni(cod)2 by Wilke et. al.1 In these and related compounds, in which only olefinic ligands are bonded to the nickel, the metal is especially reactive both in the synthesis of other compounds and in catalytic behavior. Extension of this chemistry to palladium and to platinum has hitherto been inhibited by the lack of convenient synthetic routes to zero-valent complexes of these metals in which mono- or diolefins are the only ligands. Here we described the synthesis of bis(l,5-cyclooctadiene)platinum, tris(ethylene)-platinum, and bis(ethylene)(tricyclohexylphosphine)platinum. The compound Pt(cod)2 (cod = 1,5-cyclooctadiene) was first reported by Muller and Goser,2 who prepared it by the following reaction sequence ... 

Scheme 7.3 Preparation of (fl//-franj-l,5,9-cyclododecatriene)nickel(0) (12) and its reactions with all-cis-C12H18 to the isomer 13 and with 1,5-cyclooctadiene to the bis(diolefin) nickel(0) complex 14...

If it is now assumed that cyclododecatriene-nickel could be an intermediate in the cyclododecatriene synthesis, this compound should undergo displacement reactions with other electron donors and especially with butadiene. 

Some olefin complexes may conveniently be obtained by electrochemical reduction methods. Cyclooctadiene and cyclododecatriene nickel(O) complexes such as Ni(COD)2 and Ni(CDT) may be prepared by electrochemical reduction of nickel acetylacetonate in the presence of butadiene in acetonitrile, dimethoxymethane, or DMF solutions. Complexes [Fe(CO)4 (alkene)] are reduced electrochemically to lie compounds [Fe(CO)3 (alkene)] . In the case of complexes [Fe(CO)3 (f/Miene)] (diene = BD, cyclohexadiene), during reduction, lie anions [Fe(CO)3 (diene)] are formed in which one olefin bond is decomplexed. ... 

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). 

The concept of constrained geometry is also important and this is why 7i-complexes of metal and olefins can lead to structured molecules. For example a model of cyclododecatriene-nickel shows that the nickel atom is situated exactly in the center of the ring. This picture represents a lock and key fit very precisely another analogy with an enzyme-substrate complex. 

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. 

Treatment of nickel acetylacetonate with aluminium alkyls in the presence of cyclododecatrienes or butadiene, or of bis-)p-allyl nickel with butadiene, gives cyclododecatriene nickel, a volatile blood-red crystalline compound 10.6.This 16-electron nickel complex reacts catalytically and very rapidly with butadiene at 20° liberating isomers of cyclododecatriene. The major product is the trans-trans-cis isomer small amounts of the trans-cis-cis isomer are also formed. If the reaction with butadiene is carried out at -40° the bis-w-enyl complex, 10.7, is isolated in which the ligand is the same as that found in the complex formed from butadiene and ruthenium salts (p 180). The carbonylation (Figure 53) provides evidence for the... 

Treatment of nickel acetylacetonate with alkylaluminiums in the presence of cyclododecatrienes or butadiene, or treatment of bis- r-allyl nickel with butadiene, gives cyclododecatriene nickel, a volatile blood-red crystalline compound, 9.4 [71, 72, 73]. This 16-electron nickel complex reacts... 

Cyclododecatriene nickel has also been shown to catalyse the co-cyclization of two molecules of butadiene either with one molecule of ethylene giving cyclodeca-1,5-diene or with one molecule of 2-butyne to give 1,2-dimethyl cyclodeca-1,4,8-triene [72]. 

The reaction of a mixture of 1,5,9-cyclododecatriene (CDT), nickel acetylacetonate [3264-82-2], and diethylethoxyalurninum in ether gives red, air-sensitive, needle crystals of (CDT)Ni [12126-69-1] (66). Crystallographic studies indicate that the nickel atom is located in the center of the 12-membered ring of (CDT)Ni (104). The latter reacts readily with 1,5-cyclooctadiene (COD) to yield bis(COD) nickel [1295-35-8] which has yellow crystals and is fairly air stable, mp 142°C (dec) (20). Bis(COD)nickel also can be prepared by the reaction of 1,5-COD, triethylaluminum, and nickel acetylacetonate. 

Dodecanedioic Acid. Dodecanedioic acid (DDDA) is produced commercially by Du Pont ia Victoria, Texas, and by Chemische Werke Hbls ia Germany. The starting material is butadiene which is converted to cyclododecatriene usiag a nickel catalyst. Hydrogenation of the triene gives cyclododecane, which is air oxidized to give cyclododecanone and cyclododecanol. Oxidation of this mixture with nitric acid gives dodecanedioic acid (71). 

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). 

Cyclododecene may be prepared from 1,5,9-cyclododecatriene by the catalytic reduction with Raney nickel and hydrogen diluted with nitrogen, with nickel sulfide on alumina, with cobalt, iron, or nickel in the presence of thiophene, with palladium on charcoal, with palladimn chloride in the presence of water, with palladium on barium sulfate, with cobalt acetate in the presence of cobalt carbonyl, and with cobalt carbonyl and tri- -butyl phosphine. It may also be obtained from the triene by reduction with lithium and ethylamine, by disproportionation, - by epoxidation followed by isomerization to a ketone and WoliT-Kishner reduction, and from cyclododecanone by the reaction of its hydrazone with sodium hydride. ... 

Homogeneous nickel complexes proved to be versatile catalysts in dimerization and trimerization of dienes to yield different oligomeric products.46-55 Depending on the actual catalyst structure, nickel catalyzes the dimerization of 1,3-butadiene to yield isomeric octatrienes, and the cyclodimerization and cyclotrimerization to give 1,5-cyclooctadiene and all-trans-l,5,9-cyclododecatriene, respectively46 56 [Eq. (13.13)]. Ziegler-type complexes may be used to form cis,trans,trans-1,5,9-cyclododecatriene37,57 58 [Eq. (13.14)], which is an industrial intermediate ... 

Twelve-membered rings have been obtained using coordination catalysts. The trans,trans,cis-cyclododecatriene has been prepared with a tetrabutyl titanate—diethylaluminum chloride catalyst (48,49) and with a chromium-based system (50). The trans,trans,trans- somer has been prepared with a nickel system. 

Nickel-triarylphosphite complexes catalyze the dimerisation of butadiene to cyclooctadiene. Cyclododecatriene is an unwanted by-product, which results from trimerization catalyzed by the same catalyst. Table 3.2 shows the product yields using various ligand-metal complexes (the remainder in each case is a tarry polymeric material). 

The reduction of nickel(II) in the presence of butadiene as the only available ligand (i.e., naked-nickel3) (69) produces a catalyst which is able to trimerize butadiene to a mixture of all-trans- trans,trans,cis- and trans,cis,cis-i, 5,9-cyclododecatriene in which the all-trans form predominates. 

Wilke and his co-workers have shown that zera-valent complexes, especially of nickel, obtained by reduction with aluminium alkyls can be used in a wide variety of polymerisations such as trimerisation of butadiene to trans, tran, trans-cyclododecatriene. 

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