Dienes with Functional Olefins

The codimerization of acrylates and butadiene with cobalt catalysts can be used to produce the 4,6-heptadienic-l-ester (Equation 57) [66, 67]. This reaction proceeds under very mild conditions, for instance at 40—60 °C. 

By varying the catalyst, the 2,5- and 3,5-heptadienic-l-esters could be obtained. Beger et al. [68] reported that a catalyst prepared by AlEt3 and Co(acac)3 in a ratio of 5 1 yielded a mixture of esters in about 34% yield. The analogous iron system gave similar results however, higher ratios of Al Fe (10 1 to 20 1) were required. 

The mechanism of this reaction was studied by Tolstikov [69] using deuterated butadiene. With nickel catalysts, butadiene and acrylic ester form 2 1 adducts (Equation 58) [70]. 

Instead of acrylic esters, methacrylic esters can be used [71, 72]. As catalyst, Ni(acac)2/AlEt3/phosphine yields Cjj and Cjo esters (Equation 59). 

At a temperature of 0°C and in the presence of triphenylarsine or triphenylstibine as ligands, the undecatriene-2-carboxylic ester is formed 

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Four-carbon-chain extensions have been very successful with conjugated dienes as the functionalized olefins. We have used a few other compounds also, but they are of limited value, such as N-3-butenylphthalimide. The last compound is only useful with aromatic or certain vinyl halides where mixtures of allylic amines would not be formed. A typical diene example is the reaction of vinyl bromide with butadiene and piperidine which gives E-N-(2,5-hexadienyl)-piper-idine in 70% yield (7). The product of this reaction can be reacted again and used to extend the carbon chains by six atoms (see below). The reactions of conjugated dienes can be used to produce conjugated trienes also (4). 

The Ziegler system ML -A1(C2H5)3 (M=Ni, Co or Fe n=2, 3 L=acac or Cl) has been used mostly in the addition of trialkyl and triphenylsilanes to conjugated dienes and trienes (especially Ni(acac)2-A1(C2H5)3) as well as in hydrosilylation of olefins with functional groups (the three-component system with additional PPh3) [2, 5]. 

Moreover, and more importantly for practical purposes, functionalized olefins with nearly all kinds of substituents attached to the olefin can be dihydroxylated. Thus, acrylic acid esters, unsaturated amides and ketones, dienes, enynes, vinyl silanes, acrolein acetals, and allylic halides, as well as allylic ethers and sulfur-... 

Coordination polymerization of dienes has progressed significantly within the last decade. Selective polymerization of 1,3-dienes is reinforced by conventional transition metal catalysts and by new organolanthanide catalysts. Nonconjugated dienes also polymerize selectively to produce polymers with cyclic units or vinyl pendant groups. Living polymerization of dienes has become common, which enabled preparation of block copolymers of dienes with alkenes and other monomers. Another new topic in this field is the polymerization of allenes and methylenecycloalkanes catalyzed by late transition metal complexes. These reactive dienes and derivatives provide polymers with novel structure as well as functionalized polymers. The precision polymerization of 1,2-, 1,3-, and l,n-dienes, achieved in recent years, will be developed to construct new polymer materials with olefin functionality. 

The next approach for obtaining higher molecular weight polymers was to explore acyclic diene metathesis (ADMET) polymerizations.The aim was to achieve higher molecular weight flame-resistant polymers. We modeled the reaction using aliphatic diene monomers such as 1,5-hexadiene and 1,9-deca-diene under test conditions to optimize conditions before making BPC-derived products. At this point, we decided to functionalize the BPC with an olefin. 

Various papers describe the aqueous biphasic hydroformylation for simple olefins as well as for functionalized olefins or dienes [154-174] (cf. the Section 6.1). In recent work [175], the synthesis of n-nonanal by consecutive isomerization and hydroformylation reactions of trans-4-octene has been described. The catalyst used was the in situ combination of Rh(acac)(CO)2 and the chelate phosphite BIPHE-PHOS. Performing the reaction in propylene carbonate the selectivity to n-nonanal could be raised up to 95%. If after the reaction the product is extracted with dodec-... 

Olefin metathesis has become a leading method for assembling macrocycles. Of particular efficacy in these reactions are the second-generation catalysts like (4a). Fiirstner reported that dienes with ester functionality could be... 

The synthesis of a,co-difunctional telomers by cross-metathesis between cyclic olefins and acyclic functionalized olefins is possible in the presence of functional-group-tolerant catalysts. Thus, cross-metathesis of dimethyl hex-3-enedioate with cycloocta-1,5-diene (Pinazzi 1980 Reyx 1982b, 1990), cyclopentene (Reyx 1986, 1987), or norbomene (Cramail 1991a) in the presence of the catalyst system WCV Mc4Sn allows the synthesis of a,m-difunctional oligomers, e.g. reaction (2). 

The Wacker reaction has been applied to numerous simple olefins such as a-olefins and cycloalkenes, or to functionalized olefins such nitroethylene, acrylonitrile, styrene, allyl alcohol, or maleic acid [3]. The carbonyl group is formed at the carbon atom of the double bond where the nucleophile would add in a Markovnikov addition. Reversal of the regioselectivity has only been observed with particular substrates such as 1,5-dienes [9]. Conversion and selectivity for the oxidation of these olefins were found to be very dependent on the water solubility of the olefin. Indeed, high molecular weight olefins do not react under the standard... 

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