Nitroalkane, telomerization with

The most characteristic reaction of butadiene catalyzed by palladium catalysts is the dimerization with incorporation of various nucleophiles [Eq. (11)]. The main product of this telomerization reaction is the 8-substituted 1,6-octadiene, 17. Also, 3-substituted 1,7-octadiene, 18, is formed as a minor product. So far, the following nucleophiles are known to react with butadiene to form corresponding telomers water, carboxylic acids, primary and secondary alcohols, phenols, ammonia, primary and secondary amines, enamines, active methylene compounds activated by two electron-attracting groups, and nitroalkanes. Some of these nucleophiles are known to react oxidatively with simple olefins in the presence of Pd2+ salts. Carbon monoxide and hydrosilanes also take part in the telomerization. The telomerization reactions are surveyed based on the classification by the nucleophiles. 

The results obtained from subsequent studies indicate that this same approach can be used to promote telomerization of butadiene with p-dicarbonyl compounds, nitroalkanes, and enamines. ... 

Telomerization is defined as an oligomerization of dienes accompanied by addition of a heteroatom or carbon nucleophilic reagent10. It is catalyzed by various organometallic compounds of transition metals, especially palladium compounds. The nucleophiles, such as water, alcohols, amines or carboxylic acids, as well as enamines, nitroalkanes and stabilized carban-ions, are mainly introduced in the terminal position of the dimeric molecule in excellent yield10. It is also possible to direct the reaction towards an internal product functionalization. Telo-merizations with heteronucleophiles are regarded as heterocarborative addition reactions and are described in Section 1.5.8.4. 

Nitrodienes by Telomerization of Butadiene with Nitroalkanes General Procedure12 ... 

Dicarborative telomerization has also been successfully applied to intramolecular cyclization reactions. Various tetraenes with enamines, indole, nitroalkanes or carbonyl-stabilized carba-nions give good yields of carbocyclic or heterocyclic five-membered rings, with predominantly the trans arrangement of the two different unsaturated side chains14,15. 

In what follows, the telomerization of butadiene with acetic acid, alcohols, phenol, C—H-acidic compounds and nitroalkanes will be considered. Also some examples of carboxytelomerization and the telomerization of substituted dienes will be given. In all reactions trifunctional compounds are formed which contain two double bonds and one functional group. 

Methylene compounds which contain only one electronegative group are normally inactive in telomerization. One exception is the nitroalkanes, which react very smoothly with butadiene [21, 22]. The telomerization of nitromethane in the presence of [PdCl2(PPh3)2] and sodium hydroxide at room temperature produces three nitro-compounds which are accompanied by a small amount of branched products (Equation 18). 

Tsuji has described the preparation of long-chain amines by the palladium-catalysed telomerization of butadiene with ammonia, tertiary amines are formed, whereas nitroalkanes undergo replacement of the a-hydrogen atoms with octa-2,7-dienyl groups. Nickel(0) complexes catalyse a similar telomerization. ... 

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