Butadiene, catalyzed reactions with carbon dioxide

Dienes, especially butadiene, also react with carbon dioxide. Inotie and his co-workeis found that Pd(dppe)j catalyzes the telomerization of butadiene and CO to give the y-lactone 2 Cthylidcnc-5 hcpien-4-oUde in about a S% yield [182, 183]. The distribution of the products evidently depends on the solvent used and polar aproiic solvents such as DMF, DMSOand 1 mielhyl-2-pyrrolidone are most suitable for lactone formation. A temperature of 120 C is required. When the reaction is carried out at temperatures below lOO C and terminated before the complete conwrsion of butadiene, the free organic acids (the precursors of the >4actone) are isolated up to 10%. 

Table 1 Palladium-catalyzed reaction of carbon dioxide with butadiene ...

The palladium catalyzed reaction of butadiene with carbon dioxide affords mixtures of the cyclic adducts 32 and 33 and linear adducts. The yield of the six-membered ring lactone increases when using a catalyst containing more basic phosphine ligands (PCys, P-i-Prs). ... 

The reaction of butadiene with carbon dioxide to give a 5-lactone is not known. However, this reaction can be accomplished starting with the mono-epoxide 90 and reacting it with carbon monoxide. When the reaction is catalyzed by iron or cobalt, the shown 5-lactone 91 is formed. However, if a rhodium catalyst is used a y3,y-unsaturated lactone 92 is... 

Addition of water to dienes is catalyzed by palladium complexes. The reaction has been used for synthesizing unsaturated alcohols and ethers from aliphatic conjugated C4 and Cg olefins 248). In particular, the hydration of butadiene with water in the presence of bis(2,4-pentane-dionato)palladium and triphenylphosphine gave 2,7-octadien-l-ol, l,7-octadien-3-ol, and 1,3,5,7-octatetraene 18). The reaction was accelerated by carbon dioxide. Compounds Pd(PPh3)4 and Pd(02C0)-(PPh3)2 were also effective. 

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