Pd-Based Catalyst System

The results on Pd complexes as catalyst for the 1 1 codimerization are very limited at this time (85-87). Schneider (85, 86) found that palladous chloride in conjunction with dibutylaluminum chloride catalyzes the formation of exclusively trans-1,4-hexadiene as the 1 1 codimerization product of ethylene and butadiene. A vyn-7r-crotylpalladium complex was postulated as the key intermediate. The criterion for selectivity toward 

Although Pd-based catalyst systems form only the desirable trans-1,4-hexadiene, their industrial value is very doubtful because of the reported poor yield of the C6 diene and the very low activity of the dimerization reactions compared to other catalyst systems. 

10 (1963) Angew. Chem., Int. Ed. Engl. 2, 105 (1963), and references cited therein. 

Natta and L. Porri, in Polymer Chemistry of Synthetic Rubber (J. P. Kennedy and E. Tomquist, eds.), Part 2, Chapter 7. (Interscience), Wiley, New York, 1968— 1969. 

Schneider, Symposium of Homogeneous Catalytic Reactions involving Palladium. Division of Petroleum Chemistry, Inc. and Division of Inorganic Chemistry, Organometallic Subdivision, American Chemical Society, Minneapolis, Minnesota, 1969. 

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