Ethylene codimerization with styrene

Asymmetric Codimerization of Styrene with Ethylene Influence of the Complex Anion of the Catalyst on Optical Yield... 

Finally, in the codimerization of styrene with ethylene to optically active 3-phenyl-1-butene (52) (Table XI), it has been shown that the complex anion (Y) can exert a strong influence on the optical yield 103, 105). 

Nickel allyl complexes in the presence of chiral bidentate ligands catalyze the enantioselective codimerization of ethylene with norbornene and with styrene 129... 

When isopropylidenecyclqnopane (29a equation 10) or diphenylmethylenecyclt ropane (29b) is used, the codimerizations with alkenes such as ethylene, styrene or norbomene giving alkyiidene-cyclopentanes are achieved under mild conditions in more than 75% yields. ... 

Codimerization of styrene and ethylene giving 3-phenyl-l-butene is another example of asymmetrically induced hydrovinylation. With catalyst precursors obtained from (jt-allyl)NiX or (> 3-cyclooct-5-enyl)NiX (X = various anions) modified with bis(menthyl)methylphosphane. ]<)- and (S)-3-phenyl-1 -butene in up to 37% ee is obtained, depending on the counterion X of the catalytic system13. 

For the codimerization of ethylene and styrene, a pressure membrane reactor was developed and the reaction ran almost without any isomerization of the products or formation of side products. These undesired side reactions are often observed at high conversion. Nevertheless, the space-time yield dropped to zero within 15 residence times and low retention of the dendrimer as well as precipitation of palladium on the membrane were found. Larger dendritic catalysts with higher retentions did not show much improvement, indicating that catalyst deactivation was indeed the major problem. 

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