Highly Selective Dimerization and Trimerization of Isobutene to Linearly Linked Products by Using Nickel Catalysts |
| |
Authors: | Prof. Arno Behr Nils Rentmeister Thomas Seidensticker Jonas Vosberg Dr. Stephan Peitz Dr. Dietrich Maschmeyer |
| |
Affiliation: | 1. Lehrstuhl für Technische Chemie, Technische Universit?t Dortmund, Emil‐Figge‐Str. 66, 44227 Dortmund (Germany), Fax: (+49)?231‐755‐2311;2. Evonik Industries, Paul‐Baumann‐Str.?1, 45772 Marl (Germany) |
| |
Abstract: | The unique linear linkage of isobutene to generate highly valuable C8 precursors for plasticizers is feasible by using special nickel catalysts. (4‐Cyclooctene‐1‐yl)(1,1,1,5,5,5‐hexafluoro‐2,4‐acetylacetonato)nickel and aluminum‐alkyl‐activated nickel acetylacetonates produce isobutene dimers with high selectivities of up to 95 %. Moreover, selectivity for the head‐to‐head products (2,5‐dimethylhexenes) is remarkably high at up to 99 %. Additionally, novel C12 isobutene trimers are also formed with a very high selectivity of up to 99 % for the linear linkage. The trimer structure (2,5,8‐trimethylnonenes) reflects the stepwise characteristic of the reaction mechanism. Pathways of insertion and activation and the deactivation processes of the catalyst are discussed in detail. |
| |
Keywords: | dimerization head‐to‐head linkages homogeneous catalysis isobutene nickel |
|
|