Acetylene Oligomerization with Metallocene Catalysts and Triethylaluminium: The Peculiar Course of the Aufbau Reaction with Acetylene

The oligomerization of acetylene to liquid-range products has been investigated. While early transition metal and lanthanide metallocenes do not appear to be very effective catalysts, stoichiometric chain growth at triethylaluminum is observed, which leads to acetylene oligomers. This reaction produces an unexpected distribution of branched oligomers, and some possible routes to these products have been explored. Efforts to promote chain transfer at aluminum centered on the introduction of dihydrogen and high concentrations of Cp 2ZrCl 2. While some evidence of chain termination was found, the process was not made catalytic in terms of aluminum. © 2009 American Chemical Society.