Regioselective trimeric cyclization of propylene to substituted cyclopentanes catalyzed by zirconocene complexes

Oligomerization of propylene catalyzed by C2ZrCl2/ethylaluminoxane or/E3Al at low Al/Zr ratios and high temperature regioselectively afforded trimeric carbocyclic products, 1,1,3-trimethylcyclopentane and 1,1,3,4-tetramethylc yclopentane, along with C-6 and C-9 chain olefins. The product distribution was affected by the reaction temperature, the pressure of propylene, the r atio of Al/Zr and the reaction time. The combined selectivity of two five-m embered cyclic products attained 61 % under the optimized condition. The pa thway of regioselective cyclo-trimerization of propylene to substituted cyc lopentanes is discussed. (C) 2001 Elsevier Science B.V. All rights reserved .