Asymmetric hydrodimerization of styrene by a chiral zirconium complex containing a tetradentate [OSSO]-type bis(phenolato) ligand

The chiral non racemic (A.R.R)-[OSSO]Zr(CH2Ph)(2) (1a) activated by methylaluminoxane (MAO) and in presence of H-2 produces the chiral hydrodimer (S)-1,3-diphenylbutane with good selectivity respect to the achiral 1,4-diphenylbutane. The absolute configuration of the chiral dimer and the effect of the hydrogen pressure on the ratio between 1,3-diphenylbutane and 1,4-diphenylbutane give useful information about the regiochemistry and stereochemistry of insertion of the styrene into the Zr-H bond. (C) 2011 Elsevier B.V. All rights reserved.