Asymmetric deuteration and deuteriooligomerization of 1-pentene

1-Pentene has been polymerized in the presence of deuterium using as catalyst precursors Al(CH₃)-O]n and (−)-ethylenebis(4,5,6,7-tetrahydro)-(R)-1-indenylzirconium derivatives ((−)-(R)-EBTHI-ZrX₂, X = CH₃ (I); X = (R)-1′,1″-bi-2-naphtholate (II)). The investigation of 1,2-dideuteriopentane and of the deuteriooligomers thus obtained shows that the (Re) enantioface of the olefin is predominantly involved in the deuteration but its (Si) enantioface in the dimerization and oligomerization. These results, which show the participation of the growing chain in the enantioface discrimination in the stereospecific polymerization of 1-pentene are discussed on the basis of a simple stereochemical model for the transition state of the olefin insertion step.