Stereoselective synthesis of bridged metallocene complexes

摘要

The present invention provides methods of making stereo-enriched ansa-metallocene compounds using an unchelated amine compound. Generally, these methods result in a rac:meso isomer selectivity of the stereo-enriched ansa-metallocene compound of greater than 4:1.

主权项

1. A racemic ansa-metallocene compound having formula (I):
E(CpRAn)2M(NR2)m  (I);wherein:
M is Ti, Zr, Hf, Cr, Sc, Y, La, or a lanthanide; Cp is a cyclopentadienyl, indenyl, or fluorenyl group; E is a substituted or unsubstituted bridging chain of 2 to 8 silicon, germanium, or tin atoms, wherein any substituents on atoms of the bridging chain independently are H or a hydrocarbyl group having up to 18 carbon atoms; each R independently is H, a hydrocarbyl, hydrocarbylsilyl, hydrocarbylamino, or hydrocarbyloxide group having up to 18 carbon atoms, or each NR2 group is a heterocyclic group having up to 18 carbon atoms; each RA independently is H or a hydrocarbyl, hydrocarbylsilyl, hydrocarbylamino, or hydrocarbyloxide group having up to 18 carbon atoms; m is 2 when M is Ti, Zr, or Hf; m is 1 when M is Cr, Sc, Y, La, or a lanthanide; n is 0, 1, 2, 3, or 4 when Cp is an indenyl group; and n is 1, 2, 3, or 4 when Cp is a cyclopentadienyl or a fluorenyl group.