Preparation of silicon-bridged metallocene compounds
AssigneeBasell Polyolefine GmbH
InventorsLuigi Resconi, Simona Guidotti, Davide Balboni
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Abstract
A process for obtaining silicon-bridged metallocene compounds comprising the following steps: a) reacting, at a temperature of between −10° C. and 70° C., the starting ligand with about 2 molar equivalents of an alkylating agent; b) after the reaction has been completed, adding at least 2 molar equivalents of an alkylating agent that can be also different from the first one; and c) reacting, at a temperature of between −10° C. and 70° C., the product obtained from step b) with at least 1 molar equivalent of a compound of formula ML′s, wherein M is a transition metal; s is an integer corresponding to the oxidation state of the metal; and L′ is an halogen atom selected from chlorine, bromine and iodine.
Claims10
A process for preparing silicon-bridged metallocene compounds of formula (I):
- (Cp)(SiR12)(Cp)MLq (I)
- wherein (SiR12) is a divalent group bridging the two Cp rings, the R1 groups, equal to or different from each other, are hydrogen atoms, or linear or branched, saturated or unsaturated C1–C20 alkyl, C3–C20 cycloalkyl, C6–C20 aryl, C7–C20 alkylaryl or C7–C20 arylalkyl groups, two R1 can optionally join to form a 3–7 membered ring;
- Cp, equal to or different from each other, is a substituted or unsubstituted cyclopentadienyl group, optionally condensed to one or more substituted or unsubstituted, saturated, unsaturated or aromatic rings, containing from 4 to 6 carbon atoms, optionally containing one or more heteroatoms;
- M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups of the Periodic Table of the Elements (IUPAC version);
- the substituents L, equal to or different from each other, are monoanionic sigma ligands selected from the group consisting of linear or branched, saturated or unsaturated C1–C20 alkyl, C3–C20 cycloalkyl, C6–C20 aryl, C7–C20 alkylaryl and C7–C20 arylalkyl groups, optionally containing one or more Si or Ge atoms;
- q is an integer ranging from 0 to 2, being equal to the oxidation state of the metal M minus 2;
- said process comprises the following steps:
- a) reacting, at a temperature of between −10° C. and 70° C., a ligand of formula (Y-Cp)(SiR12)(Cp-Y) with about 2 molar equivalents of an alkylating agent of formula THw, LjB or LMgL′, wherein T is lithium, sodium or potassium, H is an hydrogen atom, w is 0 or 1, when w is 0 the compound THw is metallic lithium, sodium or potassium, when w is 1 the compound of formula THw is an hydride of lithium, sodium or potassium;
- L′ is an halogen atom selected from chlorine, bromine and iodine;
- B is an alkali or alkali-earth metal;
- and j is 1 or 2, j being equal to 1 when B is an alkali metal, and j being equal to 2 when B is an alkali-earth metal;
- the groups Y, the same or different from each other, are suitable leaving groups;
- b) after the reaction has been completed, adding at least q molar equivalents of an alkylating agent of formula LjB or LMgL′;
- and
- c) reacting, at a temperature of between −10° C. and 70° C., the product obtained from step b) with at least 1 molar equivalent of a compound of formula ML′s, wherein s is an integer corresponding to the oxidation state of the metal and ranges from 3 to 6;
- and L′ is an halogen atom selected from chlorine, bromine and iodine.
Dependencies are inferred from the claim text.