(±)-1, a recently discovered, valuable, floral-type odorant, has been synthesized by a straightforward procedure (Scheme 1). To determine the properties of the enantiomers of 1, their separation by preparative HPLC and the determination of their absolute configuration by X-ray crystallography were carried out (Figure). Furthermore, the analogues 2–6 were synthesized, either from differently methylated
Substituted indenyl containing metal complexes and olefin polymerization
申请人:The Dow Chemical Company
公开号:US06015868A1
公开(公告)日:2000-01-18
Group 4 metal complexes comprising an indenyl group substituted in the 2 or 3 position with at least one group selected from hydrocarbyl, fluoro-substituted hydrocarbyl, hydrocarbyloxy-substituted hydrocarbyl, dialkylamino-substituted hydroacrbyl, silyl, germyl and mixtures thereof, said indenyl group further being covalently bonded to the metal by means of a divalent ligand group, catalytic derivatives thereof and their use as olefin polymerization catalysts are disclosed.
Process for the Preparation of Atactic 1-Butene Polymers
申请人:Resconi Luigi
公开号:US20090005523A1
公开(公告)日:2009-01-01
A process for obtaining atactic 1-butene polymer optionally containing at least one comonomer selected from ethylene, propylene or an alpha-olefin of formula CH
2
═CHR
o
, wherein R
o
is a linear or branched C
3
-C
20
alkyl group, comprising the step of polymerizing 1-butene and optionally ethylene, propylene or said alpha-olefin, in the presence of a catalyst system obtainable by contacting:
a) at least one metallocene compound of formula (I) in its meso or meso-like form
wherein
M is an atom of a transition metal; p is an integer from 0 to 3; X, same or different, is a hydrogen atom, a halogen atom, or a hydrocarbon group; L is a divalent C
1
-C
40
hydrocarbon radical optionally containing heteroatoms belonging to groups
13
-
17
of the Periodic Table of the Elements; R
1
and R
2
, are C
1
-C
40
hydrocarbon radicals; T, equal to or different from each other, is a moiety of formula (IIa) or (IIb):
wherein R
3
is a C
1
-C
40
hydrocarbon radical; R
4
and R
6
, are hydrogen atoms or C
1
-C
40
hydrocarbon radicals; R
5
is a C
1
-C
40
hydrocarbon radical; R
7
and R
8
, equal to or different from each other, are hydrogen atoms or C
1
-C
40
hydrocarbon radicals; and
b) an alumoxane or a compound capable of forming an alkyl metallocene cation;
A process for preparing 1-butene polymers, comprising polymerizing 1-butene or copolymerizing 1-butene with ethylene, propylene or an alpha-olefin of formula CHT
2
=CHT wherein T is a C
3
-C
10
alkyl group, in the presence of a catalyst system obtainable by contacting: A) a metallocene compound belonging to formula (I): wherein M is zirconium titanium or hafnium; X, equal to or different from each other, is a hydrogen atom, a halogen atom, a hydrocarbon radical optionally containing heteroatoms; R
4
, R
5
, R
6
, R
7
, R
8
, R
9
, R
10
, R
11
, R
12
and R
13
are hydrogen atoms, or C
1
-C
4O
hydrocarbon radicals optionally containing heteroatoms; R
1
, R
2
and R
3
, are linear or branched, C
1
-C
2o
-alkyl radicals, optionally containing heteroatoms: B) a Jumoxane or a compound capable of forming an alkyl metallocene cation; and optionally C) organo aluminum compound.
Catalyst combination, isotactic polymers, method for producing linear isotactic polymers, and the use of said polymers
申请人:Rieger Bernhard
公开号:US20070015657A1
公开(公告)日:2007-01-18
The present invention relates to a catalyst combination for producing linear isotactic polymers containing an asymmetrical metal complex and also an activator.