Organic compounds -- part of the class 532-570 series – Organic compounds – Heavy metal containing
Reexamination Certificate
1999-04-02
2001-05-01
Nazario-Gonzalez, Porfirio (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heavy metal containing
C556S023000, C556S028000, C556S136000, C556S137000, C502S155000
Reexamination Certificate
active
06225488
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to highly active catalysts for olefin metathesis reactions, and the preparation of the catalysts. The invention also relates to the olefin metathesis reactions catalyzed with the catalysts of the invention.
A number of catalysts have been developed recently for initiating olefin metathesis reactions, including ring-opening metathesis polymerization (ROMP) of cyclo-olefins, ring-closing metathesis (RCM) of dienes to form ring-closed products, depolymerization of unsaturated polymers to form the depolymerized products, synthesis of telechelic polymers by reaction of a cyclic olefin with a functionalized olefin, and synthesis of cyclic olefins by self-metathesis of an acyclic olefin or cross-metathesis of two acyclic olefins. Those well defined catalysts usually have a metal-carbon double bond (metal-carbene or -alkylidene) that can coordinate to the alkene moiety of the olefin and, for example, can initiate readily the ring opening of cyclo-olefin monomers. Most of the metals that exhibit remarkable activity in such catalysts are second-or third-row mid-to late- transition metals. Although the specific reason for their degree of activity has not been clearly established, many theories have been put forward, the most prevalent of which expounds that late transition metals exhibit greater robustness towards the impurities that may inherently be present within a reaction system and consequently resist degradation.
Among olefins, cyclic olefins like norbornene (NB) or endo-dicyclopentadiene (DCPD) which possess a strained double bond can readily undergo ring opening metathesis polymerization (ROMP) because the ring opened product is thermodynamically favored. The above-mentioned catalysts are particularly active in catalyzing the ROMP of such ring-strained cyclo-olefins.
The catalysts that have received the greatest exposure in the literature by far are those designed by Schrock et al., as reported in Schrock et al., J. Am. Chem. Soc., 1990, 112, 3875, and by Grubbs's group, as reported in Nguyen et al., J. Am. Chem. Soc., 1993, 115, 9858; Nguyen et al., J. Am. Chem. Soc., 1992, 114, 3974; and Grubbs et al., WO98/21214 (1998). The Grubbs catalyst (a ruthenium carbene) is slightly more versatile than the Schrock catalyst (a molybdenum alkylidene) because of its ease of synthesis as well as its utility from a commercial viewpoint. Recently, Cox and co-workers reported in Cox et al., Inorg. Chem., 1990, 29, 1360; Cox, et al., J. Chem. Soc., Chem. Commun., 1988, 951-953; and Porri et al, Tetrahedron Letters, No. 47., 1965, 4187-4189, the synthesis of a class of metal catalysts based on ruthenium metal. These catalysts consist primarily of a bis-allyl ligand wrapping the metal, along with two or three acetonitrile ligands. Additionally, these catalysts possess a mono- or di-anion that is virtually (i.e., almost) coordinated to the metal center, which is therefore considered to be formally in the +4 oxidation state. These complexes in conjunction with a diazo ethyl acetate have been used by Herrmann's group, as reported in Herrmann et al., Angew. Chem. Int'l. Ed. Engl., 1996, 35, 1087, to investigate the polymerization (specifically the ROMP) of NB. Herrmann has conjectured that the active species in the catalyst system is a metal carbene generated in situ when the ruthenium reacts with the diazo alkyl compound (such as diazo ethyl acetate).
A disadvantage of the above catalysts is that for the ROMP of cyclic olefins these catalysts must be used with a co-catalyst such as a diazo alkyl compound, which requires special caution in handling because of the instability of the diazo group.
SUMMARY OF THE INVENTION
One aspect of the invention is to provide catalysts which are highly active in initiating metathesis reactions in olefins.
Another aspect of the invention is to provide catalysts which are highly active in the ring-opening polymerization (ROMP) of cyclo-olefin monomers without requiring the presence of a co-catalyst such as a diazo alkyl compound.
Another aspect of the invention is to provide methods for the preparation in good yield of the catalysts for metathesis reactions in olefins.
Yet another aspect of the invention is to provide a highly effective method for polymerizing olefins, in particular cyclo-olefins, using the catalysts of the invention.
DESCRIPTION OF THE INVENTION
The catalysts of the present invention are cationic complexes represented by formulas (I), (II) and (III) below, wherein the central metal atom M, which may be ruthenium or osmium, is in the +4 oxidation state, has an electron count of 14, and is penta-coordinated, and the counter-anion A is virtually coordinated to the central metal atom M. That is, the anion A is almost coordinated to the central metal atom M without being bonded as a ligand thereto.
wherein M is ruthenium or osmium;
each of X
1
and X
2
, which may be the same or different, is a C
3
-C
20
hydrocarbon group having an allyl moiety as an end group bonded to the central metal atom M, said hydrocarbon group being optionally substituted on its backbone with up to three substituents independently selected from the group consisting of a C
1
-C
20
alkyl, a C
1
-C
20
alkoxy, and a C
6
-C
20
aryl, and further optionally having up to three functional groups independently selected from the group consisting of hydroxyl; nitro, a halogen, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, and carbamate; or
X
1
and X
2
together constitute a group which results from dimerization of a C
4
-C
10
alkene and has at each end an allyl moiety bonded to the central metal atom M, said group resulting from the alkene dimerization being optionally substituted on its backbone with up to three substituents independently selected from the group consisting of a C
1
-C
20
alkyl, a C
1
-C
20
alkoxy, and a C
6
-C
20
aryl, and further optionally having up to three functional groups independently selected from the group consisting of hydroxyl, nitro, a halogen, thiol, thioether, ketone, aldehyde, ester, ether, amine, imine, amide, carboxylic acid, disulfide, carbonate, isocyanate, carbodiimide, carboalkoxy, and carbamate;
L
1
is a neutral electron donor ligand;
L
2
is a carbene group represented by the formula
wherein each of R and R
1
is independently selected from the group consisting of hydrogen, C
1
-C
20
alkyl, C
2
-C
20
alkenyl, C
2
-C
20
alkynyl, C
6
-C
20
aryl, C
1
-C
20
carboxylate, C
1
-C
20
alkoxy, C
2
-C
20
alkenyloxy, C
2
-C
20
alkynyloxy, C
6
-C
20
aryloxy, C
2
-C
2
20
alkoxycarbonyl, C
1
-C
20
alkylthio, C
1
-C
20
alkylsulfonyl, and C
1
-C
20
alkyl sulfinyl, wherein each of R and R
1
optionally may have up to three substituents selected from the group consisting of C
1
-C
5
alkyl, a halogen, C
1
-C
5
alkoxy, and C
6
-C
10
aryl;
L
3
is a neutral electron donor ligand which may be the same as or different from L
1
, or L
3
is a halide group;
A is a counter anion coordinated to the central metal atom M but only weakly coordinated so that A is not bonded as a ligand to the central metal atom M; and
n is 1 when L
3
is a halide, and n is 2 when L
3
is a neutral electron donor ligand;
wherein M, X
1
, X
2
and A are as defined above in formula (I);
L
11
is a neutral electron donor ligand;
L
12
is a solvent molecule capable of coordination to the central metal atom M; and
L
13
is a C
1
-C
20
alkyl;
wherein M, X
1
, X
2
, and A are as defined above in formula (I);
L{circumflex over ( )}L is a neutral bidentate ligand coordinated to the central metal atom M through two atoms which may be the same or different, each of which is independently selected from the group consisting of a phosphorus atom, a nitrogen atom and an arsenic atom; and
L
14
is selected from the group consisting of a C
1
-C
20
alkyl, a C
3
-C
20
carbene neutral electron donor ligand, a solvent molecule capable of coordinating with the central metal M, and a halide; and
n is 1 when
Kyllingstad Vernon L.
Mukerjee Shakti L.
Armstrong Westerman Hattori McLeland & Naughton LLP
Nazario-Gonzalez Porfirio
Nippon Zeon Co. Ltd.
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