U.S. patent application number 09/935659 was filed with the patent office on 2002-03-21 for preparation of bissilylnorbornane compounds.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. Invention is credited to Endo, Mikio, Kubota, Tohru, Tonomura, Yoichi.
Application Number | 20020035286 09/935659 |
Document ID | / |
Family ID | 18744608 |
Filed Date | 2002-03-21 |
United States Patent
Application |
20020035286 |
Kind Code |
A1 |
Tonomura, Yoichi ; et
al. |
March 21, 2002 |
PREPARATION OF BISSILYLNORBORNANE COMPOUNDS
Abstract
A bissilylnorbornane compound is prepared by reacting
2,5-norbornadiene with a hydrogenchlorosilane in the presence of a
mixture of a palladium compound and a phosphite or a palladium
complex having a phosphite ligand as a catalyst. The
bissilylnorbornane compound can be produced in high yields while
suppressing formation of by-product nortricyclene.
Inventors: |
Tonomura, Yoichi;
(Niigata-ken, JP) ; Kubota, Tohru; (Niigata-ken,
JP) ; Endo, Mikio; (Niigata-ken, JP) |
Correspondence
Address: |
MILLEN, WHITE, ZELANO & BRANIGAN, P.C.
2200 CLARENDON BLVD.
SUITE 1400
ARLINGTON
VA
22201
US
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
Tokyo
JP
|
Family ID: |
18744608 |
Appl. No.: |
09/935659 |
Filed: |
August 24, 2001 |
Current U.S.
Class: |
556/466 |
Current CPC
Class: |
C07F 7/14 20130101 |
Class at
Publication: |
556/466 |
International
Class: |
C07F 007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
JP |
2000-255899 |
Claims
1. A process for preparing a bissilylnorbornane compound of the
following general formula (2): 6wherein "a" is 0, 1 or 2, by
reacting 2,5-norbornadiene with a hydrogenchlorosilane compound of
the following general formula (1):HSi(CH.sub.3).sub.aCl.sub.3-a
(1)wherein "a" is 0, 1 or 2 in the presence of a catalyst which is
a mixture of a palladium compound and a phosphite or a palladium
complex having a phosphite coordinated thereto.
2. The process of claim 1 wherein the phosphite has the following
general formula (3): 7wherein R.sup.1, R.sup.2 and R.sup.3, which
may be the same or different, are substituted or unsubstituted
monovalent hydrocarbon groups having 1 to 10 carbon atoms, at least
one of R.sup.1, R.sup.2 and R.sup.3 being a branched aliphatic
monovalent hydrocarbon group, cyclic aliphatic monovalent
hydrocarbon group or trialkylsilyl-substituted aliphatic monovalent
hydrocarbon group.
3. The process of claim 1 wherein the hydrogenchlorosilane compound
of formula (1) is trichlorosilane.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] This invention relates to the preparation of
bissilylnorbornane compounds by hydrosilylating
2,5-norbornadiene.
[0003] 2. Background Art
[0004] Bissilylnorbornane compounds of the following general
formula (2): 1
[0005] wherein "a" is 0, 1 or 2 have excellent properties including
hardness and scratch resistance because of the norbornane skeleton
within its molecule. They are thus useful as coupling agents to be
added to paints for automotive painting and building painting,
crosslinking agents and adhesives. They are also useful
intermediates to alkoxysilane coupling agents.
[0006] For the preparation of these compounds, it is regarded best
to start with 2,5-norbornadiene and add a hydrogenchlorosilane
compound to the two double bonds in 2,5-norbornadiene. One such
process using a radical initiator is disclosed in Japanese
Publication of International Patent Application (JP-A) No.
11-500129. This process, however, has the drawbacks that there is a
hazard because of the radical initiator having a risk of explosion,
and reaction control is difficult. The radical initiator must be
replenished in sequence, requiring complex steps. Moreover, the
proportion of a bissilylated product, bistrichlorosilylnorbornane
in the reaction solution is as low as 40%, and reactivity is poor.
Thus the process is disadvantageous in industrial practice.
[0007] Other processes proposed thus far include reaction of
2,5-norbornadiene with a hydrogenchlorosilane compound in the
presence of a platinum catalyst (J. Gen. Chem. USSR, 31, 4, 1109)
and in the presence of a palladium catalyst (Tetrahedron Lett., 33
(1992), 7185). The former process relates to monosilylation, with
the yield of monosilylated compound being as low as 44.3%. The low
yield of the monosilylated compound of the following formula (4) is
accounted to the formation of nortricyclene of the following
formula (5). 2
[0008] If the nortricyclene compound forms upon hydrosilylation of
the monosilylated compound following monosilylation, the yield of
the bissilylated compound becomes low because the nortricyclene
compound is no longer hydrosilylated. To obtain the bissilylated
compound In good yields, the formation of the nortricyclene
compound must be minimized.
[0009] The latter process must use an organic phosphorus compound,
which requires many stages of synthesis and is thus expensive, as a
ligand to palladium atom. The reaction must be carried out at a low
temperature over 24 hours in order to suppress the formation of the
nortricyclene compound. If the temperature is raised to reduce the
reaction time, more nortricyclene forms. The process is not
advantageous to produce the desired compound on an industrial
scale.
SUMMARY OF THE INVENTION
[0010] An object of the invention is to provide a process for
preparing a bissilylnorbornane compound of formula (2) in an
efficient and economical manner.
[0011] The invention is directed to a process for preparing a
bissilylnorbornane compound of the following formula (2): 3
[0012] wherein "a" is 0, 1 or 2, by reacting 2,5-norbornadiene with
a hydrogenchlorosilane compound of the following general formula
(1):
HSi (CH.sub.3).sub.aCl.sub.3-a (1)
[0013] wherein "a" is 0, 1 or 2. It has been found that when both a
palladium compound and a phosphite are used as the catalyst, the
formation of nortricyclene is minimized and the bissilylnorbornane
compound of formula (2) is obtained in high yields.
[0014] Therefore, the invention provides a process for preparing a
bissilylnorbornane compound of the formula (2) by reacting
2,5-norbornadiene with a hydrogenchlorosilane compound of the
formula (1) in the presence of a catalyst which is a mixture of a
palladium compound and a phosphite or a palladium complex having a
phosphite coordinated thereto.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] In the inventive process, the hydrogenchlorosilane compound
used as a starting reactant has the general formula (1):
HSi(CH.sub.3).sub.aCl.sub.3-a (1)
[0016] wherein "a" is 0, 1 or 2. Illustrative of the compound are
trichlorosilane, methyldichlorosilane and dimethylchlorosilane.
[0017] The blending ratio of the hydrogenchlorosilane compound to
2,5-norbornadiene is not critical although it is preferred from the
reactivity and productivity standpoints to use 1.0 to 3.0 mol,
especially 1.5 to 2.5 mol of the hydrogenchlorosilane compound per
mol of 2,5-norbornadiene.
[0018] Examples of the palladium compound used herein include
palladium acetate, palladium chloride, sodium palladium chloride,
dichlorobis(benzonitrile)palladium,
dichloro(1,5-cyclooctadiene)palladium- , and
di-.mu.-chlorobis(.pi.-allyl)dipalladium.
[0019] The amount of the palladium compound used is not critical
although it is preferred from the reactivity and productivity
standpoints to use 0.000001 to 0.01 mol, especially 0.00001 to
0.001 mol of the palladium compound per mol of 2,5-norbornadiene.
Less than 0.000001 mol of the palladium compound may fail to
develop the desired catalysis whereas more than 0.01 mol of the
palladium compound may fail to achieve a reaction promoting effect
enough to compensate for such increments.
[0020] Illustrative examples of the phosphite include trimethyl
phosphite, triethyl phosphite, tripropyl phosphite, tributyl
phosphite, triisobutyl phosphite, tripentyl phosphite, trineopentyl
phosphite, tri(2-ethylhexyl)phosphite, triisopropyl phosphite,
tri-s-butyl phosphite, tri-t-butyl phosphite, tri-t-amyl phosphite,
tricyclopentyl phosphite, tricyclohexyl phosphite, triphenyl
phosphite, tribenzyl phosphite, tris(trimethylsilylmethyl)
phosphite, tris(1-trimethylsilyleth- yl)phosphite,
tris(2-trimethylsilylethyl)phosphite, and
tris(3-trimethylsilylpropyl)phosphite. From the reactivity and
selectivity standpoints, compounds of the following general formula
(3) are especially preferred. 4
[0021] Herein R.sup.1, R.sup.2 and R.sup.3, which may be the same
or different, are substituted or unsubstituted monovalent
hydrocarbon groups having 1 to 10 carbon atoms. At least one of
R.sup.1, R.sup.2 and R.sup.3 is a branched aliphatic monovalent
hydrocarbon group, cyclic aliphatic monovalent hydrocarbon group or
trialkylsilyl-substituted aliphatic monovalent hydrocarbon
group.
[0022] The substituted or unsubstituted monovalent hydrocarbon
groups include straight, branched or cyclic aliphatic monovalent
hydrocarbon groups, preferably straight, branched or cyclic alkyl
groups, aryl groups and aralkyl groups, and
trialkylsilyl-substituted monovalent hydrocarbon groups
corresponding to the foregoing hydrocarbon groups in which one or
more hydrogen atoms thereon are substituted with trialkylsilyl
groups, especially trialkylsilyl-substituted aliphatic monovalent
hydrocarbon groups. Illustrative examples include methyl, ethyl,
propyl, n-butyl, pentyl, hexyl, phenyl, benzyl, isopropyl,
isobutyl, s-butyl, t-butyl, neopentyl, isoamyl, t-amyl,
2-ethylhexyl, cyclobutyl, cyclopentyl, cyclohexyl,
trimethylsilylmethyl, 1-trimethylsilylethyl, 2-trimethylsilylethyl
and 3-trimethylsilylpropyl.
[0023] At least one of R.sup.1, R.sup.2 and R.sup.3 is a branched
aliphatic hydrocarbon group, cyclic aliphatic hydrocarbon group or
trialkylsilyl-substituted aliphatic hydrocarbon group, for example,
isopropyl, isobutyl, s-butyl, t-butyl, neopentyl, isoamyl, t-amyl,
2-ethylhexyl, cyclobutyl, cyclopentyl, cyclohexyl,
trimethylsilylmethyl, 1-trimethylsilylethyl, 2-trimethylsilylethyl
or 3-trimethylsilylpropyl.
[0024] Illustrative preferred examples of the phosphite of the
formula (3) include triisopropyl phosphite, tri-s-butyl phosphite,
tricyclohexyl phosphite, tris(trimethylsilylmethyl)phosphite,
tris(1-trimethylsilylethy- l)phosphite,
tris(2-trimethylsilylethyl)phosphite, and
tris(3-trimethylsilylpropyl)phosphite. Of these, triisopropyl
phosphite and tri-s-butyl phosphite are especially preferred.
[0025] The amount of the phosphate used is not critical although it
is preferred to use 1 to 4 mol of the phosphate per mol of
palladium atom in the palladium compound. Less than 1 mol of the
phosphite may lead to a lowering of reaction selectivity whereas
more than 4 mol of the phosphite may lead to a loss of catalytic
activity.
[0026] Instead of using the palladium compound in admixture with
the phosphate, a complex may be used which is obtained by premixing
the palladium compound with the phosphite and effecting reaction
between them. If desired, the resulting complex is isolated and
purified prior to use.
[0027] Illustrative examples of the complex include palladium
dichlorobistriethyl phosphite, palladium dichlorobistriisopropyl
phosphate, palladium dichlorobistri-s-butyl phosphate, and
palladium dichlorobistricyclohexyl phosphite. The amount of the
complex used may be similar to that of the palladium compound.
[0028] For reaction of 2,5-norbornadiene with hydrogenchlorosilane
to take place, the reaction temperature is preferably 0.degree. C.
to 200.degree. C., especially 10.degree. C. to 140.degree. C.,
under atmospheric pressure or applied pressure, though not
critical.
[0029] Although the reaction proceeds in a solventless system, a
solvent may be used. Exemplary suitable solvents used herein
include hydrocarbon solvents such as pentane, hexane, cyclohexane,
benzene, toluene, and xylene, ether solvents such as diethyl ether,
tetrahydrofuran, and dioxane, ester solvents such as ethyl acetate
and butyl acetate, aprotic polar solvents such as acetonitrile, and
chlorinated hydrocarbon solvents such as dichloromethane and
chloroform. These solvents may be used alone or in admixture of
any.
[0030] The aforementioned reaction yields an organosilicon compound
of the general formula (2): 5
[0031] wherein "a" is 0, 1 or 2. Illustrative of the compound are
bis(trichlorosilyl)norbornane, bis(methyldichlorosilyl)-norbornane,
and bis(dimethylchlorosilyl)norbornane.
EXAMPLE
[0032] Examples of the invention are given below by way of
illustration and not by way of limitation.
Example 1
[0033] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 92.1 g (1.0 mol) of
2,5-norbornadiene, 28.6 mg of dichloro(cyclooctadiene)palladium and
50.1 mg of tri-s-butyl phosphate and heated at 80.degree. C. After
the internal temperature became stabilized, 271.0 g (2.0 mol) of
trichlorosilane was added dropwise over 5 hours. After the
completion of dropwise addition, the reaction solution was stirred
at 80.degree. C. for one hour. The reaction solution was distilled,
collecting 283.1 g of bis(trichlorosilyl)norborna- ne as a fraction
having a boiling point of 110-115.degree. C./27 Pa (yield 78%).
Example 2
[0034] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 92.1 g (1.0 mol) of
2,5-norbornadiene, 28.6 mg of dichloro(cyclooctadiene)palladium and
41.6 mg of triisopropyl phosphite and heated at 80.degree. C. After
the internal temperature became stabilized, 271.0 g (2.0 mol) of
trichlorosilane was added dropwise over 5 hours. After the
completion of dropwise addition, the reaction solution was stirred
at 80.degree. C. for one hour. The reaction solution was distilled,
collecting 268.7 g of bis(trichlorosilyl)norborna- ne as a fraction
having a boiling point of 110-115.degree. C./27 Pa (yield 74%).
Example 3
[0035] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 92.1 g (1.0 mol) of
2,5-norbornadiene, 28.6 mg of dichloro(cyclooctadiene)palladium and
33.2 mg of triethyl phosphite and heated at 80.degree. C. After the
internal temperature became stabilized, 271.0 g (2.0 mol) of
trichlorosilane was added dropwise over 5 hours. After the
completion of dropwise addition, the reaction solution was stirred
at 80.degree. C. for one hour. The reaction solution was distilled,
collecting 235.7 g of bis(trichlorosilyl)norborna- ne as a fraction
having a boiling point of 110-115.degree. C./27 Pa (yield 65%).
Comparative Example 1
[0036] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 92.1 g (1.0 mol) of
2,5-norbornadiene, 28.6 mg of dichloro(cyclooctadiene)palladium and
52.5 mg of triphenyl phosphine and heated at 80.degree. C. After
the internal temperature became stabilized, 271.0 g (2.0 mol) of
trichlorosilane was added dropwise over 5 hours. At the end of
dropwise addition, refluxing of unreacted trichlorosilane was
observed. After the completion of dropwise addition, the reaction
solution was stirred at 80.degree. C. for one hour. The reaction
solution was distilled, collecting 159.7 g of
bis(trichlorosilyl)norbornane as a fraction having a boiling point
of 110-115.degree. C./27 Pa (yield 44%).
Comparative Example 2
[0037] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 92.1 g (1.0 mol) of
2,5-norbornadiene, 28.6 mg of dichloro(cyclooctadiene)palladium and
93.7 mg of 2-(diphenylphosphino)-2'-methoxy-1,1'-binaphthyl and
heated at 80.degree. C. After the internal temperature became
stabilized, 271.0 g (2.0 mol) of trichlorosilane was added dropwise
over 5 hours. At the end of dropwise addition, refluxing of
unreacted trichlorosilane was observed. After the completion of
dropwise addition, the reaction solution was stirred at 80.degree.
C. for one hour. The reaction solution was distilled, collecting
165.3 g of bis(trichlorosilyl)norbornane as a fraction having a
boiling point of 110-115.degree. C./27 Pa (yield 46%).
Reference Example 1
Synthesis of bis(trimethoxysilyl)norbornane
[0038] A flask equipped with a stirrer, reflux condenser, dropping
funnel and thermometer was charged with 181.6 g (0.5 mol) of
bis(trichlorosilyl)norbornane synthesized in Example 1, 364.4 g
(3.6 mol) of triethylamine and 1,000 ml of toluene and heated at
50.degree. C. After the internal temperature became stabilized,
115.2 g (3.6 mol) of methanol was added dropwise over 5 hours.
After the completion of dropwise addition, the reaction solution
was stirred at 70.degree. C. for 2 hours. The reaction solution was
cooled to room temperature whereupon the resulting salt was removed
by filtration and the filtrate was distilled. There was collected
154.3 g of bis(trimethoxysilyl)norbornane as a fraction having a
boiling point of 113-117.degree. C./27 Pa (yield 92%).
[0039] There has been described a process of producing
bissilylnorbornane compounds in high yields while suppressing
formation of by-product nortricyclene which causes low yields.
[0040] Japanese Patent Application No. 2000-255899 is incorporated
herein by reference.
[0041] Although some preferred embodiments have been described,
many modifications and variations may be made thereto in light of
the above teachings. It is therefore to be understood that the
invention may be practiced otherwise than as specifically described
without departing from the scope of the appended claims.
* * * * *