U.S. patent application number 15/345962 was filed with the patent office on 2017-05-11 for bisphosphites having 2,4-dimethylphenyl units and use thereof as ligands in hydroformylation.
This patent application is currently assigned to EVONIK DEGUSSA GMBH. The applicant listed for this patent is EVONIK DEGUSSA GMBH. Invention is credited to Katrin Marie DYBALLA, Robert FRANKE, Dirk FRIDAG, Dieter HESS.
Application Number | 20170129838 15/345962 |
Document ID | / |
Family ID | 54539874 |
Filed Date | 2017-05-11 |
United States Patent
Application |
20170129838 |
Kind Code |
A1 |
DYBALLA; Katrin Marie ; et
al. |
May 11, 2017 |
BISPHOSPHITES HAVING 2,4-DIMETHYLPHENYL UNITS AND USE THEREOF AS
LIGANDS IN HYDROFORMYLATION
Abstract
The invention relates to bisphosphites having 2,4-dimethylphenyl
units and a method for the preparation thereof. Furthermore, the
invention relates to the use of the compounds as ligands in a
ligand-metal complex. The compound, and also the complex, may be
used as a catalytically active composition in hydroformylation
reactions.
Inventors: |
DYBALLA; Katrin Marie;
(Recklinghausen, DE) ; FRANKE; Robert; (Marl,
DE) ; FRIDAG; Dirk; (Haltern am See, DE) ;
HESS; Dieter; (Marl, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EVONIK DEGUSSA GMBH |
Essen |
|
DE |
|
|
Assignee: |
EVONIK DEGUSSA GMBH
Essen
DE
|
Family ID: |
54539874 |
Appl. No.: |
15/345962 |
Filed: |
November 8, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B01J 31/185 20130101;
C07F 15/0073 20130101; C07C 47/21 20130101; C07C 45/50 20130101;
B01J 31/0237 20130101; C07C 47/02 20130101; C07C 29/14 20130101;
C07F 9/145 20130101; B01J 2531/822 20130101; B01J 2231/321
20130101; C07C 45/74 20130101; C07C 29/177 20130101; C07F 15/008
20130101; C07C 45/50 20130101; C07C 47/02 20130101; C07C 45/74
20130101; C07C 47/21 20130101; C07C 29/177 20130101; C07C 31/125
20130101 |
International
Class: |
C07C 47/02 20060101
C07C047/02; C07F 15/00 20060101 C07F015/00; B01J 31/18 20060101
B01J031/18; C07F 9/145 20060101 C07F009/145 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2015 |
EP |
15193607 |
Claims
1. Compound of the formula (I): ##STR00011## where R.sup.2,
R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl.
2. Compound according to claim 1, where R.sup.2 is selected from:
-Me, -tBu, --OMe.
3. Compound according to claim 1, where R.sup.2 is --OMe.
4. Compound according to claim 1, where R.sup.4 is selected from:
-Me, -tBu, --OMe.
5. Compound according to claim 1, where R.sup.4 is -tBu.
6. Compound according to claim 1, according to the formula (1):
##STR00012##
7. Complex according to the formula (II): ##STR00013## where
R.sup.2, R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl; and M is
selected from: Rh, Ru, Co, Ir.
8. Complex according to the formula (III): ##STR00014## where
R.sup.2, R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl; and M is
selected from: Rh, Ru, Co, Ir.
9. Complex according to claim 7, where M=Rh.
10. Use of a compound according to claim 1, in a ligand-metal
complex for catalysis of a hydroformylation reaction.
11. Process comprising the following process steps: a) initially
charging an olefin, b) adding a complex according to claim 7, c)
feeding in H.sub.2 and CO, d) heating the reaction mixture, wherein
the olefin is converted to an aldehyde.
12. Process comprising the following process steps: a) initially
charging an olefin, b) adding a compound according to claim 1 and a
substance including a metal selected from: Rh, Ru, Co, Ir, c)
feeding in H.sub.2 and CO, d) heating the reaction mixture, wherein
the olefin is converted to an aldehyde.
13. Complex according to claim 8, where M=Rh.
Description
[0001] The invention relates to bisphosphites having
2,4-dimethylphenyl units and a method for the preparation thereof.
Furthermore, the invention relates to the use of the compounds as
ligands in a ligand-metal complex. The compound, and also the
complex, may be used as a catalytically active composition in
hydroformylation reactions.
[0002] Phosphorus-containing compounds, as ligands, play a crucial
role in a multitude of reactions. Said compounds include phosphite
ligands, i.e., compounds comprising P--O bonds, used in
hydrogenation, hydrocyanation and especially hydroformylation.
[0003] The reactions between olefin compounds, carbon monoxide and
hydrogen in the presence of a catalyst to give the aldehydes
comprising one additional carbon atom are known as hydroformylation
or oxo synthesis. In these reactions, compounds of the transition
metals of group VIII of the Periodic Table of the Elements are
frequently employed as catalysts. Known ligands include, for
example, compounds of the phosphine, phosphite and phosphonite
classes each comprising trivalent phosphorus P.sup.III. A good
overview of the status of hydroformylation of olefins is found in
R. Franke, D. Selent, A. Borner, "Applied Hydroformylation", Chem.
Rev., 2012, DOI:10.1021/cr3001803.
[0004] The literature discloses the synthesis of symmetric
bisphosphites, as disclosed in U.S. Pat. No. 4,769,498 for example,
and the use thereof in catalytically active transition
metal-containing compositions for the hydroformylation of
unsaturated compounds.
[0005] In U.S. Pat. No. 4,769,498, and also in U.S. Pat. No.
5,723,641, preferably symmetric bisphosphites are prepared and used
as ligands for hydroformylation. The symmetric bisphosphite ligands
used in the hydroformylation are prepared at low temperatures.
Adherence to these low temperatures is absolutely necessary since
according to these US documents higher temperatures would lead to
rearrangements and ultimately to asymmetric bisphosphites.
[0006] One of the best catalysts at present for the
hydroformylation of olefins is to use an asymmetrical bisphoshite
as ligand,
4,8-di-tert-butyl-2,10-dimethoxy-6-((3,3',5,5'-tetramethyl-2'-((2,4,8,10--
tetramethyldibenzo[d,f][1,3,2]dioxa
phosphepin-6-yl)oxy)-[1,1'-biphenyl]-2-yl)oxy)dibenzo[d,f][1,3,2]
dioxaphosphepine. This is characterized by a very good yield in
combination with very good regioselectivity.
[0007] However, this ligand is very expensive to prepare due to its
many synthetic stages. Since the price of ligands has an essential
influence of the overall cost-effectiveness of a method, it is
desirable to find alternative ligands with comparably good
properties (yield and regioselectivity) but which are more
cost-effective in terms of their preparation.
[0008] The technical object of the invention is the provision of a
novel ligand which does not have the above-detailed disadvantages
from the prior art in the hydroformylation of unsaturated
compounds, but instead has the following properties:
1) a good activity/yield, 2) a high n-regioselectivity with respect
to hydroformylation, 3) comparatively favourable preparation.
[0009] The object is achieved by a compound according to claim
1.
[0010] Compound of the formula (I):
##STR00001##
where R.sup.2, R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl.
[0011] In the context of the invention, the expression
"--(C.sub.1-C.sub.12)-alkyl" encompasses straight-chain and
branched alkyl groups. Preferably, these groups are unsubstituted
straight-chain or branched --(C.sub.1-C.sub.8)-alkyl groups and
most preferably --(C.sub.1-C.sub.6)-alkyl groups. Examples of
--(C.sub.1-C.sub.12)-alkyl groups are especially methyl, ethyl,
propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,
n-pentyl, 2-pentyl, 2-methylbutyl, 3-methylbutyl,
1,2-dimethylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl,
1-ethylpropyl, n-hexyl, 2-hexyl, 2-methylpentyl, 3-methylpentyl,
4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl,
2,2-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl,
3,3-dimethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl,
1-ethylbutyl, 1-ethyl-2-methylpropyl, n-heptyl, 2-heptyl, 3-heptyl,
2-ethylpentyl, 1-propylbutyl, n-octyl, 2-ethylhexyl,
2-propylheptyl, nonyl, decyl.
[0012] The elucidations relating to the expression
"--(C.sub.1-C.sub.12)-alkyl" also apply to the alkyl groups in
--O--(C.sub.1-C.sub.12)-alkyl, i.e. in --(C.sub.1-C.sub.12)-alkoxy.
Preferably, these groups are unsubstituted straight-chain or
branched --(C.sub.1-C.sub.6)-alkoxy groups.
[0013] Substituted --(C.sub.1-C.sub.12)-alkyl groups and
substituted --(C.sub.1-C.sub.12)-alkoxy groups, depending on their
chain length, may have one or more substituents; the substituents
are mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl.
[0014] In one embodiment, R.sup.2, R.sup.3, R.sup.4 are selected
from: --H, -Me, -tBu, --OMe, -iPr.
[0015] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe, -iPr.
[0016] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe.
[0017] In one embodiment, R.sup.2 is selected from: -Me, -tBu,
--OMe.
[0018] In one embodiment, R.sup.2 is selected from: -tBu,
--OMe.
[0019] In one embodiment, R.sup.2 is selected from: -Me, --OMe.
[0020] In one embodiment, R.sup.2 is --OMe.
[0021] In one embodiment, R.sup.3 is --H.
[0022] In one embodiment, R.sup.4 is selected from: -Me, -tBu,
--OMe.
[0023] In one embodiment, R.sup.4 is selected from: -tBu,
--OMe.
[0024] In one embodiment, R.sup.4 is selected from: -Me, -tBu.
[0025] In one embodiment, R.sup.4 is -tBu.
[0026] In one embodiment, the compound has the formula (1):
##STR00002##
[0027] As well as the compounds, also claimed are complexes
comprising the compound.
[0028] Complex according to the formula (II):
##STR00003##
where R.sup.2, R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl; and M is
selected from: Rh, Ru, Co, Ir.
[0029] In a preferred embodiment, M=Rh.
[0030] In one embodiment, R.sup.2, R.sup.3, R.sup.4 are selected
from: --H, -Me, -tBu, --OMe, -iPr.
[0031] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe, -iPr.
[0032] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe.
[0033] In one embodiment, R.sup.2 is selected from: -Me, -tBu,
--OMe.
[0034] In one embodiment, R.sup.2 is selected from: -tBu,
--OMe.
[0035] In one embodiment, R.sup.2 is selected from: -Me, --OMe.
[0036] In one embodiment, R.sup.2 is --OMe.
[0037] In one embodiment, R.sup.3 is --H.
[0038] In one embodiment, R.sup.4 is selected from: -Me, -tBu,
--OMe.
[0039] In one embodiment, R.sup.4 is selected from: -tBu,
--OMe.
[0040] In one embodiment, R.sup.4 is selected from: -Me, -tBu.
[0041] In one embodiment, R.sup.4 is -tBu.
[0042] Complex according to the formula (III):
##STR00004##
where R.sup.2, R.sup.3, R.sup.4 are selected from: --H,
--(C.sub.1-C.sub.12)-alkyl, --O--(C.sub.1-C.sub.12)-alkyl, wherein
the alkyl groups mentioned may be substituted as follows:
substituted --(C.sub.1-C.sub.12)-alkyl groups and substituted
--(C.sub.1-C.sub.12)-alkoxy groups, depending on their chain
length, may have one or more substituents; the substituents are
mutually independently selected from
--(C.sub.3-C.sub.12)-cycloalkyl,
--(C.sub.3-C.sub.12)-heterocycloalkyl, --(C.sub.6-C.sub.20)-aryl,
fluorine, chlorine, cyano, formyl, acyl or alkoxycarbonyl; and M is
selected from: Rh, Ru, Co, Ir.
[0043] In a preferred embodiment, M=Rh.
[0044] In one embodiment, R.sup.2, R.sup.3, R.sup.4 are selected
from: --H, -Me, -tBu, --OMe, -iPr.
[0045] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe, -iPr.
[0046] In one embodiment, R.sup.2, R.sup.4 are selected from: -Me,
-tBu, --OMe.
[0047] In one embodiment, R.sup.2 is selected from: -Me, -tBu,
--OMe.
[0048] In one embodiment, R.sup.2 is selected from: -tBu,
--OMe.
[0049] In one embodiment, R.sup.2 is selected from: -Me, --OMe.
[0050] In one embodiment, R.sup.2 is --OMe.
[0051] In one embodiment, R.sup.3 is --H.
[0052] In one embodiment, R.sup.4 is selected from: -Me, -tBu,
--OMe.
[0053] In one embodiment, R.sup.4 is selected from: -tBu,
--OMe.
[0054] In one embodiment, R.sup.4 is selected from: -Me, -tBu.
[0055] In one embodiment, R.sup.4 is -tBu.
[0056] In addition to the compound and the complexes comprising the
compound, the use of compound (I) and the complexes (II) or (III)
for catalysis of a hydroformylation reaction is also claimed.
[0057] Use of the compound (I) in a ligand-metal complex for
catalysis of a hydroformylation reaction.
[0058] Use of the complex (II) for catalysis of a hydroformylation
reaction.
[0059] Use of the complex (III) for catalysis of a hydroformylation
reaction.
[0060] Furthermore, the hydroformylation process is also claimed in
which the compound (I) or the complex (II) or (III) is used.
[0061] Process comprising the following process steps:
a) initially charging an olefin, [0062] b) adding an
above-described complex, or an above-described compound and a
substance including a metal selected from: Rh, Ru, Co, Ir, c)
feeding in H.sub.2 and CO, d) heating the reaction mixture, wherein
the olefin is converted to an aldehyde.
[0063] Process steps a) to c) can be carried out here in any
desired sequence.
[0064] The compound may be used as a ligand in a ligand-metal
complex.
[0065] An excess of ligands can also be used in this case and each
ligand is not necessarily present bound in the form of a
ligand-metal complex but is present as free ligand in the reaction
mixture.
[0066] The reaction is conducted under customary conditions.
[0067] Preference is given to a temperature of 80.degree. C. to
160.degree. C. and a pressure of 1 to 300 bar. Particular
preference is given to a temperature of 100.degree. C. to
160.degree. C. and a pressure of 15 to 250 bar.
[0068] In a preferred embodiment, the metal is Rh.
[0069] The reactants for the hydroformylation in the process of the
invention are olefins or mixtures of olefins, especially
monoolefins having 2 to 24, preferably 3 to 16 and particularly
preferably 3 to 12 carbon atoms, having terminal or internal C--C
double bonds, for example 1-propene, 1-butene, 2-butene, 1- or
2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene,
1-, 2- or 3-hexene, the C.sub.6 olefin mixture obtained in the
dimerization of propene (dipropene), heptenes, 2- or
3-methyl-1-hexenes, octenes, 2-methylheptenes, 3-methylheptenes,
5-methyl-2-heptene, 6-methyl-2-heptene, 2-ethyl-1-hexene, the
C.sub.8 olefin mixture obtained in the dimerization of butenes
(di-n-butene, diisobutene), nonenes, 2- or 3-methyloctenes, the
C.sub.9 olefin mixture obtained in the trimerization of propene
(tripropene), decenes, 2-ethyl-1-octene, dodecenes, the C.sub.12
olefin mixture obtained in the tetramerization of propene or the
trimerization of butenes (tetrapropene or tributene), tetradecenes,
hexadecenes, the C.sub.16 olefin mixture obtained in the
tetramerization of butenes (tetrabutene), and olefin mixtures
prepared by cooligomerization of olefins having different numbers
of carbon atoms (preferably 2 to 4).
[0070] The process according to the invention using the ligands
according to the invention can be used to hydroformylate
.alpha.-olefins, terminally branched, internal and internally
branched olefins. The high yield of terminal hydroformylated
olefins is notable in this case, even when only a low proportion of
olefins having terminal double bonds was present in the
reactant.
[0071] The invention is to be illustrated in greater detail
hereinafter by working examples.
GENERAL PROCEDURE SPECIFICATIONS
[0072] All the preparations which follow were carried out under
protective gas using standard Schlenk techniques. The solvents were
dried over suitable desiccants before use (Purification of
Laboratory Chemicals, W. L. F. Armarego (Author), Christina Chai
(Author), Butterworth Heinemann (Elsevier), 6th edition, Oxford
2009).
[0073] Phosphorus trichloride (Aldrich) was distilled under argon
before use. All preparative operations were effected in baked-out
vessels. The products were characterized by means of NMR
spectroscopy. Chemical shifts (.delta.) are reported in ppm. The
.sup.31P NMR signals were referenced as follows:
SR.sub.31P=SR.sub.1H*(BF.sub.31P/BF.sub.1H)=SR.sub.1H*0.4048 (Robin
K. Harris, Edwin D. Becker, Sonia M. Cabral de Menezes, Robin
Goodfellow, and Pierre Granger, Pure Appl. Chem., 2001, 73,
1795-1818; Robin K. Harris, Edwin D. Becker, Sonia M. Cabral de
Menezes, Pierre Granger, Roy E. Hoffman and Kurt W. Zilm, Pure
Appl. Chem., 2008, 80, 59-84).
[0074] The recording of nuclear resonance spectra was effected on
Bruker Avance 300 or Bruker Avance 400, gas chromatography analysis
on Agilent GC 7890A, elemental analysis on Leco TruSpec CHNS and
Varian ICP-OES 715, and ESI-TOF mass spectrometry on Thermo
Electron Finnigan MAT 95-XP and Agilent 6890 N/5973
instruments.
General Reaction Equation (Comparative Ligands)
##STR00005##
[0075] General Reaction Equation (Inventive Ligand)
##STR00006##
[0077] As is clear by means of comparing the two reaction schemes,
fewer synthetic stages are required for compound (1) than for
compound (4) or (5). In the preparation of compound (1), the
2,4-dimethylphenol does not have to be first coupled to a biphenol,
but can be reacted directly with PCl.sub.3 to give the
corresponding chlorophosphite.
Preparation of bis(2,4-dimethylphenyl)chlorophosphite
##STR00007##
[0079] 50 g of PCl.sub.3 (0.363 mol) and 86 g of pyridine (1.076
mol) in 380 ml of dry toluene were initially charged in a secured
1200 ml glass reactor provided with a dropping funnel. The milky
yellow PCl.sub.3/pyridine solution was cooled down to -7.degree. C.
with stirring. 86 ml of 2,4-dimethylphenol (0.720 mol) were then
added to the dropping funnel and dissolved in 380 ml of dry
toluene. To carry out the reaction, the phenol/toluene solution was
added dropwise slowly and steadily to the PCl.sub.3/pyridine
solution. The reaction mixture was brought to room temperature
overnight with stirring.
[0080] For workup, the hydrochloride formed was filtered off and
rinsed with 60 ml of dry toluene and the resulting mother liquor
was concentrated to dryness under reduced pressure.
[0081] For further work-up, the crude solution was distilled. For
this purpose, a pear-shaped flask was filled with the crude
solution, on which flask a short distillation apparatus without
cooling jacket was placed. The thermometer was placed at the upper
opening, and at the other end a spider with four further
pear-shaped flasks was attached. Subsequently, this apparatus was
attached to a cold trap and from there to the high vacuum pump. The
pear-shaped flask with the crude ligand to be distilled was heated
by means of an oil bath. Firstly, the forerun was removed at a top
temperature of 25-30.degree. C. The spider was then further rotated
and the main run was removed at a top temperature of 140.degree. C.
When no more drops appeared in the main run, the distillation was
stopped, the pump was shut down and the main run in the relevant
pear-shaped flask was removed, sealed and analysed.
Result:
[0082] Total mass: 56.7 g (46% yield)
Preparation of
3,3'-di-tert-butyl-5,5'-dimethoxy-[1,1'-biphenyl]-2,2'-diyltetrakis(2,4-d-
imethylphenyl)bis(phosphite)
##STR00008##
[0084] In a 1000 mL Schlenk flask, 260 ml of dry acetonitrile were
added to 51.86 g (0.153 mol) of
bis(2,4-dimethylphenyl)chlorophosphite at room temperature with
stirring and the chlorophosphite was dissolved.
[0085] In a second 250 ml Schlenk flask, 12.4 ml (0.153 mol) of
pyridine and 155 ml of dry acetonitrile were added to 20.1 g (0.056
mol) of
3,3'-di-tert-butyl-5,5'-dimethoxy-[1,1'-biphenyl]-2,2'-diol. The
chlorophosphite solution in the Schlenk flask was then cooled to
0.degree. C. The biphenol/pyridine solution was then slowly added
dropwise with vigorous stirring. The reaction mixture was
maintained at this temperature for ca. 3 h and then very slowly
brought to room temperature overnight.
[0086] The suspension was then filtered off, washed thoroughly with
30 ml of acetonitrile and dried.
Result:
[0087] Mass: 44.01 g (yield: 85%)
Reduction of Chlorine Level
[0088] In order to decrease the chlorine content in this crude
ligand, this ligand was purified.
[0089] The chlorine contents reported are meant as total chlorine
contents.
[0090] The total chlorine content is determined according to
Wickbold: sample preparation according to DIN 51408 and analysis by
ion chromatography according to DIN EN ISO 10304.
[0091] 5.15 g of
3,3'-di-tert-butyl-5,5'-dimethoxy-[1,1-biphenyl]-2,2'-diyltetrakis(2,4-di-
methylphenyl)bis(phosphite) in a first 250 ml Schlenk flask with 15
ml of degassed toluene and 5 ml of pyridine at 100.degree. C. were
stirred until the
3,3'-di-tert-butyl-5,5'-dimethoxy-[1,1'-biphenyl]-2,2'-diyltetr-
akis(2,4-dimethylphenyl)bis(phosphate) had dissolved. After all had
dissolved, the temperature was maintained for a further 15 min and
then cooled to 90.degree. C.
[0092] Meanwhile, 100 ml of heptane and 5 ml of pyridine were
placed in a second 250 ml Schlenk flask and this solution was
cooled down to 0.degree. C. Subsequently, the solution from the
first Schlenk flask was added via a frit to the second Schlenk
flask with the cold heptane/pyridine solution and stirred at
0.degree. C. for 3 h. No precipitate was observed. By means of a
vacuum pump, the solvent mixture was drawn off until the solid had
precipitated and was dried. After that, 50 ml of acetonitrile was
given onto the dried solid. This suspension has been stirred for
two days at room temperature, fritted and dried by means of a
vacuum pump.
Result:
[0093] Mass: 3.7 g
[0094] Chlorine determination: 20/20 ppm
Procedure for the Catalysis Experiments
Experimental Description--General
[0095] In a 100 ml autoclave from Parr Instruments, cis-2-butene
was hydroformylated with the aid of synthesis gas pressure
(CO/H.sub.2=1:1 (% by vol.)). As the precursor, Rh(acac)(CO).sub.2
was initially charged in toluene. The ligand was used in a molar
excess of 4:1 relative to rhodium. Tinuvin 770DF was used as
stabilizer in a molar ratio to the ligand of ca. 1:1. In addition,
as GC standard, ca. 0.5 g of tetraisopropylbenzene (TIPB) was
added. About 6 g of reactant were metered in after the reaction
temperature envisaged had been attained.
[0096] During the reaction, the pressure was kept constant via
synthesis gas regulation with a mass flow meter. The stirrer speed
was 1200 min.sup.-1. Samples were taken from the reaction mixture
after 12 hours. The results of the experiments are summarized in
Table 1.
##STR00009##
Experimental Description--Specific
[0097] In a 100 ml autoclave from Parr Instruments, 5.6 g of
cis-2-butene were hydroformylated at 120.degree. C. and 20 bar
synthesis gas pressure. As the precursor, 0.0056 g of
Rh(acac)(CO).sub.2 was initially charged in 48.8 g of toluene. As
the ligand, 0.0779 g of ligand was used in the catalyst mixture
solution. 0.0416 g of Tinuvin 770DF was added as the organic amine,
and a GC standard. The reactant was metered in after attainment of
the reaction temperature envisaged.
[0098] During the reaction, the pressure was kept constant via
synthesis gas regulation with a mass flow meter. Samples were taken
from the reaction mixture after 12 hours.
[0099] Furthermore, compound (5), its symmetrical isomer compound
(4) and compound (6) were tested under corresponding conditions.
These compounds were prepared according to WO 2014/056733 A1, EP 2
907 819 A1 and WO 2007/109005A2 respectively.
[0100] In Table 1 the hydroformylation results of cis-2-butene at
20 bar synthesis gas pressure are shown.
##STR00010##
TABLE-US-00001 TABLE 1 Aldehyde yield in Regioselectivity Entry
Ligand [%] n-pentanal in % 1 5 95 94 2 4 66 90 3 1* 95 98 4 6 79 98
*inventive compound
Definition of the Selectivity:
[0101] in hydroformylation, there is the n/iso selectivity
(n/iso=the ratio of linear aldehyde (=n) to branched (=iso)
aldehyde). In this case, the n-pentanal regioselectivity signifies
that this amount of linear product was formed. The remaining
percentages then correspond to the branched isomer. Rate of
selectivity was estimated by gas chromatography.
[0102] Ligands (5) (entry 1) and (6) (entry 4) have a very good
n-pentanal regioselectivity and achieve good or at least moderate
yields of aldehydes. Isomer (4) (entry 2) has a lower n-pentanal
selectivity of only 90% and distinctly lower activities, i.e.
yields. The best selectivity of 98% is achieved with the ligand (1)
according to the invention. Beyond that, ligand (1) has an
excellent yield of 95%.
[0103] The experiments carried out demonstrate that the objects
presented are achieved by the compound (1) according to the
invention.
* * * * *