Title of Invention

A RUTHENIUM COMPLEX WITH A CHIRAL FERROCENYL-DIPHOSPHINE LIGAND FOR HOMOGENEOUS CATALYSIS AND A PROCESS FOR PREPARING THE SAME

Abstract The invention relates to ruthenium complexes with a chiral ferrocenyldiphosphine ligand, wherein the ruthenium has the oxidation state (+II) and the chiral ferrocenyldiphosphine ligand has bidentate P-P coordination to the ruthenium. The ruthenium complexes are cyclic and with the ferrocenyldiphosphine ligand have an at least eight-membered ring. The ferrocenyldiphosphine ligands are selected from the group consisting of Taniaphos, Taniaphos-OH and Walphos ligands. A process for preparing the Ru complexes is described. The Ru complexes are used as catalysts for homogeneous asymmetric catalysis for preparing organic compounds.
Full Text Ruthenium complexes with (F-P)-coordinated
ferrocenyldiphosphine ligands, process £or preparing
them, and their use in homogeneous catalysis
Description
The present invention relates to ruthenium complexes
for homogeneous catalysis. In particular, the invention
relates to ferrocene-containing, P-P-coordinated
ruthenium complexes with chiral diphosphine ligands
(known as ferrocenyldiphosphine ligands) and a process
for preparing them. The invention further relates to
the use of these complexes as catalysts for homogeneous
catalytic hydrogenation.
Chiral ferrocenyldiphosphines have proven to be
valuable ligands for catalytically active metal
complexes which are used in homogeneous catalysis for
the enantioselective hydrogenation of organic
conqpounds. Fields of use are the preparation of
intermediates or active compounds, for example
pharmaceuticals, pesticides, flavors or fragrances.
Among the diphosphines having a ferrocene framework,
l-sec-phosphino-2-(2'-sec-phosphino-1-benzyl)-
ferrocenes, for excunple, have proven to be valuable
ligands for noble metal complexes for the
enantioselective hydrogenation of organic compounds.
Ligands of this type are referred to by the name
"Taniaphos" and are described in WO 00/37478. Further
examples of diphosphines having a ferrocene framework
are 1-(a-sec-phosphinoalkyl)-2-(sec-phosphinoaryl)-
ferrocenes which are disclosed in WO 02/02578 (trivial
neune "Walphos") .
In enantioselective hydrogenation, these diphosphine
ligands are used together with suitable noble metal
complexes. The reaction of asymmetric ferrocenyl-
diphosphine ligands with organometallic Ru con^ovinds
leads to mixtures of complexes which have monodentate
coordination of the P atoms of the phosphine ligand,
cf. equ. (1):
Equation (1) :

According to equ. (1) , an isomer mixture of
monodentate, P-coordinated Ru conplexes in which in
each case, only one of the P atoms of the
ferrocenyldiphosphine ligcuid is bound to the ruthenium
is present. The two isomers in equation (1) can be
distinsruished, for example, by means of ^^P-NMR
spectroscopy. Simultaneous coordination of both P atoms
of the ferrocenyldiphosphine ligand in a ruthenium
coirplex (hereinafter referred to as "bidentate"
coordination or "P-P coordination") has hitherto not
been observed.
Organometallic Ru conpounds used in these hydro-
genations are, for example, [Ru(COD)y2]x- [Ru(NBD)Y2]x/
[Ru(aromatic)Y2]x or [Ru(COD) (2-methylallyl) 2] (where X
= 2; Y = halide, COD = 1,5-cyclooctadiene, NBD =
norbornadiene, aromatic = for example, p-cumene or
another benzene derivative).
EP 1622920B1 discloses transition metal complexes with
ferrocenyldiphosphine ligands. Complexes having
specific P-P coordination of the phosphine ligands are
not described, and in addition the diphosphine ligands
disclosed have phosphine groups which are located on
different ferrocene rings of the ligand system.

Although WO 00/37478 describes transition metal
complexes which contain a metal atom of transition
group 7 or 8 and in which both P atoms of the
ferrocenyldiphosphine ligand are simultaneously
coordinated to the central atom, the complexes are
neither isolated nor characterized. No process for
preparing them is described; rather, the complexes are
generated shortly before use by combining the ligands
and the appropriate treinsition metal salts in the
reaction solvent ("in situ") .
These in-si tu processes are prior art. Thus,
ferrocenyldiphosphine ligands are reacted with
ruthenitim complexes in an in-situ procedure; cf.
Angewandte Chemie 1999, 111, No. 21, 3397-3400. Here,
[Ru(COD) (C4H7)2]HBr (COD = cycloocta-1,5-diene, C4H7 =
2-(T|^-)methylallyl) is used as Ru complex and 3-keto
esters of the type R-C0-CH2-CO-OEt are hydrogenated in
ethcmol at 50°C under 50 bar of hydrogen. The seime Ru
starting coitpound is used in Tetrahedron Asymmetry 1^
(2004) 91-102 and the catalyst is prepared in situ.
Adv, Synth. Catal. 2003, 345, 160-164 describes phenyl-
ferrocenylethyldiphosphine ligands of the "Walphos"
type. Dimeric [RUI2 (p-cvimene) ]2 is used as Ru-containing
catalyst precursor in the hydrogenation and the
catalyst is formed in situ.
However, no studies on the structure of the metal
complexes generated in situ have hitherto been carried
out; the corresponding con^lexes were not isolated but
used directly in the reaction mixture for homogeneous
catalysis, in particular for catalytic hydrogenation.
Disadvantages of the catalytic hydrogenation processes
which have been described up to now and the catalysts
used therein are, in particular, the low enantio-
selectivities and a high consumption of noble metal
catalysts, i.e. a low substrate/catalyst (S/C) ratio,
and long hydrogenation times.
It was therefore an object of the present invention to
provide inproved catalysts for homogeneous, asymmetric
hydrogenation.
This object is achieved by provision of the rutheniiom
complexes of the types (A) and (B) as claimed in
claim 1 of the invention. Furthermore, a process for
preparing the complexes of the invention is disclosed
in claim 11. Preferred embodiments are described in the
subordinate claims dependent thereon.
The present invention describes ruthenium complexes
with a chiral ferrocenyldiphosphine ligand for
homogeneous catalysis, wherein the ruthenium has the
oxidation state (+11) and the ferrocenyldiphosphine
ligands have bidentate P-P coordination to the Ru. The
ruthenium complexes are cyclic and with the
ferrocenyldiphosphine ligaund have an at least eight-
membered ring. The ferrocenyldiphosphine ligands are,
for example, selected from the group consisting of
"Taniaphos" and "Walphos' ligands, but are not
restricted to these ligands.
The present invention further provides a process for
preparing the ruthenium complexes of the invention, in
which specific Ru starting compounds are reacted with a
chiral ferrocenyldiphosphine ligand.
In the search for well-defined Ru complexes with
ferrocenyldiphosphine ligands, it has surprisingly been found that simultaneous coordination of both P atoms of
the ferrocenyldiphosphine ligands to a central Ru atom
can be achieved under particular conditions. This gives
cyclic Ru complexes which have an at least eight-

membered ring in their structure (number of ring
members r > 8) .
The effect of P-P coordination is obtained by use of
specific ferrocenyldiphosphine ligands which have at
least seven ring-forming atoms in their structure and
are therefore sterically capable of forming an at least
eight-membered ring with the central Ru atom. The
phosphino groups are preferably located on one (i.e. on
the Scune) cyclopentadienyl ring of the ferrocene
molecule.
Example of suitable ferrocenyldiphosphine ligands are
ligands of the Taniaphos type and their derivatives,
for exainple Taniaphos-OH or Taniaphos-OMe, etc.
However, it is also possible to use ligands of the
"Walphos" type. Examples of suitable ferrocenyl-
diphosphine ligands for preparing the Ru complexes of
the invention are:
(S) -l-diphenylphosphino-2- [ (R) -a- (N,N-dimethyl-
amino) -o- (diphenylphosphinophenyl) methyl] ferrocene
(= Taniaphos TOOl-1)
(R) -l-diphenylphosphino-2- [ (S) -a- {N,N-dimethyl-
amino) -o- (diphenylphosphinophenyl)methyl] ferrocene
(= Taniaphos TOOl-2)
(S) -l-dicyclohexylphosphino-2- [ (R) -a- (N, N-di-
methylamino) -o- (dicyclohexylphosphinophenyl) -
methyl]ferrocene (= Taniaphos T002-1)
(R)~l-dicyclohexylphosphino-2-[(S)-a-(N,N-di-
methylamino) -o- (dicyclohexylphosphinophenyl) -
methyl]ferrocene {= Taniaphos T002-2);
(S)-l-diphenylphosphino-2-[a-(S)-hydroxy-(o-di-
phenylphosphinophenyl)methyl]ferrocene ("Taniaphos
OH"); and derivatives of this type;
(S) -l-diphenylphosphino-2- [a- (S) -methoxy (o-di-
phenylphosphinopheny 1 )methyl]ferrocene ("Taniaphos
OMe'); cind derivatives of this type (cf.
WO 2003/076451);
(R) -1-[(R)-2- (2'-diphenylphosphinophenyl)ferro-
cenyl]ethyIdi(bis-3,5-trifluoromethylphenyl)-
phosphine {Walphos WOOl-1);
(S) -l-[ (S)-2- (2'-diphenylphosphinophenyl)ferro-
cenyl]ethyldi(bis-3,5-trifluoromethylphenyl)-
phosphine (Walphos WOOl-2);
(R)-1-[(R)-2-(2'-diphenylphosphinophenyl)ferro-
cenyl]ethyldiphenylphosphine (Walphos WO02-1) ;
(S)-l-[(S)-2-(2'-diphenylphosphinophenyl)ferro-
cenyl]ethyldiphenylphosphine (Walphos W002-2);
(R)-l-[(R)-2-{2'-diphenylphosphinophenyl)ferro-
cenyl]ethyldicyclohexylphosphine (Walphos W003-1);
(S)-1-[(S)-2-(2'-diphenylphosphinophenyl)ferro-
cenyllethyldicyclohexylphosphine (Walphos W003-1);
(R) -1- [ (R) -2- (2'-di(3,5-dimethyl-4-methoxyphenyl)-
phosphinophenyl)ferrocenyl]ethyldi(bis-3,5-tri-
fluoromethyl)phenyl)phosphine (walphos W005-1) ;
(S)-1-[(S)-2-(2'-di(3,5-dimethyl-4-methoxyphenyl)-
phosphinophenyl)ferrocenyl]ethyldi(bis-3,5-tri-
fluoromethylphenyl)phosphine (Walphos W005-2);
(R)-1-[(R)-2-(2'-diphenylphosphinophenyl)ferro-
cenyl]ethyldi(3,5-xylyl)phosphine (Walphos W006-
1);
(S)-1-[(S)-2-(2'-diphenylphosphinophenyl)ferro-
cenyljethyldi (3, 5-xylyl)phosphine (Walphos W006-
2);
(R) -1- [ (R) -2- (2 ' -dicyclohexylphosphinophenyl) -
ferrocenyl]ethyldi(3, 5-trifluoromethyl)phenyl) -
phosphine (Walphos W008-1) ;
(S) -1- t (S) -2- (2 ' -dicyclohexylphosphinophenyl) -
f errocenyl ] ethyldi (3, 5-trif luoromethyl) phenyl) -
phosphine {Walphos W008-2).
These chiral ferrocenyldiphosphine ligands are in most
cases commercially available. Use of these ligands in
the preparative process of the invention gives cyclic
Ru coitplexes which have an eight-meihbered ring in their
structure. However, other chiral ferrocenyldiphosphine
ligands are also suitable as long as they allow
formation of an at least eight-membered ring (number of
ring members r > 8).
In the present preparative process, the effect of P-P
coordination is achieved by use of specific Ru starting
compounds which are present in the oxidation state
(+11) and have at least two neutral 2-electron donor
ligands Ld- They have the following general formula

where
Ru is in the oxidation state +11,
n is an integer equal to or greater than 3,
Lo is an neutral ligand,
Z is at least one n-bonded organic ligand and
E' is the anion of an oxo acid or complex acid.
The at least three neutral ligands Ld generally belong
to the class of 2-electron donor ligands such as
secondary or tertiary phosphines or N-heterocyclic
carbene ligands (knovm as NHC ligands). The ligands Ld
are preferably solvent ligands which are bound to the
central Ru atom. At least two of these ligands are
replaced in the reaction by a chiral diphosphine
ligand. Exanqples of suitable ligands Ld are ligands
from the group consisting of alcohols, ethers, amines,
acid eunides, lactams eind sulfones; for example
acetonitrile (CH3CN). diethyl ether (DEE), water (H2O)
or acetone. It is also possible to use cyclic ligands
such as tetrahydrofuran (THF), dioxane, pyridine,
imidazole or thiophene. Mixed systems having different
types of ligands, for example ones containing phosphine
ligands and/or carbene ligands and/or solvent ligands,
are also possible.
Furthermore, the Ru starting compound has at least one
n-bonded organic ligand Z. Z encompasses substituted or
unsubstituted cyclic or open-chain dienyl ligands in
general, for example substituted or unsubstituted
pentadienyl or heptadienyl ligands.
For clarification, such dienyl ligands are, when bonded
to the Ru, negatively charged, i.e. anionic.
Preference is given to using 2,4-dimethylpentadiene,
2,3,4-trimethylpentadiene, cycloheptadiene, cycloocta-
diene, norbornadiene, etc. The ligeuids Z can also be
present in the protonated state and have protons in an
"agostic interaction*.
Most preferably, for Z, one negatively charged open-
/ chain dienyl ligand, for example 2,4-dimethyl-
pentadienyl- or 2,3,4-trimethylpentadienyl- is
employed.
The Ru starting compound is present as cation having a
single positive charge emd has, as further constituent
E", the anion of an oxo acid or complex acid as
counterion. Exaunples of E" are HSO4', CF3SO3', C104',
BF4", B(aryl)4', SbF6' and PF6'.
Examples of suitable Ru starting compounds are
[Ru(2,4-dimethylpentadienyl) (CH3CN)3]*BF4' or [Ru(2,4-
dimethylpentadienyl) (acetone) 3] *BF4*.
The Ru starting compound can be prepared in various
process steps from known Ru precursor compounds by
reaction with the appropriate ligand LD, and isolated.
The Ru precursor conpound can be protonated before
reaction with the neutral ligand Ld in order to achieve
improved ligand replacement by Ld-
As Ru precursors, it is possible to use the compounds
mentioned above, e.g. bis (?5-(2,4-dimethylpenta-
dienyDRu, [Ru{COD)Cl2]2, [Ru(norbomadiene)Cl2]2,
[Ru(p-cumene)l2]2 or [Ru{COD)(2-methylallyl)2]. These Ru
compounds are commercially available. The preparation
procedures for the Ru starting compound have to be
adjusted depending on the precursor compound used.
A preferred Ru precursor conprises negatively charged Z
ligands, such as, for example, bis diS-(2,4-dimethyl-
pentadienyDRu. The preparation of the Ru starting
compoxmd typically proceeds in two steps:
Step A (protonation):
[Zi-Ru] + H* E => [Zz-Ru-H ]+ + E'

step B (ligand exchange) :
[Z2-Ru-H]+E- + dLd => [Z-Ru (LD)n r E" + Z-H
It has been found that reaction of the Ru starting
compounds with the appropriate chiral ferrocenyl-
diphosphine ligands (hereinafter represented as
P(l)-P(2) for short) gives the Ru complexes of the
invention. The formation of the ferrocenyldiphosphine
conplex then occurs in step C. The preparative process
of the invention is shown in general form in equ. (2):
The reaction of equ. (2) gives the novel Ru complexes
of type (A) . To prepare the Ru complexes of type (A) ,
the ferrocenyldiphosphine ligands are reacted with the
above-described Ru starting compound, resulting in at
least two of the ligands Ld being replaced by the
chiral diphosphine ligands in the reaction. If the Ru
starting compoiind has more than two ligands Ld, the
remaining ligands Ld remain coordinated to the
ruthenium. They can be replaced or eliminated in a
subsequent step. The preparation of the Ru complexes is
preferably carried out vmder a protective gas
atmosphere using the Schlenk technique and oxygen-free
solvents. The ferrocenyldiphosphine ligands are
typically reacted with the Ru starting compound in a
suitable solvent at temperatures in the range from 20
to 80°C, preferably in the range from 20 to 60°C and
particularly preferably at room temperature (25°C) ,
while stirring. Suitable solvents are chlorinated

hydrocarbons such as chloroform, methylene chloride,
trichloroethane or dichloroethane. The reaction times
range from 1 hour to 10 hours. It can be advantageous
to use the ligand in a small excess in the preparation
of the Ru complexes. The excess can be in the range
from 1 to 10 mol% (based on the Ru starting compound) .
The subsequent isolation, washing and purification
steps are well known to those skilled in the art. To
remove solvent residues, the product is dried under
reduced pressure.
In a further embodiment, the present invention
encompases Ru complexes of type (B) . These complexes
bear no net charge and have a negatively charged ligand
Lz in addition to the P-P-coordinated ferrocenyl-
diphosphine ligand, the n-bonded organic ligand Z and,
if appropriate, the ligcuid Ld-
This ligand Lz can be introduced by replacement of one
of the ligands Ld by a halide ion (fluoride, chloride,
bromide or iodide) or a pseudohalide ion (e.g. CN",
SCN', cyanate, isocyanate, etc.). The Ru complex of
type (B) is preferably prepared from the complex of
type (A) by subsequent ligand exchange, for example by
replacement of an acetonitrile molecule by iodide (cf.
example 2):
Step D (replacement of the ligand Ld by negatively
charged ligands Lz) according to equ. (3).
To carry out step D, the cationic Ru complex (type A)
is dissolved in a dipolar, aprotic solvent, for example
acetone or THF, and reacted with ligand Lz at
temperatures in the range from 20 to 50°C. The product
generally precipitates and can be separated off.
The novel Ru complexes of type (A)
where, in each case,
Ru is in the oxidation state +11,
n is an integer equal to or greater than 3,
Ld is an neutral ligand,
Z is at least one n-bonded organic ligand,
E" is an anion of an oxo acid or complex acid and
Lz is at least one anionic ligand
and the ferrocenyldiphosphine ligand P(l)-P(2) has
bidentate P-P coordination, are effective homogeneous
catalysts for the asymmetric hydrogenation of prochiral
organic confounds.
They are therefore used as catalysts for homogeneous
asymmetric catalysis, for exanple for the enantio-
selective hydrogenation of multiple bonds. For the
purposes of the present invention, multiple bonds are
double bonds between a carbon atom and a further carbon
atom (C=C) or oxygen atom (C=0) or nitrogen atom (C=N).
Furthermore, the ruthenium complexes of the invention
can also be used as catalysts for other asymmetric
reactions. These include C-C, C-0, C-N, C-P, C-Si, C-B
or C-halogen bond formation reactions. Examples are
asynmietric cyclization reactions, asymmetric oligo-
merizations and asymmetric polymerization reactions.
The novel Ru complexes of type (A) and (B) are used as
defined compounds and display, for example, very good
catalytic properties in hydrogenation. In comparison,
Ru complexes which only have single, monodentate
coordination of the P atoms of the
ferrocenyldiphosphine ligands or Ru compounds which are
used together with the ferrocenyldiphosphine ligands in
the in-situ process display poorer catalytic
properties.
The following examples illustrate the invention.
EXAMPLES
Example 1:
Preparation of (t]5-2, 4-djjBethylpazitadienyl) - (CH3CN) -
(Taniaphos T001-l}rutheniua(II) tetrafluoroborate
a) Preparation of (n4-2,4-dimethylpentadiene-'n2-C,H)-
(115-2, 4-dimethylpentadienyl) ruthenium tetrafluoro-
borate
In a 100 ml Schlenk tube provided with a magnetic
stirrer, 1.1 g (3.77 mmol) of bis (Ti5-2, 4-dimethylpenta-
dienyl) ruthenium (from Colonial Metals Inc., Elkton,
MD, USA) are dissolved in 50 ml of diethyl ether. At
room temperature, 0.51 ml (3.77 mmol) of a 54% strength
HBF4-Et20 solution (from Aldrich) is added dropwise over
a period of 10 minutes. After the addition is complete,
the mixture is allowed to settle and the completeness
of the precipitation is checked by addition of a
further drop of HBF4-Et20. The supernatant solvent is
taken off and the solid is washed twice with diethyl
ether. The light-yellow residue is dried under reduced
pressure. Yield: 1.43 g (100%).
b) Preparation of the_____acetonitrile complex
(115-2, 4-dimethylpentadienyl) - (CH3CN) 3rutheni\am(II)
te tra fluoroborate
0.41 g of (1.1 mmol) of (Ti4-2,4-dimethylpentadiene-Ti2-
C,H) -115-2, 4-dimethylpentadienyl)rutheniiam tetrafluoro-
borate; prepared in step a) , is admixed with 10 ml of
acetonitrile. The orange solution is stirred for
10 minutes and the solvent is then removed under
reduced pressure to give an orange solid. Yield: 0.44 g
(100%).
c) Reaction with Taniaphos T 001-1
Taniaphos SL-TOOl-1 (from Solvias, Basel, CH; 400 mg,
0.58 mmol) is placed in a round-bottom flask provided
with a magnetic stirrer and the Ru starting compound
(236 mg, 0.58 mmol) prepared in b) is then added. The
reactants are dissolved in 10 ml of CH2CI2 and the
mixture is stirred at room temperature for three hours.
The solution becomes deep red. The solvent is taken off
under reduced pressure and the solid residue is washed
with diethyl ether. The product is collected and dried
in a high vacuum. Yield: 90%, red-orange solid, two
diastereomers having a de of 75%.
Characterization:
1H NMR (CD2Cl2, major) 5: -1.76 (b, IH, pentadienyl) ,
0.15 (b, IH, pentadienyl). 0.765 (t, IH, J = 6.41 Hz,
pentadienyl) , 1.24 (b, 3H. pentadienyl-CH^) , 1.81 (s,
6H, N(CH3)2), 2.34 (m, 3H. pentadienyl-CHj) , 2.88 (s,
3H, CH3CN) , 3.63 (b, IH) , 3.66 (m, IH) , 3.76 (s, 5H) ,
4.39 (t, IH, J = 2.4 Hz), 4.87 (m, IH) , 4.89 {m, IH) ,
5.90 (s, IH) , 6.02 (t, 2H) , 6.90-8.20 {m, 21H) , 8.80
(dd, IH, J = 7.6 Hz, J = 14.3 Hz).
"P NMR (CD2CI2) S: 36.54 (d, Jpp = 34.6 Hz), 31.59 (d,
Jpp = 34.6 Hz), "f NMR (CD2CI2) 5: -149.87 (s) . The P-P
coordination according to the invention is evidenced by
the fact that 2 P signals having chemical shifts which
are relatively close together (8: 36.54 ppm (d, J^p =
34.6 Hz) and 31.59 ppm (d, Jpp = 34.6 Hz)) occur in the
31P NMR and a coupling between P(l) and P(2) of 34.6 Hz
is observed. Signals of a noncoordinated P atom are not
found.
The complex according to the invention gives vejry good
yields when used as catalyst for enantioselective
catalytic hydrogenation.
Example 2
Preparation of (ti5-2,4-dliiisthylpentadienyl) (iodo)-
(Taniaphos TOOl-1)ruthenium(II)
The Taniaphos complex (115-2,4-dimethylpentadienyl)-
(CH3CN) (Taniaphos TOOl-1)ruthenium (II) tetrafluoro-
borate is prepared as described in exeuttple Ic) . 100 mg
of this compoiind are dissolved in 4 ml of acetone, an
excess of 2 equivalents of potassium iodide (80 mg) is
added and the mixture is stirred at room temperature
for 10 hours. The precipitated solid is filtered off
and washed firstly with water and then with cold
acetone. This gives a mixture of two diastereomers
having a de of 60% as a yellow-orange solid in a yield
of 85%.
Characterization:
1H NMR (CD2CI2, major) 6: -2.06 (m, IH) , -0.13 (m, IH) ,
0.93 (m, IH) , 1.29 (s, 3H), 1.95 (s, 6H>, 2.81 (s, 3H),
3.28 (m, IH), 3.76 (m, IH), 3.80 (s, 5H), 4.17 (m, IH),
4.75 (m, IH) , 5.54 (m, IH) , 6.07 (m, 2H) , 6.6-7.8 (m,
21H), 9.25 (m, IH) , 9.63 (m, IH) .
^^P NMR (CD2CI2) 5: 39.88 ppm (d, Jpp = 40.5 Hz), 29.96
mm (d, Jpp = 40.5 Hz). MS (FAB) m/e: 1012 [M*+l] , 884
[M*-I], 788 [M*-I-pentadienyl] . The P-P coordination
according to the invention is evidenced by the fact
that only 2 P signals having chemical shifts which are
relatively close together (6: 39.88 ppm and 29.96 ppm)
occur in the ¦'^P NMR and a coupling of 40.5 Hz between
P(l) and P(2) is observed.
Use for catalytic hydrogenation:
The (Taniaphos TOOl-1)(iodo)ruthenium(II) complex
prepared as described in example 2 is used for the
asyimnetric hydrogenation of trans-2-methyl-2-butenoic
acid. The hydrogenation is carried out in an autoclave
under 50 bar of hydrogen; solvent: methanol;
ten^erature: 50°C. A little methanolic HCl is added.
After a reaction time of 18 hours, the hydrogen
pressure is vented. Analysis of the crude material
indicates a conversion of > 90% and an enantiomeric
excess (ee) of > 40%. The substrate/catalyst ratio
(S/C) is > 500.
The complex according to the invention thus gives very
good results when used as catalyst for enantioselective
catalytic hydrogenation.
Exanple 3
Preparation of (T]5-2,4-diinethylpentadieny-l) (lodo)-
(Tanlaphos "OH) rutheniua (II)
In a round-bottom flask provided with a magnetic
stirrer, the acetonitrile complex (ti5-2, 4-diraethyl-
pentadienyl) (CH3CN)3ruthenivun{II) tetraf luoroborate
prepared as described in example lb) (288 mg,
0.71 iranol] is dissolved in 15 ml of methylene chloride
and stirred with (S, S)-Taniaphos-OH (288 mg, 0.71 mmol)
at room tenperature for 3 hours. The solution becomes
deep red. The solvent is removed under reduced pressure
and the residue is washed with diethyl ether. The
(Taniaphos-OH)ruthenium(II) tetrafluoroborate complex
obtained is not isolated further but dissolved in 20 ml
of acetone. Excess potassium iodide (33 0 mg, 2 mmol) is
added and the solution is stirred for a further
10 hours. The precipitated yellow-orange solid is
filtered off and washed with water and acetone. This
gives a product comprising a mixture of two
diastereomers in a virtually equimolar ratio. Yield:
90%. The P-P coordination of the Taniaphos-OH ligand is
evidenced by the ^^P-NMR.
The Ru complex gives good yields when used as catalyst
for enantioselective catalytic hydrogenation.
CoMparative Preparation of an Ru coanplex with P-monocoordinated
£erroce]^ldiplioaphine ligaads
The reaction of Taniaphos SL-TOOl-1 with the
commercially available ruthenivim complex [RuCl2(p-
cumene)]2 (from Umicore, Hanau) in THF at room
teit^perature gives, in accordance with equ. (1), a 2:1

mixture of two Isomers which were identified as
P-monocoordinated complexes by means of '^P
spectroscopy. The spectrum displays four different
signals (•'^P NMR in CD2CI2: 5 = 49 ppm and -13 ppm for
the isomer present in the lesser amount, 5 = 35 ppm and
-15 ppm for the predominant isomer) . Here, the signals
having a negative chemical shift (5 = -13 ppm and
-15 ppm) can be assigned to the noncoordinated P atoms
of the ligand in each case.
When the mixture is refluxed for 2 hours, the isomer
which is present in the predominant proportion is
formed; isolation is effected by precipitation with
hexane. Bidentate P-P coordination of the ferrocenyl-
diphosphine ligand is not observed.
Use for catalytic hydrogenation:
The Ru complex mixture prepared as described in
con^jarative example 1 is used for the asymmetric
hydrogenation of treins-2-methyl-2-butenoic acid. The
hydrogenation is carried out in an autoclave lander
50 bar of hydrogen; solvent: methanol; tenperature:
50°C. A little methanolic HCl is added. After a
reaction time of 18 hours, the hydrogen pressure is
vented. Analysis of the crude material indicates
incomplete reaction and an ee of substrate/catalyst ratio (S/C) is 200.
These results can be compared with the results of
exeuiple 2. They demonstrate the superiority of the Ru
complexes of the invention having P-P coordination of
the ferrocenyldiphosphine ligands in the asyiranetric
hydrogenation of chiral organic confounds.
Claims
1. A ruthenium conplex with a chiral ferrocenyl-
diphosphine ligand for homogeneous catalysis
corresponding to the general formula
where
Ru is in the oxidation state +11,
n is an integer equal to or greater than 3,
Ld is an neutral ligand,
Z is at least one n-bonded organic ligand,
E' is the anion of an oxo acid or conplex acid and
Lz is at least one anionic ligand
and the ferrocenyldiphosphine ligand P{l)-P(2) has
bidentate P-P coordination.
2. The ruthenium conplex as claimed in claim 1,
wherein the chiral ferrocenyldiphosphine ligand
P(l)-P(2) together with the ruthenium forms an at
least eight-membered ring.

3. The ruthenivun complex as claimed in claim 1 or 2,
wherein the chiral ferrocenyldiphosphine ligand
P(l)-P(2) is selected from the group consisting of
Taniaphos, Taniaphos-OH, Taniaphos-OMe and Walphos
ligands.
4. The ruthenium complex as claimed in any of
claims 1 to 3, wherein Ld is selected from the
class of 2-electron donor ligemds and encompasses
secondary or tertiary phosphines or N-heterocyclic
carbene ligands (known as NHC ligands).
5. The ruthenium complex as claimed in any of
claims 1 to 4, wherein Ld is a solvent ligand
selected from the group consisting of acetonitrile
(CH3CN), diethyl ether (DEE), water (H2O) , acetone,
tetrahydrofuran (THF), dioxane, pyridine,
imidazole and thiophene.
6. The ruthenium conplex as claimed in any of
claims 1 to 5, wherein Z is at least one
substituted or unsubstituted cyclic or open-chain
dienyl ligand, for example at least one
substituted or \insubstituted pentadienyl or hepta-
di eny1 1igand.
7. The ruthenium complex as claimed in any of
claims 1 to 6, wherein Z is at least one ligand
selected from the group consisting of 2,4-di-
methylpentadiene, 2,3,4-trimethylpentadiene,
cycloheptadiene, cyclooctadiene and norbornadiene.
8. The ruthenivun conrplex as claimed in any of
claims 1 to 7, wherein E" is an anion selected
from the group consisting of HSO4', CF2SO3', CIO4",
BF4', B(aryl)4", SbFg" and PFs".

9. The ruthenium complex as claimed in any of
claims 1 to 8, wherein Lj is at least one anionic
ligand selected from the group consisting of
halides and pseudohalides.
10. The ruthenium coit^lex as claimed in any of
claims 1 to 9, wherein (S)-l-diphenylphosphino-2-
[ (R) -a- (N,N-dimethylamino) -o- (diphenylphosphino-
phenyl)methyl]ferrocene (= Taniaphos TOOl-1);
(R) -l-diphenylphosphino-2- [ (S) -a- (N, N-dimethyl-
amino) -o- (diphenylphosphinopheny 1) methyl] ferrocene
(= Taniaphos TOOl-2); (S)-1-dicyclohexylphosphino-
2- [ (R) -a- (N,N-dijnethylamino) (dicyclohexyl-
phosphinophenyl)methyl]ferrocene {= Taniaphos
T002-1) or (R)-l-dicyclohexylphosphino-2-[(S)-a-
(N,N-dimethylamino) (dicyclohexylphosphinophenyl) -
methyl]ferrocene (= Taniaphos T002-2) is used as
chiral ferrocenyldiphosphine ligand.
11. A process for preparing ruthenium complexes with a
chiral ferrocenyldiphosphine ligand which has
bidentate P-P coordination, characterized in that
an Ru starting conpound of the general fonmila
IZ-RU-(I.D)a]*B-
where
Ru is in the oxidation state +11,
n is an integer equal to or greater than 3,
Ld is an neutral ligand,
Z is at least one n-bonded organic ligand and
E is the anion of an oxo acid or complex acid,
is reacted with a chiral ferrocenyldiphosphine
ligand.

12. The process as claimed in claim 11, wherein the
chiral ferrocenyldiphosphine ligand is selected
from the group consisting of Taniaphos,
Taniaphos-OH, Taniaphos-OMe and Walphos ligands.
13. The process as claimed in claim 11 or 12, wherein
Ld is selected from the class of 2-electron donor
ligands and encompasses secondary or tertiary
phosphines or N-heterocyclic carbene ligands
(known as NHC ligands).
14. The process as claimed in any of claims 11 to 13,
wherein Lp is a solvent ligand selected from the
group consisting of acetonitrile (CH3CN) , diethyl
ether (DEE), water (HjO), acetone, tetrahydrofuran
(THF), dioxane, pyridine, imidazole and thiophene.
15. The process as claimed in any of claims 11 to 14,
wherein Z is at least one substituted or
unsubstituted cyclic or open-chain dienyl ligand,
for excunple at least one substituted or
unsubstituted pentadienyl or heptadienyl ligand.
16. The process as claimed in any of claims 11 to 15,
wlierein Z is at least one ligand selected from the
group consisting of 2,4-dimethylpentadiene,
2,3,4-trimethylpentadiene, cycloheptadiene, cyclo-
octadiene and norbomadiene.
17. The process as claimed in any of claims 11 to 16,
wherein E" is an anion selected from the group
consisting of HSO4', CF3SO3', C104', BF4', B(aryl)4',
SbF6~ and PF6".
18. The process as claimed in any of claims 11 to 17
which further comprises replacement of at least
one neutral ligand Ld by at least one anionic

ligand Lz selected from the group consisting of
halides and pseudohalides.
19. A ruthenium complex with a chiral ferrocenyl-
diphosphine ligand, which has bidentate P-P
coordination to the Ru(II) and can be obtained by
a process as claimed in any of claims 11 to 18.
20. The use of the ruthenium complexes as claimed in
any of claims 1 to 10 as catalysts for homogeneous
asytnmetric catalysis for preparing organic
compounds.
21. The use of the ruthenivun complexes as claimed in
any of claims 1 to 10 as catalysts for the
homogeneous asymmetric catalytic hydrogenation of
organic compounds.
22. The use of the ruthenium complexes as claimed in
any of claims 1 to 10 as catalysts for the
enantioselective hydrogenation of C=C, C=0 or C=N
multiple bonds.


The invention relates to ruthenium complexes with a chiral
ferrocenyldiphosphine ligand, wherein the ruthenium has the oxidation
state (+II) and the chiral ferrocenyldiphosphine ligand has bidentate P-P
coordination to the ruthenium. The ruthenium complexes are cyclic and
with the ferrocenyldiphosphine ligand have an at least eight-membered
ring. The ferrocenyldiphosphine ligands are selected from the group
consisting of Taniaphos, Taniaphos-OH and Walphos ligands. A process
for preparing the Ru complexes is described. The Ru complexes are used
as catalysts for homogeneous asymmetric catalysis for preparing organic
compounds.

Documents:

3866-KOLNP-2009-(03-09-2014)-PETITION UNDER RULE 137.pdf

3866-kolnp-2009-abstract.pdf

3866-kolnp-2009-claims.pdf

3866-KOLNP-2009-CORRESPONDENCE 1.1.pdf

3866-KOLNP-2009-CORRESPONDENCE 1.2.pdf

3866-kolnp-2009-correspondence.pdf

3866-kolnp-2009-description (complete).pdf

3866-kolnp-2009-form 1.pdf

3866-KOLNP-2009-FORM 18.pdf

3866-kolnp-2009-form 2.pdf

3866-kolnp-2009-form 3.pdf

3866-kolnp-2009-form 5.pdf

3866-kolnp-2009-international publication.pdf

3866-kolnp-2009-international search report.pdf

3866-KOLNP-2009-PA.pdf

3866-kolnp-2009-pct priority document notification.pdf

3866-kolnp-2009-pct request form.pdf

3866-kolnp-2009-specification.pdf

3866-KOLNP-2009-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf


Patent Number 265985
Indian Patent Application Number 3866/KOLNP/2009
PG Journal Number 13/2015
Publication Date 27-Mar-2015
Grant Date 26-Mar-2015
Date of Filing 06-Nov-2009
Name of Patentee UMICORE AG & CO. KG
Applicant Address RODENBACHER CHAUSSEE 4, 63457 HANAU-WOLFGANG, GERMANY
Inventors:
# Inventor's Name Inventor's Address
1 DOPPIU, ANGELINO JAKOBSTRASSE 20, 63500 SELIGENSTADT, GERMANY
2 RIVAS-NASS, ANDREAS EDELSTEINSTRASSE 42, 69198 SCHRIESHEIM, GERMANY
3 KARCH, RALF BAHNHOFSTRASSE 33D, 63801 KLEINOSTHEIM, GERMANY
4 SALZER, ALBRECHT BURGSTRASSE 74, 52074 AACHEN, GERMANY
5 LANGENSCHEIDT, NADINE MELATENER STRASSE 56, 52074 AACHEN, GERMANY
6 WINDE, ROLAND HUEHNERWEG 18, 60599 FRANKFURT, GERMANY
7 MAYRHOFER, STEFANIE LINDENALLEE 13, 63486 BRUCKHOEBEL, GERMANY
PCT International Classification Number C07F17/02; B01J31/24; C07F17/00
PCT International Application Number PCT/EP2008/003695
PCT International Filing date 2008-05-08
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2007 022 389 2007-05-10 Germany