Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2001-11-13
2003-05-20
Rotman, Alan L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S020000, C549S027000, C549S359000, C556S021000, C556S022000, C568S012000
Reexamination Certificate
active
06566521
ABSTRACT:
SUMMARY OF THE INVENTION
Novel bidentate phosphine ligands and a process for preparing linear aldehydes by hydroformylating internal olefins using said phosphine ligands.
STATE OF THE ART
Linear aldehydes, particularly butyraldehyde, are of great industrial importance and, after further processing to the alcohols, are widely used in the plasticizer, solvent and polymer sector. Since mixtures of internal olefins, such as raffinate II, are produced in large amounts as a by-product in refining and cracking in the oil-processing industry, hydroformylating internal olefins to produce linear aldehydes is of great industrial interest.
The term “internal olefins” means those olefins which have at least one non-terminal double bond. However, this does not mean that internal olefins may not have a terminal double bond. Therefore, the term “internal olefin” is also taken to mean, for example, a compound such as 1,3-pentadiene.
It is known to prepare aldehydes by hydroformylating olefins using a catalyst with linear and branched aldehydes generally being formed simultaneously:
For a reaction of this type, bidentate ligands are also used as a catalyst component. In this case, for example, the ligand can be used together with a metal or in the form of a complex with a metal.
The term “bidentate ligand” means here and hereinafter molecules of the formula
R═P-E-P═R
wherein, —P═R and R═P— are individually organic cyclic groups in which the phosphorous atoms are part of the cyclic system and are linked to the cyclic system via a phosphorus-carbon bond or a phosphorus-oxygen bond; and E is a bridging group which links the corresponding phosphorus atoms of the two organic cyclic groups.
For industrial hydroformylation reactions, a high selectivity for the linear or branched aldehydes is particularly necessary. This selectivity is generally expressed by what is termed the l/b ratio=(linear aldehyde)·(branched aldehyde)
−1
. The hydroformylation is described by Frohning and Kohlpaintner in
Applied Homogeneous Catalysis with Organometallic Compounds
, Ed. B. Cornils, W. A. Hermann; VCH, Weinheim 1966, Vol. 1, pp. 29-104. Another example of the use of bidentate ligands in catalytic reactions is the hydrogenation described by Brunner in
Applied Homogeneous Catalysis with Organometallic Compounds
, Ed. B. Cornils, W. A. Hermann; VCH, Weinheim 1966, Vol. 1, pp. 201-219.
EP-0 530 015 A1 describes the use of ligands of the type R═P-E-P═R, such as the ligand of the formula
which are used in metal catalysts for the chiral synthesis of pharmaceuticals and novel intermediates. JP 07082281 A2 (JP 93-225998) discloses that ligands of this structural type can be used in hydroformylation for the synthesis of branched olefins with high selectivity.
Hopps describes in J. Organ. Chem., 1981, Vol 46, pp. 4422-4427, the use of a ligand of the type R═P-E-P═R, such as the ligand of the formula
for the asymmetric hydroformylation of vinyl acetate, vinyl propionate and vinyl benzoate, the selectivity for the branched aldehydes being 75-95%.
EP-0 213 639 B1 describes a bidentate phosphite ligand of the type R═P-E-P═R, where P═R or R═P are individually organic cyclic groups in which the phosphorus atoms are part of the cyclic system and are linked to the cyclic system via a phosphorus-oxygen bond, and E is a bridging group which links the two phosphorus atoms of the two organic cyclic groups and where the phosphorus atom is linked to the bridging group E via a phosphorus-oxygen bond. These ligands are, for example, a ligand of the formula
and can be used for hydroformylating internal olefins to produce linear aldehydes. The multistage synthesis of this ligand and the lower stability of phosphite ligands compared with phosphine ligands in general is, however, a disadvantage for industrial implementation.
OBJECTS OF THE INVENTION
It is an object of the invention to provide novel ligands and a process for hydroformylating internal olefins to produce linear aldehydes, which overcomes the disadvantages of the processes described for hydroformylating internal olefins and which converts internal olefins to produce linear aldehydes with high selectivity.
These and other objects of the invention will become obvious from the following detailed description.
THE INVENTION
The novel ligands of the invention are bidentate phosphine ligands of the formula
wherein R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen, fluorine, alkyl of 1 to 8 carbon atoms, alkoxy of 1 to 8 carbon atoms, acyloxy of an organic carboxylic acid of 1 to 8 carbon atoms, aryl of 6 to 18 carbon atoms, aryloxy of 6 to 18 carbon atoms, —CN, —CF
3
, —CHO, —SO
3
H, —SO
3
M, —SO
2
R, —SOR, —NH
2
, —NH-alkyl of 1 to 8 carbon atoms, —N-alkyl
2
of 1 to 8 carbon atoms, —NHCO-alkyl, —N-(alkyl)—(CO-(alkyl) where the alkyl have 1 to 4 carbon atoms, —COO-alkyl of 1 to 8 carbon atoms, —CONH
2
, —CO-alkyl of 1 to 8 carbon atoms, —NHCOH, —NHCOO-alkyl of 1 to 4 carbon atoms, —CO-aryl of 1 to 8 carbon atoms, —COO-aryl of 1 to 8 carbon atoms, —CHCH—CO
2
-alkyl of 1 to 8 carbon atoms, —PO-(-aryl)
2
of 1 to 8 carbon atoms, —PO-(alkyl
2
) of 1 to 4 carbon atoms; M is a cation selected from the group consisting of alkali metal ions, alkaline earth metal ions, —NR
2
H
2
, —NR
3
H, —NRH
3
, —NR
4
, —NH
4
, —PR
2
H
2
, —PR
3
H, —PRH
3
, —PR
4
and —PH
4
; or R1, R2, R3 and R4, with one another, together form at least one aliphatic or aromatic ring of 5 to 20 carbon atoms; E is a bridge linking the two phosphorus atoms, where the number of atoms situated between the two phosphorus atoms is 2 and 6, selected from the group consisting of C, N, Si, S, O, P, Fe and As; X is selected from the group consisting of —O—, —S—, —Si(R
a
)
2
—, —Si(OR
a
)
2
—, —N(C(O)R
a
)—, —N(R
b
)—, —C(R
c
)(R
c
)—, —C(O)—, —N(SiR
d
)—, —P(R
d
)—, —P(O)(R
d
)—, —C═C(R
c
)(R
c
)— and —P(OR
d
)— wherein
R
a
is alkyl of 1 to 8 carbon atoms,
R
b
is aryl of 6 to 18 carbon atoms,
R
c
is selected from the group consisting of hydrogen, alkyl of 1 to 8 carbon atoms, aryl of 6 to 18 carbon atoms, alkoxy of 1 to 8 carbon atoms, aryloxy of 6 to 18 carbon atoms, R
a
(O)— and R
b
(O); and
R
d
is one of R
a
or R
b
.
According to a preferred embodiment, E is one of the following groups:
wherein X is selected from the group consisting of —O—, —S—, —Si(R
a
)
2
—, —Si(OR
a
)
2
—, —N(C(O)R
a
)—, —N(R
b
)—, —C(R
c
)(R
c
)—, —C(O)—, —N(SiR
d
)—, —P(R
d
)—, —P(O)(R
d
)—, —C═C(R
c
)(R
c
)— and —P(OR
d
)—,
R
a
is alkyl of 1 to 8 carbon atoms
R
b
is aryl of 6 to 18 carbon atoms
R
c
is selected from the group consisting of hydrogen, alkyl of 1 to 8 carbon atoms, aryl of 6 to 18 carbon atoms, alkoxy of 1 to 8 carbon atoms, aryloxy of 6 to 18 carbon atoms, R
a
(O)— or R
b
(O)—; and R
d
is one of R
a
or R
b
;
Y is oxygen or sulfur; and
R5s are individually aryl of 6 to 18 carbon atoms or alkyl of 1 to 8 carbon atoms.
In accordance with a further preferred embodiment of the invention, E is one of the following groups:
where R6 is alkyl of 1 to 8 carbon atoms or aryl of 6 to 18 carbon atoms; Z is oxygen or nitrogen, and n is an integer of 2 to 6.
The phosphine ligands of the invention are used, in particular, in a process for preparing linear aldehydes by hydroformylating internal olefins of 4 to 12 carbon atoms in the presence of a bidentate phosphine ligand of the formula
wherein R1, R2, R3, R4, M, E and X are defined as above.
According to a preferred embodiment of the process of the invention, E is one of the following groups:
wherein X, Y, R
5
and R
6
are defined as above.
In accordance with a further preferred embodiment of the process, E is one of the following groups:
where R
6
is an alkyl of 1 to 8 carbon atoms or aryl of 6 to 18 carbon atoms; Z is oxygen or nitrogen; and n is an integer of 2 to 6.
It has proved to be particularly expedient if the reaction is carried out in the presence of rhodium at a concentration of from 1 to 1000 ppm, preferably from 10 to 250 ppm, based on the total reaction mix
Geissler Holger
Kamer Paul C. J.
van der Veen Lars A.
van Leeuwen Petrus W. N. M.
Celanese GmbH
Covington Raymond
Muserlian Lucas and Mercanti
Rotman Alan L.
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