Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
1999-08-19
2002-01-08
Solola, T. A. (Department: 1626)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S221000, C549S222000
Reexamination Certificate
active
06337406
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to chiral phospholanes derived from natural products, and asymmetric catalysis using these phospholanes.
2. Description of Related Arts
Many chiral phosphine ligands have been explored for practical application in asymmetric catalysis, but few chiral ligands or motifs are efficient for the synthesis of commercially useful chiral molecules in industry.
Among known chiral phosphines, several are made from electron-donating chiral phospholanes. One example is the Brunner phospholane shown below. Brunner, H., Organometal. Chem. (1987) 328, 71. However, poor enantioselectivities were observed.
The ligands DuPhos™ and BPE have been used effectively for certain asymmetric hydrogenation reactions. See U.S. Pat. Nos. 5,329,015; 5,202,493; and 5,329,015; Burk, M. J., J.Am. Chem. Soc. (1991) 113, 8518; Burk, M. J., J. Am. Chem. Soc. (1993) 115, 10125; Burk, M. J., J. Am. Chem. Soc. (1996) 118, 5142. These ligands, however, are not effective for some other asymmetric reactions. Moreover, synthesis of these ligands can be difficult, involving a tedious Kolbe reaction. Also, several liquid DuPhos™/BPE ligands are air-sensitive and therefore difficult to handle.
The chiral phosphine RoPhos and its use in Rh-catalyzed asymmetric hydrogenation have been reported. Holz, J. et al., A. J. Org. Chem. (1998) 63, 8031; EP 0889 048. Chiral phosphine X1 has also been reported. Carmichael, D. et al., Chem. Commun. (1999) 261. However, the synthesis is tedious, involving a P stereogenic center.
The inventor has found that it was not possible to make hydroxy analogs of RoPhos using the experimental procedure disclosed in J. Org. Chem. (1998) 63, 8031. A new synthetic route has been developed. Unique properties are associated with hydroxyl phospholanes. An efficient route to these compounds has also been developed by this inventor. Based on this hydroxyl phospholane framework, a polymer chain or a soluble species such as SO
3
−
, PO
3
2−
, (CH
2
CH
2
O)
n
CH
2
CH
2
OH (n=1, 2, 3) can be introduced.
SUMMARY OF THE INVENTION
One aspect of the invention is a ligand of formula A, A′, B, B′, C, C′, D, or D′, or the corresponding enantiomer:
Another aspect of the invention is a compound of the formula E:
Another aspect of the invention is a catalyst including one of the compounds A-E above, wherein the compound is in the form of a complex with a transition metal.
Another aspect of the invention is a process for preparing a compound of formula B, by reacting a compound of formula B
x
with a phosphine:
Another aspect of the invention is a process that includes subjecting a substrate to an asymmetric reaction in the presence of one of the above-described ligands, wherein said asymmetric reaction is a hydrogenation, hydride transfer, hydrosilylation, hydroboration, hydrovinylation, olefin metathesis, hydroformylation, hydrocarboxylation, allylic alkylation, cyclopropanation, Diels-Alder, Aldol, Heck, [m+n] cycloaddition, or Michael addition reaction.
Accordingly, one advantage of the invention is in providing chiral ligands that can be made in large scale from inexpensive natural products such as D-mannitol or tartaric acids. Another advantage is in providing new chiral ligands A′-D′ in
FIG. 3
, in which the relative configuration of the four stereogenic centers around the phospholane differs from A-D.
Yet another advantage is in providing chiral ligands that are solid and/or more air-stable due to added functional groups, and are more easily handled compared to air-sensitive liquids such as DuPhos™/BPE ligands. Yet another advantage is in providing chiral ligands that have functional groups on the phospholanes that can be key stereochemistry-defining groups, such as a hemilabile anchor, a hydrogen bonding source, or a cation binding site through a crown ether. Yet another advantage is in providing chiral ligands that have additional functional groups on the phospholanes with water-soluble properties and a convenient site to link a polymer support.
Yet another advantage of the invention is in providing catalysts for a variety of asymmetric reactions such as hydrogenation, hydride transfer reaction, hydrosilylation, hydroboration, hydrovinylation, olefin metathesis, hydroformylation, hydrocarboxylation, allylic alkylation, cyclopropanation, Diels-Alder reaction, Aldol reaction, Heck reaction, Baylis-Hillman reaction and Michael addition can be explored based on these innovative ligand systems.
Yet another advantage of the invention is in providing a variety of methods to make both enantiomers of chiral phosphines. Besides D-mannitol, other chiral pool materials such as D and L-tartaric acids can also be used as suitable starting materials for ligand synthesis. Only one phospholane enantiomer can be conveniently obtained using D-mannitol as the starting material while both phospholane enantiomers can be easily obtained when using D and L-tartaric acids for the ligand synthesis.
Both the foregoing general description and the following detailed description of the invention are exemplary and explanatory only and are not necessarily restrictive of the claimed invention.
REFERENCES:
patent: 5202493 (1993-04-01), Burk
patent: 5329015 (1994-07-01), Burk
patent: 0889048 (1999-01-01), None
patent: WO 91/17998 (1991-11-01), None
patent: 92/19630 (1992-11-01), None
Li et al. Tetrahedron letters, pp. 6701-6704, 1999.*
Applicant is a Co-author.*
Cited on International Search Report.*
Enantioselective Catalysis, 101[1] Synthesis and Coordination Properties of (3'S,4'S)-(+)-1,2-Bis(3',4'-demethoxy-phospholano)benzene, a New Chiral Diphosphane(XP-002124372), H. Brunner, et al., 1996 Verlag der Zeitschrift Für Naturforschung, pp1210-1212.
Brunner, H., et al., Asymmetric Catalyses, J. Organomet. Chem., vol. 328, pp. 71-80 (1987).
Burk, M.J., et al., A Convenient Asymmetric Synthesis of &agr;-1-Arylalkylamines through the Enantioselective Hydrogenation of Enamides, J. Am. Chem. Soc., vol. 118, pp. 5142-5143 (1996).
Burk, M.J., et al., Preparation and Use of C2-Symmetric Bis(phospholanes), J. Am. Chem. Soc., vol. 115, pp. 10125-10138 (1993).
Burk M.J., C2-Symmetric Bis(phospholanes) and Their Use in Highly Enantioselective Hydrogenation Reactions, J. Am. Chem. Soc., vol. 113, pp. 8518-8519 (1991).
Carmichael, D., et al., Hybrid P-chiral diphosphines for asymmetric hydrogenation, Chem. Commun., pp. 261-262 (1999).
Colobert, F., et al., Enantioselective Approach to Polyhydroxylated Compounds Using Chiral Sulfoxides, J. Org. Chem., vol. 63, pp. 8918-8921 (1998).
Ghosh, A.K., Stereocontrolled Synthesis of HIV-1 Protease Inhibitors with C2-Axis of Symmetry, Tetrahedron Letters, vol. 32, No. 41, pp. 5729-5732 (1991).
Holz, J., et al., Synthesis of a New Class of Functionalized Chiral Bisphospholane Ligands, J. Org. Chem., vol. 63, p. 8031 (1998).
Sawada T., et al., Facile Asymmetric Synthesis of the D-Myo-Inositol Derivative, Tetrahedron Letters, vol. 37, No. 6, pp. 885-886 (1996).
Kim, B.M., Cyclic Sulfates Containing Acid-Sensitive Groups and Chemoselective Hydrolysis of Sulfate Esters, Tetrahedron Letters, vol. 30, No. 6, pp. 655-658 (1989).
Nugiel, D., et al., Preparation and Structure—Activity Relationship of Novel P1/P1′-Substituted Cyclic Urea-Based Human Immunodeficiency Virus Type-1 Protease Inhibitors, J. Med. Chem., vol. 39, pp. 2156-2169 (1996).
Poitout, L., Polyhydroxylated Piperidines and Azepanes from D-Mannitol Synthesis of 1-Deoxynojirimycin and Analogues, Tetrahedron Letters, vol. 35, No. 20, pp. 3293-3296 (1994).
Ohlandt Greeley Ruggiero & Perle L.L.P.
Solola T. A.
The Penn State Research Foundation
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