Chapter 5
Oxygenation Reactions Catalyzed by Supported Sulfonated Metalloporphyrins Bernard Meunier and Sandro Campestrini
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Laboratoire de Chimie de Coordination du Centre National de la Recherche Scientifique, 205 route de Narbonne, 31077 Toulouse Cédex, France A new trend in the field of oxidations catalyzed by metalloporphyrin complexes is the use of these biomimetic catalysts on various supports: ion-exchange resins, silica, alumina, zeolites or clays. Efficient supported metalloporphyrin catalysts have been developed for the oxidation of peroxidase-substrates, the epoxidation of olefins or the hydroxylation of alkanes. After a decade on the modeling of cytochrome P-450 with soluble metalloporphyrin complexes associated with different oxygen atom donors (1,2) (iodosylbenzene, hypochlorite, organic or inorganic peroxides, molecular oxygen in the presence of a reducing agent), a new trend in this field is the development of supported metalloporphyrin catalysts. The use of supported catalysts has the following advantages: (i) facile catalyst recovery and (ii) physical separation of active sites by dispersion on the support to avoid self-destruction of the catalyst. Metalloporphyrins can be attached to polymers by covalent links (3), but this approach requires a multi-step synthesis of the porphyrin ligand and/or a chemical modification of the polymer. The metalloporphyrin can also be held by basic residues (imidazole or pyridine) acting as axial ligands, but in this latter case, the fixation is reversible (4). Another approach is to immobilize metalloporphyrins on (i) inorganic materials (5) (silica, alumina, zeolites (6) or clays) in order to have inert supports for catalytic oxidation reactions or (ii) on organic polymer like ion-exchange resins (7). We recendy used sulfonated metalloporphyrins supported on cationic ion-exchange resins in the modeling of ligninase, a peroxidase involved in the oxidative degradation of lignin in wood (8). These peroxidase models are also highly efficient in the oxidation of recalcitrant pollutants (9) like DDT or lindane and they can be used to study the in vitro metabolism of drugs (10). Two main advantages of these resin-metalloporphyrin
0097-6156/93/0523-0058$06.00/0 © 1993 American Chemical Society In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
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5.
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Catalyzed Oxygenation Reactions
59
catalysts are that they can be used in aqueous solutions and, because of the large number of available ion-exchange resins, it is possible to design highly sophisticated catalysts based on the understanding at the molecular level of interactions between the metalloporphyrin and the support. For example, in the case of polyvinylpyridine polymer, a "proximal effect" (i.e. the strong coordination of a basic ligand to the metalloporphyrin) is provided by pyridine units of the polymer whereas the remaining residues, after protonation or methylation, are involved in electrostatic interactions with sulfonato groups of the porphyrin ligand (11). We recently reported the use of robust sulfonated iron and manganese porphyrins supported on polyvinylpyridinium polymers in olefin epoxidation and alkane hydroxylation reactions (12). Sulfonated derivatives of mestf-tetramesitylporphyrin, TMPS, /ne^-tetrakis(2,6-dichlorophenyl)porphyrin, TDCPPS, meso-tetramesitylβ-octabromoporphyrin BrgTMPS and m^-tetrakis(3-chloro-2,4,6-trimethylphenyl)β-octachloroporphyrin, C1 TMPS (see Scheme I for structures). TDCPPS and Cl^TMPS are a mixture of atropoisomers and were used as such. The manganese and iron derivatives of the non-sulfonated version of Br TMPS and Cl^TMPS have been used as soluble catalysts in oxygenation reactions performed in liquid phase (2e,13). 12
8
Preparation of supported metalloporphyrin on polyvinylpyridine polymers. Free polyvinylpyridine is obtained from an alkaline treatment of poly[4-vinylpyridinium (toluene-4-sulfonate)] crosslinked with 2% of divinylbenzene. This polymer contains 3.5 mmol of pyridine units per g of resin. Three different types of supported catalysts have been prepared: (i) by direct attachment of the manganese complex to the polymer by coordination of one pyridine unit to the complex, (ii) by further protonation of the remaining pyridine sites and creation of electrostatic interactions between polymer pyridiniums and the sulfonato groups of the metalloporphyrin and (iii) by methylation of the free pyridine units (instead of protonation) (see Scheme II). For the last two cases, [(M-Porp-S)-PVPH ][TsO"] and [(M-Porp-S)-PVPMe ][TsO~], there is an additional electrostatic interactions between the pyridinium units of the polymer and the sulfonato groups of the metalloporphyrin, assuring a second strong binding mode of the catalyst to the support. The axial ligation by pyridine in these PVP supported metalloporphyrins has been confirmed by UV-visible spectroscopy (12a). +
+
These PVP polymers provide a "proximal effect" without addition of free pyridine in the reaction mixture. Different studies have shown that only one pyridine per manganese catalyst is sufficient to enhance the rate of the catalytic oxygen atom transfer from the high-valent metal-oxo species to the organic substrate. The advantage of PVP polymer over a cationic Amberlite resin (see Scheme II for structures) have been recently illustrated in the modeling of ligninase (11). In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
d
at acidic pH an hydroxo ligand occupies the axial position whereas it is a water
molecule at basic pH values.
©
axial ligand of these water-soluble metalloporphyrins depend on the pH value,
2
o
Ο
Scheme I. Structures of sulfonated robust metalloporphyrin complexes. The
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Catalyzed Oxygenation Reactions
Cyclooctene epoxidation catalyzed by supported sulfonated metalloporphyrins. We investigated the behavior of PhIO as oxygen donor with these catalysts supported on PVP. The results of the PhIO epoxidation of cyclooctene catalyzed by [MnTMPS-PVPMe ][TsO-], [MnTDCPPS-PVPMe+][TsO-], [MnBr TMPSPVPMe ] [TsO-] and [MnCl TMPS-PVPMe+] [TsO"] are reported in Figure 1. No epoxide formation is detected when PhIO is used with PVP or methylated PVP (PhIO is not decomposed by these polymers). But for a low loading of methylated PVP by the four sulfonated manganese porphyrin complexes and a molar ratio catalyst /substrate equal to 1.3%, an efficient catalytic epoxidation of cyclooctene is observed: 90% of the olefin is converted by [MnCl TMPS-PVPMe ][TsO"] in 7 h at room temperature (the turnover rate of this reaction is 18 cycles/h, based on the first 50% of olefin conversion). The two best catalysts are halogenated on the pyrrolic β-positions, the less active being the PVP-supported MnTDCPPS, just below the activity of the analogue catalyst based on tetramesitylporphyrin. Supported iron porphyrins are less reactive than the corresponding manganese derivatives in the PhIO epoxidation of cyclooctene. 80% of olefin conversion was reached with MnBr TMPS-PVP in 2 h, whereas only 10% was obtained with FeBr TMPS-PVP in 6 h. +
+
8
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12
+
12
8
8
Recycling experiments with MnCl^TMPS immobilized on methylated PVP.
Recycling experiments were performed by re-using four times the same MnCl TMPS catalyst supported on methylated PVP in the PhIO epoxidation of cyclooctene. For [MnCl TMPS-PVPMe ][TsO-], it should be noted that the first two cycles are exactly the same, only a small activity decrease is observed for the third run. With 1 μιηοΐ of MnCl TMPS immobilized on [PVPMe ][TsO"] the total epoxide production after 4 runs is 1970 μπιοΐ. The overall selectivity based on PhIO is 65% . 12
+
12
+
12
Adamantane hydroxylation by PhIO catalyzed by M n C l T M P S supported on PVP polymers. First of all, the different forms of PVP supported MnCli TMPS were compared to the same manganese porphyrin immobilized on Amberlite-IRA-900 (Table I). The distribution of adamantane derivatives were analyzed after 2 h and 7 h of reaction at room temperature. [MnCl TMPS-PVPMe+][TsO-] gave the highest selectivity ratio for adamantanols versus adamantanone: 53, indicating that the hydroxylation reaction is actually the main oxidation reaction with this catalyst. With the same catalyst, the product distribution did not change after 2 h at room temperature, 312 pmoles of adamantanols and adamantanone were produced within 2 h compared to 322 μιτιο^ in 7 h. Amberlite is not suitable compared to methylated PVP 1 2
2
12
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
62
CATALYTIC SELECTIVE OXIDATION
+
(M-Porph-S)-PVP
[(M-Porph-S)-PVPH l[TsO'l
•0S- »
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3
+
[(M-Porph-S)-PVPMe ][TsO*î
I - SCV
» - M-1
(Μ-ΡθφΗ-5)-ΑΐΏ5βΓΐίΐβ-ΙΚΑ-900
Scheme II. Schematic representation of sulfonated metalloporphyrins supported on different polyvinylpyridine polymers and Amberlite-ERA-900. 100
Figure 1. PhIO oxidation of cyclooctene catalyzed by various sulfonated manganese
porphyrin
immobilized +
[Mn-porphyrin-S-PVPMe ][TsO-].
on
methylated
PVP,
[MnTMPS-PVPMe+HTsO"] (O),
[MnBr TMPS-PVPMe+][TsO-] ( • ), [MnTDCPPS-PVPMe+][TsO"] (•) 8
and [MnCl TMPS-PVPMe ][TsO-] (O). Conditions: cyclooctene (150 +
12
μπιοί), PhIO (750 μπιοί), Mn-porphyrin-S (2 μπιοί) immobilized on [PVPMe+][TsO"] (200 mg of PVP treated by TsOMe) in 3 mL of dichloromethane at room temperature. (Reproduced from ref. 12a. Copyright 1992 American Chemical Society.)
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
5. MEUNIER AND CAMPESTRINI
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(or even PVP) as support. Only 50 μΓηο1ε5 of adamantanols and adamantanone were formed by MnCl^TMPS-Amberlite in 7 h compared to 322 μιηο1β5 with the same catalyst on methylated PVP. Final Remarks. The main features of these PhIO oxygenations reactions catalyzed by manganese and iron porphyrins supported on cationic ion-exchange resins are the following: (i) the polyvinylpyridinium resins lead to better catalysts than other simple cationic resins, because of the proximal effect due to the coordination of a pyridine unit arising from the polymer. In addition to the known favorable role of the proximal pyridine on the different steps of the oxidant activation by the metalloporphyrin (rate enhancement of both metal-oxo formation and oxygen atom transfer steps), the double interaction of sulfonated metalloporphyrin with poly(vinylpyridinium) polymers (pyridine proximal effect and sulfonato-pyridinium interactions) immobilizes the catalyst more strictly on the support than simple electrostatic interactions on classical cationic resins. In this latter case, there is probably an equilibrium between two possible types of interactions: the "coating" mode (A in Scheme ΙΠ) and the "stacking" mode (B in Scheme ΙΠ). In mode B, the stacking of metalloporphyrin complexes enhances the bleaching of the supported catalyst when the highly reactive metal-oxo species are formed. This phenomenon was also observed by Lindsay Smith in the case of a cationic iron porphyrin catalyst supported on anionic polymers (12b) and by our group for cationic manganese porphyrins when interacting with DNA (outside binding mode versus minor groove interaction) (14). (ii) these polyvinylpyridinium supported catalysts have similar efficiency compared to the corresponding metalloporphyrin complexes in solution. (iii) the most efficient supported metalloporphyrin catalysts for oxygenation reactions are those with manganese as central metal and with halogen atoms on β-pyrrole positions. (iv) the best PVP-manganese catalysts can be recycled three or four times and more than 2000 cycles can be achieved in the epoxidation of cyclooctene before a significant loss of catalytic activity. In conclusion, the concept of the proximal effect is a key factor in metalloporphyrin-catalyzed reactions, not only for soluble complexes, but also for supported catalysts.
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
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CATALYTIC SELECTIVE OXIDATION
Table I. Oxidation of adamantane by PhIO catalyzed by MnCl TMPS immobilized on different 12
supports
a
Support
ols/one ratio
Products (μηιοί)
Yield/PhIO (in %)
(after 7 h)
PVP Downloaded by PRINCETON UNIV on August 23, 2014 | http://pubs.acs.org Publication Date: May 5, 1993 | doi: 10.1021/bk-1993-0523.ch005
[PVPH+][TsO-] +
[PVPMe ][TsO"] [PVPMe+][TsO-]b
a
Ad-2-one
Total
145
82
11
238
21
33 e
131
60
8
166(159)dl50(147) 6(6)
Amberlite-ERA-900 Amberlite-IRA-900
Ad-l-ol Ad-2-ol
c
199
24
28
322(312)
53 (51)
44(43) 26 (26)
120(120) 64(64)
6(6)
190(190)
31 (31)
30
17
3
50
16
7
28
12
3
43
13
6
Conditions: adamantane (3860 μπιοί), PhIO (750 μπιοί), MnCl TMPS (1 μπιοί) immobilized on 12
100 mg of PVP or 250 mg of protonated (or methylated) PVP, or on 250 mg of Amberlite-IRA-900, in 7 mL of CH C1 under magnetic stirring, at room temperature. 2
b
2
c
m-Cl-PhC0 H was used as oxidant (750 μπιοί). runned in the presence of pyridine (100 umol). 3
e
d data after only 2 h at room temperature. these data correspond to the molar ratio Ad-l-ol + Ad-2-ol + 2 χ Ad-2-one / PhIO in %.
Ion-exchange resin
Coating Mode (A)
Stacking Mode (B)
Scheme ΙΠ. Two possible mode of interactions (coating versus stacking) of anionic metalloporphyrins with a cationic ion-exchange resin.
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
5. MEUNIER AND CAMPESTRINI
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Acknowledgments. This work was supported by a 'Stimulation' grant from the EEC,
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including a fellowship for S. C. (on leave from Padova University). Dr Anne Robert is gratefully acknowledged for fruitful discussions throughout this work.
References (1) For review articles on metalloporphyrin-catalyzed reactions, see: (a) McMurry, T. J.; Groves, J. T. in Cytochrome P-450: Structure, Mechanism and Biochemistry, Ortiz de Montellano, P., Ed.; Plenum Press: New York, 1986, Chapter I. (b) Meunier, Β. Bull. Soc. Chim. Fr. 1986, 578-594. (c) Montanari, F.; Banfi, S.; Quici, S. Pure Appl. Chem. 1989, 61, 1631-1636. (d) Mansuy, D. Pure Appl. Chem. 1990, 62, 741-746. (e) Meunier, Β. Chem. Rev. in press. (2) For some recent articles on metalloporphyrin-catalyzed oxidations, see: (a) Brown, R. B.; Hill, C. L. J. Org. Chem. 1988, 53, 5762-5768. (b) Robert, Α.; Meunier, Β. New J. Chem. 1988,12,885-896. (c) Groves, J. T.; Viski, P. J. Am. Chem. Soc. 1989,111,8537-8538. (d) Traylor, T. G.; Hill, K. W.; Fann, W. P.; Tsuchiya, S.; Dunlap, Β. E. ibid. 1992, 114, 1308-1312. (d) Collman, J. P.; Brauman, J. I.; Hampton, P. D.; Tanaka, H.; Scott Bohle, D.; Hembre, R. T. J. Am. Chem. Soc. 1990, 112, 7980-7984. (e) Hoffmann, P.; Labat, G.; Robert, Α.; Meunier, Β. Tetrahedron Lett. 1990, 31, 1991-1994. (f) Murata, K.; Panicucci, R.; Gopinath, E.; Bruice, T. C. J. Am. Chem. Soc. 1990,112,6072-6083. (g) Ellis, P. E.; Lyons, J. E. Coord. Chem. Rev. 1990, 105, 181-193. (h) Robert, Α.; Loock, B.; Momenteau, M.; Meunier, Β. Inorg. Chem. 1991, 30, 706-711. (3) (a) Leal, O.; Anderson, D. L.; Bowman, R. G.; Basolo, F.; Burwell, R. L. J. Am. Chem. Soc. 1975, 97, 5125-5129. (b) Tatsumi, T.; Nakamura, M.; Tominaga, H. Chem. Lett. 1989, 419-420. (c) Rollmann, L. D. ibid. 1975, 97, 2132-2136. (4) Tsuchida, E.; Honda, K.; Hasegawa, E. Biochem. Biophys. Acta 1975, 393, 483-495 and references therein. (5) (a) Fukuzumi, S.; Mochizuki, S.; Tanaka, T. Israel J. Chem. 1987/88, 28, 29-36. (b) Kameyama, H.; Suzuki, H.; Amano, A. Chem. Lett. 1988, 1117-1120. (c) Barloy, L.; Battioni, P.; Mansuy, D. J. Chem. Soc., Chem. Commun. 1990, 1365-1367. (d) Nakamura, M.; Tatsumi, T.; Tominaga, H. Bull. Chem. Soc. Jpn. 1990, 63, 3334-3336. (e) Barloy, L.; Lallier, J. P.; Battioni, P.; Mansuy, D.; Piffard, Y.; Tournoux, M.; Valim, J. B.; Jones, W. New J. Chem. 1992, 16, 71-80. (f) Bedoui, F.; Gutiérrez Granados, S.; Devynck, J.; Bied-Charreton, C. ibidem 1991, 15, 939-941.
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.
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CATALYTIC SELECTIVE OXIDATION
(6) for zeolite-encapsulated iron phthalocyanine or manganese Schiff base complexes, see: (a) Herron, N.; Stucky, G. D.; Tolman, C. A. J. Chem. Soc., Chem Commun. 1986, 1521-1522. (b) Herron, N. J. Coord. Chem. 1988, 19, 25-38. (c) Bowers, C.; Dutta, P. K. J. Catal. 1990, 122, 271-279. (7) (a) Wöhrle, D.; Gitzel, J.; Krawczyk, G.; Tsuchida, E.; Ohno, H.; Okura, I.; Nishisaka, T. J. Macromol. Sci. Chem. 1988, A25, 1227-1254. (b) Saito, Y.; Mifume, M.; Nakayama, H.; Odo, J.; Tanaka, Y.; Chikuma, M.; Tanaka, H. Chem.
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Pharm. Bull. 1987, 35, 869-872.
(8) Labat, G.; Meunier, Β. J. Org. Chem. 1989, 54, 5008-5011. (b) Labat, G.; Meunier, Β. New J. Chem. 1989,13,801-804. (9) Labat, G; Sens, J. L.; Meunier, Β. Angew. Chem., Int. Ed. Engl. 1990, 29, 1471-1473. (10) Bernadou, J.; Bonnafous, M.; Labat, G.; Loiseau, P.; Meunier, Β. Drug Metab. Disp. 1991, 19, 360-365. (11) Labat, G.; Meunier, B. C. R. Acad. Sci. Paris 1990, 311 II, 625-630. (12) (a) Campestrini, S.; Meunier, B. Inorg. Chem. 1992, 31, 1999-2006. (b) for an other recent report on olefin epoxidations by PhIO catalyzed by iron porphyrins supported on ion-exchange resins see also: Leanord, D. R.; Lindsay Smith, J. R. J. Chem. Soc. Perkin Trans 2, 1990, 1917-1923 and same authors J. Chem. Soc.
Perkin Trans 2, 1991, 25-30. (c) The use of a manganese porphyrin bound to colloidal anion-exchange particles in the NaOCl epoxidation of styrene appeared in the literature during preparation of the present article: Turk, H.; Ford, W. T.J.Org. Chem. 1991, 56, 1253-1260. (13) Hoffmann, P.; Robert, Α.; Meunier, Β. Bull. Soc. Chim. Fr. 1992, 129, 85-97. (14) (a) Ding, L.; Bernadou, J.; Meunier, Β. Bioconjugate Chem. 1991, 2, 201-206. (b) Pitié, M.; Pratviel, G.; Bernadou, J.; Meunier, Β. Proc. Natl. Acad. Sci. USA 1992, 89, 3967-3971. RECEIVED October 30, 1992
In Catalytic Selective Oxidation; Oyama, S., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1993.