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D. Mohajer, Z. Solati / Tetrahedron Letters 47 (2006) 7007–7010
Table 4. Catalytic activities of various MnPor(OAc) species for
epoxidation of styrene in the presence of n-Bu4NOAc and n-Bu4NF
saltsa
6. (a) Meunier, B. Inorg. Chem. 1988, 27, 161–164; (b)
Mohajer, D.; Tangestaninejad, S. Tetrahedron Lett. 1994,
35, 945–948; (c) Baciocchi, E.; Boschi, T.; Galli, C.; Lapi,
A.; Tagliatesta, P. Tetrahedron 1997, 53, 4497–4502; (d)
Konishi, K.; Oda, K.; Nishida, K.; Aida, T.; Inoue, S. J.
Am. Chem. Soc. 1992, 114, 1313–1318; (e) Guilment, E.;
Meunier, B. Tetrahedron Lett. 1982, 23, 2449–2452; (f)
Mansuy, D.; Battioni, P.; Renaud, J. P. J. Chem. Soc.,
Chem. Commun. 1985, 155–157.
Salts
MnPor(OAc)
TPP
TMP
TDCPP
TPFPP
n-Bu4NOAc
n-Bu4NF
19
14
5
2
10
2
98b
91c
a The molar ratios for catalyst–co-catalyst–substrate–oxidant and the
general reaction conditions are the same as those for Table 1, with
10 min reaction times.
b 1 min reaction time.
c 2 min reaction time.
7. (a) Thellend, A.; Battioni, P.; Mansuy, D. J. Chem. Soc.,
Chem. Commun. 1994, 1035–1036; (b) Rebelo, S. L. H.;
Simoes, M. M. Q.; Neves, M. G. M. S.; Cavaleiro, J. A. S.
˜
J. Mol. Catal. A: Chem. 2003, 201, 9–22.
8. (a) Ellis, P. E., Jr.; Lyons, J. E. J. Chem. Soc., Chem.
Commun. 1989, 1315–1316; (b) Collman, J. P.; Chein, A.
S.; Eberspacher, T. A.; Zhong, M.; Brauman, J. I. Inorg.
Chem. 2000, 39, 4625–4629.
room temperature. The very high stability of n-tetra-
butylammonium salt co-catalysts and moderate stability
of MnTPFPP(OAc) catalyst toward oxidative degrada-
tion would seem to make these catalytic systems very
suitable for achieving high turnover numbers for epoxi-
dation of alkenes.
9. Rocha Gansalves, A.-M. d0A.; Johnstone, R.-A. W.;
Pereira, M.-M.; Shaw, J. J. Chem. Soc., Perkin Trans. 1
1991, 645–649.
10. The synthesis of n-Bu4NHSO5 was based on the proce-
dures given by: Compestrini, S.; Meunier, B. Inorg. Chem.
1992, 31, 1999–2006, and Ref. 5d. Freshly prepared n-
Bu4NHSO5 was a much stronger oxidant than com-
mercially available samples. Since the oxidizing ability of
n-Bu4NHSO5 samples reduces with time, in order to
obtain reproducible results, the freshly prepared oxidant
was refrigerated and used within three days. Caution: n-
Bu4NHSO5 should be considered as a potential explosive.
11. The free base porphyrins and MnPor(OAc) were synthe-
sized by standard methods: TPFPPH2 = meso-tetrakis-
(pentafluorophenyl)porphyrin (Lindsey, J. S.; Schreiman,
I. C.; Hsu, H. C.; Marguerettaz, A. M. J. Org. Chem.
1987, 52, 827–836); TPPH2 = meso-tetraphenylporphyrin
(Adler, A. D.; Longo, F. R.; Finarelli, J. D.; Goldmacher,
J.; Assour, J.; Korsakoff, L. J. Org. Chem. 1967, 32, 476);
TMPH2 = meso-tetrakis(2,4,6-trimethylphenyl)porphyrin
and TDCPPH2 = meso-tetrakis(2,6-dichlorophenyl)por-
phyrin (Hoffman, P.; Robert, A.; Meunier, B. Bull. Soc.
Chim. Fr. 1992, 129, 85–97); MnTPFPP(OAc) (Kadish, K.
M.; Araullo-McAdams, C.; Han, B. C.; Franzen, M. M.
J. Am. Chem. Soc. 1990, 112, 8364–8368); MnTPP(OAc),
MnTMP(OAc), and MnTDCPP(OAc) (Adler, A. D.;
Longo, F. R.; Kampas, F.; Kim, J. J. Inorg. Nucl. Chem.
1970, 32, 2443–2445).
12. (a) n-Bu4NOAc was prepared by adding tetrabutylammo-
nium hydrogen sulfate (6.5 mmol) to a solution of sodium
acetate (32.5 mmol) in water (40 mL). The mixture was
stirred for 30 min and then extracted with CH2Cl2 (80 mL)
and the extract dried over magnesium sulfate. After
filtration and evaporation of the solvent, the remaining
paste was washed with hexane (10 mL) and dried under
vacuum. Other tetrabutylammonium salts were prepared
by exchanging Brꢁ in n-Bu4NBr with other anions by a
similar procedure to the above. (b) n-Bu4NFÆ3H2O and
n-Bu4NBr were purchased from Fluka.
Acknowledgement
This work was supported by the Shiraz University
Research Council.
Supplementary data
Supplementary data associated with this article can be
References and notes
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13. A mixture of the alkene (1 mmol), MnTPFPP(OAc)
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,
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