Angewandte
Chemie
[
[
1] E. Frankland, Justus Liebigs Ann. Chem. 1849, 71, 171.
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[
[
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aminoalcohol as the auxiliary ligand) was completed after
[
4b]
1
6 h under similar conditions.
Furthermore, despite the high reactivity of 2 towards
enones, the regio- and chemoselective epoxidation of arte-
misia ketone is feasible as illustrated in Equation (3). Thus, 2
1999, 64, 8149.
[
5] For a recent review on the asymmetric epoxidation of electron-
deficient olefins see: M. J. Porter, J. Skidmore, Chem. Commun.
2000, 1215.
[
6] Selected recent examples: a) S. Bazin, L. Feray, D. Siri, J. V.
Naubron, M. P. Bertrand, Chem. Commun. 2002, 2 506; b) K.
Yamada, H. Fujihara, Y. Yamamoto, Y. Miwa, T. Taga, K.
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Bertrand, L. Feray, R. Nouguier, P. Perfetti, J. Org. Chem.
1999, 64, 9189; f) I. Ryu, F. Araki, S. Minakata, M. Komatsu,
Tetrahedron Lett. 1998, 39, 6335.
is highly selective for the electron-deficient alkene unit in the
presence of b-functionalized unconjugated alkene. Based on
these initial studies we anticipate that using 2 will allow the
epoxidation of a wide range of enones.
Further studies on the interaction of zinc alkyl complexes
with dioxygen and the reactivity of zinc alkylperoxides are in
progress along with developing the epoxidation of enones.
[
7] a) J. Lewi n´ ski, J. Zachara, P. Gos, E. Grabska, T. Kopec, I.
Madura, W. Marciniak, I. Prowotorow, Chem. Eur. J. 2000, 6,
3
215; b) J. Lewi n´ ski, J. Zachara, E. Grabska, J. Am. Chem. Soc.
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Soc. 1990, 112, 2963; f) W. M. Cleaver, A. R. Barron, J. Am.
Chem. Soc. 1989, 111, 8967; g) V. E. Shklover, Yu. T. Struchkov,
V. A. Dodonov, T. I. Zinoveva, V. L. Antonovskii, Metalloorg.
Khim. 1988, 1, 1140; h) Z. A. Starikowa, T. M. Shchegoleva,
V. K. Trunov, I. E. Pokrovskaya, E. N. Kanunnikova, Kristallog-
rafiya 1979, 24, 1211.
Experimental Section
2
: A stirred solution of [(BDI)ZnEt] (1.02g, 2mmol) in toluene
3
(5 cm ) was cooled to 08C, then an excess of dry dioxygen (1 atm) was
introduced. After 5 min the excess of O was removed (the reaction
2
mixture was cooled to À788C, then the system was purged with
[
8] a) J. Lewi n´ ski, J. Zachara, I. Justyniak, Chem. Commun. 2002,
nitrogen using a vacuum/nitrogen line). The mixture was stored at
1586; b) J. Lewinski, J. Zachara, P. Horeglad, D. Glinka, J.
´
1
À208C and white crystalline product deposited; yield: 90%. H NMR
Lipkowski, I. Justyniak, Inorg. Chem. 2001, 40, 6086; c) J.
Lewi n´ ski, J. Zachara, T. Kopec, K. B. Starowieyski, J. Lipkowski,
I. Justyniak, E. Kolodziejczyk, Eur. J. Inorg. Chem. 2001, 1123;
d) C. S. Branch, J. Lewi n´ ski, I. Justyniak, S. G. Bott, J. Lipkow-
ski, A. R. Barron, J. Chem. Soc. Dalton Trans. 2001, 1253.
9] Selected recent examples: a) P. L. Holland, W. B. Tolman, J. Am.
Chem. Soc. 1999, 121, 7270; b) C. M. Cui, H. W. Roesky, H. G.
Schmidt, M. Noltemeyer, H. J. Hao, F. Cimpoesu, Angew. Chem.
(
400 MHz, C D ): d = 1.02(t, J = 6.8 Hz, 6H, OCH CH ) 1.15 (d, J =
6
6
2
3
7
.0 Hz, 24H, CH(CH ) ), 1.20 (d, J = 7.0 Hz, 24H, CH(CH ) ), 1.66 (s,
3 2 3 2
1
2H, CCH ), 3.31 (m, 8H, CH(CH ) ), 3.84 (q, J = 6.8 Hz, 4H,
3
3 2
OCH CH ), 4.88 (s, 2H, CH), 7.12ppm (m, 16H, Ar); IR (Nujol): ~n =
2
3
1
547 (m), 1526 (s), 1462 (s), 1436 (s), 1407 (s), 1317 (s), 1265 (m), 1253
[
(
(
6
m), 1235 (w), 1180 (m), 1160 (w), 1137 (w), 1107 (w), 1100 (w), 1058
w), 1036 (w), 1022 (w),937 (w), 854 (w), 796 (m), 760 (m), 729 (m),
À1
94 (w), 638 (w), 563 (w), 529 cm (w); elemental analysis (%) calcd
2
000, 112, 4444; Angew. Chem. Int. Ed. 2000, 39, 42 74; c) N. J.
Hardman, B. E. Eichler, P. P. Power, Chem. Commun. 2000,
991; d) V. C. Gibson, J. A. Segal, A. J. P. White, D. J. Williams, J.
for C H N O Zn ·0.95 toluene: C70.21, H 8.54, N 4.75; found: C
6
2
92
4
4
2
7
0.12, H 8.56, N 4.78.
1
Epoxidation of enones: To a stirred solution of 2 (2mmol) in
3
Am. Chem. Soc. 2001, 122, 7120; e) D. J. E. Spencer, A. M.
Reynolds, P. L. Holland, B. A. Jazdzewski, C. Duboc-Toia, L.
Le Pape, S. Yokota, Y. Tachi, S. Ito, W. B. Tolman, Inorg. Chem.
toluene (5 cm ) was added the corresponding enone (1.9 mmol) at
0
8C and the reaction mixture was stirred for 15 min and the crude
1
mixture was analyzed by H NMR. Then the solution was treated with
KF (3.5 g, 60 mmol) and water (1.2mL, 67 mmol). The organic
products formed were extracted with ethyl ether and the conversion
2002, 41, 6307.
[
10] Selected recent examples: a) B. M. Chamberlain, M. Cheng,
D. R. Moore, T. M. Ovitt, E. B. Lobkovsky, G. W. Coates, J. Am.
Chem. Soc. 2001, 123, 3229; b) M. Cheng, D. R. Moore, J. J.
Reczek, B. M. Chamberlain, E. B. Lobkovsky, G. W. Coates, J.
Am. Chem. Soc. 2001, 123, 8738; c) J. Prust, A. Stasch, W. J.
Zheng, H. W. Roesky, E. Alexopoulos, I. Uson, D. Bohler, T.
Schuchardt, Organometallics 2001, 20, 3825; d) A. P. Dove, V. C.
Gibson, E. L. Marshall, A. J. P. White, D. J. Williams, Chem.
Commun. 2001, 283; e) D. R. Moore, M. Cheng, E. B. Lobovsky,
G. W. Coates, Angew. Chem. 2002, 114, 27119; Angew. Chem.
Int. Ed. 2002, 41, 2599.
1
was analyzed by liquid chromatography (HPLC) and H NMR.
Additionally, the a,b-epoxyketones were isolated by flash chroma-
tography.
Received: May 21, 2003
Revised: June 25, 2003 [Z51940]
Keywords: asymmetric epoxidation · enones · N ligands ·
.
peroxides · zinc
Angew. Chem. Int. Ed. 2003, 42, 4643 –4646
ꢀ 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4645