20
Table 5
a
Tandem epoxidation-ring opening reactions using TMSN3
.
Entry
Alkene
Solvent
T (◦C)b
Yield (%)
Epoxidation
Ring-Opening
Global
1
2
3
4
Cyclohexene
Cyclooctene
1-Octene
DCM
DCE
DCE
DCE
25
65c
65
65
89
97
71
40
80
46
<5
<5
71
45
–
1-Hexene
–
a
Reaction conditions: 1 mmol of CHP, 2 mmol of alkene, 2.4 mmol of TMSN3, 28 mg of Ti catalyst and 0.1 mmol of YbCl3.
Epoxidation and ring-opening were carried out at the same temperature.
Ring-opening was carried out at 85 ◦C.
b
c
high when cyclic alkenes were used (Table 4, entries 1 and 5). In
co-financed by the European Regional Development Funds) is
gratefully acknowledged.
addition, the mixture of catalysts can be recovered and reused up
to three times with only a slight decrease in global yield. The results
in table below show that this drop in the global yield is due to the
epoxide ring-opening step. We observed that in this precise step,
Unfortunately, the efficiency of the one-pot method is much lower
when linear alkenes are used.
As in the case of using TMSCN, relatively high global yields of
azidohydrins (Table 5) were obtained with cyclic olefins, above all
for cyclohexene (71%). However, epoxides from linear alkenes were
not able to give the ring-opening reaction, showing again that the
success of this type of combined systems is far from evident and
important limitations can be found depending on the substrate,
reagents, catalysts, and reaction conditions.
References
[1] B.J. Cohen, M.A. Kraus, A. Patchornik, J. Am. Chem. Soc. 103 (1981) 7620–7629.
[2] F. Gelman, J. Blum, D. Avnir, J. Am. Chem. Soc. 122 (2000) 11999–12000.
[3] K. Motokura, N. Fujita, K. Mori, T. Mizugaki, K. Ebitani, K. Kaneda, J. Am. Chem.
Soc. 127 (2005) 9674–9675.
[4] N.T.S. Phan, C.S. Gill, J.V. Nguyen, Z.J. Zhang, C.W. Jones, Angew. Chem. Int. Ed.
45 (2006) 2209–2212.
[5] K.K. Akagawa, S. Sakamoto, K. Kudo, Tetrahedron Lett. 48 (2007) 985–987.
[6] A.W. Pilling, J. Boehmer, D.J. Dixon, Angew. Chem. Int. Ed. 46 (2007)
5428–5430.
[7] R. Abu-Reziq, D. Wang, M. Post, H. Alper, Chem. Mater. 20 (2008)
2544–2550.
[8] M.J. Climent, A. Corma, S. Iborra, M. Mifsud, A. Velty, Green Chem. 12 (2010)
99–107.
[9] J.M. Fraile, R. Mallada, J.A. Mayoral, M. Menéndez, L. Roldán, Chem. Eur. J. 16
(2010) 3296–3299.
[10] R.A. Sheldon, M.C.A. van Vliet, Oxidation, in: R.A. Sheldon, H. van Bekkum (Eds.),
Fine Chemicals through Heterogeneous Catalysis, Wiley-VCH, Weinheim, 2001,
pp. 473–490.
4. Conclusions
[11] R.A. Sheldon, J.A. Van Doorn, J. Catal. 31 (1973) 427–437.
[12] J.M. Fraile, J.I. García, J.A. Mayoral, L.C. de Mènorval, F. Rachdi, J. Chem Soc.,
Chem. Commun. (1995) 539–540.
[13] C. Cativiela, J.M. Fraile, J.I. García, J.A. Mayoral, J. Mol. Catal. A 112 (1996)
259–267.
[14] J.M. Fraile, J.I. García, J.A. Mayoral, F. Figueras, Tetrahedron Lett. 37 (1996)
5995–5996.
[15] K. Arai, M.M. Salter, Y. Yamashira, S. Kobayashi, Angew. Chem. Int. Ed. 46 (2007)
955–957.
[16] E. Tokuoka, S. Kotani, H. Matsunaga, T. Ishizuka, S. Hashimoto, M. Kakaijama,
Tetrahedron: Asymmetry 16 (2005) 2391–2392.
[17] Y.J. Chen, C. Chen, Tetrahedron: Asymmetry 18 (2007) 1313–1319.
[18] S. Matsunaga, J. Das, J. Roels, E.M. Vogl, M. Yamamoto, I. Iada, K. Yamaguchi, M.
Shibasaki, J. Am. Chem. Soc. 122 (2000) 2252–2260.
[19] E.J. Corey, R.K. Bakshi, S. Shibata, C.P. Chen, V.K. Singh, J. Am. Chem. Soc. 109
(1987) 925–926.
[20] L.E. Martinez, J.L. Leighton, D.H. Carsten, E.N. Jacobsen, J. Am. Chem. Soc. 117
(1995) 5897–5898.
The combination of alkene epoxidation and epoxide ring open-
ing is possible by the use a silica-supported titanium catalyst and
ytterbium chloride. The main problem is the uncatalyzed reaction
of hydroperoxides and concomitant alcohols with the nucle-
ophile used in the ring opening reaction, which forces to use an
excess of nucleophile to compensate its consumption in these side
reactions.
The best results are obtained with highly reactive cycloalkenes,
cyclohexene and cyclooctene, as substrates, whereas linear alkenes
lead to lower yields. Furthermore, this heterogeneous system can
be recovered and reused up to three times with only a slight loss in
global yield.
However this combination is not possible in the case of electron-
deficient alkenes, as ytterbium chloride is poisoned by the presence
of the basic catalyst needed to perform the epoxidation reaction.
[21] B.M.L. Dioos, P.A. Jacobs, Appl. Catal. A 281 (2005) 181–188.
[22] B.M.L. Dioos, W.A. Geurts, P.A. Jacobs, Catal. Lett. 97 (2004) 125–129.
[23] A.E. Vougiokas, H.B. Kagan, Tetrahedron Lett. 28 (1987) 5513–5516.
[24] M.B. Cole, K.D. Shimizu, C.A. Krueger, J.P.A. Harrity, M.L. Snapper, A.H. Hoveyda,
Angew. Chem. Int. Ed. 35 (1996) 1668–1671.
Acknowledgements
[25] K.D. Shimizu, M.B. Cole, C.A. Krueger, K.W. Kuntz, M.L. Snapper, A.H. Hoveyda,
Angew. Chem. Int. Ed. 36 (1997) 1704–1707.
[26] N. Oguni, Y. Miyagi, K. Ito, Tetrahedron Lett. 39 (1998) 9023–9026.
[27] S.E. Schaus, E.N. Jacobsen, Org. Lett. 2 (2000) 1001–1004.
[28] J.M. Fraile, J.I. García, J.A. Mayoral, E. Vispe, J. Catal. 189 (2000) 40–51.
Financial support from the Spanish Ministerio de Ciencia e
Innovación (projects CTQ2008-05138 and Consolider Ingenio 2010
CSD2006-0003), and the Diputación General de Aragón (E11 Group