Table 3 Initial study of asymmetric Mukaiyama aldol reaction of
silyloxyfuran 1 with aldehydesa
framework of the Polish Innovation Economy Operational
Program (contract no. POIG.02.01.00-12-023/08).
Notes and references
1 Modern Aldol Reactions, ed. R. Mahrwald, Wiley-VCH, Weinheim,
2004.
2 B. Schetter and R. Mahrwald, Angew. Chem., Int. Ed., 2006, 45,
7506–7525.
3 G. Casiraghi, F. Zanardi, G. Appendino and G. Rassu, Chem.
Rev., 2000, 100, 1929–1972.
4 G. Casiraghi, L. Battistini, C. Curti, G. Rassu and F. Zanardi,
Chem. Rev., 2011, 111, 3076–3154.
Entry
R
Ligand
Yieldb [%]
eec [%]
5 For examples of Lewis acid promoted asymmetric vinylogous
Mukaiyama aldol reaction of silyloxyfuran see: (a) D. A. Evans,
M. C. Kozlowski, J. A. Murry, C. S. Burgey, K. R. Campos,
B. T. Connell and R. J. Staples, J. Am. Chem. Soc., 1999, 121,
669–685; (b) M. Szlosek and B. Figadere, Angew. Chem., Int. Ed.,
2000, 39, 1799–1801; (c) L. Palombi, M. R. Acocella, N. Celenta,
A. Massa, R. Villano and A. Scettri, Tetrahedron: Asymmetry, 2006, 17,
3300–3303; (d) M. Frings, I. Atodiresei, Y. Wang, J. Runsink, G. Raabe
and C. Bolm, Chem.–Eur. J., 2010, 16, 4577–4587; (e) H. Yanai,
A. Takahashi and T. Taguchi, Chem. Commun., 2010, 46, 8728–8730.
6 Reaction of Sn-enolate: (a) C. Mukai, S. Hirai, I. J. Kim, M. Kido
and M. Hanaoka, Tetrahedron, 1996, 52, 6547–6560;
(b) C. W. Jefford, D. Jaggi and J. Boukouvalas, J. Chem. Soc.,
Chem. Commun., 1988, 1595–1596.
7 For uncontrolled synthesis of a- and g-products that have been
observed for analogous lithium enolate of 2(5H)-furanone see:
(a) D. W. Brown, M. M. Campbell, A. P. Taylor and X. Zhang,
Tetrahedron Lett., 1987, 28, 985–988; for meanwhile published
iridium-catalyzed alpha- and enantioselective allylation of tri-
methylsilyloxyfuran see: (b) W. Chen and J. F. Hartwig, J. Am.
Chem. Soc., 2012, 134, 15249–15252.
1
2
3
4
5
6
7
8
9
Ph
Ph
Ph
Ph
4
5
6
6
6
6
6
6
6
59
46
63
83
69
52
42
63
73
20
Rac
50
70d
66d
64d
68d
53
4-Me–C6H4
2-Me–C6H4
4-MeO–C6H4
Bu
Oct
56
a
Reactions were performed with 1 (0.85 mmol), aldehyde (0.71 mmol),
Zn(OTf)2 (10 mol%), ligand (12 mol%) in EtOH–H2O (9 : 1, 2 mL) at
b
À30 1C for 4 h. Isolated yield after column chromatography.
c
Enantiomeric excess was determined by HPLC analysis on chiral
d
phase (Chiralpak AD-H) columns. Reactions were performed with 1
(0.85 mmol), aldehyde (0.71 mmol), Zn(OTf)2 (10 mol%), ligand
(12 mol%), PhCOOH (0.07 mmol, 10 mol%) in EtOH–H2O (9 : 1,
2 mL) at À30 1C for 12 h.
8 For two non-asymmetric examples of Morita–Baylis–Hillman reaction
see (a) Y. Sohtome, N. Takemura, R. Takagi, Y. Hashimoto and
K. Nagasawa, Tetrahedron, 2008, 64, 9423–9429; (b) A. Bugarin and
B. T. Connell, J. Org. Chem., 2009, 74, 4638–4641.
9 For most recent review see: R. N. Butler and A. G. Coyne, Chem.
Rev., 2010, 110, 6302–6337.
10 J. Mlynarski and J. Paradowska, Chem. Soc. Rev., 2008, 37, 1502–1511.
11 (a) J. Jankowska and J. Mlynarski, J. Org. Chem., 2006, 71,
1317–1321; (b) J. Jankowska, J. Paradowska, B. Rakiel and
J. Mlynarski, J. Org. Chem., 2007, 72, 2228–2231.
12 For more prominent examples see: (a) S. Kobayashi and S. Nagayama,
J. Am. Chem. Soc., 2000, 122, 11531; (b) T. Hamada, K. Manabe,
S. Ishikawa, S. Nagayama, M. Shiro and S. Kobayashi, J. Am. Chem.
Soc., 2003, 125, 2989; (c) Y. Mei, P. Dissanayake and M. J. Allen,
J. Am. Chem. Soc., 2010, 132, 12871; (d) H.-J. Li, H.-Y. Tian,
Y.-C. Wu, Y.-J. Chen, L. Liu, D. Wang and C.-J. Li, Adv. Synth.
Catal., 2005, 347, 1247–1256.
enantioselectivities (entries 4–7). This tendency was not general,
and a Brønsted acid additive was unwelcome for the reaction of
aliphatic substrates.16
In conclusion, we observed unprecedented formation of
a-substituted a,b-unsaturated-g-lactone in the catalytic aqueous
Mukaiyama aldol reaction of 2-(trimethylsiloxy)-furan and
aldehydes. A wide range of chiral a-butenolides could be obtained
from the broad scope of aldehydes in good yield and in good
enantioselectivities. This is also the first example of asymmetric
Mukaiyama aldol reaction of 2-(trimethylsiloxy)-furan and
aldehydes controlled by a chiral zinc-based Lewis acid. Although,
enantioselectivities need further improvement, the concept we
have developed might be an efficient and missing methodology
for the construction of the enantioselective a-butenolides that
exist in many biologically active natural products.
13 (a) Y. Matsuoka, R. Irie and T. Katsuki, Chem. Lett., 2003,
584–585; (b) S. Onitsuka, Y. Matsuoka, R. Irie and T. Katsuki,
Chem. Lett., 2003, 974–975.
The project operated within the Foundation for Polish
Science TEAM Programmes co-financed by the EU European
Regional Development Fund. The research was carried out
with the equipment purchased thanks to the financial support
from the European Regional Development Fund in the
14 S. Kobayashi and C. Ogawa, Chem.–Eur. J., 2006, 12, 5954–5960.
15 T. Ollevier and B. Plancq, Chem. Commun., 2012, 48, 2289–2291.
16 For other examples of Brønsted acid-assisted chiral Lewis acid, see:
(a) K. Ishihara and H. Yamamoto, J. Am. Chem. Soc., 1994,
116, 1561; (b) K. Manabe, Y. Mori, S. Nagayama, K. Odashima
and S. Kobayashi, Inorg. Chim. Acta, 1999, 296, 158.
c
This journal is The Royal Society of Chemistry 2012
Chem. Commun., 2012, 48, 11029–11031 11031