Amberlite IRA900F as a Solid Fluoride Source
new compounds and characterization data (1H and 13C NMR spec-
troscopic data, elemental analysis) are reported below.
4.93 (dd, J = 11.0, 13.0 Hz, 1 H CHH), 7.02–7.25 (m, 4 H) ppm.
13C NMR (50.3 MHz, CDCl3): δ = 20.8, 22.1, 24.8, 45.3, 50.8, 52.0,
76.8, 128.6, 129.0, 132.7, 137.5, 176.3 ppm. C14H19NO4 (265):
calcd. C 63.38, H 7.22, N 5.28; found C 63.35, H 7.30, N 5.24.
Procedure for the Amb-F-catalyzed [3+2] Cycloaddition of Nitroeth-
enes (1a–d) with TMSN3 (2): In a screw-capped vial equipped with
a magnetic stirrer was consecutively added (E)-2-aryl-1-cyano-1-
nitroethenes 1a–d (1.0 mmol), TMSN3 (0.34 g, 3.0 mmol), and
Amb-F (0.10 g, 0.25 mmol, 2.6 mmol/g), and the resulting mixture
was stirred at the temperature and for the time reported in Table 1.
At the end of the reaction, ethyl acetate was added, the catalyst
was recovered by filtration, and the organic layer was evaporated
under high vacuum to give pure products 3a–d (90–95% yield; see
Table 1).
Amb-F-Catalyzed Michael Additions of Ethyl Nitroacetate (11) to
β-Nitrostyrenes 8a–c in SolFC: In a screw-capped vial equipped
with a magnetic stirrer was consecutively added β-nitrostyrene 8a,
8b, or 8c (1.0 mmol), ethyl nitroacetate (0.13 g, 1.0 mmol), and
Amb-F (0.02 g, 0.05 mmol, 2.6 mmol/g), and the resulting mixture
was stirred at 40 °C for the time reported in Table 4. At the end of
the reaction, ethyl acetate was added, the catalyst was recovered by
filtration, and the organic layer was evaporated under high vacuum
to give pure products 12a (93% yield, 0.26 g), 12b (96% yield,
0.28 g) or 12c (94% yield, 0.30 g). Physical data for 12a: charac-
Amb-F-Catalyzed Multicomponent Synthesis of 1H-1,2,3-Triazoles
3e and 3f: In a screw-capped vial equipped with a magnetic stirrer
was added 2,4-dichlorobenzaldehyde (0.174 g, 1.0 mmol), nitroace-
tonitrile[10] (0.13 g, 1.5 mmol), TMSN3 (0.35 g, 3.0 mmol), and
Amb-F (0.10 g, 0.25 mmol, 2.6 mmol/g), and the reaction mixture
was stirred for 12 h at 60 °C. At the end of the reaction, ethyl ace-
tate was added, the catalyst was recovered by filtration, and the
organic layer was concentrated under vacuum and then purified by
silica gel flash chromatography (petroleum ether/EtOAc, 8:2) to
give pure 3e in 80% yield (0.190 g). A similar protocol furnished
pure product 3f in 75% yield (0.167 g; see Scheme 1).
terized as
a
1:1 diastereoisomeric mixture. Oil. 1H NMR
(400 MHz, CDCl3): δ = 1.10 (t, J = 7.0 Hz, 3 H, CH2-CH3), 1.30
(t, J = 7.1 Hz, 3 H, CH2-CH3), 4.13 (q, J = 7.1 Hz, 4 H, 2ϫCH2),
4.27–4.30 (m, 2 H, 2ϫAr-CH), 4.50–4.55 (m, 2 H, 2ϫCHH-NO2),
4.88–5.00 (m, 2 H, 2ϫCHH-NO2), 5.50 (d, J = 8.0 Hz, 1 H, CHH),
5.58 (d, J = 9.4 Hz, 1 H, CHH), 7.20–7.48 (m, 10 H, Ar) ppm. 13
C
NMR (100.6 MHz, CDCl3): δ = 13.5, 13.6, 43.8, 43.9, 63.6, 63.8,
75.7, 75.8, 88.8, 89.1, 127.8, 128.0, 129.2, 129.2, 129.3, 129.4, 132.7,
133.2, 162.2, 162.7 ppm. Physical data for 12b: characterized as a
1:1 diastereoisomeric mixture. Oil. 1H NMR (400 MHz, CDCl3): δ
= 1.13 (t, J = 7.1 Hz, 3 H, CH2-CH3), 1.31 (t, J = 7.1 Hz, 3 H,
CH2-CH3), 2.31 (s, 3 H, CH3), 2.32 (s, 3 H, CH3), 4.15 (q, J =
7.1 Hz, 2 H, CH2-CH3), 4.31 (q, J = 7.1 Hz, 2 H, CH2-CH3), 4.45–
4.50 (m, 2 H, Ar-CH), 4.85–4.98 (m, 4 H, CH2-NO2), 5.48 (d, J =
8.0 Hz, 1 H, CH), 5.55 (d, J = 9.5 Hz, 1 H, CH), 7.10–7.18 (m, 8
H, Ar) ppm. 13C NMR (100.6 MHz, CDCl3): δ = 13.3, 13.6, 21.0,
43.5, 43.6, 63.5, 63.8, 75.8, 75.9, 88.9, 89.3, 127.6, 127.9, 129.6,
130.0, 139.1, 139.2, 162.2, 162.8 ppm. Physical data for 12c: charac-
Procedure for the Amb-F-Catalyzed 1,3-Dipolar Cycloaddition of
Nitriles 4a–c with TMSN3 (2): In a screw-capped vial equipped
with a magnetic stirrer was consecutively added aryl nitriles 4a–c
(1.0 mmol), TMSN3 (0.34 g, 3.0 mmol), and Amb-F (0.20 g,
0.50 mmol, 2.6 mmol/g), and the resulting mixture was stirred at
60 °C for the time reported in Scheme 2. At the end of the reaction,
ethyl acetate was added, the catalyst was filtered off, and the or-
ganic solvent was removed under vacuum to give pure products
5a–c (75–78% yield; see Scheme 2).
terized as
a
1:1 diastereoisomeric mixture. Oil. 1H NMR
(400 MHz, CDCl3): δ = 1.20 (t, J = 7.1 Hz, 3 H, CH2-CH3), 1.29
(t, J = 7.1 Hz, 3 H, CH2-CH3), 4.22–4.32 (m, 4 H, CH2-CH3), 4.95–
5.17 (m, 6 H, Ar-CH, CH2-NO2), 5.71 (d, J = 6.9 Hz, 1 H, CH),
5.83 (d, J = 8.8 Hz, 1 H, CH), 7.20–7.60 (m, 8 H, Ar) ppm. 13C
NMR (100.6 MHz, CDCl3): δ = 13.5, 13.6, 40.3, 40.8, 63.8, 73.9,
74.0, 86.8, 87.9, 127.7, 127.8, 130.4, 130.4, 130.5, 130.7, 130.8,
134.0, 162.2, 162.7 ppm.
Amb-F-Catalyzed β-Azidation of α,β-Unsaturated Acids and Esters
6a–d: In a screw-capped vial equipped with a magnetic stirrer was
consecutively added α,β-unsaturated acids or esters 6a–d
(1.0 mmol), TMSN3 (0.23 g, 2.0 mmol), and Amb-F (0.10 g,
0.25 mmol, 2.6 mmol/g), and the mixture was allowed to react un-
der the conditions reported in Table 2. At the end of the reaction,
ethyl acetate was added, the catalyst was recovered by filtration,
and the organic solvent was evaporated under vacuum to give prod-
ucts 7a–d in 95% purity (70–86% yield; see Table 2).
Acknowledgments
Amb-F-Catalyzed Michael Additions of Dimethylsilyl Ketene Acetal
(9) to β-Nitrostyrenes 8a,b in SolFC: In a screw-capped vial
equipped with a magnetic stirrer was consecutively added β-nitro-
styrene 8a or 8b (1.0 mmol), dimethylsilyl ketene acetal (9) (0.52 g,
3.0 mmol), and Amb-F (5–10 mol-%, 2.6 mmol/g), and the mixture
was allowed to react under the conditions reported in Table 3. At
the end of the reaction, ethyl acetate was added, the catalyst was
filtered off, and the organic solvent was removed under vacuum.
Crude products 10a,b were purified by silica gel flash chromatog-
raphy (petroleum ether/EtOAc, 9:1) to give pure 10a (88% yield,
We gratefully acknowledge the Ministero dell’Università e della
Ricerca (MiUR) and the Università degli Studi di Perugia for fin-
ancial support (COFIN 2006: “Ecofriendly organic syntheses medi-
ated by new catalytic systems”). We also wish to thank Merck’s
Chemistry Council for an ADP grant.
[1] a) J. O. Metzger, Angew. Chem. Int. Ed. 1998, 37, 2975–2978;
b) R. S. Varma, Green Chem. 1999, 1, 43–55; c) K. Tanaka, F.
Toda, Chem. Rev. 2000, 100, 1025–1074; d) R. S. Varma, Pure
Appl. Chem. 2001, 73, 193–198; e) G. W. V. Cave, C. L. Raston,
J. L. Scott, Chem. Commun. 2001, 2159–2169; f) K. Tanaka in
Solvent-Free Organic Synthesis, Wiley-VCH, Weinheim, 2003.
[2] a) J. H. Clark, Chem. Rev. 1980, 80, 429–452; b) C. H.
Heathcok in Comprehensive Organic Synthesis (Eds.: B. M.
Trost, I. Fleming), Pergamon, Oxford, 1991, vol. 2, pp. 133–
340.
[3] Various alumina supports have been used: a) T. Ando, J. Yama-
waki, T. Kawabe, S. Sumi, T. Hanufusa, Bull. Chem. Soc. Jpn.
1982, 55, 2504–2507; b) J. H. Clark, D. G. Cork, M. S. Robert-
son, Chem. Lett. 1983, 1145–1148; c) J. H. Clark, D. G. Cork,
H. W. Gibbs, J. Chem. Soc. Perkin Trans. 1 1983, 2253–2258;
1
0.22 g) and 10b (70% yield, 0.18 g). Physical data for 10a: Oil. H
NMR (200 MHz, CDCl3): δ = 1.16 (s, 3 H, CH3), 1.20 (s, 3 H,
CH3), 3.58 (s, 3 H, OCH3), 3.77 (dd, J = 4.3, 11.0 Hz, 1 H, CH),
4.76 (dd, J = 4.3, 13.1 Hz, 1 H, CHH), 4.96 (dd, J = 11.0, 13.1 Hz,
1 H, CHH), 7.12–7.31 (m, 5 H, Ar) ppm. 13C NMR (50.3 MHz,
CDCl3): δ = 22.1, 24.9, 45.3, 51.2, 52.0, 76.9, 127.9, 128.3, 128.8,
135.9, 176.2 ppm. C13H17NO4 (251): calcd. C 62.14, H 6.82, N
1
5.57; found C 62.15, H 6.80, N 5.44. Physical data for 10b: Oil. H
NMR (200 MHz, CDCl3): δ = 1.16 (s, 3 H, CH3), 1.92 (s, 3 H,
CH3), 2.30 (s, 3 H, Ar-CH3), 3.69 (s, 3 H, OCH3), 3.73 (dd, J =
4.3, 11.0 Hz, 1 H, CH), 4.75 (dd, J = 4.3, 13.0 Hz, 1 H, CHH),
Eur. J. Org. Chem. 2008, 3928–3932
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
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