Synlett 2008(7): 1076-1080  
DOI: 10.1055/s-2008-1042924
LETTER
© Georg Thieme Verlag Stuttgart · New York

Formal [2+3] Cycloaddition between Substituted Phenols and Allylsilane

Didier Bérard, Léanne Racicot, Cyrille Sabot, Sylvain Canesi*
Laboratoire de Méthodologie et Synthèse de Produits Naturels, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC, H3C 3P8, Canada
Fax: +1(514)9874054; e-Mail: canesi.sylvain@uqam.ca;
Further Information

Publication History

Received 29 December 2007
Publication Date:
17 March 2008 (online)

Abstract

Treatment of various substituted phenols in the presence of allyltrimethylsilane, iodobenzene diacetate, and perfluorinated alcohol promotes oxidative formal [2+3] cycloaddition in moderate to useful yields.

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TFE (pKa ca. 12.4, nucleophilicity ca. -2.8); HFIP (pKa ca. 9.3, nucleophilicity ca. -4.2).

16

Reaction effected with HFIP as solvent is easier to purify by chromatography than with TFE as solvent.

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NMR Data (Table 1) Entry 1: 1H NMR (300 MHz, CDCl3): δ = 7.31 (d, 1 H, J = 1.7 Hz), 7.27 (dd, 1 H, J = 8.2, 1.7 Hz), 6.76 (d, 1 H, J = 8.2 Hz), 4.92 (m, 1 H), 3.29 (dd, 1 H, J = 15.4, 8.2 Hz), 2.81 (dd, 1 H, J = 15.4, 8.2 Hz), 1.34 (dd, 1 H, J = 14.3, 6.6 Hz), 1.11 (dd, 1 H, J = 14.3, 8.8 Hz), 0.24 (s, 9 H), 0.11 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 156.8, 130.8, 128.7, 128.6, 126.4, 122.5, 122.5, 118.5, 112.1, 82.9, 36.9, 25.6, -0.7.
Entry 2: 1H NMR (300 MHz, CDCl3): δ = 7.32 (d, 1 H, J = 1.7 Hz), 7.08 (dd, 1 H, J = 8.2, 1.7 Hz), 6.66 (d, 1 H, J = 8.2 Hz), 4.90 (m, 1 H), 3.26 (dd, 1 H, J = 15.4, 8.2 Hz), 2.82 (dd, 1 H, J = 15.4, 8.2 Hz), 1.26 (m + s, 4 H), 1.05 (dd, 1 H, J = 14.3, 8.8 Hz), 0.09 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 158.0, 129.4, 127.6, 124.8, 118.4, 110.0, 82.9, 38.1, 25.1,
-0.8.
Entry 3: 1H NMR (300 MHz, CDCl3): δ = 7.23 (d, 1 H, J = 1.7 Hz), 7.18 (dd, 1 H, J = 8.2, 1.7 Hz), 6.60 (d, 1 H, J = 8.2 Hz), 4.93 (m, 1 H), 3.27 (dd, 1 H, J = 15.4, 8.2 Hz), 2.79 (dd, 1 H, J = 15.4, 8.2 Hz), 1.30 (dd, 1 H, J = 14.3, 6.6 Hz), 1.09 (dd, 1 H, J = 14.3, 8.8 Hz), 0.09 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 158.0, 129.4, 127.6, 124.8, 118.4, 110.0, 82.9, 38.1, 25.1, -0.8.
Entry 4: 1H NMR (300 MHz, CDCl3): δ = 7.41 (d, 1 H, J = 1.7 Hz), 7.36 (dd, 1 H, J = 8.2, 1.7 Hz), 6.51 (d, 1 H, J = 8.2 Hz), 4.92 (m, 1 H), 3.26 (dd, 1 H, J = 15.4, 8.2 Hz), 2.77 (dd, 1 H, J = 15.4, 8.2 Hz), 1.29 (dd, 1 H, J = 14.3, 6.6 Hz), 1.07 (dd, 1 H, J = 14.3, 8.8 Hz), 0.08 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 159.3, 136.6, 133.5, 130.4, 111.5, 82.8, 37.8, 25.1, -0.9.
Entry 5: 1H NMR (300 MHz, CDCl3): δ = 6.71 (s, 1 H), 6.62 (d, 1 H, J = 8.2 Hz), 6.58 (d, 1 H, J = 8.2 Hz), 4.85 (m, 1 H), 3.71 (s, 3 H), 3.21 (dd, 1 H, J = 15.4, 8.2 Hz), 2.74 (dd, 1 H, J = 15.4, 8.2 Hz), 1.28 (dd, 1 H, J = 14.3, 6.6 Hz), 1.07 (dd, 1 H, J = 14.3, 8.8 Hz), 0.07 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 153.7, 128.3, 113.1, 112.5, 111.3, 108.9, 82.3, 56.0, 38.6, 25.1, -0.8.
Entry 6: 1H NMR (300 MHz, CDCl3): δ = 7.01 (d, 1 H, J = 1.7 Hz), 6.94 (dd, 1 H, J = 8.2, 1.7 Hz), 6.67 (d, 1 H, J = 8.2 Hz), 4.91 (m, 1 H), 3.81 (t, 2 H, J = 6.4 Hz), 3.26 (dd, 1 H, J = 15.4, 8.2 Hz), 2.79 (m, 3 H), 1.33 (dd, 1 H, J = 14.3, 6.6 Hz), 1.09 (dd, 1 H, J = 14.3, 8.8 Hz), 0.10 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 158.1, 129.7, 128.3, 127.8, 125.4, 109.0, 82.3, 63.9, 38.5, 38.2, 25.2, -0.8.
Entry 7: 1H NMR (300 MHz, CDCl3): δ = 7.68 (d, 2 H, J = 8.2 Hz), 7.29 (d, 2 H, J = 8.2 Hz), 6.85 (d, 1 H, J = 1.7 Hz), 6.76 (dd, 1 H, J = 8.2, 1.7 Hz), 6.60 (d, 1 H, J = 8.2 Hz), 4.89 (m, 1 H), 4.40 (t, 1 H, J = 6.6 Hz), 3.21 (dd, 1 H, J = 15.4, 8.2 Hz), 3.15 (q, 2 H, J = 6.6 Hz), 2.74 (dd, 1 H, J = 15.4, 8.2 Hz), 2.66 (t, 2 H, J = 6.6 Hz), 2.42 (s, 3 H), 1.31 (dd, 1 H,
J = 14.3, 6.6 Hz), 1.09 (dd, 1 H, J = 14.3, 8.8 Hz), 0.09 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 158.3, 143.3, 136.8, 129.6, 128.8, 128.0, 127.9, 127.0, 125.1, 109.1, 82.4, 44.5, 38.1, 35.0, 25.2, 21.5, -0.9.
Entry 8: 1H NMR (300 MHz, CDCl3): δ = 7.31 (d, 1 H, J = 1.7 Hz), 7.27 (dd, 1 H, J = 8.2, 1.7 Hz), 6.76 (d, 1 H, J = 8.2 Hz), 4.92 (m, 1 H), 3.29 (dd, 1 H, J = 15.4, 8.2 Hz), 2.81 (dd, 1 H, J = 15.4, 8.2 Hz), 1.34 (dd, 1 H, J = 14.3, 6.6 Hz), 1.11 (dd, 1 H, J = 14.3, 8.8 Hz), 0.24 (s, 9 H), 0.11 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 160.2, 133.3, 130.5, 129.7, 127.0, 108.9, 82.2, 38.0, 25.3, -0.7.
Entry 9: 1H NMR (300 MHz, CDCl3): δ = 7.29 (t, 2 H, J = 8.2 Hz), 7.02 (t, 1 H, J = 8.2 Hz), 6.94 (d, 2 H, J = 8.2 Hz), 6.85 (d, 1 H, J = 1.7 Hz), 6.79 (dd, 1 H, J = 8.2, 1.7 Hz), 6.68 (d, 1 H, J = 8.2 Hz), 4.93 (m, 1 H), 3.26 (dd, 1 H, J = 15.4, 8.2 Hz), 2.79 (dd, 1 H, J = 15.4, 8.2 Hz), 1.34 (dd, 1 H, J = 14.3, 6.6 Hz), 1.13 (dd, 1 H, J = 14.3, 8.8 Hz), 0.10 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 158.8, 155.7, 149.6, 129.4, 128.7, 122.0, 119.3, 117.3, 117.0, 109.3, 82.7, 38.4, 25.2,
-0.8.

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NMR Data Compound 13: 1H NMR (300 MHz, CDCl3): δ = 7.76 (d, 1 H, J = 8.2 Hz), 7.63 (d, 1 H, J = 8.2 Hz), 7.54 (d, 1 H, J = 8.2 Hz), 7.43 (t, 1 H, J = 8.2 Hz), 7.27 (d, 1 H, J = 8.2 Hz), 7.05 (d, 1 H, J = 8.2 Hz), 5.10 (m, 1 H), 3.56 (dd, 1 H, J = 14.8, 8.8 Hz), 3.03 (dd, 1 H, J = 14.8, 8.2 Hz), 1.37 (dd, 1 H, J = 13.7, 6.6 Hz), 1.18 (dd, 1 H, J = 14.3, 8.8 Hz), 0.11 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 156.8, 130.8, 128.9, 128.7, 128.6, 126.4, 122.5, 122.5, 118.5, 112.1, 82.9, 36.9, 25.6,
-0.7.
Compound 15: 1H NMR (300 MHz, CDCl3): δ = 6.35 (s, 2 H), 4.92 (m, 1 H), 3.84 (s, 3 H), 3.77 (s, 3 H), 3.22 (dd, 1 H, J = 15.4, 8.2 Hz), 2.79 (dd, 1 H, J = 15.4, 8.2 Hz), 1.42 (dd, 1 H, J = 14.3, 6.6 Hz), 1.19 (dd, 1 H, J = 14.3, 8.8 Hz), 0.10 (s, 9 H). 13C NMR (75 MHz, CDCl3): δ = 154.4, 144.3, 141.9, 128.3, 101.4, 99.1, 82.9, 56.0, 38.9, 30.9, 25.0, -0.9.

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NMR Data of Compound 17
1H NMR (300 MHz, CDCl3): δ = 7.53 (m, 2 H), 7.36 (m, 3 H), 6.33 (s, 1 H), 6.29 (s, 1 H), 4.89 (m, 1 H), 3.83 (s, 3 H), 3.73 (s, 3 H), 3.06 (dd, 1 H, J = 15.4, 8.2 Hz), 2.69 (dd, 1 H, J = 15.4, 8.2 Hz), 1.69 (dd, 1 H, J = 14.3, 6.6 Hz), 1.39 (dd, 1 H, J = 14.3, 8.8 Hz), 0.38 (s, 3 H) 0.37 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 154.4, 144.3, 141.8, 138.2, 133.5, 129.1, 128.2, 127.8, 101.3, 99.1, 82.6, 55.9, 38.7, 24.3, -2.2, -2.4.