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The Journal of Organic Chemistry
1-(m-Tolyl)-6,9,9-trimethyl-9H-tribenzo[b,d,f]silepin (2g). Isolated by thinꢀlayer chromatography
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(hexane/dichloromethane = 20/1, 3 times, Rf = 0.5). The title compound was obtained as white solid
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(18.3 mg, 92%). Mp 131ꢀ133 °C; H NMR δ 7.46ꢀ7.38 (m, 4H), 7.34 (d, J = 7.4 Hz, 1H), 7.28 (s, 1H),
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7.06 (d, J = 7.4 Hz, 1H), 7.02ꢀ6.96 (m, 2H), 6.91 (d, J = 7.6 Hz, 1H), 6.85 (s, 1H), 6.80 (ddd, J = 7.4,
7.4, 1.4 Hz, 1H), 6.73 (d, J = 7.2 Hz, 1H), 6.68 (d, J = 7.8 Hz, 1H), 2.33 (s, 3H), 2.21 (s, 3H), 0.75 (s,
3H), ꢀ0.03 (s, 3H); 13C NMR δ 146.6, 143.4, 143.0, 142.9, 142.8, 141.9, 139.4, 139.0, 138.8, 137.1,
132.5, 131.0, 130.9, 130.8, 130.7, 130.2, 129.8, 127.7, 127.3, 127.1, 127.0, 126.9, 126.6, 125.6, 21.4,
21.4, ꢀ4.1, ꢀ5.5; HRMS(ESI, positive) calcd for C28H27Si [M+H]+: 391.1877; found: 391.1877.
9,9-Dimethyl-9H-dibenzo[b,f]naphtho[1,2-d]silepine (2h). Isolated by thinꢀlayer chromatography
(hexane/dichloromethane = 20/1, 5 times, Rf = 0.5). The title compound was obtained as a white solid
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(9.5 mg, 57%). Mp 56ꢀ60 °C; H NMR δ 7.89 (d, J = 8.5 Hz, 2H), 7.68 (d, J = 8.5 Hz, 1H), 7.58ꢀ7.55
(m, 3H), 7.50ꢀ7.45 (m, 2H), 7.42ꢀ7.37 (m, 2H), 7.35ꢀ7.7.29 (m, 3H), 7.28ꢀ7.24 (m, 1H, overlapped with
CHCl3), 0.73 (s, 3H), ꢀ0.41 (s, 3H); 13C NMR δ 146.5, 1443.5, 142.9, 142.0, 138.3, 137.4, 133.1, 132.8,
132.3, 131.2, 130.9, 129.8, 129.7, 129.2, 127.8, 127.8, 127.7, 127.6, 126.5, 126.1, 126.1, 125.7, ꢀ4.6,
ꢀ5.5; HRMS(ESI, positive) calcd for C24H21Si [M+H]+: 337.1407; found: 337.1407.
1,9,9-Trimethyl-9H-tribenzo[b,d,f]silepin
(2i).
Isolated
by
thinꢀlayer
chromatography
(hexane/dichloromethane = 20/1, twice, Rf = 0.5). The title compound was obtained as pale yellow oil
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(4.0 mg, 24%). H NMR δ 7.48ꢀ7.47 (m, 1H), 7.43 (d, J = 7.4 Hz, 1H), 7.40 (dd, J = 7.3, 1.2 Hz, 1H),
7.34 (dd, J = 7.5, 1.4 Hz, 1H), 7.30ꢀ7.25 (m, 3H, overlapped with CHCl3), 7.23ꢀ7.18 (m, 4H), 2.17 (s,
3H), 0.70 (s, 3H), ꢀ0.29 (s, 3H); 13C NMR δ 146.7, 143.4, 142.3, 142.2, 141.6, 140.1, 136.9, 130.9,
130.9, 130.7, 129.5, 129.4, 129.2, 129.2, 128.0, 126.9, 126.0, 125.8, 22.3, ꢀ4.5, ꢀ5.5; HRMS(ESI,
positive) calcd for C21H21Si [M+H]+: 301.1407; found: 301.1408.
9,9-Dimethyl-1-(4-hydroxyphenyl)-9H-tribenzo[b,d,f]silepin-7-ol (3b). Isolated by thinꢀlayer
chromatography (hexane/ethyl acetate = 1/1, Rf = 0.5). The title compound was obtained as a white
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solid (7.7 mg, 68%). Mp 200ꢀ203 °C; H NMR δ 7.44ꢀ7.39 (m, 2H), 7.37ꢀ7.32 (m, 3H), 7.03 (ddd, J =
7.4, 7.4, 1.1 Hz, 1H), 6.91 (d, J =2.1 Hz, 1H), 6.86ꢀ6.83 (m, 3H), 6.81 (dd, J = 8.3, 2.8 Hz, 1H), 6.70 (d,
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