The Journal of Organic Chemistry
Note
2H), 4.12 (s, 1H), 2.43−2.34 (m, 4H); 13C NMR (100 MHz, CDCl3)
δ 147.6, 147.3, 144.6, 141.8, 139.8, 128.8 (q, JF = 31.8 Hz), 128.4,
128.2, 128.2, 127.4, 126.0, 124.6 (q, JF = 271.9 Hz), 124.5, 124.4 (q, JF
= 3.9 Hz), 121.1 (q, JF = 3.7 Hz), 120.6, 119.9, 47.3, 34.4, 31.5; EI-MS
(m/z, relative intensity) 338 (M+, 100), 319 (10), 247 (50), 233 (45),
178 (30), 105 (50), 92 (70); HRMS (ESI) calcd for C22H17F3 [M]+,
338.1282; found, 338.1286; IR (film): 3129, 1328, 1160, 1117, 1065,
743, 700 cm−1.
141.4, 128.6, 128.1 (q, JF = 32.3 Hz), 127.2, 127.1, 125.2 (q, JF = 3.7
Hz), 124.4 (q, JF = 271.8 Hz), 124.2, 120.0, 47.1, 34.3, 31.1; EI-MS
(m/z, relative intensity) 338 (M+, 70), 319 (5), 179 (100), 165 (80);
HRMS (ESI) calcd for C22H17F3 [M] +, 338.1282; found, 338.1285; IR
(film): 2918, 2846, 1455, 1334, 1161, 1121, 1065, 737 cm−1.
2-Methyl-9-(4-(trifluoromethyl)phenethyl)-9H-fluorene (3n). Yield
1
99% (104 mg); white solid; mp 72−73 °C; Rf = 0.30 (PE); H NMR
(400 MHz, CDCl3) δ 7.73 (d, J = 7.5 Hz, 1H), 7.65 (d, J = 7.7 Hz,
1H), 7.50 (d, J = 7.4 Hz, 1H), 7.44 (d, J = 7.3 Hz, 2H), 7.36 (t, J = 7.3
Hz, 1H), 7.30−7.27 (m, 2H), 7.19 (d, J = 7.7 Hz, 1H), 7.14 (d, J = 8.0
Hz, 2H), 4.04 (s, 1H), 2.43 (s, 3H), 2.38−2.37 (m, 4H); 13C NMR
(100 MHz, CDCl3) δ 146.8, 146.6, 146.4, 141.5, 138.7, 136.9, 128.6,
128.1 (q, J = 32.3 Hz), 128.0, 127.2, 126.6, 125.1 (q, J = 3.8 Hz),
9-Phenethyl-2-(trifluoromethoxy)-9H-fluorene (3h). Yield 76%
(81 mg); colorless oil; Rf = 0.38 (PE); 1H NMR (400 MHz,
CDCl3) δ 7.70 (dd, J = 7.6, 5.1 Hz, 2H), 7.52 (d, J = 7.3 Hz, 1H),
7.38−7.34 (m, 3H), 7.24−7.21 (m, 3H), 7.14 (q, J = 7.3 Hz, 1H), 7.06
(d, J = 7.1 Hz, 2H), 4.06 (d, J = 5.3 Hz, 1H), 2.40−2.31 (m, 4H); 13C
NMR (100 MHz, CDCl3) δ 148.8, 148.5 (q, JF = 1.4 Hz), 147.1, 141.9,
140.1, 140.0, 128.4, 128.3, 127.3, 125.9, 124.4, 120.7 (q, JF = 256.7
Hz), 120.6, 120.1, 120.1, 117.4, 47.3, 34.6, 31.5; EI-MS (m/z, relative
intensity) 354 (M+, 85), 262 (90), 249 (50), 165 (20), 152 (100), 105
(70), 92 (70); HRMS (EI) calcd for C22H17F3O [M]+, 354.1231;
found, 354.1210; IR (film): 1455, 1257, 1220, 1164, 743, 697 cm−1.
9-(4-Chlorophenethyl)-9H-fluorene (3i). Yield 90% (82 mg); white
solid; mp 80−81 °C; Rf = 0.40 (PE); 1H NMR (400 MHz, CDCl3) δ
7.76 (d, J = 7.4 Hz, 2H), 7.51 (d, J = 7.3 Hz, 2H), 7.37 (t, J = 7.4 Hz,
2H), 7.33−7.29 (m, 2H), 7.16 (t, J = 8.3 Hz, 2H), 6.97 (t, J = 8.3 Hz,
1H), 7.10 (t, J = 6.0 Hz, 2H), 4.07 (t, J = 4.3 Hz, 1H), 2.43−2.32 (m,
4H); 13C NMR (100 MHz, CDCl3) δ 146.8, 141.3, 140.8, 131.5,
129.7, 128.4, 127.2, 127.0, 124.2, 120.0, 47.1, 34.6, 30.7; EI-MS (m/z,
relative intensity) 304 (M+, 50), 179 (100), 165 (70), 139 (20); 19F
NMR (470 MHz, CDCl3) δ −139.5 (m, 2F), −143.8 (m, 2F); HRMS
(ESI) calcd for C21H17Cl [M]+, 304.1018; found, 304.1020; IR (film):
3063, 1495, 1448, 802, 734 cm−1.
9-(4-Chlorophenethyl)-2-methyl-9H-fluorene (3j). Yield 99% (94
mg); colorless oil; Rf = 0.30 (PE); 1H NMR (400 MHz, CDCl3) δ 7.71
(d, J = 7.5 Hz, 1H), 7.63 (d, J = 7.7 Hz, 1H), 7.49 (t, J = 7.4 Hz, 1H),
7.39−7.23 (m, 3H), 7.20−7.11 (m, 3H), 6.97 (d, J = 8.4 Hz, 2H), 4.00
(s, 1H), 2.43 (s, 3H), 2.32−2.31 (m, 4H); 13C NMR (100 MHz,
CDCl3) δ 147.0, 146.6, 141.4, 140.9, 138.7, 136.9, 131.4, 130.0, 128.4,
128.0, 127.1, 126.5, 125.0, 124.2, 119.7, 119.6, 47.0, 34.6, 30.8, 21.8;
EI-MS (m/z, relative intensity) 318 (M+, 50), 207 (20), 193 (100),
178 (60), 165 (15); HRMS (ESI) calcd for C22H19Cl [M]+, 318.1175;
found, 318.1176; IR (film): 2918, 1455, 1325, 1164, 1123, 1067, 832,
767 cm−1.
F
F
124.9, 124.4 (q, JF = 271.7 Hz), 124.2, 119.7, 119.6, 47.0, 34.3, 31.1,
21.7; EI-MS (m/z, relative intensity) 352 (M+, 70), 333 (10), 281
(10), 253 (10), 207 (30), 193 (100), 179 (80); HRMS (ESI) calcd for
C23H19F3 [M]+, 352.1438; found, 352.1438; IR (film): 2921, 1325,
1163, 1121, 1067, 823 cm−1.
2-Fluoro-9-(4-(trifluoromethyl)phenethyl)-9H-fluorene (3o). Yield
1
74% (79 mg); white solid; mp 63−64 °C; Rf = 0.30 (PE); H NMR
(400 MHz, CDCl3 ) δ 7.81−7.61 (m, 2H), 7.50 (d, J = 7.4 Hz, 1H),
7.45 (d, J = 8.1 Hz, 2H), 7.38 (t, J = 7.4 Hz, 1H), 7.34−7.21 (m, 1H),
7.20 (dd, J = 8.8, 1.9 Hz, 1H), 7.13 (d, J = 8.0 Hz, 2H), 7.08 (td, J =
8.8, 2.3 Hz, 1H), 4.06 (d, J = 4.3 Hz, 1H), 2.41−2.33 (m, 4H); 13C
NMR (100 MHz, CDCl3) δ 162.6 (d, JF = 245.4 Hz), 148.8 (d, JF =
8.0 Hz), 146.3, 146.2, 140.5, 137.3 (d, JF = 2.1 Hz), 128.6, 128.2 (q, JF
= 32.3 Hz), 127.4, 126.8, 125.2 (q, JF = 3.8 Hz), 124.3 (d, JF = 271.7
Hz), 124.2, 120.9 (d, JF = 8.8 Hz), 119.7, 114.4 (d, JF = 23.0 Hz),
111.6 (d, JF = 22.8 Hz), 47.2 (d, JF = 2.1 Hz), 34.2, 30.9; 19F NMR
(470 MHz, CDCl3 ) δ −62.4 (s, 3F), −115.0 (s, 1F); EI-MS (m/z,
relative intensity) 356 (M+, 60), 281 (15), 207 (80), 197 (100), 183
+
(70), 133 (20); HRMS (ESI) calcd for C22H16F4 [M] , 356.1188;
found, 356.1194; IR (film): 2918, 1455, 1325, 1164, 1123, 1067 cm−1.
9-(4-Vinylphenethyl)-9H-fluorene (3p). Yield 63% (56 mg); white
1
solid; mp 49−50 °C; Rf = 0.55 (PE); H NMR (400 MHz, CDCl3) δ
7.77 (d, J = 7.3 Hz, 2H), 7.55 (d, J = 7.4 Hz, 2H), 7.37 (d, J = 6.9 Hz,
2H), 7.32 (td, J = 7.4, 1.2 Hz, 2H), 7.27 (d, J = 8.1 Hz, 2H), 7.05 (d, J
= 8.1 Hz, 2H), 6.66 (dd, J = 17.6, 10.9 Hz, 1H), 5.67 (dd, J = 17.6, 0.7
Hz, 1H), 5.17 (dd, J = 10.9, 0.6 Hz, 1H), 4.07 (t, J = 4.7 Hz, 1H),
2.40−2.32 (m, 4H); 13C NMR (100 MHz, CDCl3) δ 147.0, 142.1,
141.3, 136.7, 135.2, 128.5, 127.1, 127.0, 126.2, 124.3, 119.9, 113.0,
47.2, 34.7, 31.2; EI-MS (m/z, relative intensity) 296 (M+, 80), 192
(20), 179 (100), 165 (80), 131 (50), 118 (60); HRMS (ESI) calcd for
C23H20 [M]+, 296.1565; found, 296.1567; IR (film): 2976, 2924, 2855,
1449, 1118, 839, 741, 658 cm−1.
9-(4-Chlorophenethyl)-2-fluoro-9H-fluorene (3k). Yield 96% (93
1
mg); colorless oil; Rf = 0.40 (PE); H NMR (400 MHz, CDCl3) δ
7.74−7.60 (m, 2H), 7.49 (d, J = 7.5 Hz, 1H), 7.36 (t, J = 7.3 Hz, 1H),
7.29 (td, J = 7.4, 1.0 Hz, 1H), 7.25−7.13 (m, 3H), 7.07 (td, J = 8.8, 2.3
Hz, 1H), 6.96 (d, J = 8.4 Hz, 2H), 4.02 (t, J = 4.3 Hz, 1H), 2.33−2.27
(m, 4H); 13C NMR (100 MHz, CDCl3) δ 162.6 (d, JF = 245.1 Hz),
149.0 (d, JF = 8.0 Hz), 146.6, 146.6, 140.5, 137.3, 131.6, 129.6, 128.4,
127.3, 126.7, 124.2, 120.8 (d, JF = 8 8 Hz), 119.7, 114.3 (d, JF = 22.9
Hz), 111.6 (d, JF = 22.7 Hz), 47.2 (d, JF = 2.2 Hz), 34.5, 30.6; EI-MS
(m/z, relative intensity) 322 (M+, 60), 281 (10), 253 (10), 207 (20),
197 (100), 183 (20); HRMS (ESI) calcd for C21H16ClF [M]+,
322.0924; found, 322.0925; IR (film): 2923, 2853, 1454, 827, 766,
757, 740, 728 cm−1.
General Procedure for Pd(0)-Catalyzed Tandem Coupling
Reaction (for Scheme 5). 2,2′-Dibromobiphenyls (0.30 mmol), 1,1-
dibronates 4 (0.39 mmol), Pd(PtBu3)2 (0.015 mmol), and 1.5 mL of
dioxane were mixed in an oven-dried reaction flask. Ten molar NaOH
(aq) (1.5 mmol, 150 μL) was added using a syringe pump over 8 h.
The mixture was stirred at room temperature under a nitrogen
atmosphere for 48 h. When the reaction was completed, the crude
mixture was cooled to room temperature. Five milliliters of Et2O was
added to the mixture, and the mixture was filtered through Celite. The
solvents were evaporated under reduced pressure, and the crude
residue was purified by flash chromatography on silica gel.
9-(4-Fluorophenethyl)-9H-fluorene (3l). Yield 89% (77 mg);
1
colorless oil; Rf = 0.20 (PE); H NMR (400 MHz, CDCl3) δ 7.76
9H-Fluorene (5a).6 Yield 74% (38 mg); white solid; Rf = 0.43 (PE);
1H NMR (400 MHz, CDCl3) δ 7.79 (d, J = 7.5 Hz, 2H), 7.54 (d, J =
(d, J = 7.4 Hz, 2H), 7.52 (d, J = 7.3 Hz, 2H), 7.37 (d, J = 7.2 Hz, 2H),
7.31 (td, J = 7.4, 1.1 Hz, 2H), 7.05−6.96 (m, 2H), 6.94−6.83 (m, 2H),
4.05 (s, 1H), 2.33−2.33 (m, 4H); 13C NMR (100 MHz, CDCl3) δ
161.2 (d, JF = 243.4 Hz), 146.9, 141.3, 138.0 (d, JF = 3.0 Hz), 129.6 (d,
JF = 7.9 Hz), 127.1, 127.0, 124.3, 120.0, 115.0 (d, JF = 21.0 Hz), 47.2,
34.9, 30.6; EI-MS (m/z, relative intensity) 288 (M+, 70), 179 (100),
165 (70), 123 (15); HRMS (ESI) calcd for C21H17F[M]+, 288.1314;
found, 288.1323; IR (film): 2977, 2860, 1509, 1119, 740 cm−1.
9-(4-(Trifluoromethyl)phenethyl)-9H-fluorene (3m). Yield 98%
(99 mg); white solid; mp 78−79 °C; Rf = 0.35 (PE); 1H NMR
(400 MHz, CDCl3) δ 7.76 (d, J = 7.4 Hz, 2H), 7.51 (d, J = 7.4 Hz,
2H), 7.44 (d, J = 8.0 Hz, 2H), 7.38 (t, J = 7.3 Hz, 2H), 7.31 (td, J =
7.3, 1.1 Hz, 2H), 7.12 (d, J = 8.0 Hz, 2H), 4.07 (d, J = 4.3 Hz, 1H),
2.40−2.33 (m, 4H); 13C NMR (100 MHz, CDCl3) δ 146.6, 146.6,
7.4 Hz, 2H), 7.37 (t, J = 7.3 Hz, 2H), 7.30 (td, J = 7.4, 1.1 Hz, 2H),
3.90 (s, 2H); 13C NMR (101 MHz, CDCl3) δ 143.2, 141.7, 126.7,
126.7, 125.0, 119.9, 36.9.
2-Methyl-9H-fluorene (5b).6 Yield 65% (35 mg); white solid; Rf =
1
0.41 (PE); H NMR (400 MHz, CDCl3) δ 7.72 (d, J = 7.5 Hz, 1H),
7.65 (d, J = 7.7 Hz, 1H), 7.49 (d, J = 7.5 Hz, 1H), 7.33 (t, J = 7.4 Hz,
2H), 7.29−7.22 (m, 1H), 7.16 (d, J = 7.7 Hz, 1H), 3.83 (s, 2H), 2.41
(s, 3H); 13C NMR (100 MHz, CDCl3) δ 143.5, 143.1, 141.8, 139.1,
136.6, 127.6, 126.7, 126.2, 125.8, 125.0, 119.6, 119.5, 36.8, 21.6.
2-Chloro-9H-fluorene (5c).6 Yield 57% (30 mg); white solid; Rf =
1
0.41 (PE); H NMR (400 MHz, CDCl3) δ 7.74 (d, J = 7.5 Hz, 1H),
7.68 (d, J = 8.1 Hz, 1H), 7.57−7.46 (m, 2H), 7.44−7.27 (m, 3H), 3.88
E
J. Org. Chem. XXXX, XXX, XXX−XXX