J
A. D. Benischke et al.
Paper
Synthesis
4
13C NMR (CDCl3, 100 MHz): δ = 149.2, 145.2 (q, JC,F = 1.8 Hz), 136.8,
1.0 h at the given temperature. The crude product was purified by
flash column chromatography (SiO2, isohexane–EtOAc = 19:1, Rf =
0.40) to afford 4f (194 mg, 0.72 mmol, 72%) as a colorless liquid.
2
3
129.0, 128.4, 128.3 (q, JC,F = 32 Hz), 125.4, 125.2 (q, JC,F = 3.8 Hz)
124.3 (q, 1JC,F = 271 Hz), 41.1, 34.3, 31.2.
19F NMR (CDCl3, 376 MHz): δ = –62.3.
IR (ATR): 1712, 1597, 1584, 1488, 1271, 1256, 1176, 1148, 1100, 871
cm–1
.
MS (EI, 70 eV): m/z (%) = 292 (18), 278 (17), 277 (100), 158 (22).
HRMS (EI, 70 eV): m/z calcd for C18H19F3: 292.1439; found: 292.1426.
1H NMR (CDCl3, 400 MHz): δ = 8.00 (d, J = 8.3 Hz, 2 H), 7.29 (d, J = 8.3
Hz, 2 H), 7.24 (t, J = 7.9 Hz, 1 H), 6.80 (dd, J = 8.1, 2.6 Hz, 2 H), 6.76–
6.73 (m, 1 H), 4.39 (q, J = 7.1 Hz, 2 H), 4.03 (s, 2 H), 3.80 (s, 3 H), 1.41
(t, J = 7.1 Hz, 3 H).
Ethyl 4-[4-(tert-Butyl)benzyl]benzoate (4d)
According to GP4, Ni(acac)2 (12.8 mg, 0.05 mmol, 5.0 mol%), 4-fluoro-
styrene (24.4 mg, 0.20 mmol, 20 mol%), ethyl 4-iodobenzoate (3a;
276 mg, 1.00 mmol, 1.00 equiv), and freshly distilled THF (1.0 mL)
were used. The reaction mixture was cooled to 0 °C, [4-(tert-bu-
tyl)benzyl]manganese(II) chloride (1b; 3.30 mL, 1.20 mmol, 1.20
equiv, 0.37 M in THF) was added dropwise and the resulting solution
was stirred for 1.0 h. Purification of the crude product by flash col-
umn chromatography (SiO2, isohexane–EtOAc = 99:1, Rf = 0.34) led to
the desired product 4d (210 mg, 0.71 mmol, 71%) as a colorless liquid.
13C NMR (CDCl3, 100 MHz): δ = 166.4, 159.6, 146.0, 141.5, 129.6,
129.4, 128.7, 128.3, 121.1, 114.6, 111.4, 60.6, 54.9, 41.7, 14.2.
MS (EI, 70 eV): m/z (%) = 271 (18), 270 (100), 225 (49), 197 (27), 164
(18), 152 (14), 121 (18), 112 (10).
HRMS (EI, 70 eV): m/z calcd for C17H18O3: 270.1256; found: 270.1251.
Ethyl 3-(2-Chlorobenzyl)benzoate (4g)
With reference to GP4, Ni(acac)2 (12.8 mg, 0.05 mmol, 5.0 mol%), 4-
fluorostyrene (24.4 mg, 0.20 mmol, 20 mol%), ethyl 3-iodobenzoate
(3e; 276 mg, 1.00 mmol, 1.00 equiv), and freshly distilled THF (1.0
mL) were used. The reaction mixture was cooled to 0 °C, (2-chloro-
benzyl)manganese(II) chloride (1d; 5.50 mL, 1.20 mmol, 1.20 equiv,
0.22 M in THF) was added dropwise and the resulting reaction mix-
ture was stirred for 1.0 h. The crude product was purified by flash col-
umn chromatography (SiO2, isohexane–EtOAc = 99:1, Rf = 0.20) to af-
ford 4g (197 mg, 0.71 mmol, 71%) as a pale yellow oil.
IR (ATR): 2961, 1714, 1609, 1576, 1269, 1176, 1098, 1020, 755, 739
cm–1
.
1H NMR (CDCl3, 400 MHz): δ = 7.92 (d, J = 8.3 Hz, 2 H), 7.27 (d, J = 8.3
Hz, 2 H), 7.22 (d, J = 8.4 Hz, 2 H), 7.06 (d, J = 8.4 Hz, 2 H), 4.32 (q, J = 7.1
Hz, 2 H), 3.96 (s, 2 H), 1.34 (t, J = 7.1 Hz, 3 H), 1.26 (s, 9 H).
13C NMR (CDCl3, 100 MHz): δ = 167.1, 149.6, 147.0, 137.6, 130.2,
129.4, 129.0, 128.9, 125.9, 61.2, 41.9, 34.9, 31.8, 14.8.
MS (EI, 70 eV): m/z (%) = 296 (21), 282 (19), 281 (100).
IR (ATR): 1714, 1588, 1472, 1442, 1392, 1366, 1304, 1276, 1184, 744
HRMS (EI, 70 eV): m/z calcd for C20H24O2: 296.1776; found: 296.1770.
cm–1
.
1H NMR (CDCl3, 400 MHz): δ = 7.94–7.89 (m, 2 H), 7.40–7.34 (m, 3 H),
7.21–7.13 (m, 3 H), 4.37 (q, J = 7.1 Hz, 2 H), 4.16 (s, 2 H), 1.39 (t, J = 7.1
Hz, 3 H).
13C NMR (CDCl3, 100 MHz): δ = 166.4, 139.6, 137.9, 134.0, 133.2,
130.8, 130.5, 129.9, 129.4, 128.3, 127.7, 127.4, 126.7, 60.8, 38.8, 14.1.
4-(3-Methoxybenzyl)benzonitrile (4e)
Based on GP4, Ni(acac)2 (12.8 mg, 0.05 mmol, 5.0 mol%), 4-fluorosty-
rene (24.4 mg, 0.20 mmol, 20 mol%), 4-iodobenzonitrile (3d; 229 mg,
1.00 mmol, 1.00 equiv), and freshly distilled THF (1.0 mL) were used.
The mixture was cooled to 0 °C, (3-methoxybenzyl)manganese(II)
chloride (1c; 3.80 mL, 1.20 mmol, 1.20 equiv, 0.32 M in THF) was add-
ed dropwise and the resulting solution was stirred for 1.0 h at the pri-
or adjusted temperature. Purification of the crude product by flash
column chromatography (SiO2, isohexane–EtOAc = 19:1, Rf = 0.23)
gave 4e (123 mg, 0.55 mmol, 55%) as a pale yellow liquid.
MS (EI, 70 eV): m/z (%) = 275 (16), 274 (66), 239 (13), 230 (15), 229
(100), 166 (21), 165 (74).
HRMS (EI, 70 eV): m/z calcd for C16H15ClO2: 274.0761; found:
274.0751.
IR (ATR): 2226, 1598, 1488, 1464, 1256, 1148, 1046, 1020, 840, 780
1-Fluoro-3-[4-(trifluoromethyl)benzyl]benzene (4h)
cm–1
.
With reference to GP4, Ni(acac)2 (12.8 mg, 0.05 mmol, 5.0 mol%), 4-
fluorostyrene (24.4 mg, 0.20 mmol, 20 mol%), 4-iodobenzotrifluoride
(3c; 272 mg, 1.00 mmol, 1.0 equiv), and freshly distilled THF (1.0 mL)
were used. The reaction mixture was cooled to 0 °C and a solution of
(3-fluorobenzyl)manganese(II) chloride (1e; 4.00 mL, 1.20 mmol,
1.20 equiv, 0.30 M in THF) was added dropwise at the given tempera-
ture and the mixture was stirred for 1.0 h. Purification of the crude
product by flash column chromatography (SiO2, isohexane, Rf = 0.45)
afforded 4h (187 mg, 0.74 mmol, 74%) as a colorless liquid.
1H NMR (CDCl3, 600 MHz): δ = 7.57 (d, J = 8.5 Hz, 2 H), 7.29 (d, J = 8.6
Hz, 2 H), 7.25–7.21 (m, 1 H), 6.79 (dd, J = 8.0, 2.2 Hz, 1 H), 6.76 (d, J =
9.1 Hz, 1 H), 6.72–6.69 (m, 1 H), 4.00 (s, 2 H), 3.78 (s, 3 H).
13C NMR (CDCl3, 150 MHz): δ = 159.8, 146.4, 140.8, 132.2, 129.6,
129.5, 121.2, 118.9, 114.9, 111.6, 110.0, 55.1, 41.9.
MS (EI, 70 eV): m/z (%) = 224 (17), 223 (100), 222 (19), 208 (41), 192
(20), 190 (31), 180 (42), 165 (15), 152 (11), 121 (14).
HRMS (EI, 70 eV): m/z calcd for
223.0990.
C15H13NO: 223.0997; found:
IR (ATR): 1613, 1589, 1509, 1486, 1449, 1417, 1321, 1250, 1160, 1018
cm–1
.
1H NMR (CDCl3, 400 MHz): δ = 7.59 (d, J = 8.1 Hz, 2 H), 7.32 (dd, J = 8.3,
2.2 Hz, 2 H), 7.30–7.26 (m, 1 H), 7.03–6.86 (m, 3 H), 4.06 (s, 2 H).
Ethyl 4-(3-Methoxybenzyl)benzoate (4f)
According to GP4, Ni(acac)2 (12.8 mg, 0.05 mmol, 5.0 mol%), 4-fluoro-
styrene (24.4 mg, 0.20 mmol, 20 mol%), ethyl 4-iodobenzoate (3a;
276 mg, 1.00 mmol, 1.00 equiv), and freshly distilled THF (1.0 mL)
were used. The mixture was cooled to 0 °C, (3-methoxybenzyl)man-
ganese(II) chloride (1c; 3.80 mL, 1.20 mmol, 1.20 equiv, 0.32 M in
THF) was added dropwise, and the resulting solution was stirred for
13C NMR (CDCl3, 100 MHz): δ = 162.9 (d, 1JC,F = 246 Hz), 144.2 (q, 4JC,F
=
1.8 Hz), 142.3 (d, 3JC,F = 7.2 Hz), 129.9 (d, 3JC,F = 8.3 Hz), 129.0, 128.6 (q,
2JC,F = 32 Hz), 125.4 (q, 2JC,F = 3.8 Hz), 124.4 (d, 4JC,F = 2.8 Hz), 124.1 (q,
2
2
1JC,F = 270 Hz), 115.7 (d, JC,F = 21 Hz), 113.3 (d, JC,F = 21 Hz), 41.2 (d,
4JC,F = 1.6 Hz).
19F NMR (CDCl3, 376 MHz): δ = –113.1, –62.4.
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2017, 49, A–Q