P. Liu et al. / Tetrahedron 66 (2010) 631–636
635
7.99; N, 4.52. 1H NMR (400 MHz, CDCl3):
7.00 (s, 2H), 3.97–3.85 (m, 2H), 1.49 (s, 18H), 1.43 (m, 6H), 1.28 (s,
18H).
d
7.74 (s, 2H), 7.44 (s, 2H),
pressure. The residue was purified by flash column chromatogra-
phy on silica gel eluting with petroleum to give the corresponding
coupling products.
4.2.2. Synthesis of complex 2. To a solution of ligand L3 (2.0 mmol)
in C2H5OH (20 mL) was added PdCl2(CH3CN)2 (2.0 mmol). The
resulting solution was refluxed for 4 h, stand a period time at
room temperature, after the solid was filtrated and washed twice
with CHCl3, which was dissolved with larger ethanol, the filtrate
was evaporated to give a yellow solid product in 60% yield. Anal.
Calcd for C21H27ClN2OPd: C, 54.20; H, 5.85; N, 6.02; Found: C,
4.3.1. 4-Fluoro-40-(4-propyl-cyclohexyl)-biphenyl (8o). 1H NMR (400
MHz, CDCl3):
d
0.91 (t, J¼7.2 Hz, 3H), 1.02–1.11 (m, 2H), 1.20–1.39 (m,
5H), 1.44–1.50 (m, 2H), 1.90 (t, J¼6.4, 4H), 2.47–2.53 (m, lH), 7.07–
7.12 (m, 2H), 7.27 (d, J¼8.0 Hz, 2H), 7.46 (d, J¼8.0 Hz, 2H), 7.50–7.54
(m, 2H). 13C NMR (100 MHz, CDCl3):
d 14.61, 20.23, 33.77, 34.54,
37.23, 39.91, 44.47, 115.59, 115.80, 127.07, 127.49, 128.63, 137.95,
147.26. HRMS (EI), m/z: C21H25F, calculated: 296.1940; found,
296.1945.
53.95; H, 5.80; N, 5.93. 1H NMR (400 MHz, DMSO-d6):
d 8.91 (s,
1H), 8.17 (d, 1H, J1¼8.4 Hz), 7.48 (d, J¼2.0 Hz, 1H), 7.37 (d, J¼2.0 Hz,
1H), 7.34 (m, 1H), 7.26 (s, 2H), 7.24 (d, J¼6.0 Hz, 2H), 1.35 (s, 9H),
4.3.2. 4-Fluoro-40-(4-pentyl-cyclohexyl)-biphenyl (8p). 1H NMR (400
1.27 (s, 9H). 13C NMR (100 MHz, DMSO-d6):
d
162.93, 153.80,
MHz, CDCl3):
d
0.90 (t, J¼7.2 Hz, 3H), 1.02–1.11 (m, 2H), 1.20–1.39 (m,
147.88, 139.95, 138.42, 129.46, 127.54, 120.19, 116.75, 35.80, 34.12,
31.61, 29.86; HRMS (EI), m/z: [MꢂCl]þ, calculated for: 429.1158;
found, 429.1149.
5H), 1.44–1.50 (m, 2H), 1.90 (t, J¼6.4, 4H), 2.48–2.54 (m, lH), 7.08–
7.12 (m, 2H), 7.27 (d, J¼8.0 Hz, 2H), 7.46 (d, J¼8.0 Hz, 2H), 7.50–7.54
(m, 2H). 13C NMR (100 MHz, CDCl3):
d 14.24, 22.87, 26.82, 32.40,
33.81, 34.55, 37.55, 37.57, 44.48,115.56, 115.78, 127.04, 127.46,128.77,
137.94,147.24,161.26,161.40,163.71,163.86. HRMS (EI), m/z: C23H29F,
calculated: 324.2253; found, 324.2256.
4.2.3. Synthesis of complex 3. To a solution of benzene-1,2-diamine
(2.0 mmol) in C2H5OH (20 mL) was added PdCl2(CH3CN)2
(2.0 mmol). The resulting solution was stirred for 5 h at room
temperature, after the solid was filtrated and washed twice with
EtOH give a yellow solid product in 90% yield. 1H NMR (400 MHz,
4.3.3. 4-Fluoro-40-(40-pentyl-bicyclohexyl-4-yl)-biphenyl (8q). 1H NMR
(400 MHz, CDCl3):
d
0.89 (t, J¼6.4 Hz, 3H), 0.97–1.33 (m, 18H), 1.73–
DMSO-d6):
d
7.17 (m, 2H), 7.08 (m, 2H), 7.01 (s, 4H).
1.96 (m, 9H), 2.49 (m, 1H), 7.08–7.12 (m, 2H), 7.27 (d, J¼8.0 Hz,
2H), 7.46 (d, J¼8.0 Hz, 2H), 7.50–7.54 (m, 2H). 13C NMR (100 MHz,
4.2.4. Synthesis of complex 4. To a solution of ligand L2 (2.0 mmol)
in CHCl3 (20 mL) was added in the CH3CN solution of PdCl2(CH3CN)2
(2.5 mmol), the resulting solutionwas stirred for 1 h at reflux. When
the reaction completed, the mixture was cooled to room tempera-
ture, the solution was condensed to afford a crude product. Further
purification of the product was performed by a chromatography on
silica gel column (CH2Cl2 as eluent), a red solid was obtained. Anal.
Calcd for C36H46N2O2Pd: C, 67.02; H, 7.19; N, 4.34; Found: C, 66.56;
CDCl3): d 14.33, 22.93, 26.88, 30.30, 30.54, 32.45, 33.84, 34.80, 37.68,
38.12, 43.11, 43.62, 44.50, 115.59, 115.81, 127.06, 127.48, 128.63, 137.48,
137.93, 147.28, 161.23, 163.68. HRMS (EI), m/z: C29H39F, calculated:
400.2566; found, 400.2576.
4.3.4. 3,4-Difluoro-40-(4-pentyl-cyclohexyl)-biphenyl (8r). 1H NMR
(400 MHz, CDCl3):
d
0.90 (t, J¼8.0 Hz, 3H), 1.05–1.11 (m, 2H), 1.19–
1.40 (m, 5H), 1.45–1.51 (m, 2H), 1.90 (t, J¼12.0 Hz, 4H), 2.48–2.54
(m, lH), 7.16–7.23 (m, 1H), 7.28 (d, J¼8.0 Hz, 2H), 7.34–7.38 (m, 1H),
H, 7.04; N, 4.35; 1H NMR (400 MHz, CDCl3):
d 8.55 (s, 2H), 7.88 (dd,
2H, J1¼3.2 Hz, J2¼6.0 Hz), 7.54 (s, 2H), 7.30 (dd, 2H, J1¼3.2 Hz,
7.44 (d, J¼8.0 Hz, 2H). 13C NMR (100 MHz, CDCl3):
d 14.28, 22.91,
J2¼6.0 Hz), 7.20 (s, 2H), 1.55 (s, 18H), 1.34 (s, 18H). 13C NMR
26.85, 32.43, 33.81, 34.55, 37.57, 37.58, 44.53, 115.90, 116.07, 117.50,
117.68, 122.95, 127.03, 127.63, 136.89, 138.57, 147.94, 148.67, 149.56,
151.14, 151.26, 151.89, 152.02. HRMS (EI), m/z: C23H28F2, calculated:
342.2159; found, 342.2155.
(100 MHz, CDCl3):
d 166.06, 152.25, 143.71, 141.17, 136.68, 131.65,
128.31, 126.97, 119.82, 115.35, 36.17, 34.00, 31.24, 29.55.
4.2.5. Synthesis of product 5. To a solution of ligand L2 (2.0 mmol)
in C2H5OH (20 mL) was added PdCl2(CH3CN)2 (2.0 mmol). The
resulting solution was stirred for 4 h at room temperature, the
solid was filtrated and washed twice with CHCl3 to give a yellow
solid product 5 (2/3¼4:1). Anal. Calcd. For C90H116Cl6N10O4Pd5: C,
50.53; H, 5.45; N, 6.52. Found: C, 49.44; H, 5.24; N, 6.84; 1H NMR
4.3.5. 3,4,5-Trifluoro-40-(4-pentyl-cyclohexyl)-biphenyl (8s). 1H NMR
(400 MHz, CDCl3):
d
0.90 (t, J¼8.0 Hz, 3H), 1.00–1.10 (m, 2H), 1.20–
1.39 (m, 5H), 1.44–1.50 (m, 2H), 1.90 (t, J¼12.0 Hz, 4H), 2.48–2.54 (m,
lH), 7.15–7.18 (m, 2H), 7.28 (d, J¼8.0 Hz, 2H), 7.42 (d, J¼8.0 Hz, 2H).
13C NMR (100 MHz, CDCl3):
d 14.14, 22.76, 26.70, 32.26, 33.58, 34.31,
(400 MHz, DMSO-d6):
d
8.91 (s, 1H), 8.17 (d, 1H, J¼8.0 Hz), 7.48
37.34, 44.33, 110.64, 110.80, 126.72, 127.58, 128.62, 132.19, 135.68,
137.26, 148.39. HRMS (EI), m/z: C23H27F3, calculated: 360.2065;
found, 360.2063.
(d, J¼2.0 Hz, 1H), 7.37 (d, J¼2.4 Hz, 1H), 7.34 (m, 1H), 7.26 (s, 2H),
7.24 (d, J¼6.0 Hz, 2H), 7.17 (m, 2H), 7.09 (m, 2H), 7.00 (s, 4H), 1.35
(s, 9H), 1.28 (s, 9H). 13C NMR (100 MHz, DMSO-d6):
d 162.93,
153.80, 147.88, 139.95, 138.42, 129.46, 127.54, 120.19, 116.75,
35.80, 34.12, 31.61, 29.86; IR (KBr, cmꢂ1): 3437, 3200, 3044, 2957,
1603 (C]N), 1583, 1519, 1492, 1421, 1360, 1227, 1166, 751, 540.
HRMS (EI), m/z: [M(complex 2)ꢂCl]þ, calculated for: 429.1158;
found, 429.1149; [M(complex 3)ꢂ2Cl]þ, calculated for: 213.9722;
found, 213.9224.
4.4. General procedure for complex 2 catalyzed
Suzuki–Miyaura reaction of aryl chlorides
A
mixture of aryl chloride (0.25 mmol), arylboronic acid
(0.40 mmol), K3PO4$3H2O (0.50 mmol), and complex 2 (1 mol %) in
2.0 mL of DMA was stirred at 130 ꢀC under the air condition for
12 h. The reaction mixture was quenched with water and extracted
with EtOAc (2ꢃ5 mL). The solvent was concentrated under reduced
pressure. The residue was purified by flash column chromatogra-
phy on silica gel eluting with petroleum to give the corresponding
coupling products.
4.3. General procedure for complex 2 catalyzed
Suzuki–Miyaura reaction of aryl bromides
A
mixture of aryl bromide (0.50 mmol), arylboronic acid
(0.75 mmol), K3PO4$3H2O (1.20 mmol) and complex 2 (0.01 mol %,
this is obtained by dilution with EtOH) in 2.0 mL of EtOH was
stirred at 60 ꢀC under the air condition for 5.0 h. The reaction
mixture was filtered through a short pad of silica gel eluting with
5 mL of EtOAc. The filtrate was concentrated under reduced
4.5. Synthesis of polyaromatic C3-symmetric derivatives
A
mixture of aryl bromide (0.05 mmol), arylboronic acid
(0.25 mmol), K3PO4$3H2O (0.40 mmol), and complex 2 (0.1 mol %)