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dine (50.0 mg, 0.06 mmol) was suspended in methanol (30.0 mL).
Hydrochloric acid (42.0 mL, 0.42 mmol) was added and the mixture
was stirred for 2 h. After evaporation of the solvent, the product
was obtained as a yellow solid that was highly soluble in organic
solvents. 1H NMR (500.1 MHz, CD3OD/CDCl3, 298 K): d=6.58 (d,
3J8,7 =3J8’,7’ =3J1’,3’ =7.6 Hz, 6H; H-8, H-1’/H-8’), 6.85 (s, 2H; H-1), 6.96
(dd, 3J2’,1’ =3J7’,8’ =7.6 Hz, 3J2’,3’ =3J7’,6’ =7.3 Hz, 4H; H-2’/H-7’), 7.01
washed with water and brine and dried with magnesium sulfate.
After evaporation of the solvent, the crude product was purified
by column chromatography (eluent: cyclohexane/ethyl acetate=
20/1!5/1). The product was obtained as a light yellow solid
1
(211 mg, 0.48 mmol, 73%). H NMR (400.1 MHz, CDCl3, 298 K): d=
5
1.27 (s, 12H; H-16), 6.70 (ddd, 3J8,7 =7.6 Hz, 4J8,6 =1.0 Hz, J8,5
=
3
4
0.7 Hz, 1H; H-8), 6.73 (ddd, J1’,2’ =3J8’,7’ =7.7 Hz, J1’,3’ =4J8’,6’ =0.7 Hz,
(dd, 3J7,6 =7.3 Hz, 3J7,8 =7.6 Hz, 2H; H-7), 7.23 (dd, 3J3’,4’ =3J6’,5’
=
2H; H-1’/H-8’), 7.10 (ddd, 3J2’,1’ =3J7’,8’ =7.7 Hz, 3J2’,3’ =3J7’,6’ =7.5 Hz,
7.7 Hz, 3J3’,2’ =3J6’,7’ =7.3 Hz, 4H; H-3’/H-6’), 7.25 (dd, 3J6,7 =7.3 Hz,
3J6,5 =7.7 Hz, 2H; H-6), 7.63 (d, 3J3,4 =7.5 Hz, 2H; H-3), 7.72 (d,
3J4’,3’ =3J5’,6’ =7.7 Hz, 4H; H-4’/H-5’), 7.76 (d, 3J5,6 =7.7 Hz, 2H; H-5),
4J2’,4’ =4J7’,5’ =1.1 Hz, 2H; H-2’/H-7’), 7.11 (ddd, 3J7,6 =7.5 Hz, J7,8
=
=
=
3
7.6 Hz, 4J7,5 =1.1 Hz, 1H; H-7), 7.21 (s, 1H; H-1), 7.36 (ddd, J6,7
3
7.5 Hz, J6,5 =7.5 Hz, J6,8 =1.0 Hz, 1H; H-6), 7.37 (ddd, J3’,4’ =3J6’,5’
3
4
3
3
7.88 (d, J4,3 =7.5 Hz, 2H; H-4), 8.13 (brs, 2H; H-15), 8.27 (brs, 2H;
7.5 Hz, 3J3’,2’ =3J6’,7’ =7.5 Hz, 4J3’,1’ =4J6’,8’ =0.7 Hz, 2H; H-3’/H-6’),
7.84–7.88 ppm (m, 5H; H-3, H-4, H-5, H-4’/H-5’); 13C NMR
(100.6 MHz, CDCl3, 298 K): d=25.0 (C-16), 66.1 (C-9/C-9’), 83.8 (C-
15), 119.5 (C-4), 120.1 (C-4’/C-5’), 120.5 (C-5), 124.1 (C-8), 124.3 (C-
1’/C-8’), 127.8 (C-6, C-3’/C-6’), 127.9 (C-2’/C-7’), 128.5 (C-7), 130.4 (C-
1), 134.9 (C-3), 141.5 (C-12), 142.1 (C-11’/C-12’), 145.1 (C-11), 147.8
(C-10), 148.7 (C-10’/C-13’), 149.9 ppm (C-13); C-2 is invisible owing
to its coupling with 11B; 11B NMR (128.4 MHz, CDCl3, 298 K): d=30.8
(B-14); MS (EI): m/z (%): 342.1 (50) [MÀC6H12O]+, 442.02(100) [M]+;
HRMS (EI): m/z calcd for [C31H27BO2]+: 441.2140; found: 441.2132;
elemental analysis calcd (%) for C31H27BO2·1/20CH2Cl2: C 83.51, H
6.12; found: C 83.34, H 6.21.
H-16), 8.79 ppm (brs, 2H; H-18); 13C NMR (125.8 MHz, CD3OD/
CDCl3, 298 K): d=65.9 (C-9/C-9’), 120.1 (C-4’/C-5’), 120.5 (C-5), 121.1
(C-4), 122.3 (C-1), 123.3 (C-16), 123.8 (C-1’/C-8’), 123.9 (C-8), 127.1
(C-3), 127.8 (C-2’/C-7’), 127.9 (C-6 and C-3’/C-6’), 128.7 (C-7), 133.5
(C-10), 139.6 (C-14), 139.8 (C-15), 140.2 (C-12), 141.6 (C-11’/C-12’),
143.8 (C-11), 143.9 (C-18), 145.0 (C-17), 147.8 (C-10’/C-13’), 149.1 (C-
13), 150.3 ppm (C-2).
(R)-2,2’-Bis(5’-methoxy-2,2’-bipyridin-5-yl)-9,9’-spirobifluorene
(2): In a Schlenk flask equipped with reflux condenser and septum,
compound (R)-9 (70.0 mg, 0.12 mmol), 10 (85.0 mg, 0.27 mmol),
cesium fluoride (150 mg, 0.98 mmol), and [Pd(PtBu3)2] (6.00 mg)
were evacuated and flushed with argon several times. Then THF
(5.00 mL) was added and the mixture was heated at reflux for 24 h.
After cooling to room temperature, water and dichloromethane
were added. By the addition of a saturated solution of sodium car-
bonate, the pH was adjusted to eight and the aqueous layer was
extracted with dichloromethane. The combined organic extracts
were washed with brine and dried with sodium sulfate. After evap-
oration of the solvent, the crude product was purified by column
chromatography (eluent: cyclohexane/ethyl acetate=5/1+5%
triethylamine!ethyl acetate). The product was obtained as a light
5,5’-Diiodo-2,2’-bipyridine (8): In a three-necked flask equipped
with reflux condenser and a gas-washing bottle (filled with saturat-
ed solution of sodium thiosulfate), compound
7
(0.40 g,
1.33 mmol) and iodine monochloride (0.42 mL, 1.30 g,
7
7.99 mmol) in tetrachloromethane (15.0 mL) were heated at reflux
for 20 h. After cooling to room temperature, the reaction was
quenched by the addition of a solution of sodium hydrogen sulfite
(10% in water). The solution was then alkalized with a saturated
solution of sodium hydroxide and extracted with dichloromethane.
The combined organic layers were washed with water and brine,
and finally dried with magnesium sulfate. After evaporation of the
solvent, the residue was recrystallized from n-hexane to yield
yellow solid (65.0 mg, 94.9 mmol, 79%). a20 = +5418 mLdmÀ1 gÀ1
D
(c=1.09 mgmLÀ1, CHCl3); 1H NMR (300.1 MHz, CDCl3, 298 K): d=
4
1
3.89 (s, 6H; H-24), 6.81 (d, 3J8,7 =7.4 Hz, 2H; H-8), 7.04 (d, J1,3
=
a light yellow solid (316 mg, 0.78 mmol, 58%). H NMR (400.1 MHz,
3
3
4
3
5
1.7 Hz, 2H; H-1), 7.16 (ddd, J7,8 =7.4 Hz, J7,6 =7.5 Hz, J7,5 =1.0 Hz,
2H; H-7), 7.28 (dd, 3J21,20 =8.7 Hz, 4J21,23 =2.8 Hz, 2H; H-21), 7.42
(ddd, 3J6,7 =7.5 Hz, 3J6,5 =7.6 Hz, 4J6,8 =1.0 Hz, 2H; H-6), 7.69 (dd,
[D6]DMSO, 298 K): d=8.16 (dd, J3,4 =8.3 Hz, J3,6 =0.7 Hz, 2H; H-3),
3
4
4
8.33 (dd, J4,3 =8.3 Hz, J4,6 =2.1 Hz, 2H; H-4), 8.92 ppm (dd, J6,4
=
2.1 Hz, 5J6,3 =0.7 Hz, 2H; H-6); 13C NMR (75.5 MHz, [D6]DMSO,
298 K): d=95.6 (C-5), 122.2 (C-3), 145.8 (C-4), 153.3 (C-2),
155.0 ppm (C-6); MS (EI): m/z (%): 280.9 (30) [MÀI]+, 407.8 (100)
[M]+; HRMS (EI): m/z calcd for [C10H6I2N2]+: 407.8620; found:
407.8620; elemental analysis calcd (%) for C10H6I2N2: C 29.44, H
1.48, N 6.87; found: C 29.31, H 1.74, N 6.75.
4
3
4
3J3,4 =7.9 Hz, J3,1 =1.7 Hz, 2H; H-3), 7.81 (dd, J15,16 =8.4 Hz, J15,18
=
=
2.4 Hz, 2H; H-15), 7.91 (d, 3J5,6 =7.6 Hz, 2H; H-5), 7.98 (d, J4,3
7.9 Hz, 2H; H-4), 8.24 (dd, J16,15 =8.4 Hz, J16,18 =0.7 Hz, 2H; H-16),
3
3
5
3
4
8.30 (d, J20,21 =8.7 Hz, 2H; H-20), 8.33 (d, J23,21 =2.8 Hz, 2H; H-23),
8.72 ppm (dd, 4J18,15 =2.4 Hz, 5J18,16 =0.7 Hz, 2H; H-18); 13C NMR
(75.5 MHz, CDCl3, 298 K): d=55.8 (C-24), 66.3 (C-9), 120.2 (C-16),
120.5 (C-5), 120.9 (C-4), 121.1 (C-21), 121.8 (C-20), 122.7 (C-1), 124.3
(C-8), 127.0 (C-3), 128.2 (C-6), 128.4 (C-7), 135.1 (C-15), 135.5 (C-14),
137.0 (C-23), 137.6 (C-2), 141.3 (C-12), 142.0 (C-11), 147.5 (C-18),
148.8 (C-19), 149.0 (C-13), 149.8 (C-10), 154.7 (C-17), 156.2 ppm (C-
22); MS (ESI): m/z (%): 685.3 (100) [M+H]+, 707.2 (61) [M+Na]+,
1370.5 (18) [4M+2H]2+, 1392.5 (11) [4M+2Na]2+; HRMS (ESI): m/z
calcd for [C47H32N4O2+Na]+: 707.2417; found: 707.2411.
5-Iodo-5’-methoxy-2,2’-bipyridine (10): In a three-necked flask
equipped with reflux condenser and a gas-washing bottle (filled
with a saturated solution of sodium thiosulfate), compound 13
(0.20 g, 0.77 mmol) and iodine monochloride (0.12 mL, 0.38 g,
2.32 mmol) in tetrachloromethane (10.0 mL) were heated at reflux
for 20 h. After cooling to room temperature, the reaction was
quenched by the addition of a saturated solution of sodium thio-
sulfate. The solution was then alkalized with a saturated solution
of sodium hydroxide and extracted with dichloromethane. The
combined organic layers were washed with water and brine, and
finally dried with sodium sulfate. After evaporation of the solvent,
the crude product was subjected to column chromatography
(eluent: cyclohexane/ethyl acetate=5/1!2/1) to yield a pearly
2-(4,4,5,5-Tetramethyl-1,2,3-dioxaborolan-2-yl)-9,9’-spirobifluor-
ene (4): In a Schlenk flask equipped with reflux condenser and
septum, compound 3 (300 mg, 0.65 mmol), potassium acetate
(190 mg, 1.94 mmol), bis(pinacolato)diboron (180 mg, 0.71 mmol),
[PdCl2(dppf)]·CH2Cl2 (53.0 mg), and dppf (36.0 mg, 0.06 mmol) were
evacuated and flushed with argon several times. Dry 1,4-dioxane
(6.00 mL) was added and the mixture was heated at reflux for
2.5 days. After cooling to room temperature, the reaction was
quenched by the addition of water. The aqueous layer was extract-
ed with dichloromethane. The combined organic layers were
1
solid (178 mg, 0.57 mmol, 74%). H NMR (400.1 MHz, CDCl3, 298 K):
3
4
d=3.91 (s, 3H; H-7’), 7.30 (dd, J4’,3’ =8.8 Hz, J4’,6’ =3.0 Hz, 1H; H-
3
4’), 8.07 (dd, 3J4,3 =8.4 Hz, 4J4,6 =2.1 Hz, 1H; H-4), 8.11 (dd, J3,4
=
5
3
8.4 Hz, J3,6 =0.8 Hz, 1H; H-3), 8.31 (d, J3’,4’ =8.8 Hz, 1H; H-3’), 8.34
4
4
5
(d, J6’,4’ =3.0 Hz, 1H; H-6’), 8.82 ppm (dd, J6,4 =2.1 Hz, J6,3 =0.8 Hz,
ChemPlusChem 2017, 82, 758 –769
765
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