T. Mitsui et al. / Tetrahedron 71 (2015) 1509e1514
1513
product. The product was isolated by silica gel column chromatog-
150.5 ppm. C28H37Cl3N4Pd (642.40): calcd C 52.68, H 6.20, N 8.72;
found C 52.68, H 6.20, N 8.40.
raphy. White solid; 102 mg, 64% yield; mp 218e220 ꢀC. 1H NMR
(300 MHz, DMSO):
H
32.5, 35.9, 36.3, 42.5, 42.9, 58.8,114.3,156.7 ppm. C22H31N3 (337.51):
calcd C 78.29, H 9.26, N 12.45; found C 78.64, H 9.34, N 12.76.
d
¼7.87 (s,1H, CH), 2.15 (br,12H, HAd),1.89 (br, 6H,
Ad),1.73 (br,12H, HAd) ppm.13C NMR (75 MHz, CDCl3):
d
¼28.4, 29.3,
4.3.6. TAdPh-PEPPSI. According to the procedure for TAd-PEPPSI,
the reaction of 4b (400 mg, 1.05 mmol), Ag2O (255 mg,
1.10 mmol), Me4NCl (138,1.26 mmol) and PdCl2 (187 mg,1.05 mmol)
afforded TAdPh-PEPPSI. Yellow solid; 404 mg, 66% yield; mp
4.3.2. 1-Adamanthyl-4-phenyl-1,2,3-triazole (3b). Sodium ascorbate
(4.75 g, 24.0 mmol) was added to 1-azidoadamantane (1.77 g,
10.0 mmol), and CuSO4 (1.92 g, 12.0 mmol) in tert-butanol (50 mL)/
H2O(50 mL). The mixture was stirred at 60 ꢀC for 18 h. Then, the
volatile solvent was removed by reduced pressure. To NH3 aqueous
solution (30 mL) was added the remainder, and extracted with
CH2Cl2 (30 mL) for 3 times. The combined organic layers were
washed with H2O and brine, dried over MgSO4 and concentrated in
vacuum. The remaining solid was washed with hexane to yield 3b.
White solid; 2.29 g, 82% yield; mp 206e207 ꢀC. 1H NMR (300 MHz,
259e262 ꢀC. 1H NMR (300 MHz, CDCl3):
d
¼8.92 (d, J¼2.3 Hz, 1H,
Py), 8.83 (dd, J¼5.5, 1.3 Hz, 1H, HPy), 8.02 (m, 2H, HAr), 7.70 (m, 1H,
Py), 7.55 (m, 3H, HAr), 7.22 (m, 1H, HAr), 3.96 (s, 3H, NCH3), 2.97 (br,
H
H
6H, HAd), 2.39 (br, 3H, HAd),1.84 (br, 6H, HAd) ppm. 13C NMR (75 MHz,
CDCl3):
d
¼29.9, 35.7, 37.3, 43.4, 65.7, 124.6, 127.8, 128.7, 129.8, 130.6,
131.8, 132.3, 137.6, 142.4, 149.3, 150.2 ppm. C24H27Cl3N4Pd (584.28):
calcd C 49.39, H 4.66, N 9.59; found C 49.55, H 4.85, N 9.39.
4.3.7. TPh-PEPPSI. According to the procedure for TAd-PEPPSI, the
reaction of 4c (100 mg, 0.31 mmol), Ag2O (79.0 mg, 0.34 mmol),
Me4NCl (40.6 mg, 0.37 mmol) and PdCl2 (55.1 mg, 0.31 mmol)
afforded TPh-PEPPSI. Yellow solid; 88 mg, 54% yield; mp 250e254 ꢀC
CDCl3):
(m, 1H, HPh), 2.28 (br, 9H, HAd), 1.80 (br, 6H, HAd) ppm. 13C NMR
(75 MHz, CDCl3):
d¼7.86 (s,1H, CeH), 7.83 (m, 2H, HPh), 7.40 (m, 2H, HPh), 7.29
d
¼29.3, 35.7, 42.8, 59.4, 116.0, 125.4, 127.7, 128.6,
(decomp.). 1H NMR (300 MHz, CDCl3):
d
¼8.87 (d, J¼2.3 Hz, 1H, HPy),
131.0, 146.6 ppm. C18H21N3 (279.39): calcd. C 77.38, H 7.58, N 15.04;
found C 76.96, H 7.49, N 14.86.
8.77 (dd, J¼5.5, 1.3 Hz, 1H, HPy), 8.45 (dd, J¼6.6, 1.8 Hz, 2H, HPh), 8.06
(dd, J¼8.1,1.8 Hz, 2H, HPh), 7.63 (m, 7H, HAr), 7.20 (m,1H, HPy), 4.12 (s,
3H, NCH3) ppm. 13C NMR (75 MHz, CDCl3):
d¼37.7,124.6,125.1,125.7,
4.3.3. 1,4-Diadamanthyl-1,2,3-triazolium tetrafluoroborate (4a). The
triazole 3a (100 mg, 0.23 mmol) and Me3OBF4 (44.2 mg, 0.30 mmol)
were stirred under nitrogen in dry dichloromethane (10 mL) for 16 h.
The reaction was quenched with MeOH (1 mL), and the solvent was
reduced under reduced pressure. The crude product was given, and
then washed with diethyl ether and dried to give the triazolium salt
2. White solid; 92.0 mg, 91% yield; mp 260e262 ꢀC. 1H NMR
126.4, 128.9, 129.2, 130.1, 130.2, 130.4, 132.2, 132.4, 137.7, 138.9, 143.8,
149.1, 150.0, 151.2, 151.6 ppm. C20H17Cl3N4Pd (526.15): calcd. C 45.66,
H 3.26, N 10.65; found C 45.54, H 3.19, N 10.51.
4.3.8. General procedure for the Hiyama coupling reaction. Under
nitrogen, a 20 mL Schlenk tube containing a stirring bar was
charged with sodium hydroxide (120 mg, 3.0 mmol), TAd-PEPPSI
(6.4 mg, 0.010 mmol), aryl bromide 5 (1.0 mmol), trimethox-
(300 MHz, CDCl3):
H
d
¼8.14 (s,1H, CH), 4.40 (s, 3H, NCH3), 2.30 (br,12H,
Ad), 2.12 (br, 6H, HAd), 1.80 (br, 12H, HAd) ppm. 13C NMR (75 MHz,
yphenylsilane 6 (224 mL, 1.2 mmol) and 1,4-dioxane (4 mL)/H2O
CDCl3):
151.7 ppm.
d
¼28.7, 30.3, 34.4, 35.8, 36.4, 40.0, 41.6, 42.3, 66.3, 125.1,
(2 mL). The mixture was stirred at 80 ꢀC for 4 h. After the mixture
was allowed to cool to room temperature, water (5 mL) was added
and the mixture was extracted with three portions of ethyl acetate
(15 mL), dried with MgSO4, and filtered. The solvent was removed
under reduced pressure to give the crude product. The product was
isolated by PTLC (hexane/ethyl acetate).
4.3.4. 1-Adamanthyl-4-phenyl-1,2,3-triazolium
tetrafluoroborate
(4b). According to the procedure for 4a, the reaction of 3b
(300 mg, 1.07 mmol) and Me3OBF4 (207 mg, 1.40 mmol) afforded
4b. White solid; 413 mg, 98% yield; mp 238e240 ꢀC. 1H NMR
(300 MHz, CDCl3):
3H, HPh), 4.23 (s, 3H, CH3), 2.33 (br, 9H, HAd), 1.80 (s, 6H, HAd) ppm.
13C NMR (75 MHz, CDCl3):
d
¼8.46 (s, 1H, CeH), 7.66 (m, 2H, HPh), 7.55 (m,
4.3.9. General procedure for the Suzuki coupling reaction. Under ni-
trogen, a 20 mL Schlenk tube containing a stirring bar was charged
with potassium tert-butoxide (84 mg, 0.75 mmol), TAd-PEPPSI
(3.3 mg, 0.0050 mmol), aryl bromide 5 (0.50 mmol), phenyl-
boronic acid 8 (67 mg, 0.55 mmol) and dry ethanol (1.0 mL). The
mixture was stirred at 50 ꢀC for 3 h. The reaction was quenched with
water, and the mixture was extracted with ethyl acetate, dried with
Na2SO4, and filtered. The solvent was removed under reduced
pressure to give the crude product. The residue was subjected to
PTLC (hexane/ethyl acetate) to give the pure product.
d
¼29.4, 35.1, 38.5, 41.6, 66.4, 122.2,
124.8, 129.4, 129.5, 131.5, 143.1 ppm.
4.3.5. TAd-PEPPSI. Silver(I) oxide (122 mg, 0.53 mmol) and tetra-
methylammonium chloride (63.1 mg, 0.58 mmol) were added to the
solution of the imidazolium salt 4a (210 mg, 0.48 mmol) in aceto-
nitrile/dichloromethane (1:1, 10 mL) and the suspension was stirred
in a Schlenk tube covered with foil at room temperature for 5 h. The
solvent was removed under vacuum, and the residue was dissolved
with dichloromethane and filtered to another Schlenk tube. The
solvent was removed under vacuum, followed by addition of pal-
ladium(II) chloride (85.4 mg, 0.48 mmol) and 3-chloropyridine
(3.0 mL). After stirring at 90 ꢀC for 16 h under nitrogen, the re-
action mixture was cooled to room temperature, diluted with
dichloromethane (5.0 mL) and passed through a silica plug. Re-
moving the volatiles under reduced pressure gave the crude prod-
uct, which was further purified by recrystallization from hexane/
dichloromethane. Yellow needle; 128 mg, 41% yield; mp
Acknowledgements
This study was financially supported by The Institute of Science
and Engineering, Chuo University.
Supplementary data
Copies of the 1H NMR and 13C NMR spectra. Supplementary data
associated with this article can be found in the online version.
Supplementary data related to this article can be found at http://
250e255 ꢀC (decomp.). 1H NMR (300 MHz, CDCl3):
d¼9.04 (d,
J¼2.3 Hz, 1H, HPy), 8.96 (dd, J¼5.5, 1.3 Hz, 1H, HPy), 7.75 (ddd, J¼8.2,
2.3, 1.4 Hz, 1H, HPy), 7.29 (m, 1H, HPy), 4.20 (s, 3H, NCH3), 3.30 (d,
J¼2.9, 6H, HAd), 2.81 (d, J¼2.6 Hz, 6H, HAd), 2.36 (br, 3H, HAd), 2.22
(br, 3H, HAd), 1.84 (m, 12H, HAd) ppm. 13C NMR (75 MHz, CDCl3):
References and notes
d
¼14.1, 22.6, 28.4, 29.3, 29.4, 30.0, 31.5, 34.3, 35.8, 35.9, 36.3, 36.7,
41.1, 41.7, 42.5, 42.9, 43.5, 66.4, 124.8,128.4,132.5,137.6,148.3, 149.5,