LETTER
methylbenzenethiol (3.21 g, 25.88 mmol). Water was added
Chiral Elaboration of Gold Nanoparticle Surfaces
211
121. HRMS: m/z calcd for C20H33IO3: 432.1525; found:
after overnight stirring at r.t. The aqueous layer was
extracted several times with EtOAc, and the combined
organic fractions were washed with 1 M NaOH and H2O,
and dried over Na2SO4. After removal of the solvent, the
crude product was purified by column chromatography
(40% EtOAc–hexanes) to give 6 (11.47 g) in 91% yield. 1H
NMR (CDCl3): d = 1.98–2.18 (m, 4 H), 3.40–3.59 (m, 4 H),
6.10 (s, 2 H), 6.80–7.38 (m, 36 H), 7.70 (dd, 4 H), 7.90 (dd,
4 H). 13C{1H} NMR (CDCl3): d = 47.91, 68.97, 82.61,
115.20, 117.35, 120.16, 121.78, 123.77, 124.02, 125.74,
127.42, 134.31, 134.40, 141.93, 142.09, 153.46, 154.44.
MS: m/z = 973 [M+], 521, 286. HRMS: m/z calcd for
C70H55NO4: 973.4131; found: 973.4105.
432.1520.
(30) The preparation of 9a is given as a typical procedure: To a
solution of 6 (1.0 g, 1.03 mmol) in acetone (40 mL), K2CO3
(1.14 g, 8.24 mmol) was added and the mixture was brought
to reflux for 30 min. After cooling to r.t., a solution of iodide
8a (896 mg, 2.57 mmol) in acetone (10 mL) was added
slowly and the mixture was again heated to reflux for 3 d.
After cooling to r.t., H2O was added and the solution was
extracted with EtOAc. The organic layer was dried over
Na2SO4 and concentrated under reduced pressure.
Purification by column chromatography (10–30% EtOAc–
hexanes) gave the pure compound 9a (1.17 g) in 95% yield.
1H NMR (CDCl3): d = 0.71–0.75 (m, 4 H), 1.03–1.07 (m, 2
H), 1.43–1.49 (m, 2 H), 1.61–1.67 (m, 2 H), 2.15 (br s, 4 H),
3.38 (t, J = 6.4 Hz, 2 H), 3.48–3.57 (m, 4 H), 3.81 (s, 3 H),
4.45 (s, 2 H), 6.08 (s, 2 H), 6.89–7.36 (m, 40 H), 7.73 (dd,
J = 9.2, 8.4 Hz, 4 H), 7.94 (dd, J = 8.0, 9.2 Hz, 4 H). 13C{1H}
NMR (CDCl3): d = 26.06, 26.73, 27.42, 29.24, 29.74, 31.68,
52.37, 54.99, 55.23, 68.01, 70.20, 72.49, 82.18, 113.74,
116.97, 123.64, 125.58, 125.63, 128.03, 134.13, 153.16,
154.54, 159.08. MS: m/z = 1194 [M + H]+, 546, 409. HRMS:
m/z calcd for C84H75NO6: 1194.5678; found: 1194.5680.
Compound 9b: 79% yield. 1H NMR (CDCl3): d = 0.71–0.79
(m, 4 H), 0.97–1.42 (m, 10 H), 1.65–1.78 (m, 4 H), 2.19 (br
s, 4 H), 3.45–3.65 (m, 6 H), 3.80 (s, 3 H), 4.48 (s, 2 H), 6.12
(s, 2 H), 6.90–7.38 (m, 40 H), 7.73 (dd, J = 8.8, 7.6 Hz, 4 H),
7.94 (t, J = 8.8 Hz, 4 H). 13C{1H} NMR (CDCl3): d = 26.58,
27.26, 27.85, 29.89, 29.92, 30.14, 52.77, 55.55, 68.35,
70.56, 72.83, 82.54, 114.05, 115.14, 117.33, 119.94, 125.92,
128.07, 134.45, 142.05, 142.21, 153.50, 154.88, 159.39.
MS: m/z = 1250 [M+]. HRMS: m/z calcd for C88H83NO6:
1250.6299; found: 1250.6293.
(28) Compounds 7a–c were made using modifications to
reported procedures. Compound 7a is a known compound.
See: (a) Sharma, G. V. M.; Reddy, Ch. G.; Krishna, P. R. J.
Org. Chem. 2003, 68, 4574. (b) Hu, T.-S.; Yu, Q.; Wu, Y.-
L.; Wu, Y. J. Org. Chem. 2001, 66, 853. (c) Kwon, O.; Su,
D.-S.; Meng, D.; Deng, W.; D’Amico, D. C.; Danishefsky,
S. J. Angew. Chem. Int. Ed. 1998, 37, 1877. Compound 7b
is likewise known. See: (d) Imagawa, H.; Tsuchihashi, T.;
Singh, R. K.; Yamamoto, H.; Sugihara, T.; Nishizawa, M.
Org. Lett. 2003, 5, 153. (e) Hashimoto, M.; Liu, Y.; Fang,
K.; Li, H.-Y.; Campiani, G.; Nakanishi, K. Bioorg. Med.
Chem. 1999, 7, 1181. (f) The preparation of 7c was as
follows: To a suspension of 60% NaH (1.38 g, 95.79 mmol)
in THF (80 mL) and DMF (15 mL) at r.t. was added a
solution of 1,12-dodecanediol (12.92 g, 63.86 mmol) in THF
(50 mL). The mixture was stirred at r.t. for 30 min, and a
solution of p-methoxybenzyl chloride (5.0 g, 31.93 mmol) in
THF (20 mL) and TBAB (0.2 g, 0.64 mmol) were added.
The mixture was stirred at 60 °C for 4 d and then cooled to
r.t., and quenched with sat. NH4Cl. The solvent was removed
in vacuo, extracted with EtOAc, washed with H2O and brine,
dried over Na2SO4, and concentrated under reduced
Compound 9c: 81% yield. 1H NMR (CDCl3): d = 0.71–0.79
(m, 4 H), 1.19–1.45 (m, 14 H), 1.65–1.78 (m, 4 H), 2.19 (br
s, 4 H), 3.45–3.65 (m, 6 H), 3.80 (s, 3 H), 4.48 (s, 2 H), 6.12
(s, 2 H), 6.90–7.38 (m, 40 H), 7.73 (dd, J = 8.8, 7.6 Hz, 4 H),
7.94 (t, J = 8.8 Hz, 4 H). 13C{1H} NMR (CDCl3): d = 26.56,
27.28, 27.86, 29.99, 52.75, 55.44, 68.33, 70.54, 72.81,
82.53, 114.04, 115.11, 117.32, 119.92, 121.97, 123.64,
125.00–131.10 (m), 134.45, 142.20, 153.49, 154.87, 159.38.
MS: m/z = 1278 [M+], 549, 509. HRMS: m/z calcd for
C90H87NO6: 1278.6645; found: 1278.6631.
pressure. The crude material was purified by column
chromatography (30% EtOAc–hexanes) to give the pure
product 7c (5.59 g) in 54% yield. 1H NMR (CDCl3): d =
1.26–1.39 (m, 16 H), 1.54–1.70 (m, 4 H), 3.42 (t, J = 6.6 Hz,
2 H), 3.63 (q, J = 6.6 Hz, 2 H), 3.79 (s, 3 H), 4.43 (s, 2 H),
6.86 (d, J = 8.8 Hz, 2 H), 7.26 (d, J = 8.8 Hz, 2 H). 13C{1H}
NMR (CDCl3): d = 25.96, 26.42, 29.65, 29.69, 29.78, 29.99,
33.03, 55.49, 63.28, 70.46, 72.72, 113.96, 129.45, 131.03,
159.30. MS: m/z = 322 [M+], 137, 121. HRMS: m/z calcd for
C20H34O3: 322.2508; found: 322.2497.
(31) The preparation of 10a is given as a typical procedure: To a
solution of 9a (1.0 g, 0.84 mmol) in EtOAc–MeOH (1:1, 40
mL), 10% Pd/C (300 mg) was carefully added. After stirring
at r.t. for 4 d under H2 atmosphere, the catalyst was filtered
off and the filtrate was reduced to dryness in vacuo. The
crude material was purified by column chromatography
(60% EtOAc–hexanes) to afford the product 10a (587 mg) in
81% yield. 1H NMR (CDCl3): d = 0.78–1.15 (m, 6 H), 1.32–
1.41 (m, 2 H), 1.88–2.15 (m, 2 H), 2.19–2.30 (m, 2 H), 2.31–
2.42 (m, 2 H), 3.30 (t, J = 8.8 Hz, 2 H), 3.58–3.78 (m, 7 H),
4.45 (s, 2 H), 6.87–7.38 (m, 22 H), 7.80–7.95 (m, 8 H).
13C{1H} NMR (CDCl3): d = 26.16, 26.75, 27.42, 29.74,
32.57, 51.56, 54.42, 62.96, 66.42, 114.99, 116.97, 123.64,
125.58, 125.63, 128.03, 134.13, 153.16, 154.54. MS: m/z =
862 [M+], 550, 242. HRMS: m/z calcd for C58H55NO6:
862.4081; found: 862.4073.
(29) Compounds 8a–c were made using modifications to
reported procedures. Compound 8a is a known compound.
See ref. 28a–c. Compound 8b is likewise known. See ref.
28d,e. The preparation of 8c was as follows: To a solution of
7c (5.45 g, 16.90 mmol) in CH2Cl2 (100 mL) at 0 °C,
imidazole (2.3 g, 33.80 mmol) and Ph3P (8.86 g, 33.80
mmol) were added under N2 and the mixture was stirred at
the same temperature for 10–15 min. Then, I2 (8.58 g, 33.80
mmol) was added (by portion) and the mixture was stirred at
0 °C for an additional 30 min. The resultant mixture was
diluted with CH2Cl2, washed with 1 M HCl, H2O and brine,
dried over Na2SO4, and concentrated under reduced pressure
to give the crude product. Purification by column
chromatography (10% EtOAc–hexanes) afforded compound
8c (6.31 g) in 86% yield. 1H NMR (CDCl3): d = 1.26–1.39
(m, 16 H), 1.57–1.60 (m, 2 H), 1.79–1.83 (m, 2 H), 3.18 (t,
J = 7.2 Hz, 2 H), 3.43 (t, J = 6.8 Hz, 2 H), 3.80 (s, 3 H), 4.43
(s, 2 H), 6.86 (d, J = 8.8 Hz, 2 H), 7.26 (d, J = 8.8 Hz, 2 H).
13C{1H} NMR (CDCl3): d = 7.57, 26.43, 28.76, 29.63, 29.70,
29.76, 29.79, 30.01, 30.74, 33.79, 55.51, 70.46, 72.73,
113.96, 129.43, 131.05, 159.31. MS: m/z = 432 [M+], 228,
Compound 10b: 63% yield. 1H NMR (CDCl3): d = 0.82–
1.42 (m, 14 H), 1.59–1.72 (m, 2 H), 1.96–2.18 (m, 2 H),
2.25–2.35 (m, 2 H), 2.44–2.58 (m, 2 H), 3.45 (t, J = 8.8 Hz,
2 H), 3.60–3.78 (m, 7 H), 4.35 (s, 2 H), 6.87–7.38 (m, 22 H),
7.80–7.94 (m, 8 H). 13C{1H} NMR (CDCl3): d = 26.19,
26.27, 29.41, 29.44, 29.51, 29.76, 51.55, 54.23, 55.23,
66.37, 54.23, 55.23, 66.37, 70.21, 72.48, 113.72, 114.64,
116.87, 116.92, 118.94, 123.20, 124.02, 125.05, 125.16,
Synlett 2008, No. 2, 207–212 © Thieme Stuttgart · New York