4984
M.A. Lebedeva et al. / Tetrahedron 68 (2012) 4976e4985
4.12. Benzoic acid, 4-([70]fulleropyrrolidinyl carbonyl),
phenyl methyl ester, 10
143.31, 143.08, 142.99, 140.83, 140.40, 133.75, 133.72, 132.40, 132.11,
131.70, 131.35, 131.24, 130.77, 130.67, 128.45, 128.41, 128.30 (fuller-
ene cage sp2 carbons and aromatic carbons), 74.65, 74.01, 73.67,
70.49, 70.10, 68.94 (pyrrolidine ring C).
[70]Fulleropyrrolidine, 8 (42 mg, 0.048 mmol) was suspended
in freshly distilled CH2Cl2 (20 mL), DMAP (25 mg) and pyridine
(0.8 mL) were added, and the mixture was stirred for 15 min at
room temperature. A solution of terephthalic acid mono benzyl
ester mono chloride (200 mg, 0.73 mmol) in CH2Cl2 (15 mL) was
then added, and the reaction mixture was stirred for 18 h at room
temperature. After completion the solvent was removed by using
reduced pressure, and the resultant dark-brown solid was purified
by column chromatography (silica gel, toluene/MeOH 99:1). Fur-
ther purification was carried out by suspending the solid in MeOH
(20 mL), filtering, washing with MeOH (30 mL) and petroleum
ether (50 mL) and drying under vacuum to give the desired product
as a dark-brown solid (40 mg, 75%).
MALDI-TOF MS (DCTB/MeCN, m/z): 1030.5 (Mꢀ).
IR (KBr, n
, cmꢀ1): 3446 (s, OH), 3054 (w), 2805 (w), 2360 (w),
1684 (w, CO), 1635 (m, CO), 1429 (s), 1260 (m), 796 (w), 580 (w).
UVevis (CS2): lmax
(9.37), 464 (17.63), 442 (17.53), 400 (21.62).
(
3
ꢁ10ꢀ3/dmꢀ3 molꢀ1 cmꢀ1): 672 (1.78), 542
4.14. General procedure for fullerene triad synthesis via DCC-
activated acideamine coupling
Fulleropyrrolidine (1 equiv), carboxylic acid (1 equiv) and DCC
(1 equiv) were dissolved in anhydrous ODCB (concentration of
fulleropyrrolidine 0.0052 M) and stirred at room temperature un-
der Ar atmosphere for 20 h. The resulting mixture was purified by
column chromatography (silica gel, ODCB/iPrOH 99.5:0.5). Further
purification was carried out using the standard procedure by
washing product with MeOH and petroleum ether and drying un-
der vacuum.
Compound 10a: 1H NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d,
ppm): 8.24 (br s, 2H, ArH), 7.82 (br s, 2H, ArH), 7.33e7.45 (m, 5H,
CH2C6H5), 5.40 (s, 2H, CH2C6H5), 5.05 (br s, 2H, CH2), 4.79 (br s, 2H,
CH2).
Compound 10b: 1H NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d,
ppm): 8.17 (d, 2H, J¼8.51 Hz, ArH), 7.69 (d, 2H, J¼8.51 Hz, ArH),
7.33e7.45 (m, 5H, CH2C6H5), 5.37 (s, 2H, CH2C6H5), 4.79 (br s, 2H,
CH2), 4.56 4.79 (br s, 2H, CH2).
4.14.1. Benzoic acid, 4-([60]fulleropyrrolidinyl carbonyl), [60]full-
eropyrrolidinyl amide, 1. Starting from [60]fulleropyrrolidine, 7
(10 mg, 0.013 mmol), C60-fulleropyrrolidine carboxylic acid, 11
(12 mg, 0.013 mmol) and DCC (3 mg, 0.013 mmol) yielded com-
pound 1 (11 mg, 52%) as a brown solid.
13C NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d, ppm): 168.46
(C]O), 168.31 (C]O), 164.68 (C]O), 164.63 (C]O), 157.05, 155.06,
154.56, 151.73, 151.42, 151.39, 151.06, 150.97, 150.75, 150.70, 150.62,
150.32, 149.92, 149.89, 149.80, 149.42, 149.37, 149.31, 149.25, 149.08,
149.02, 149.01, 148.80, 148.38, 148.07, 147.48, 147.34, 147.20, 147.07,
147.03, 147.00, 146.90, 146.82, 146.60, 146.56, 146.24, 146.17, 146.03,
145.89,145.66,145.53,144.98, 144.81,144.50, 144.25,144.12,140.83,
140.40, 138.74, 138.59, 137.55, 137.39, 135.82, 135.80, 133.74, 133.71,
132.58, 132.51, 132.40, 132.10, 131.69, 131.35, 131.24, 130.21, 130.12,
129.16, 128.83, 128.81, 128.58, 128.57, 128.48, 128.47, 128.42, 128.30,
128.19, 128.10, 125.87, 125.53 (fullerene cage sp2 carbons and aro-
matic carbons), 72.53, 72.37, 71.68, 68.82, 67.88, 67.32 (pyrrolidine
ring C), 67.10, 67.07 (CH2C6H5).
1H NMR (400 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d
, ppm): 8.09 (s, 4H,
ArH), 5.60 (br s, 8H, CH2).
13C NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d, ppm): 168.52
(C]O), 153.09,147.43,146.46,146.25,145.78,145.56,145.45, 144.56,
143.24, 142.83, 142.30, 142.20, 142.07, 140.43, 137.49, 136.03, 130.63
(fullerene cage sp2 carbons,17 environments), 128.96,128.45 (Ar C),
71.06, 67.70 (pyrrolidine ring C).
MALDI-TOF MS (DCTB/MeCN, m/z): 1656.2 (Mꢀ).
IR (KBr, n
, cmꢀ1): 2920 (w), 2360 (w), 2342 (w), 1653 (s, C]O),
1384 (m), 574.36 (s).
UVevis (CS2): lmax
(9.15), 400 (13.26).
MALDI-TOF MS (DCTB/MeCN, m/z): 1120.4 (Mꢀ).
(
3
ꢁ10ꢀ3/dmꢀ3 molꢀ1 cmꢀ1): 716 (0.86), 436
IR (KBr, n
, cmꢀ1): 3054 (w), 2805 (w), 2360 (w), 1719 (CO, s),
1649 (CO, s), 1427 (s), 12.63 (s), 1018 (m), 728 (m), 693 (m), 670 (m),
579 (m).
4.14.2. Benzoic acid, 4-(2,2-dimethyl-[60]fulleropyrrolidinyl car-
bonyl), [60]fulleropyrrolidinyl amide, 2. Starting from [60]full-
UVevis (CS2): lmax
(
3
ꢁ10ꢀ3/dmꢀ3 molꢀ1 cmꢀ1): 672 (1.32), 542
(9.19), 464 (18.47), 443 (18.14), 401 (23.06).
eropyrrolidine,
7
(10 mg,
0.013 mmol),
dimethyl
C60-
fulleropyrrolidine carboxylic acid, 14 (12.3 mg, 0.013 mmol) and
DCC (3 mg, 0.013 mmol) yielded compound 2 (6 mg, 27%) as
a brown solid.
4.13. Benzoic acid, 4-([70]fulleropyrrolidinyl carbonyl), 12
Benzoic acid, 4-([70]fulleropyrrolidinyl carbonyl), phenyl
methyl ester, 10 (10 mg, 0.009 mmol) was suspended in CH2Cl2
(10 mL), CF3SO3H (0.05 mL) was added, and the reaction mixture
was stirred for 1 h at room temperature. The solvent was then re-
moved under reduced pressure, and the resultant brown residue
was purified by washing with diethyl ether (3ꢁ30 mL) separating
the resultant precipitate by centrifugation. The solid was then dried
under vacuum to give the product as a brown solid (8 mg, 87%).
1H NMR (400 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d
, ppm): 8.06 (m,
4H, ArH), 5.58 (s, 4H, CH2), 5.44 (s, 2H, CH2), 2.56 (s, 6H, CH3).
13C NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
, ppm): 170.60
d
(C]O), 169.95 (C]O), 154.13, 152.80, 147.52, 147.43, 146.53, 146.45,
146.24,146.14, 145.76,145.64, 145.59, 145.55, 145.48, 145.44, 145.36,
145.35,144.61,144.60,144.55,143.32,143.23,142.89,142.85,142.82,
142.36, 142.35, 142.29, 142.19, 142.05, 142.02, 141.98, 141.90, 140.45,
140.41, 139.97, 139.77, 137.22, 136.30, 136.17 (fullerene cage sp2
carbons, 39 environments), 130.61, 129.01, 128.44, 127.69 (Ar C),
79.73, 74.28, 70.55, 67.99, 66.14, 60.73 (pyrrolidine ring C), 26.69
(CH3).
Compound 12a: 1H NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d,
ppm): 8.30 (br s, 2H, ArH), 7.86 (br s, 2H, ArH), 5.08 (br s, 2H, CH2),
4.79 (br s, 2H, CH2).
Compound 12b: 1H NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d
,
MALDI-TOF MS (DCTB/MeCN, m/z): 1684.5 (Mꢀ).
ppm): 8.21 (d, 2H, J¼8.3 Hz, ArH), 7.74 (d, 2H, J¼8.3 Hz, ArH), 4.79
IR (KBr, n
, cmꢀ1): 2920 (w), 2360 (m), 2342 (m), 1653 (s, C]O),
(br s, 2H, CH2), 4.58 (br s, 2H, CH2).
1384 (m), 574 (s).
UVevis (CS2): lmax
(6.77), 397 (11.26).
13C NMR (500 MHz, 297 K, CS2/CDCl3 7:1 v/v,
d
, ppm): 169.33,
(
3
ꢁ10ꢀ3/dmꢀ3 molꢀ1 cmꢀ1): 713 (0.53), 436
168.21, 168.06 (CO), 155.05, 154.56, 151.74, 151.43, 150.98, 150.76,
150.70, 150.33, 149.93, 149.90, 149.82, 149.43, 149.37, 149.31, 149.26,
149.08, 149.02, 148.80, 148.40, 148.09, 147.48, 147.34, 147.20, 147.07,
147.04, 147.00, 146.90, 146.84, 146.60, 146.57, 146.24, 146.18, 146.04,
145.89, 145.65, 145.54, 144.98, 144.82, 144.51, 144.26, 144.13, 143.47,
4.14.3. Benzoic acid, 4-([60]fulleropyrrolidinyl carbonyl), [70]full-
eropyrrolidinyl amide, 3. Starting from [70]fulleropyrrolidine, 8
(5 mg, 0.0057 mmol), C60 carboxylic acid, 11 (5.2 mg, 0.0057 mmol)