T. Muller, W. Klopper, S. Bräse et al.
FULL PAPER
benzene (2.10 g, 1.20 equiv., 5.35 mmol) dissolved in acetonitrile
H, o-H) ppm. 13C NMR (150 MHz, CDCl
3
): δ = 64.9 (C-1), 73.1
2
(5.00 mL) was added, and the reaction mixture was heated to 90 °C
(C-sp -C60), 129.4 (C-Ar), 130.9 (C-Ar), 134.1 (C-Ar), 135.3 (C-
Ar), 138.0 (C-C60), 141.4 (C-C60), 142.3 (C-C60), 142.3 (C-C60),
143.1 (C-C60), 143.2 (C-C60), 144.0 (C-C60), 144.8 (C-C60), 144.9
(C-C60), 145.1 (C-C60), 145.4 (C-C60), 145.6 (C-C60), 145.9 (C-C60),
187.0 (C=O) ppm. MS (FAB, 3-NBA): m/z (%) = 942.8 (100) [(M
for 30 min. Upon completion of the reaction, the mixture was
washed with water (3ϫ 15.0 mL), and the organic layer was dried
with sodium sulfate. The solvent was removed, and a yellow oil was
obtained, which was mixed with diethyl ether (5.00 mL) and the
product precipitated. The suspension was stirred for 30 min to dis-
solve the impurities in the diethyl ether phase. A white solid precipi-
tated. The solid was filtered off and washed again with diethyl
+
+ 1) ]. IR (ATR): ν˜ = 2325 (vw), 1668 (w), 1579 (w), 1447 (w),
1425 (w), 1226 (w), 1176 (w), 1062 (w), 999 (w), 959 (w), 942 (w),
874 (w), 773 (w), 725 (w), 684 (w), 615 (w), 586 (w), 573 (w), 554
–
1
ether. The product was dried under vacuum for 16 h to give 1d
2 2
(w), 545 (w), 523 (m) cm . UV/Vis (CH Cl ): λ (logε) = 258
1
–1
–1
(
200 mg, 11%). H NMR (300 MHz, CDCl
3
): δ = 2.30 (s, 3 H,
(0.938), 325 (0.309), 428 (0.015), 496 (0.009 m cm ) nm.
3
3
3
CH ), 6.87 (d, J = 8.2 Hz, 2 H, Ar-H), 7.25 (d, J = 8.2 Hz, 2 H,
Tris(e,e,e)-(dibenzoylmethano)fullerene[60] (5): (50.0 mg,
C
60
Ar-H), 7.33–7.42 (m, 4 H, m-H), 7.43–7.51 (m, 2 H, p-H), 7.78 (d,
3
J = 7.1 Hz, 4 H, o-H), 15.6 (s, 1 H, OH) ppm. 13C NMR (75 MHz,
1.00 equiv., 70.0 μmol) was dissolved in anhydrous toluene
35.0 mL) under argon. Subsequently, 2-bromo-1,3-diphenylpro-
pane-1,3-dione (1b; 210 mg, 10.0 equiv., 700 μmol) and DBU
104 μL, 10.0 equiv., 700 μmol) were added. The conversion was
(
CDCl
3
): δ = 21.5 (+, CH
3
), 127.0 (q, C-Ar), 128.1 (+, C-Ar), 128.5
(
(
(
+, C-Ar), 128.7 (q, C-Ar), 129.2 (+, C-Ar), 129.3 (+, C-Ar), 130.2
(
q, C-Ar), 132.0 (+, C-Ar), 134.1 (+, C-Ar), 145.1 (q, C-Ar), 183.4
+
monitored by TLC. After 72 h, the solvent was removed, and the
residue was purified by column chromatography (column:
C=O) ppm. MS (EI, 70 eV): m/z (%) = 394 (21) [M ], 290 (33)
+
+
+
[
(M – PhCO) ], 239 (100) [(M – O
IR (ATR): ν˜ = 3056 (vw), 1594 (w), 1551 (w), 1449 (w), 1370 (m),
294 (m), 1192 (w), 1158 (m), 1090 (w), 1028 (vw), 1002 (w), 923
w), 817 (w), 804 (w), 777 (m), 725 (m), 711 (m), 687 (m), 665 (m),
2
SAr) ], 223 (92) [(M – OTs) ].
5.5ϫ15 cm, silica gel; cyclohexane/toluene, 1:1 then 1:2 then pure
toluene then toluene/ethyl acetate, 10:1) to give 5 (28.0 mg, 15%).
1
(
1
3
H NMR (600 MHz, CDCl ): δ = 7.30–7.60 (m, 6 H, Ar-H), 8.26–
1
3
–1
8.72 (m, 4 H, o-H) ppm. C NMR (150 MHz, CDCl
3
): δ = 65.7
6
42 (w), 610 (w), 568 (m), 541 (m), 516 (m), 441 (w) cm .
2
2
(
C-1), 72.1 (C-sp -C60), 72.7 (C-sp -C60), 128.4, 129.1, 129.2, 130.6,
4
2
-(Dimethyl-λ -sulfanylidene)-1,3-diphenylpropane-1,3-dione (1e):
1
1
1
30.7, 133.9, 134.0, 135.0, 135.1, 140.9, 141.5, 141.6, 143.2, 143.6,
43.7, 143.8, 143.9, 144.7, 145.9, 146.4, 146.7, 146.8, 146.8, 147.0,
To a suspension composed of N-chlorosuccinimide (920 mg,
.42 equiv., 6.85 mmol) in anhydrous dichloromethane (40.0 mL),
1
47.1, 147.8, 186.5 (C=O), 186.7 (C=O) ppm. MS (FAB, 3-NBA):
dimethyl sulfide (0.35 mL, 0.30 g, 1.00 equiv., 4.83 mmol) was
added dropwise at –78 °C, and the reaction mixture was stirred at
the same temperature for 1 h. A solution of dibenzoylmethane (1c;
+
m/z (%) = 1386.2 (100) [M ]. IR (ATR): ν˜ = 3061 (vw), 1783 (vw),
1746 (vw), 1669 (w), 1593 (w), 1577 (w), 1490 (vw), 1446 (w), 1229
(
w), 1178 (w), 1065 (vw), 1019 (vw), 1001 (vw), 963 (vw), 936 (vw),
2
.00 g, 1.85 equiv., 8.92 mmol) in dichloromethane (5.00 mL) was
added slowly. After 1 h, triethylamine (1.50 mL, 1.10 g, 1.20 equiv.,
0.9 mmol) was added, and the mixture was stirred for 1 h. The
8
6
79 (vw), 843 (vw), 804 (vw), 757 (vw), 707 (w), 683 (w), 637 (vw),
14 (vw), 551 (vw), 529 (vw), 516 (w), 488 (vw), 443 (vw) cm .
–1
1
Hexakis(dibenzoylmethano)fullerene[60] (4): A 50.0 mL Schlenk-
flask was dried under vacuum and purged with argon. C60
reaction mixture was warmed to 20 °C, and brine (20 mL) was
added. The reaction mixture was then extracted with diethyl ether
(
(
26.0 mg, 36.0 μmol, 1.00 equiv.) was dissolved in toluene
10.0 mL) and stirred for 30 min, then 2-iodo-1,3-diphenylpropane-
(3ϫ 40 mL), and the organic layer was washed with brine (3ϫ
30.0 mL) and dried with sodium sulfate. The solvent was removed,
1,3-dione (1b; 189 mg, 540 μmol, 15.0 equiv.) was added, and tri-
and the solid was stirred with diethyl ether (3ϫ 5.00 mL) to dis-
tert-butylphosphane (109 mg, 540 μmol, 15 equiv.) was added
slowly. The reaction mixture was stirred for 20 h. The conversion
was monitored by MALDI-TOF-MS (appearance of hexakis prod-
uct). The solvent was removed, and the products were purified by
column chromatography (toluene/ethyl acetate, 200:1 then slowly
increasing the amount of ethyl acetate); the hexakis product 4 was
eluted with toluene/ethyl actetate (10:1 to 5:1) to give 4 (5.60 mg,
7.5%) as a mixture with higher (dibenzoylmethano)fullerne ad-
solve impurities. The solid was filtered off and washed again with
diethyl ether. The product was dried for 16 h under vacuum to give
1
1
e (700 mg, 51%). H NMR (300 MHz, CDCl
3
): δ = 3.10 (s, 6 H,
CH
3
), 6.95–7.11 (m, 6 H, Ar-H), 7.27–7.32 (m, 4 H, Ar-H) ppm.
13
3 3
C NMR (75 MHz, CDCl ): δ = 27.0 (+, S-CH ), 88.1 (q, C=S),
1
1
27.4 (+, C-Ar), 128.6 (+, C-Ar), 129.8 (+, C-Ar), 142.0 (q, C-Ar),
91.1 (C=O) ppm. MS (EI, 70 eV): m/z (%) = 285 (12.5) [(M +
+
+
+
H) ], 284 (66.5) [M ], 224 (100) [([M + H] – Me
2
S) ], 223 [(M –
S) ], 105 [(PhCO) ]. IR (ATR): ν˜ = 3004 (vw), 2925 (vw), 1584
m), 1548 (m), 1488 (w), 1442 (vw), 1339 (m), 1262 (m), 1180 (m),
+
+
ducts (see the Supporting Information) as a yellow/orange product.
Me
(
2
1
3
H NMR (300 MHz, CDCl ): δ = 7.53–8.40 (m, 60 H, Ar-H) ppm.
+
MS (FAB, 3-NBA): m/z (%) = 2053.1 (100) [M + 1] .
1
9
162 (w), 1095 (w), 1072 (w), 1028 (w), 981 (w), 956 (w), 936 (w),
09 (w), 830 (w), 795 (w), 780 (w), 733 (m), 704 (m), 668 (w), 645
Density-Functional-Theory Computations: All calculations were
–1
(m), 548 (w), 453 (w), 421 (w) cm .
[11]
performed with the TURBOMOLE program package.
The
(
Dibenzoylmethano)fullerene[60] (2):
C
60 (200 mg, 1.00 equiv.,
structure of (dibenzoylmethano)fullerene[60] (2), hexakis(dibenz-
oylmethano)fullerene[60] (4) and the rotation of a benzoyl group
were calculated within the framework of density functional theory
(DFT). To assess the performance of different types of density
functionals, the general gradient approximation (GGA) functional
BP86, the meta-GGA functional TPSS, and the hybrid functional
B3LYP were applied. Each functional was used in combination
with the def2-SV(P) basis set, tight convergence criteria (SCF en-
2
70 μmol) was dissolved in anhydrous o-dichlorobenzene (50.0 mL)
under argon. After 30 min of stirring, a solution of DBU (60.0 μL,
.50 equiv., 405 μmol) in anhydrous o-dichlorobenzene (3.00 mL)
and a solution of 2-bromo-1,3-diphenylpropane-1,3-dione (1a;
69 mg, 2.00 equiv., 560 μmol) in anhydrous o-dichlorobenzene
3 mL) were added over a period of 1 h. After 3 h of stirring, the
1
1
(
crude material was filtered through silica gel with toluene to sepa-
rate the remaining DBU from the reaction mixture. Column
–
8
–5
ergy: 10
h h 0
E ; energy gradient: 10 E /a ) and fine quadrature grids
chromatography (column: 5.5ϫ15 cm, silica gel; toluene/cyclohex- (m5) with inclusion of derivatives of quadrature weights. The na-
ane, 1:3) gave 2 (89.0 mg, 34%). HPLC (25 °C): t
R
= 4.80 min (pu-
ture of the obtained stationary points (minimum or first-order sad-
dle point) was confirmed through analysis of the force constants
1
3
3
rity: 94%). H NMR (600 MHz, CDCl ): δ = 7.65 (t, J = 7.6 Hz,
3
3
4
H, m-H), 7.73 (t, J = 6.8 Hz, 2 H, p-H), 8.74 (d, J = 7.3 Hz, 4 and vibrational frequencies.
7912
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Eur. J. Org. Chem. 2013, 7907–7913