Synthesis of [60]fullerene-fused thiolactams and thiaimidates

Article abstract of DOI:10.1016/j.tetlet.2012.01.075

The reaction of [60]fullerene with diethyl aminomalonate hydrochloride and carbon disulfide in the presence of triethylamine gave a [60]fullerene-fused thiolactam, which could be hydrolyzed, S-alkylated, and N-acylated in high yields.

Full text of DOI:10.1016/j.tetlet.2012.01.075

Tetrahedron Letters 53 (2012) 1610–1612
Contents lists available at SciVerse ScienceDirect
Tetrahedron Letters
journal homepage: www.elsevier.com/locate/tetlet
Synthesis of [60]fullerene-fused thiolactams and thiaimidates
⇑
Jia-Xing Li, Guan-Wu Wang
Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry,
University of Science and Technology of China, Hefei, Anhui 230026, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
The reaction of [60]fullerene with diethyl aminomalonate hydrochloride and carbon disulfide in the pres-
ence of triethylamine gave a [60]fullerene-fused thiolactam, which could be hydrolyzed, S-alkylated, and
N-acylated in high yields.
Received 29 November 2011
Revised 5 January 2012
Accepted 18 January 2012
Available online 28 January 2012
Ó 2012 Elsevier Ltd. All rights reserved.
Keywords:
[60]Fullerene
Diethyl aminomalonate
Carbon disulfide
S-alkylation
N-acylation
An impressive number of fullerene derivatives have been syn-
thesized via various functionalization methods,1 and some of them
have potential applications in biology and material sciences.2 Spe-
S
Et3N
C60 + HCl H2NCH(CO2Et)2 + CS2
NH
CO2Et
CO2Et
r.t., 3 h
65%
cifically, a large variety of sulfur-containing [60]fullerene (C60
derivatives, such as C60-oligothiophene/polythiophene,3 C60-tetra-
thiofulvalene/
-extended tetrathiofulvalene,4 have been inten-
)
2
p
Scheme 1. Reaction of C60 with diethyl aminomalonate hydrochloride and CS2.
sively investigated in recent years due to their interesting
optoelectronic properties.5
A lot of reactions between C60 and sulfur-containing reagents
have been explored. These include Prato reaction using thio-
phene-containing aldehydes,3a–d nucleophilic addition of organo-
lithiums bearing a terthiophene moiety,3e Diels–Alder reaction
with dienes generated from thermal extrusion of SO2,6 [2+1]
cycloaddition with sulfonium ylides,7 [2+3] cycloaddition with
thiocarbonyl ylide8 or heterocyclic masked 1,3-dipoles 5-imino-
1,2,4-thiadiaolidine-3-ones.9 Disulfides,10 SO3,11 H2S,12 and sulfur
itself13 have been employed to functionalize fullerenes. Previously,
we reported the reaction of C60 with amino acid esters and CS2.14 As
an extension, herein we disclose the reaction of C60 with diethyl
aminomalonate and CS2 affording a fullerene product containing a
thiamide group, which can be further manipulated by hydrolysis,
alkylation, and acylation.
a base in the HCl-removal step and in the subsequent desulfuriza-
tion and deprotonation steps.14 It should be emphasized that the
reaction with 1 gave much higher yield than those with amino acid
ester hydrochlorides14 probably because the second ester group of
1 facilitated the deprotonation step to give higher concentration of
the corresponding carbanion, and thus afforded higher yield of the
cyclized product.14 In addition, ordinary primary amines in place of
1 or amino acid ester failed to give any desired fullerene products.
Compound 2 bearing a thiamide group was more stable than
the corresponding product from the reaction with amino acid ester
hydrochlorides, yet still moisture sensitive and could be converted
near quantitatively to product 3 in a mixture solution of CS2 and
THF in the presence of water at room temperature for 2 days
(Scheme 2).16
The identification of compounds 2 and 3 was made by its MS, 1H
NMR, 13C NMR, IR and UV–vis spectra.15,16 The mass spectra of 2
and 3 displayed peaks at 937 and 921, respectively, corresponding
to their molecular ions. Their 1H NMR and 13C NMR showed similar
patterns with the exception of the drastic dc chemical shift from
199.70 ppm for the C@S group in compound 2 to 169.07 ppm for
the C@O group in compound 3. The same phenomenon was ob-
served previously by us.14 The 13C NMR spectra of both 2 and 3
The reaction of C60 with diethyl aminomalonate hydrochloride
(1) in CS2 in the presence of triethylamine (Et3N) at room temper-
ature for 3 h afforded compound 2 in a 65% isolated yield along
with 30% of recovered C60 (Scheme 1).15 In the reaction, CS2 be-
haved as a reactant as well as a solvent, meanwhile Et3N acted as
⇑
Corresponding author.
E-mail address: gwang@ustc.edu.cn (G.-W. Wang).
0040-4039/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2012.01.075

J.-X. Li, G.-W. Wang / Tetrahedron Letters 53 (2012) 1610–1612
1611
The identities of products 5a–g were established by their MS, 1H
NMR, 13C NMR, FT–IR and UV–vis spectra.17 All 1H NMR spectra of
5a–g showed the expected signals. The 13C NMR spectra of 5a–g
gave no more than 30 peaks including two half-intensity ones in
the 134–151 ppm range for the 58 sp2-carbons of the C60 skeleton,
agreeing with their Cs molecular symmetry. The most striking dif-
ference in the 13C NMR spectra between 5a–e and 5f–g lies in
chemical shifts of the heterocycles. While the dc at 200.8–201.7,
84.5–85.1, 83.7–84.7, and 68.1–69.2 ppm for the heterocycle in
the N-acylated products 5f–g appeared close to that in the starting
material 2, those in the S-alkylated products 5a–e shifted to 173.6–
175.9, 94.5–95.9, 82.5–84.0, and 75.0–76.5 ppm, respectively.
In conclusion, the reaction of C60 with diethyl aminomalonate
hydrochloride and CS2 in the presence of Et3N afforded C60-fused
thiolactam 2, which contained the amino acid ester and thioamide
moieties. Thiolactam 2 could be hydrolyzed to lactam 3 quantita-
tively. More intriguingly, C60-fused thiolactam 2 could be S-alkyl-
ated and N-acylated to give additional sulfur-containing fullerene
derivatives in very high yields.
H2O
CS2-THF
S
O
NH
CO2Et
CO2Et
NH
CO2Et
CO2Et
r.t., 2 d
92%
2
3
Scheme 2. Hydrolysis of thialactam 2.
gave 29 peaks including two half-intensity lines and one overlap-
ping line in the range of 132–151 ppm for the 58 sp2-carbons of
the C60 cage, consistent with their Cs molecular symmetry. The
UV–vis spectra of 2 and 3 exhibited an absorption at 427/
428 nm, which is a characteristic peak for a 1,2-adduct of C60
14
.
Interestingly, we found that compound 2 could be further alkyl-
ated and acylated in the presence of base. The reaction of 2 with
alkylating reagents such as 2-bromo-40-methoxyacetophenone
(4a), tert-butyl 2-bromoacetate (4b), diethyl 2-bromomalonate
(4c), ally bromide (4d) or methyl iodide (4e) in the presence of
Et3N with CS2 as the solvent at room temperature for 30 min gave
the S-alkylated products 5a–e in high yields (86–95%, Table 1).17 In
contrast, the reaction of 2 with acylating reagents such as acetyl
chloride (4f) and benzoyl chloride (4g) afforded the N-acylated
products 5f and 5g in 92% and 98% yields, respectively.17 Similar
S-alkylation versus N-acylation selectivity has been reported.18,19
Synthesis of thioimines was achieved by S-alkylation of
pyrrolidin-2-thione with bromoesters in the presence of DBU,18
while preparation of 1-benzoyl thionolactams was realized by
Acknowledgment
The authors are grateful for the financial support from the Na-
tional Natural Science Foundation of China (21132007, 20972145).
References and notes
1. For selected reviews, see: (a) Taylor, R.; Walton, D. R. M. Nature 1993, 363, 685;
(b) Hirsch, A. Synthesis 1995, 895; (c) Thilgen, C.; Diederich, F. Chem. Rev. 2006,
106, 5049.
2. (a) Prato, M. Top. Curr. Chem. 1999, 199, 173; (b) Nakamura, E.; Isobe, H. Acc.
Chem. Res. 2003, 36, 807; (c) Guldi, D. M.; Zerbetto, F.; Geogakilas, V.; Prato, M.
Acc. Chem. Res. 2005, 38, 38; (d) Giacalone, F.; Martin, N. Chem. Rev. 2006, 106,
5136.
N-acylation of c-, d- and e-thionolactams with benzoyl chloride
in the presence of pyridine.19 All new compounds 5a–g were very
stable at room temperature and had good solubility in CS2 and
CHCl3.
3. (a) Beckers, E. H. A.; van Hal, P. A.; Dhanabalan, A.; Meskers, S. C. J.; Knol, J.;
Hummelen, J. C.; Janssen, R. A. J. J. Phys. Chem. A 2003, 107, 6218; (b) Guldi, D.
M.; Luo, C.; Swartz, A.; Gómez, R.; Segura, J. L.; Martín, N. J. Phys. Chem. A 2004,
108, 455; (c) Negishi, N.; Takimiya, K.; Otsubo, T.; Harima, Y.; Aso, Y. Chem. Lett.
2004, 33, 654; (d) Narutaki, M.; Takimiya, K.; Ostsubo, T.; Harima, Y.; Zhang, H.
M.; Araki, Y.; Ito, S. J. Org. Chem. 2006, 71, 1761; (e) Yamazaki, T.; Murata, Y.;
Komatsu, K.; Furukawa, K.; Morita, M.; Maruyama, N.; Yamao, T.; Fujita, S. Org.
Lett. 2004, 6, 4865.
4. For selected examples, see: (a) Guldi, D. M.; González, S.; Martín, N.; Antón, A.;
Garín, J.; Orduna, J. J. Org. Chem. 1978, 2000, 65; (b) Segura, J. L.; Priego, E. M.;
Martín, N.; Luo, C.; Guldi, D. M. Org. Lett. 2002, 2, 4021; (c) González, S.; Martín,
N.; Swartz, A.; Guldi, D. M. Org. Lett. 2003, 5, 557.
5. Sánchez, L.; Herranz, M. Á.; Martín, N. J. Mater. Chem. 2005, 15, 1409.
6. (a) Ohnp, M.; Kojima, S.; Shirakawa, Y.; Eguchi, S. Tetrahedron Lett. 1995, 36,
6899; (b) Ishida, H.; Itoh, K.; Ito, S.; Ono, N.; Ohno, M. Synlett 2001, 296; (c)
Watanabe, N.; Kihara, N.; Furusho, Y.; Takata, T.; Araki, Y.; Ito, O. Angew. Chem.,
Int. Ed. 2003, 42, 681; (d) Enes, R. F.; Tomé, A. C.; Cavaleiro, J. A. S. Tetrahedron
2005, 61, 1423; (e) Yang, H.-T.; Wang, G.-W.; Xu, Y.; Huang, J.-C. Tetrahedron
Lett. 2006, 47, 4129.
7. (a) Wang, Y. H.; Cao, J. R.; Schuster, D. I.; Wilson, S. R. Tetrahedron Lett. 1995, 36,
6843; (b) Ma, B.; Bunker, C. E.; Guduru, R.; Zhang, X.-F.; Sun, Y.-P. J. Phys. Chem.
A 1997, 101, 5626; (c) Tada, T.; Ishida, Y.; Saigo, K. J. Org. Chem. 2006, 71, 1633.
8. (a) Ishida, H.; Ohno, M. Tetrahedron Lett. 1999, 40, 1543; (b) Ishida, H.; Itoha, K.;
Ohno, M. Tetrahedron 2001, 57, 1737.
9. Duczek, W.; Tittelbach, F.; Costisella, B.; Niclas, H. J. Tetrahedron 1996, 52, 8733.
10. (a) Westmeyer, M. D.; Galloway, C. P.; Rauchfuss, T. B. Inorg. Chem. 1994, 33,
4615; (b) Westmeyer, M. D.; Rauchfuss, T. B.; Verma, A. K. Inorg. Chem. 1996,
35, 7140; (c) Takaguchi, Y.; Katayose, Y.; Yanagimoto, Y.; Motoyoshiya, J.;
Aoyama, H.; Wakahara, T.; Maeda, Y.; Akasaka, T. Chem. Lett. 2003, 32, 1124.
11. (a) Miller, G. P.; Buretea, M. A.; Bernardo, M. M.; Hsu, C. S.; Fang, H. L. J. Chem.
Soc., Chem. Commun. 1994, 1549; (b) Chen, B.-H.; Huang, J.-P.; Wang, L. Y.;
Shiea, J.; Chen, T.-L.; Chiang, L. Y. J. Chem. Soc., Trans. Perkin 1 1998, 1171.
12. Darwish, A. D.; Kroto, H. W.; Taylor, R.; Walton, D. R. M. Fullerene Sci. Technol.
1993, 1, 571.
13. (a) Giesa, S.; Gross, J. H.; Hull, W. E.; Lebedkin, S.; Gromov, A.; Gleiter, R.;
Krätschmer, W. Chem. Commun. 1999, 465; (b) Murata, Y.; Murata, M.;
Komatsu, K. Chem. Eur. J. 2003, 9, 1600.
14. Wang, G.-W.; Li, J.-X.; Li, Y.-J.; Liu, Y.-C. J. Org. Chem. 2006, 71, 680.
15. A mixture of C60 (28.8 mg, 0.04 mmol), diethyl aminomalonate hydrochloride
(1) (0.05 mmol), carbon disulfide (16 mL), and triethylamine (0.40 mL) was
stirred at room temperature for 3 h (monitored by TLC). After evaporation in
vacuo, the reaction mixture was separated on a silica gel column with CS2 and
then CS2/ethyl acetate as the eluent to give unreacted C60 (8.5 mg, 30%) and
Table 1
Product yields for the reaction of 2 with 4a–h
R
S
4a-e
N
CO2Et
CO2Et
S
RX, Et3N
r.t., 30 min
5a-e
5f-g
NH
CO2Et
S
CO2Et
4f-g
2
N R
CO2Et
CO2Et
Entry
1
RX
Product
Yielda (%)
O
Br
5a
95
O
O
O
O
O
2
3
5b
5c
93
86
Br
O
O
Br
4
5
5d
5e
89
91
Br
O
H3C–I
O
6
5f
92
Cl
7
5g
98
Cl
a
Isolated yield.

1612
J.-X. Li, G.-W. Wang / Tetrahedron Letters 53 (2012) 1610–1612
product 2 (27.0 mg, 65%). 1H NMR (300 MHz, CS2/DMSO-d6): d 12.0 (s, 1H),
(C@O), 164.50 (C@O), 149.73, 148.00, 146.91 (1C), 146.75 (1C), 146.03, 145.87,
145.79, 145.69, 145.67, 145.61, 145.31, 145.15, 145.04 (4C), 144.89, 143.91,
143.88, 142.72, 142.50, 142.40, 142.14, 141.91, 141.70, 141.53, 141.31, 141.26,
140.25, 138.96, 135.56, 135.19, 95.11 (1C, C(COC2H5)2), 83.02 (1C, sp3-C of C60),
76.06 (1C, sp3-C of C60), 62.62 (OCH2CH3), 62.57 (OCH2CH3), 52.87 (1C, SCH),
4.40–4.27 (m, 4H), 1.34 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CS2/DMSO-d6
with Cr(acac)3 as relaxation reagent, all 2C unless indicated): d 197.70 (1C,
C@S), 163.75 (C@O), 150.22, 147.34, 146.92, 145.90 (1C), 145.47 (1C), 144.74,
146.63, 144.54, 144.32, 144.29, 143.96 (4C), 143.81, 143.63, 143.51, 142.95,
142.52, 141.19, 141.13, 141.10, 140.82, 140.78, 140.33, 140.14, 139.93, 139.75,
138.76, 137.09, 134.90, 132.16, 81.51 (1C), 81.24 (1C, sp3-C of C60), 69.27 (1C,
13.88 (OCH2CH3), 13.86 (OCH2CH3); FT–IR m
/cmꢀ1 (KBr): 2976, 1742, 1618,
1462, 1441, 1367, 1295, 1258, 1168, 1137, 1090, 1025, 863, 577, 527; UV–vis
(CHCl3) kmax (nm): 256 (5.00), 315 (4.48), 427 (3.37), 686 (2.51); MS (ꢀESI): m/
z 1095 (Mꢀ). Compound 5d: 1H NMR (300 MHz, CDCl3) d 6.30–6.16 (m, 1H),
5.51 (d, J = 16.9 Hz 1H), 5.32 (d, J = 10.0 Hz, 1H), 4.53–4.36 (m, 4H), 4.27 (d,
J = 7.0 Hz, 2H), 1.38 (t, J = 7.2 Hz, 6H); 13C NMR (75 MHz, CDCl3, with Cr(acac)3
as relaxation reagent) (all 2C unless indicated): d 175.79 (1C, C@N), 167.13
(C@O), 150.37, 149.05, 147.23 (1C), 147.08 (1C), 146.35, 146.31, 146.18,
146.08, 145.98, 145.91, 145.51, 145.47, 145.34 (4C), 145.23, 144.23, 144.21,
143.03, 142.80, 142.70, 142.46, 142.23, 141.95, 141.86, 141.67, 141.64, 140.44,
139.32, 135.57, 135.54, 132.23 (1C, CH@CH2), 119.37 (1C, CH@CH2), 95.91 (1C,
C(COC2H5)2), 84.03 (1C, sp3-C of C60), 76.19 (1C, sp3-C of C60), 62.95 (OCH2CH3),
sp3-C of C60), 61.79 (OCH2CH3), 12.96 (OCH2CH3), FT–IR /cmꢀ1 (KBr) 3451,
m
2976, 1750, 1496, 1463, 1366, 1297, 1259, 1214, 1171, 1137, 1092, 1049, 858,
578, 527; UV–vis (CHCl3) kmax (nm) (log
e) 2.56 (4.95), 315 (4.45), 428 (3.28),
686 (2.30); MS (ꢀESI): m/z 937 (Mꢀ).
16. Compound
2
(14.8 mg, 0.016 mmol) was added to
a
mixture of CS2-THF
L of water, the reaction mixture was vigorously
stirred at room temperature for 2 days, compound was converted to
(16.5 mL, 10:1) containing 10
l
2
compound 3 quantitatively. After evaporation of solvents, the residue was
separated on a silica gel column with CS2/THF as the eluent to give compound 3
(13.4 mg, 92%). 1H NMR (300 MHz, CS2/DMSO-d6): d 10.19 (s, 1H), 4.33 (q,
J = 7.1 Hz, 4H), 1.33 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CS2/DMSO-d6 with
Cr(acac)3 as relaxation reagent, all 2C unless indicated): d 169.07 (1C, C@O),
165.38 (C@O), 150.09, 148.13, 146.49, 146.15 (1C), 145.64 (1C), 145.38, 145.03,
144.98, 144.69, 144.65, 144.28 (4C), 144.14, 143.96, 143.89, 143.22, 142.86,
141.64, 141.44, 141.42, 141.10, 140.98, 140.71, 140.46, 140.39, 140.14, 139.54,
137.46, 135.19, 133.65, 74.55 (1C), 73.09 (1C, sp3-C of C60), 68.93 (1C, sp3-C of
35.15 (1C, SCH2), 14.08 (OCH2CH3); FT–IR
1461, 1428, 1365, 1259, 1229, 1126, 1085, 1039, 922, 889, 865, 576, 527; UV–
vis (CHCl3) kmax (nm): (log ) 257 (5.02), 313 (4.52), 427 (3.37), 688 (2.30); MS
m
/cmꢀ1 (KBr): 2975, 1741, 1604,
e
(ꢀESI): m/z 977 (Mꢀ). Compound 5e: 1H NMR (300 MHz, CS2/DMSO-d6): d
4.36–4.25 (m, 4H), 2.91 (s, 3H), 1.34 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CS2/
DMSO-d6 with Cr(acac)3 as relaxation reagent, all 2C unless indicated): d
174.63 (1C, C@N), 164.88 (C@O), 149.50, 148.06, 145.88 (1C), 145.75 (1C),
145.19, 145.03, 144.97, 144.85, 144.65, 144.59, 144.26, 144.20, 144.03, 143.99,
143.88, 143.01, 142.92, 141.77, 141.53, 141.42, 141.22, 140.94, 140.68, 140.56,
140.42, 140.39, 139.12, 137.88, 134.31, 134.09, 94.52 (1C, C(COC2H5)2), 82.48
(1C, sp3-C of C60), 75.04 (1C, sp3-C of C60), 61.35 (OCH2CH3), 14.45 (1C, SCH3),
C60), 61.80 (OCH2CH3), 13.22 (OCH2CH3); FT–IR
1722, 1462, 1438, 1365, 1296, 1250, 1227, 1179, 1089, 1009, 859, 763, 575,
m
/cmꢀ1 (KBr) 3386, 2974, 1747,
527; UV–vis (CHCl3) kmax (nm) (log
e) 2.56 (4.96), 313 (4.43), 427 (3.31), 686
(2.30); MS (ꢀESI) m/z 921 (Mꢀ).
17. Typical procedure for the synthesis of 5a–g:
A
mixture of
2
(9.4 mg,
L) was
0.01 mmol), 4a (0.02 mmol, 0.04 mmol for 4b–g), and Et3N (50
l
13.30 (OCH2CH3); FT–IR m
/cmꢀ1 (KBr): 2976, 1740, 1605, 1462, 1427, 1365,
stirred in CS2 (10 mL) at room temperature for 30 min. Then the solution
was separated on a silica gel column with CS2/ethyl acetate as the eluent to
1260, 1130, 1088, 1039, 890, 865, 730, 577, 527; UV–vis (CHCl3) kmax (nm)
(log
e
): 256 (4.95), 313 (4.43), 427 (3.28), 690 (2.31); MS (ꢀESI): m/z 951 (Mꢀ).
give product 5a–g. Compound 5a: 1H NMR (300 MHz, CDCl3)
d
8.20 (d,
Compound 5f: 1H NMR (300 MHz, CDCl3) d 4.42 (q, J = 7.2 Hz, 4H), 3.16 (s, 3H),
1.36 (t, J = 7.2 Hz, 6H); 13CNMR (75 MHz, CS2/CDCl3, with Cr(acac)3 as
relaxation reagent) (all 2C unless indicated): d 200.80 (1C, C@S), 175.27 (1C,
C@O), 164.59 (C@O), 150.80, 147.62 (1C), 147.53, 147.45, 147.26 (1C), 146.39,
146.34, 145.99 (4C), 145.78, 145.50, 145.43, 145.32, 145.27, 145.14, 144.44,
144.10, 142.73 (6C), 142.30 (4C), 141.83, 141.78, 141.34, 141.09, 140.44,
139.09, 136.81, 134.01, 85.05 (1C, C(COC2H5)2), 84.72 (1C, sp3-C of C60), 68.09
(1C, sp3-C of C60), 63.45 (OCH2CH3), 27.59 (1C, CH3), 13.90 (OCH2CH3); FT–IR
J = 8.8 Hz, 2H), 7.04 (d, J = 8.8 Hz, 2H), 5.14 (s, 2H), 4.48–4.32 (m, 4H), 3.93 (s,
3H), 1.34 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CDCl3, with Cr(acac)3 as
relaxation reagent) (all 2C unless indicated) d 191.73 (1C, C@O), 175.88 (1C,
C@N), 167.12 (C@O), 164.29 (1C, aryl C), 150.28, 148.94, 147.38 (1C), 147.19
(1C), 146.47, 146.43, 146.31, 146.15, 146.09, 146.04, 145.66, 145.62, 145.47
(4C), 145.34, 144.35, 144.32, 143.13, 142.92, 142.83, 142.55, 142.38, 142.11,
141.96, 141.77, 141.73, 140.65, 139.40, 135.77, 135.72, 131.33 (aryl C), 128.76
(1C, aryl C), 114.14 (aryl C), 95.84 (1C, C(COC2H5)2), 83.92 (1C, sp3-C of C60),
76.49 (1C, sp3-C of C60), 63.08 (OCH2CH3), 55.71 (1C, OCH3), 40.48 (1C, SCH2),
(KBr)
m
/cmꢀ1: 2978, 2923, 1764, 1743, 1513, 1434, 1365, 1268, 1240, 1222,
):
1142, 1085, 1014, 863, 780, 615, 594, 527; UV–vis (CHCl3) kmax (nm) (log
e
14.14 (OCH2CH3); FT–IR
1440, 1424, 1262, 1172, 1136, 1088, 1036, 830, 578, 527; UV–vis (CHCl3) kmax
(nm) (log
m
/cmꢀ1 (KBr): 2925, 1740, 1673, 1599, 1511, 1462,
255 (5.01), 316 (4.57), 428 (3.32), 682 (2.39); MS (+ESI): m/z 1002 (M+Na+).
Compound 5g: 1H NMR (300 MHz, CS2/CDCl3) d 8.19 (d, J = 7.8 Hz, 2H), 7.64 (t,
J = 7.4 Hz, 1H), 7.53 (t, J = 7.5 Hz, 2H), 4.48–4.37 (m, 4H), 1.33 (t, J = 7.2 Hz, 6H);
13C NMR (75 MHz, CS2/CDCl3, with Cr(acac)3 as relaxation reagent, all 2C unless
indicated): d 201.73 (1C, C@S), 172.54 (1C, C@O), 164.52 (C@O), 150.71, 147.32
(3C), 147.04, 146.96 (1C), 146.20, 146.10, 145.77 (6C), 145.61, 145.28, 145.08
(4C), 144.91, 144.27, 143.87, 142.53 (6C), 142.08 (4C), 141.66, 141.51, 141.30,
140.92, 140.35, 138.73, 137.13, 133.92, 133.41 (1C, aryl C), 132.87 (1C, aryl C),
129.96 (aryl C), 128.53 (aryl C), 84.54 (1C, C(COC2H5)2), 83.72 (1C, sp3-C of C60),
e
): 257 (5.00), 312 (4.53), 427 (3.33), 689 (2.29); MS (ꢀESI): m/z 1085
(Mꢀ). Compound 5b: 1H NMR (300 MHz, CDCl3) d 4.48–4.36 (m, 4H), 4.40 (s,
2H), 1.56 (s, 9H), 1.37 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CDCl3, with
Cr(acac)3 as relaxation reagent) (all 2C unless indicated) d 175.42 (1C, C@N),
167.01 (C@O), 166.90 (1C, C@O), 150.29, 148.88, 147.29 (1C), 147.13 (1C),
146.37, 146.33, 146.23, 146.09, 146.03, 145.96, 145.57, 145.55, 145.39 (4C),
145.27, 144.26 (4C), 143.06, 142.85, 142.75, 142.49, 142.28, 142.02, 141.89,
141.70, 141.65, 140.53, 139.35, 135.75, 135.60, 95.81 (1C, C(COC2H5)2), 83.76
(1C, sp3-C of C60), 82.80 (1C, OC(CH3)3), 76.41 (1C, sp3-C of C60), 63.00
69.18 (1C, sp3-C of C60), 63.43 (OCH2CH3), 13.79 (OCH2CH3), FT–IR (KBr)
2922, 1748, 1721, 1449, 1359, 1298, 1252, 1193, 1087, 1078, 1009, 774, 717,
685, 651, 527; UV–vis (CHCl3) kmax (nm) (log ) 255 (5.07), 317 (4.64), 428
(3.43), 683 (2.63); MS (+ESI) m/z 1064 (M+Na+).
m
/cmꢀ1
(OCH2CH3), 36.01 (1C, SCH2), 28.06 (3C, C(CH3)3), 14.08 (OCH2CH3); FT–IR
m/
e
cmꢀ1 (KBr): 2976, 1739, 1608, 1461, 1391, 1368, 1299, 1260, 1141, 1088, 1040,
890, 857, 578, 527; UV–vis (CHCl3) kmax (nm): (log
e) 258 (5.00), 314 (4.52), 427
18. (a) Russowsky, D.; da Silveira Neto, B. A. Tetrahedron Lett. 2004, 45, 1437; (b)
Neto, B. A. D.; Lapis, A. A. M.; Bernd, A. B.; Russowsky, D. Tetrahedron 2009, 65,
2484.
(3.40), 456 (3.21); MS (ꢀESI): m/z 1051 (Mꢀ). Compound 5c: 1H NMR
(300 MHz, CDCl3) d 5.78 (s, 1H), 4.42–4.32 (m, 8H), 1.42 (t, J = 7.1 Hz, 6H),
1.41 (t, J = 7.1 Hz, 6H); 13C NMR (75 MHz, CS2/CDCl3, with Cr(acac)3 as
19. Lacroix, S.; Rixhon, V.; Marchand-Brynaert, J. Synthesis 2006, 2327.
relaxation reagent) (all 2C unless indicated)
d 173.59 (1C, C@N), 165.98