Synthesis of fullerooxazoles: Novel reactions of [60]fullerene with nitriles promoted by ferric perchlorate

Article abstract of DOI:10.1021/jo8007868

(Chemical Equation Presented) The ferric perchlorate-mediated reactions of C₆₀ with various nitriles in o-dichlorobenzene under nitrogen atmosphere afforded the rare fullerooxazoles, which would be difficult to prepare by other methods. A possible reaction mechanism for the formation of the fullerooxazoles was proposed.

Full text of DOI:10.1021/jo8007868

ketones,2,3 1,3-dicarbonyl compounds such as malonate esters,3a,4
ꢀ-keto esters,3,5 and ꢀ-diketones,3,5,6 and carboxylic acid
derivatives such as carboxylic acids,7 carboxylic anhydrides,7b
and malonic acids7b give a diversity of fullerene products that
incorporate with the desired different structural motifs. Although
numerous reactants have been employed to the reactions with
C60, the reactions of nitriles with C60 have been seldom explored.
Up to now, only a few works describing the reactions of C60
involving the cyano group were reported.3a,4b,c,8 Bingel reported
the reactions of bromomalononitrile and ethyl bromocyanoac-
etate with C60 in the presence of a base to afford methano-
fullerenes.8a Jagerovic et al. realized the synthesis of a C60-
fused tetrahydrofuran derivative by thermal reaction of C60 with
tetracyanoethene oxide.8b We described the thermal reactions
of 2-cyano-2-ethoxycarbonyl-3-aryloxiranes with C60 to give
exclusively or predominantly cis isomers of C60-fused tetrahy-
drofuran derivatives.8c We also reported the reactions of C60
with cyano-containing active methylene compounds to give
methanofullerenes under solvent-free mechanical milling condi-
tions in the presence of a base3a or mediated by Mn(OAc)3 ·
3H2O,4b as well as to afford an unsymmetrical 1,4-adduct
generated from the radical reaction promoted by
Mn(OAc)3 ·3H2O.4c However, the direct reaction of C60 with
the unsaturated carbon-nitrogen triple bond moiety of nitriles
has not been reported to date.
Synthesis of Fullerooxazoles: Novel Reactions of
[60]Fullerene with Nitriles Promoted by Ferric
Perchlorate
Fa-Bao Li,† Tong-Xin Liu,† and Guan-Wu Wang*,†,‡
Hefei National Laboratory for Physical Sciences at
Microscale and Department of Chemistry, UniVersity of
Science and Technology of China, Hefei, Anhui 230026,
People’s Republic of China, and State Key Laboratory of
Applied Organic Chemistry, Lanzhou UniVersity, Lanzhou,
Gansu 730000, People’s Republic of China
gwang@ustc.edu.cn
ReceiVed April 8, 2008
Although a large variety of fullerene reactions have been
explored extensively over the past two decades, the reactions
of C60 promoted by metal salts are relatively scarce. Gan and
co-workers reported the reactions of tert-butyl hydroperoxide
with fullerenes catalyzed by metal salts such as Ru(PPh3)3Cl2,
FeCl3, Fe(NO3)3, and RuCl3 to produce the first fullerene mixed
peroxides C60(O)(OOtBu)4 and C70(OOtBu)10.9a Shigemitsu et
al. described the reactions of fullerene epoxides C60On (n ) 1,
2) with benzaldehyde derivatives in the presence of N-(1-
phenethyl)-2-cyanopyridinium hexafluoroantimonate to give
fullerene acetals.9b Rubin and co-workers reported the synthesis
of a novel compound with complete saturation of a single six-
membered ring on fullerene C60 through a remarkable double
5-exo-trig addition of alkoxyl radicals promoted by Pb(OAc)4.9c
Troshina et al. described the Pb(OAc)4-mediated oxidative
coupling reactions of C60 with amino acid esters to obtain
pyrrolidinofullerene derivatives.9d More recently, Itami’s group
reported the Ru-catalyzed arylation and alkenylation of C60 by
organoboron compounds.9e Recently we have successfully
applied Mn(OAc)3 ·2H2O to the reactions of C60 for the first
time.10 We reported the Mn(OAc)3 ·2H2O-mediated reactions
of C60 with various active methylene compounds, aromatic
The ferric perchlorate-mediated reactions of C60 with various
nitriles in o-dichlorobenzene under nitrogen atmosphere
afforded the rare fullerooxazoles, which would be difficult
to prepare by other methods. A possible reaction mechanism
for the formation of the fullerooxazoles was proposed.
Many chemical reactions have been discovered for the func-
tionalizations of fullerenes to prepare various fullerene products,1
which may have promising applications in life science and
materials science. Diverse types of organic molecules have been
utilized as starting materials in fullerene chemistry. For example,
the reactions of [60]fullerene (C60) with various aldehyes2 and
† University of Science and Technology of China.
‡ Lanzhou University.
(1) For reviews, see: (a) Taylor, R.; Walton, D. R. M. Nature 1993, 363,
685. (b) Hirsch, A. Synthesis 1995, 895. (c) Diederich, F.; Thilgen, C. Science
1996, 271, 317. (d) Hirsch, A. Top. Curr. Chem. 1999, 199, 1. (e) Yurovskaya,
M. A.; Trushkov, I. V. Russ. Chem. Bull. Int. Ed 2002, 51, 367. (f) Thilgen, C.;
Diederich, F. Chem. ReV. 2006, 106, 5049. For some recent papers see: (g)
Brough, P.; Klumpp, C.; Bianco, A.; Campidelli, S.; Prato, M. J. Org. Chem.
2006, 71, 2014. (h) Ito, H.; Ishida, Y.; Saigo, K. J. Org. Chem. 2006, 71, 4759.
(i) Chuang, S.-C.; Sander, M.; Jarrosson, T.; James, S.; Rozumov, E.; Khan,
S. I.; Rubin, Y. J. Org. Chem. 2007, 72, 2716. (j) Xiao, Z.; Yao, J.; Yang, D.;
Wang, F.; Huang, S.; Gan, L.; Jia, Z.; Jiang, Z.; Yang, X.; Zheng, B.; Yuan, G.;
Zhang, S.; Wang, Z. J. Am. Chem. Soc. 2007, 129, 16149. (k) Tzirakis, M. D.;
Orfanopoulos, M. Org. Lett. 2008, 10, 873. (l) Matsuo, Y.; Zhang, Y.; Nakamura,
E. Org. Lett. 2008, 10, 1251. (m) Yang, X.; Huang, S.; Jia, Z.; Xiao, Z.; Jiang,
Z.; Zhang, Q.; Gan, L.; Zheng, B.; Yuan, G.; Zhang, S. J. Org. Chem. 2008, 73,
2518.
(4) (a) Camps, X.; Hirsch, A. J. Chem. Soc., Perkin Trans. 1 1997, 1595.
(b) Zhang, T.-H.; Lu, P.; Wang, F.; Wang, G.-W. Org. Biomol. Chem. 2003, 1,
4403. (c) Wang, G.-W.; Zhang, T.-H.; Cheng, X.; Wang, F. Org. Biomol. Chem.
2004, 2, 1160.
(5) (a) Ohno, M.; Yashiro, A.; Eguchi, S. Chem. Commun. 1996, 291. (b)
Li, C.; Zhang, D.; Zhang, X.; Wu, S.; Gao, X. Org. Biomol. Chem. 2004, 2,
3464.
(2) (a) Prato, M.; Maggini, M. Acc. Chem. Res. 1998, 31, 519. (b) Wang,
G.-W.; Li, F.-B.; Chen, Z.-X.; Wu, P.; Cheng, B.; Xu, Y. J. Org. Chem. 2007,
72, 4479. (c) Thayumanavan, R.; Hawkins, B. C.; Keller, P. A.; Pyne, S. G.;
Ball, G. E. Org. Lett. 2008, 10, 1315.
(6) Jensen, A. W.; Khong, A.; Saunders, M.; Wilson, S. R.; Schuster, D. I.
J. Am. Chem. Soc. 1997, 119, 7303.
(7) (a) Nierengarten, J.-F.; Nicoud, J.-F. Tetrahedron Lett. 1997, 38, 7737.
(b) Wang, G.-W.; Li, F.-B.; Zhang, T.-H. Org. Lett. 2006, 8, 1355.
(8) (a) Bingel, C. Chem. Ber. 1993, 126, 1957. (b) Jagerovic, N.; Elguero,
J.; Aubagnac, J.-L. J. Chem. Soc., Perkin Trans. 1 1996, 499. (c) Wang, G.-W.;
Yang, H.-T.; Wu, P.; Miao, C.-B.; Xu, Y. J. Org. Chem. 2006, 71, 4346.
(3) (a) Zhang, T.-H.; Wang, G.-W.; Lu, P.; Li, Y.-J.; Peng, R.-F.; Liu, Y.-
C.; Murata, Y.; Komatsu, K. Org. Biomol. Chem. 2004, 2, 1698. (b) Wang,
G.-W.; Li, F.-B. Org. Biomol. Chem. 2005, 3, 794.
10.1021/jo8007868 CCC: $40.75
Published on Web 07/17/2008
2008 American Chemical Society
J. Org. Chem. 2008, 73, 6417–6420 6417

TABLE 1. Yields and Reaction Conditions for the Fe(ClO4)3 ·6H2O
methyl ketones, ꢀ-enamino carbonyl compounds, and carboxylic
acid derivatives affording singly bonded fullerene dimers,4b 1,4-
adducts and 1,16-adduct of C60,4b,c C60-fused dihydrofuran
derivatives,3b methanofullerenes,3b,4b C60-fused pyrroline deriva-
tives,11 and C60-fused lactone derivatives.7b Interestingly,
Mn(OAc)3 ·2H2O could also be employed to transform the in
situ generated ArC60-H into ArC60-OAc in a one-pot proce-
dure.12 We also investigated the Cu(OAc)2 ·H2O-mediated
reactions of C60 with ketonic compounds to afford the metha-
nofullerenes and C60-fused dihydrofuran derivatives.3b
(FEP)-Mediated Reaction of C60 with 4-Tolunitrile 1a
molar ratio reaction temp reaction time yield of recovered
entry [C60:FEP:1]
(°C)
(min)
2a (%)
C60 (%)
1
2
3
4
5
6
7
8
1:1:100
1:1:100
1:1:100
1:1:50
1:1:200
1:2:50
120
100
140
120
120
120
120
120
15
30
5
10
30
5
22
19
19
14
19
19
23
23
51
66
53
53
68
41
54
47
In efforts to extend the reactions of C60 promoted by metal
salts, we were determined to explore more metal oxidant-
mediated reactions of C60. To the best of our knowledge, the
Fe(ClO4)3 ·6H2O-mediated reaction of C60 has not been reported
until today. In continuation of our interest in fullerene
chemesitry,2b,3,4b,c,8c,10–13 herein we describe the Fe(ClO4)3 ·6H2O-
promoted reactions of C60 with various nitriles to afford the
scarce fullerooxazoles.
1:2:100
1:2:200
5
8
SCHEME 1. Fe(ClO4)3 ·6H2O-Mediated Reactions of C60
with Nitriles 1a-h
4-Tolunitrile (1a) was first chosen to react with C60 in the
presence of Fe(ClO4)3 ·6H2O. At the onset, the mixture of
Fe(ClO4)3 ·6H2O (0.25 mmol) and 4-tolunitrile (5 mmol) was
first dissolved in a chosen polar solvent (1 mL) such as dimethyl
sulfoxide (DMSO) or N,N-dimethylformamide (DMF), then an
o-dichlorobenzene (ODCB, 6 mL) solution of C60 (0.05 mmol)
was added. The resulting solution was heated with vigorous
stirring in an oil bath preset at 120 °C under nitrogen atmosphere
for 5 h. To our disappointment, no obvious reaction was
observed even in the presence of a large excess of 4-tolunitrile
or by raising the reaction temperature and extending the reaction
time. To successfully realize the Fe(ClO4)3 ·6H2O-mediated
reaction of C60 with 4-tolunitrile, various reaction conditions
have been examined. To our delight, the reaction was found to
proceed well and gave fullerooxazole 2a in 22% yield when
the mixture of Fe(ClO4)3 ·6H2O and 4-tolunitrile (1:100) was
directly melted in an oil bath preset at 120 °C under nitrogen
atmosphere, followed by the addition of the ODCB solution of
C60, and then the reaction mixture was heated with vigorous
stirring under protection of nitrogen at 120 °C (entry 1, Table
1). Decreasing or increasing the reaction temperature did not
improve the yield of product 2a (entries 2 and 3, Table 1). Other
reaction conditions for the reaction of C60 with 4-tolunitrile
giving fullerooxazole 2a were also examined. These results are
summarized Table 1. No benefit to the yield of product 2a could
be achieved by variation of the amount of 4-tolunitrile (entries
4 and 5, Table 1). Similar results were obtained by increasing
the amount of Fe(ClO4)3 ·6H2O to 2 equiv (entries 6-8, Table
1). However, the reaction became much faster and thus easily
out of control. Therefore, the reagent molar ratio of C60:
Fe(ClO4)3 ·6H2O:1a as 1:1:100 and the reaction temperature as
120 °C were chosen as the optimized reaction conditions.
With the optimized conditions in hand, this reaction was
extended to other nitriles such as benzonitrile (1b), 4-methoxy-
benzonitrile (1c), 3,4-dimethoxybenzonitrile (1d), 4-bromoben-
zonitrile (1e), 4-nitrobenzonitrile (1f), phenylacetonitrile (1g),
and ethyl cyanoacetate (1h), giving fullerooxazole derivatives
2b,14 2c,14 2d, 2e,14 2f, 2g, and 2h, respectively (Scheme 1).
The reaction conditions and yields for the Fe(ClO4)3 ·6H2O-
promoted reactions of C60 with nitriles 1a-h under nitrogen
atmospheric conditions are summarized in Table 2.
As can be seen from Table 2, aromatic nitriles bearing either
electron-withdrawing groups or electron-donating groups (1a-f)
as well as aliphatic nitriles (1g and 1h) could be successfully
utilized to prepare fullerooxazoles. All of the examined nitriles
1a-h gave fullerooxazoles 2a-h in moderate to good yields,
ranging from 41% to 84% based on consumed C60. In the case
of 1e and 1f, the prior addition of some amount of ODCB (1
mL) before the addition of C60 (dissolved in 6 mL of ODCB)
to the molten mixture of Fe(ClO4)3 ·6H2O with 1e or 1f
successfully avoided the resolidification of the molten mixture
because of higher melting points of nitriles 1e and 1f than other
nitriles. It should be noted that for the reaction of C60 with ethyl
cyanoacetate 1h, some unknown byproducts were obtained
besides the predominant product 2h. Surprisingly, acetonitrile,
the simplest aliphatic nitrile, did not react with C60 under the
same conditions.
(9) (a) Gan, L.; Huang, S.; Zhang, X.; Zhang, A.; Cheng, B.; Cheng, H.; Li,
X.; Shang, G. J. Am. Chem. Soc. 2002, 124, 13384. (b) Shigemitsu, Y.; Kaneko,
M.; Tajima, Y.; Takeuchi, K. Chem. Lett. 2004, 33, 1604. (c) Chuang, S.-C.;
Clemente, F. R.; Khan, S. I.; Houk, K. N.; Rubin, Y. Org. Lett. 2006, 8, 4525.
(d) Troshina, O. A.; Troshin, P. A.; Peregudov, A. S.; Lyubovskaya, R. N.
MendeleeV Commun. 2007, 17, 113. (e) Nambo, M.; Noyori, R.; Itami, K. J. Am.
Chem. Soc. 2007, 129, 8080.
Products 2b,14 2c,14 and 2e14 are known compounds, and their
identities were confirmed by comparison of their spectral data
with those reported in the literature. New compounds 2a, 2d,
2f, 2g, and 2h were unambiguously characterized by their MS,
1H NMR, 13C NMR, FT-IR, and UV-vis spectra. All of the
MALDI FT-ICR mass spectra of these fullerooxazole products
(10) For a review see: Wang, G.-W.; Li, F.-B. J. Nanosci. Nanotechnol. 2007,
7, 1162.
(11) Wang, G.-W.; Yang, H.-T.; Miao, C.-B.; Xu, Y.; Liu, F. Org. Biomol.
Chem. 2006, 4, 2595.
(12) Chen, Z.-X.; Wang, G.-W. J. Org. Chem. 2005, 70, 2380.
(13) For our other representative papers see: (a) Wang, G.-W.; Zhang, X.-
H.; Zhan, H.; Guo, Q.-X.; Wu, Y.-D. J. Org. Chem. 2003, 68, 6732. (b) Wang,
G.-W.; Li, J.-X.; Li, Y.-J.; Liu, Y.-C. J. Org. Chem. 2006, 71, 680. (c) Wang,
G.-W.; Chen, X.-P.; Cheng, X. Chem. Eur. J. 2006, 12, 7246. (d) Wang, G.-W.;
Li, F.-B.; Xu, Y. J. Org. Chem. 2007, 72, 4474.
(14) Averdung, J.; Mattay, J.; Jacobi, D.; Abraham, W. Tetrahedron 1995,
51, 2543.
6418 J. Org. Chem. Vol. 73, No. 16, 2008

TABLE 2. Reaction Temperatures, Reaction Times, and Yields of
SCHEME 2. Proposed Reaction Mechanism for the
Formation of Fullerooxazoles
a
Fullerooxazoles 2a-h and Recovered C60
olefins with substituted diethyl R-benzylmalonates or diethyl
(pyridylmethy1)malonates, we propose a possible reaction
mechanism for the formation of fullerooxazoles 2a-h from the
Fe(ClO4)3 ·6H2O-mediated reactions of C60 with nitriles 1a-h,
as shown in Scheme 2. The additions of nucleophiles including
water to metal-activated organonitriles have been reported.17
Similarly, nitrile 1 reacts with one molecule of H2O in the
presence of Fe(ClO4)3 ·6H2O to generate Fe(III)-complex 3,
which is consistent with the reddening of the molten mixtures
from nitriles and Fe(ClO4)3 ·6H2O, indicating the formation of
complexes between Fe(III) and nitriles.16b Homolytical addition
of 3 to C60 produces fullerenyl radical 4, followed by coordina-
tion with another molecule of Fe(ClO4)3 ·6H2O to generate
Fe(III)-complex 5 and subsequent intramolecular cyclization
with the loss of Fe(II) species to afford fullerooxazole deriva-
tives 2a-h. Alternatively, fullerenyl radical 4 could be oxidized
to the corresponding fullerenyl cation, followed by cyclization
with the loss of H+ to give the fullerooxazole derivatives. The
addition of water to nitrile 1 affording intermediate 3 would be
facilitated with an electron-withdrawing R group. This proposed
reaction mechanism could reasonably explain the failed reaction
with acetonitrile due to the electron-donating property of the
methyl group.
a Molar ratio of C60:Fe(ClO4)3 ·6H2O:nitrile 1 ) 1:1:100. b Yield
based on consumed C60. c After the mixture of Fe(ClO4)3 ·6H2O with 1e
or 1f was melted, ODCB (1 mL) was added at the molten temperature
(above 140 °C for 1e and above 170 °C for 1f), followed by addition of
the ODCB (6 mL) solution of C60 at the reaction temperature.
gave the correct molecular ion peaks. In the 13C NMR spectra
of compounds 2a, 2d, 2f, 2g, and 2h, the peak for the CdN
carbon appeared at 163.77-167.66 ppm, and the two sp3-
carbons of the C60 skeleton were located at 97.02-97.83 and
91.42-91.99 ppm, close to those of other fullerene derivatives,
of which the oxygen atom2b,7b,13d and nitrogen atom11 are
connected to the C60 skeleton, respectively. No more than 29
peaks including some overlapped ones for the 58 sp2-carbons
of the C60 moiety were observed in the range of 135.60-148.94
ppm, consistent with the Cs symmetry of their molecular
structures. The IR spectra of 2a, 2d, 2f, 2g, and 2h showed
absorptions at 1638-1663 cm-1 due to the CdN group. Their
UV-vis spectra exhibited a peak at 413-416 nm, which is a
diagnostic absorption for the 1,2-adduct of C60, to which the
oxygen atom is directly attached.7b
In summary, Fe(ClO4)3 ·6H2O has been successfully utilized
in the free radical reactions of C60 for the first time. The reactions
of C60 with nitriles in the presence of Fe(ClO4)3 ·6H2O afforded
the scarce fullerooxazole derivatives.18 The direct melting of
nitriles and Fe(ClO4)3 ·6H2O proved to be crucial for the
successful realization of the reaction. The current method
provided a facile one-step route for the synthesis of fulleroox-
azoles. A plausible reaction mechanism for the formation of
fullerooxazoles was proposed.
Fullerooxazoles were previously prepared by two steps, that
is, photochemical reactions of C60 with arylazides14 or thermal
reactions with azidoformates and hydroxamic acid derivatives,15
followed by rearrangement of the formed fulleroaziridines to
fullerooxazoles. Our current one-step approach to the synthesis
of fullerooxazoles from cheap and easily available nitriles and
Fe(ClO4)3 ·6H2O is obviously more straightforward and practical
than the previous protocols.14,15
On the basis of the previously suggested mechanisms for the
radical reactions of C60 promoted by Mn(OAc)3 ·2H2O3b,5b,11
and Cu(OAc)2 ·H2O,3b together with the reaction mechanism
for the ferric perchlorate-mediated oxidative additions16 of
Experimental Section
Preparation of Fullerooxazoles 2a-h. A mixture of nitrile 1a
(1b, 1c, 1d, 1e, 1f, 1g, or 1h, 5 mmol) and ferric perchlorate
hexahydrate (23.0 mg, 0.05 mmol) was melted in an oil bath preset
at 120 °C in a 50-mL round-bottomed flask equipped with a reflux
condenser, nitrogen inlet and outlet, and a magnetic stirrer, then
C60 (36.0 mg, 0.05 mmol, dissolved in 7 mL of o-dichlorobenzene)
was added and the resulting solution was heated with vigorous
stirring at 120 °C under nitrogen atmosphere. The reaction was
monitored by TLC and stopped at the designated time. The reaction
(16) (a) Citterio, A.; Sebastiano, R.; Marion, A.; Santi, R. J. Org. Chem.
1991, 56, 5328. (b) Citterio, A.; Sebastiano, R.; Carvayal, M. C. J. Org. Chem.
1991, 56, 5335.
(15) (a) Banks, M. R.; Cadogan, J. I. G.; Gosney, I.; Hodgson, P. K. G.;
Langridge-Smith, P. R. R.; Rankin, D. W. H. J. Chem. Soc., Chem. Commun.
1994, 1365. (b) Banks, M. R.; Cadogan, J. I. G.; Gosney, I.; Hodgson, P. K. G.;
Langridge-Smith, P. R. R.; Millar, J. R. A.; Taylor, A. T. Tetrahedron Lett.
1994, 35, 9067.
(17) Kukushkin, V. Yu.; Pombeiro, A. J. L. Chem. ReV. 2002, 102, 1771.
(18) After our work had been completed, an independent work on the reaction
of electrochemically generated C60 anion in benzonitrile to afford fullerooxazole
product 2b was published: Zheng, M.; Li, F.-F.; Ni, L.; Yang, W. W.; Gao, X.
J. Org. Chem. 2008, 73, 3159.
J. Org. Chem. Vol. 73, No. 16, 2008 6419

mixture was passed through a silica gel plug to remove any
insoluble material. After the solvent was evaporated in vacuo, the
residue was separated on a silica gel column with carbon disulfide/
toluene as the eluent to give unreacted C60 and fullerooxazole.
1020, 982, 929, 864, 850, 702, 526; UV-vis (CHCl3) λmax/nm (log
ꢀ) 255 (5.05), 316 (4.65), 416 (3.51), 689 (2.27); MALDI FT-ICR
MS m/z calcd for C67H4N2O3 [M-] 884.02219, found 884.02167.
1
2g: H NMR (300 MHz, CS2/CDCl3) δ 7.61 (d, J ) 7.2 Hz,
1
2H), 7.40 (t, J ) 7.2 Hz, 2H), 7.33 (t, J ) 7.2 Hz, 1H), 4.22 (s,
2H); 13C NMR (75 MHz, CS2/CDCl3 with Cr(acac)3 as relaxation
reagent) (all 2C unless indicated) δ 167.66 (1C), 147.68 (1C),
147.28, 145.86 (5C), 145.74, 145.58, 145.54, 145.26, 145.03,
144.95, 144.71, 144.60, 144.26, 144.05, 143.74, 142.88, 142.28,
142.24, 142.17, 141.84, 141.75 (4C), 141.59, 141.48, 141.42,
139.90, 139.11, 137.22, 135.60, 133.82 (1C, aryl C), 128.80 (aryl
C), 128.58 (aryl C), 127.14 (1C, aryl C), 97.09 (1C, sp3-C of C60),
91.48 (1C, sp3-C of C60), 34.82 (1C); FT-IR ν/cm-1 (KBr) 2922,
2852, 1658, 1493, 1452, 1425, 1267, 1213, 1178, 1131, 1060, 980,
937, 721, 695, 600, 574, 526; UV-vis (CHCl3) λmax/nm (log ꢀ)
256 (5.05), 316 (4.56), 414 (3.47), 683 (2.38); MALDI FT-ICR
MS m/z calcd for C68H7NO [M-] 853.05276, found 853.05298.
2a: H NMR (300 MHz, CS2/CDCl3) δ 8.37 (d, J ) 8.1 Hz,
2H), 7.46 (d, J ) 8.1 Hz, 2H), 2.57 (s, 3H); 13C NMR (75 MHz,
CS2/CDCl3 with Cr(acac)3 as relaxation reagent) (all 2C unless
indicated) δ 165.38 (1C), 147.82 (1C), 147.66, 147.41 (1C), 146.00,
145.98, 145.86, 145.70, 145.65, 145.38, 145.22, 145.09, 144.83,
144.72, 144.45, 144.19, 143.88, 143.30, 142.75 (1C, aryl C), 142.39,
142.36, 142.29, 141.95 (4C), 141.87, 141.73, 141.61, 141.58,
140.01, 139.22, 137.51, 135.88, 129.22 (aryl C), 128.97 (aryl C),
123.66 (1C, aryl C), 97.02 (1C, sp3-C of C60), 91.77 (1C, sp3-C of
C60), 21.62 (1C); FT-IR ν/cm-1 (KBr) 2919, 2850, 1639, 1510,
1427, 1321, 1179, 1141, 1087, 1023, 983, 932, 824, 720, 660, 603,
562, 525; UV-vis (CHCl3) λmax/nm (log ꢀ) 257 (5.17), 315 (4.68),
414 (3.55), 687 (2.42); MALDI FT-ICR MS m/z calcd for C68H7NO
[M-] 853.05276, found 853.05277.
1
2h: H NMR (300 MHz, CS2/CDCl3) δ 4.38 (q, J ) 7.1 Hz,
2H), 3.98 (s, 2H), 1.44 (t, J ) 7.1 Hz, 3H); 13C NMR (75 MHz,
CS2/CDCl3 with Cr(acac)3 as relaxation reagent) (all 2C unless
indicated) δ 165.64 (1C), 163.12 (1C), 147.78 (1C), 147.37 (1C),
146.94, 145.97 (4C), 145.85, 145.68, 145.63, 145.38, 145.06,
145.03, 144.81, 144.71, 144.31, 144.12, 143.82, 142.65, 142.38,
142.33, 142.27, 141.94, 141.84, 141.81, 141.69, 141.56, 141.49,
139.99, 139.23, 137.34, 135.76, 97.42 (1C, sp3-C of C60), 91.42
(1C, sp3-C of C60), 61.59 (1C), 34.82 (1C), 14.11 (1C); FT-IR
ν/cm-1 (KBr) 2922, 2852, 1744, 1663, 1550, 1532, 1462, 1433,
1
2d: H NMR (300 MHz, CS2/CDCl3) δ7.99 (dd, J ) 8.3, 1.6
Hz, 1H), 7.90 (d, J ) 1.6 Hz, 1H), 7.02 (d, J ) 8.3 Hz, 1H), 4.02
(s, 3H), 3.99 (s, 3H); 13C NMR (75 MHz, CS2/CDCl3 with Cr(acac)3
as relaxation reagent) (all 2C unless indicated) δ 164.99 (1C),
152.61 (1C, aryl C), 148.94 (1C), 147.98, 147.94 (1C), 147.53 (1C),
146.13, 146.10, 145.98, 145.83, 145.78, 145.49, 145.31, 145.21,
144.96, 144.84, 144.57, 144.34, 144.02, 143.54, 142.53, 142.50,
142.43, 142.11 (4C), 142.01, 141.86, 141.75 (4C), 140.17, 139.34,
137.64, 135.93, 122.87 (1C, aryl C), 119.10 (1C, aryl C), 111.66
(1C, aryl C), 110.69 (1C, aryl C), 97.15 (1C, sp3-C of C60), 91.94
(1C, sp3-C of C60), 55.71 (1C), 55.62 (1C); FT-IR ν/cm-1 (KBr)
2924, 2850, 1638, 1512, 1458, 1423, 1315, 1272, 1227, 1177, 1139,
1092, 1025, 986, 938, 871, 810, 770, 705, 569, 526; UV-vis
(CHCl3) λmax/nm (log ꢀ) 257 (5.11), 314 (4.74), 413 (3.62), 682
(2.42); MALDI FT-ICR MS m/z calcd for C69H9NO3 [M-]
899.05824, found 899.05574.
1369, 1269, 1183, 1031, 982, 942, 605, 527; UV-vis (CHCl3) λmax
/
nm (log ꢀ) 255 (5.09), 316 (4.61), 414 (3.63), 687 (2.46); MALDI
FT-ICR MS m/z calcd for C65H7NO3 [M-] 849.04259, found
849.04247.
Acknowledgment. We are grateful for the financial support
from National Natural Science Foundation of China (Nos.
20572105 and 20621061), National Basic Research Program
of China (2006CB922003), and K. C. Wong Education Founda-
tion, Hong Kong.
1
2f: H NMR (300 MHz, CS2/CDCl3) δ 8.66 (d, J ) 8.7 Hz,
2H), 8.48 (d, J ) 8.7 Hz, 2H); 13C NMR (75 MHz, CS2/CDCl3
with Cr(acac)3 as relaxation reagent) (all 2C unless indicated) δ
163.77 (1C), 150.03 (1C, aryl C), 148.08 (1C), 147.66 (1C), 146.96,
146.28 (4C), 146.14, 145.98, 145.93, 145.69, 145.27, 145.19,
145.10, 145.00, 144.45, 144.38, 144.07, 142.83 (1C, aryl C), 142.69,
142.62 (6C), 142.20, 142.11, 142.06, 141.99, 141.85, 141.71,
140.36, 139.55, 137.64, 136.06, 130.06 (aryl C), 123.75 (aryl C),
97.83 (1C, sp3-C of C60), 91.99 (1C, sp3-C of C60); FT-IR ν/cm-1
(KBr) 2920, 2851, 1645, 1598, 1522, 1461, 1430, 1345, 1320, 1090,
1
Supporting Information Available: H NMR spectra of
2a-h as well as 13C NMR spectra of 2a, 2b, 2d, 2f, 2g, and
2h. This material is available free of charge via the Internet at
http://pubs.acs.org.
JO8007868
6420 J. Org. Chem. Vol. 73, No. 16, 2008