Hypervalent iodine reagent mediated reaction of [60]fullerene with amines

Article abstract of DOI:10.1021/jo402079m

The hypervalent iodine reagent mediated reaction of C₆₀ with various readily available amines for the easy preparation of iminofullerenes has been developed. The reaction between C₆₀ and sulfonamides can be effectively controlled to

Full text of DOI:10.1021/jo402079m

Note
pubs.acs.org/joc
Hypervalent Iodine Reagent Mediated Reaction of [60]Fullerene with
Amines
Chun-Bao Miao,*,† Xin-Wei Lu,† Ping Wu,‡ Jiaxing Li,§ Wen-Long Ren,† Meng-Lei Xing,†
Xiao-Qiang Sun,† and Hai-Tao Yang*,†
†School of Petrochemical Engineering, Changzhou University, Changzhou 213164, People’s Republic of China
‡College of Chemistry and Chemical Engineering, Key Laboratory of Coordination Chemistry and Functional Materials in
Universities of Shandong, Dezhou University, Dezhou 253023, People’s Republic of China
§Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei
230031, People’s Republic of China
S
* Supporting Information
ABSTRACT: The hypervalent iodine reagent mediated
reaction of C60 with various readily available amines for the
easy preparation of iminofullerenes has been developed. The
reaction between C60 and sulfonamides can be effectively
controlled to selectively synthesize azafulleroids or aziridino-
fullerenes under PhI(OAc)2/I2 or PhIO/I2/CuCl/lutidine
conditions, respectively. For phosphamide and urea, only
one isomer is obtained. However, carbamate gives three kinds
of products. Interestingly, the reaction of C60 with alkylamines
allows the effective synthesis of aziridinofullerenes and
regioselective cis-1-bisaziridinofullerenes.
hemical functionalization allows the preparation of
various fullerene derivatives for further investigation of
We have been interested in developing new modification
methods to prepare fullerene derivatives with a desired or as yet
unknown specific skeleton.8 The combination of PhI(OAc)2
and I2 to generate alkoxyl, sulfonamidyl, phosphoramidyl,
carbamoyl, or amidyl radicals for further transformation in
organic synthesis has been well documented.9 As is known to
all, fullerene is an efficient radical scavenger and a large number
of radical reactions of fullerenes have been reported.1
Therefore, we conceived of using the PhI(OAc)2/I2 system as
a radical initiator and investigating its application in fullerene
functionalizations. Recently, we exploited a PhI(OAc)2/I2-
mediated reaction of C60 with carboxylic amides for the easy
preparation of fullerooxazoles.10 As a continuation of our
research on the application of the PhI(OAc)2/I2 system in
fullerene chemistry, in this context, we report the reaction of
C60 with other easily available amines such as sulfonamides,
phosphamides, ureas, carbamates, arylamines, and alkylamines
under the hypervalent iodine/I2 system for the convenient
synthesis of aziridinofullerenes or azafulleroids (Scheme 1).
We started our study with the reaction of C60 with
tolylsulfonamide 1a in the presence of PhI(OAc)2 (2 equiv)
and I2 (2 equiv) in chlorobenzene (Table 1, entry 1). After the
mixture was stirred for 4 h at room temperature, azafulleroid 2a
was generated in 59% yield accompanied by a trace of
aziridinofullerene 3a. It is worth noting that both PhI(OAc)2
C
their interesting physical properties and biological activities.
Among them, the introduction of an N1 unit on the fullerene
sphere to construct iminofullerenes such as azafulleroids ([6,5]-
opened) and aziridinofullerenes ([6,6]-closed) constitutes a
large class of nitrogen-containing fullerene derivatives. Partic-
ularly, azafulleroids are key precursors for the synthesis of open-
cage fullerene or azafullerene (C59N),1 and aziridinofullerene is
a diverse platform for the synthesis of a variety of fullerene
derivatives via acid-catalyzed ring-opening reactions.2 The
iminofullerenes are commonly prepared through 1,3-dipolar
cycloaddition of organic azides to C60, followed by extrusion of
N2 from the (triazolino)fullerene adducts under thermal or
photolytic conditions.3 The biggest problem was that the two
isomers (azafulleroids and aziridinofullerenes) were always
generated together, and control of the distribution was rather
difficult. Furthermore, the explosiveness and toxicity of azides
needs to be considered seriously in operation processes.
Recently, the acid-catalyzed denitrogenation of triazolinofuller-
enes to afford the exclusive aziridinofullerene was reported.4
Although some new synthetic routes to aziridinofullerenes were
recently developed starting from the chloramines,5 iminophe-
nyliodinanes,2 sulfilimines,6 and N,N-dihalosulfonamides,7 the
substrates were mainly limited to those amines bonding a
strongly electron withdrawing group to the nitrogen atom such
as sulfonyl, phosphonyl, and carbonyl groups. Moreover, most
of the starting materials need to be prepared beforehand from
the corresponding amines.
Received: September 19, 2013
© XXXX American Chemical Society
A
dx.doi.org/10.1021/jo402079m | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
However, the iminophenyliodinane but not the easily available
sulfonamide was used as the starting material. If I2 were to be
replaced by CuCl/lutidine, the aziridinofullerene 3a might be
formed as the predominant product. Thus, the selective
synthesis of azafulleroids and aziridinofullerenes from the easily
available sulfonamides would be realized, mediated by PhI-
(OAc)2. To test this hypothesis, the reaction of C60 with 1a and
PhI(OAc)2 was carried out in the presence of 10 mol % of
CuCl and 20 mol % of lutidine. To our disappointment, only a
trace of aziridinofullerene 3a was observed by TLC. Both
prolonging the reaction time and increasing the reaction
temperature did not lead to any increase in the yield. When
PhI(OAc)2 was replaced by PhIO, to our delight, aziridino-
fullerene 3a was obtained in 50% yield as the sole product after
stirring for 20 h at room temperature (Table 1, entry 2). Other
sulfonamides such as methylsulfonamide (1b), 4-nitrobenzo-
sulfonamide (1c), and 4-methoxybenzosulfonamide (1d) were
then tested, and this type of selective synthesis of azafulleroids
and aziridinofullerenes was also applicable (Table 1, entries 3−
8).
Scheme 1
Table 1. Selective Synthesis of Aziridinofullerenes and
Azafulleroids from Sulfonamides Mediated by Hypervalent
Iodine Reagents
Encouraged by this result, the phosphamides 1e,f were
subjected to the reaction. However, two entirely different
results were obtained (Scheme 3). Under the PhI(OAc)2/I2
c
yield
Scheme 3. Reaction of C60 with Phosphamides under the
PhI(OAc)2/I2 System
entry
substrate
conditions
time (h)
2
3
a
1
1a
1a
1b
1b
1c
1c
1d
1d
A
B
A
B
A
B
A
B
4
20
6
59
0
trace
50
b
2
a
3
49
0
trace
34
b
4
20
4
a
5
50
0
trace
38
b
6
20
4
a
7
54
0
trace
46
b
8
20
a
Conditions: C60 (36 mg):1:PhI(OAc)2:I2 = 1:2:2:2, room temper-
b
ature, 12 mL of chlorobenzen. Conditions: C60 (36 mg):1:PhIO:-
CuCl:lutidine =1:2:2:0.2:0.4, room temperature, 12 mL of chlor-
obenzene. Isolated yield.
conditions, diethyl amidophosphonate 1e gave the single
aziridinofullerene 3e in 21% yield. In contrast, diphenylphos-
phinamide 1f gave the exclusive azafulleroid 2f in 11% yield.
Using PhIO instead of PhI(OAc)2 resulted in no improvement
in the yield of 2f. Up to this point, we still had no reasonable
explanation for the distinction on starting from the similar
phosphamides.
Next, amines linking with a carbonyl group on the nitrogen
atom were examined (Scheme 4). In case of the reaction of C60
with urea 1g in the presence of PhI(OAc)2/I2, the aziridino-
fullerene 2g was formed selectively in 12% yield.11 For n-butyl
carbamate 1h, which has a structure similar to urea 1g, only a
trace of transformation was observed by TLC even after stirring
at room temperature for 24 h. When PhIO was used instead of
PhI(OAc)2, in spite of no noticeable change for the reaction of
c
and I2 are crucial to the successful reaction and no reaction
occurred in the absence of either one. On the basis of our
previous research on the PhI(OAc)2/I2-mediated reaction of
C60 with carboxylic amides,10 the N,N-diiodotolylsulfonamide,
which might be generated in situ from iminophenyliodinane
and I2, was deemed to be the key intermediate. To verify this
conjecture, C60 (36 mg) was treated with iminophenyliodinane
(2 equiv) and I2 (2 equiv) in 12 mL of chlorobenzene (Scheme
2). Azafulleroid 2a was produced, as expected, in 55% yield
after 4 h. On the other hand, the Itami group has reported the
CuCl-catalyzed reaction of C60 with iminophenyliodinane for
the convenient and selective synthesis of aziridinofullerene.2
C
60 with urea 1g, a great improvement in product yield for the
reaction of C60 with 1h was achieved. There were two main
fractions other than C60 in the process of separation of the
reaction mixture on a silica gel column using CS2 as the eluent.
The first fraction was identified as aziridinofullerene 3h (15%),
and the second fraction (27%) contained two inseparable
Scheme 2. Reaction of C60 with Iminophenyliodinane in the
Presence of I2
1
components with a molar ratio of 1:4 as determined by H
NMR. Further 13C NMR analysis and comparison of the
spectral pattern with those of those reported fullerene
derivatives proved that the two isomers were the major
fullerooxazole 4 and minor azafulleroid 2h (see the Supporting
Information).3g,10
B
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Note
fullerene bis-adducts showed similar UV−vis absorption
patterns within that range.15,16 The 13C NMR and UV−vis
spectral patterns of 7a are nearly the same as those of reported
cis-1-bis-adducts in Akasaka and Nagase’s work6b (see the
Supporting Information), which strongly demonstrated that 7a
was the cis-1 isomer.
Scheme 4. Reaction of C60 with Urea and Carbamate under
the Hypervalent Iodine/I2 System
To the best of our knowledge, the cis-1-bisaziridinofullerene
is hard to prepare because eight possible addition sites exist for
2-fold additions. So far, only the Akasaka and Nagase group
evolved a synthetic methodology for the regioselective synthesis
of cis-1-bisaziridinofullerene with sulfilimine.6b However, only
the sulfilimine with an alkyl substituent could afford the cis-1-
bisadduct. An aryl substituent of sulfilimine only afforded the
azafulleroid accompanied by the minor product monoaziridino-
fullerene. Most recently, we exploited a CuCl2-mediated
reaction of C60 with electron-deficient amines for the
preparation of aziridinofullerenes and cis-1-bisaziridino-
fullerenes.14 Nevertheless, the substrates were restricted to
those aromatic amines bearing a strongly electron withdrawing
group. Although in an earlier stage the Hirsch group reported
the preparation of eight isomers of C60(NCO2R)2,15a the
isolated cis-1 isomer in their work contained two open
transannular [6,6] bonds. All in all, we have provided a new
method to prepare cis-1-bisaziridinofullerenes from easily
available alkylamines mediated by PhI(OAc)2/I2, which is a
good complement to the existing methodologies for the
preparation of cis-1-bisaziridinofullerenes.
To further extend the scope of our protocol, we next turned
our attention to investigating the reactivity of ordinary amines
such as aryl- and alkyl amines (Scheme 5). No reaction
Scheme 5. Reaction of C60 with Alkylamines under the
PhI(OAc)2/I2 System To Afford Aziridinofullerenes and
Regioselective cis-1-Bisaziridinofullerenes
To further confirm the structure of 7, the relative energies of
the eight possible isomer of bis-adducts 7a were calculated at
the B3LYP/6-31G* level with the geometry optimized by the
AM1 semiempirical method.17 The results showed that the cis-1
isomer was the most stable (see the Supporting Information).
Hirsch had also summarized that sterically nondemanding
addends prefer the cis-1 position for the 2-fold addition.18
On the basis of our previous work,10 a plausible reaction
pathway is proposed in Scheme 5. The reaction of amine with
PhI(OAc)2 or PhIO affords iminophenyliodinane A. In the
presence of I2, A was converted to the key intermediate N,N-
diiodoamine B, which undergoes N−I bond cleavage to
produce the nitrogen radical C, and follow-up capture by C60
generates the fullerene radical D. Elimination of another iodine
radical from D generates the azafulleroid or aziridinofullerene.
At present, we have no definite answer about the selective
formation of azafulleroid or aziridinofullerene from D. When R
is a sulfonyl group, CuCl-catalyzed degradation of iminophe-
nyliodinane A furnishes the carbene E and iodobenzene. The
reaction of C60 with E provides the exclusive aziridinofullerene.
In summary, the reaction of C60 with different readily
available amines mediated by the hypervalent iodine/I2 system
was disclosed. For sulfonamides, azafulleroids or aziridino-
fullerenes could be selectively obtained under the PhI(OAc)2/
I2 or PhIO/I2/CuCl/lutidine system, respectively. No obvious
occurred between C60 and 4-methylaniline 5c under PhI-
(OAc)2/I2 conditions. In contrast, when benzylamine 5a was
employed in the reaction, the aziridinofullerene 6a was
generated in 22% yield together with 16% of the unanticipated
cis-1-bis-adduct 7a, and no azafulleroid was formed. It must be
noted that the feeding order of starting materials was critical to
the success of this reaction. When the benzylamine and I2 were
added together and stirred for a moment before addition of
PhI(OAc)2, a very low transformation was observed, which
might be attributable to the quick formation of a complex
between the alkylamine and I2.12 When PhI(OAc)2 and
benzylamine 5a were added together to a solution of C60, the
mixture was stirred for 20 min at room temperature, and then I2
was added and the mixture was stirred for an additional 5 h, the
reaction proceeded well to give the desired products.
Interestingly, the bis-adduct 7a was regioselectively produced
as a cis-1 isomer, although eight possible regioisomers of the
bis-adduct might exist. The n-butylamine 5b also gave similar
result with 5a under the same conditions. Despite the fact that
the Gan group has reported the PhI(OAc)2/I2-promoted
reaction of C60 with glycine methyl ester under ultrasonic
irradiation to generate aziridinofullerene, only the mono-adduct
was observed in their research.13
Scheme 6. Proposed Mechannism
The structure of 7a was confirmed by 13C NMR and UV−vis
analysis (see the Supporting Information).6b,14 UV−vis spectral
patterns within the region 400−700 nm are powerful evidence
for fullerene structural assignments, and the same type of
C
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Note
Reaction of C60 with Alkylamines 5a,b in the Presence of the
PhI(OAc)2/I2 System. A solution of C60 (72.0 mg, 0.1 mmol) in 25
mL of PhCl was stirred and heated to 80 °C until the C60 dissolved
entirely. After the solution was cooled to room temperature,
PhI(OAc)2 (64.5 mg, 0.2 mmol) and alkylamines 5 (0.2 mmol)
were added, and the mixture was stirred for 20 min at room
temperature. Then I2 (50.8 mg, 0.2 mmol) was added, and the mixture
was stirred for an additional 4−6 h at room temperature until no
change occurred (detected by TLC). The same workup process as
above gave the mono-adducts 6 and cis-1-bis-addducts 7 (6a,4 18.3 mg,
22%; 7a, 15.5 mg, 17%; 6b,4 12.5 mg, 16%; 7b, 12.3 mg, 14%).
2a: 1H NMR (500 MHz, CS2-DMSO-d6) δ 8.01 (d, J = 8.2 Hz, 2H),
7.44 (d, J = 8.1 Hz, 2H), 2.56 (s, 3H); 13C NMR (125 MHz, CS2-
DMSO-d6) (all 2C unless indicated) δ 147.39, 146.55, 143.93 (1C),
143.87, 143.47, 143.41, 143.34, 143.33 (3C), 143.26, 143.17, 143.13,
142.98, 142.86, 142.81 (1C), 142.61, 142.41, 142.18, 142.17, 141.93,
141.89, 140.85, 139.20, 138.87, 138.84 (1C), 137.75, 137.52, 137.09,
137.05 (1C), 135.13 (1C), 134.90, 133.98, 133.35, 129.17 (aryl C),
128.15 (aryl C), 21.10 (1C).
reaction regularity was observed for phosphamide, urea, and
carbamate. With alkylamines, the aziridinofullerenes and
regioselective cis-1-bisaziridinofullerenes were afforded under
PhI(OAc)2/I2 conditions.
EXPERIMENTAL SECTION
■
Typical Procedure for the Synthesis of Azafulleroids 2a−d
from the Reaction of C60 with Sulfonamides in the Presence of
the PhI(OAc)2/I2 System. A mixture of C60 (36.0 mg, 0.05 mmol),
sulfonamides 1a−d (0.1 mmol), and 12 mL of PhCl was stirred and
heated to 80 °C until the entire dissolution of C60. The solution was
cooled to room temperature, and then PhI(OAc)2 (32.2 mg, 0.1
mmol) and I2 (25.4 mg, 0.1 mmol) were added. The mixture was
stirred at room temperature until no change occurred (detected by
TLC), and then 10 mL of aqueous solution of sodium thiosulfate was
added to remove the excessive iodine. The organic layer was separated,
and the aqueous phase was extracted twice with 10 mL of toluene. The
combined organic layers were dried over sodium sulfate, filtered, and
evaporated to dryness. The residue was purified on a silica gel column
using CS2 as the eluent to give unreacted C60 and azafulleroids 2a−d
(2a,3f 26.2 mg, 59%; 2b,3f 19.9 mg, 49%; 2c,7 22.8 mg, 50%; 2d,3f 24.6
mg, 54%).
2b: 1H NMR (500 MHz, CS2-DMSO-d6) δ 3.53 (s, 3H); 13C NMR
(125 MHz, CS2-DMSO-d6) (all 2C unless indicated) δ 146.67, 146.47,
145.02 (1C), 143.83, 143.48, 143.38, 143.34, 143.30, 143.22, 143.15,
143.00, 142.85, 142.82 (1C), 142.63, 142.49, 142.25, 142.22, 142.17,
142.11 (1C), 142.03, 141.89, 140.91, 139.30, 138.94, 137.91, 137.73,
137.69 (1C), 137.15, 135.12, 134.10, 133.34, 40.58 (1C).
Typical Procedure for the Synthesis of Aziridinofullerenes
3a−d from the Reaction of C60 with Sulfonamide under the
PhIO/I2/CuCl/Lutidine Conditions. A mixture of C60 (36.0 mg, 0.05
mmol), sulfonamides 1a-d (0.1 mmol), and 12 mL of PhCl was stirred
and heated to 80 °C until the entire dissolution of C60. The solution
was cooled to room temperature, and then PhIO (22.0 mg, 0.1 mmol),
CuCl (1.0 mg, 0.01 mmol), and lutidine (2.2 mg, 0.02 mmol) were
added. The mixture was stirred at room temperature for 20 h, and then
10 mL of an aqueous solution of sodium thiosulfate was added to
remove the excess iodine. The organic layer was separated, and the
aqueous phase was extracted twice with 10 mL of toluene. The
combined organic layers were dried over sodium sulfate, filtered, and
evaporated to dryness. The residue was purified on a silica gel column
using CS2 as the eluent to give unreacted C60 and aziridinofullerenes
3a−d (3a,3f 22.4 mg, 50%; 3b,3f 13.7 mg, 34%; 3c,7 17.6 mg, 38%;
3d,3f 20.9 mg, 46%). Aziridinofullerenes 3 have less polarity than
azafulleroids 2 on TLC, and the 1H NMR spectra of aziridinofullerenes
3 have a downfield shift in comparison to those of azafulleroids 2.)
Reaction of C60 with Phosphamides 1e,f or Urea 1g under
PhI(OAc)2/I2 Conditions. A mixture of C60 (36.0 mg, 0.05 mmol),
phosphamides or urea (1e−g, 0.1 mmol), and 12 mL of PhCl was
stirred and heated to 80 °C until the entire dissolution of C60. The
solution was cooled to room temperature, and then PhI(OAc)2 (32.2
mg, 0.1 mmol) and I2 (25.4 mg, 0.1 mmol) were added. The mixture
was stirred at room temperature until no change occurred (detected by
TLC; for 1e, the reaction mixture was irradiated with a 250 W high-
pressure mercury lamp), and then 10 mL of aqueous solution of
sodium thiosulfate was added to remove the excess iodine. The organic
layers were separated, and the aqueous phase was extracted twice with
10 mL of toluene. The combined organic layers were dried over
sodium sulfate, filtered, and evaporated to dryness. The residue was
purified on a silica gel column using CS2/toluene as the eluent to give
unreacted C60 and the products 3e5b (9.2 mg, 21%), 2f7 (5.3 mg,
11%), and 3g (5.3 mg, 12%).
Reaction of C60 with n-Butyl Carbamate 1h under PhIO/I2
Conditions. A mixture of C60 (72.0 mg, 0.1 mmol), n-butyl carbamate
1h (23.5 mg, 0.2 mmol), and 25 mL of PhCl was stirred and heated to
80 °C until the entire dissolution of C60. The solution was cooled to
room temperature, and then PhIO (44.0 mg, 0.2 mmol), and I2 (50.8
mg, 0.2 mmol) were added. The mixture was stirred at room
temperature for 5 h, and then 15 mL of an aqueous solution of sodium
thiosulfate was added to remove the excess iodine. The organic layer
was separated, and the aqueous phase was extracted twice with 15 mL
of toluene. The combined organic layers were dried over sodium
sulfate, filtered, and evaporated to dryness. The residue was purified on
a silica gel column using CS2 as the eluent to give unreacted C60,
aziridinofullerene 3h (12.4 mg, 15%), and a mixture of 4 and 2h (22.8
mg, 27%) in turn.
1
2f: H NMR (500 MHz, CS2-DMSO-d6) δ 8.22−8.27 (m, 4H),
7.51−7.59 (m, 6H); 13C NMR (125 MHz, CS2-DMSO-d6) (all 2C
unless indicated) δ 147.45, 145.95 (d, J3,C−P = 4.8 Hz), 144.67, 144.53,
144.28, 144.15, 144.12 (4C), 143.97 (3C), 143.82, 143.73, 143.56,
143.46 (1C), 143.39, 143.21, 143.17, 143.05, 143.03, 142.78, 142.26,
141.32, 140.48 (1C), 139.81, 139.03, 138.61, 138.56 (1C), 138.24,
137.59, 136.54 (d, J3,C−P = 4.4 Hz), 135.32, 133.94, 133.16 (d, J3,C−P
=
9.4 Hz, 4C, aryl C), 132.67 (d, J4,C−P = 2.7 Hz, aryl C), 129.95 (d,
J1,C−P = 132.7 Hz, aryl C), 128.95 (d, J2,C−P = 13.0 Hz, 4C, aryl C).
1
3a: H NMR (500 MHz, CS2-CDCl3) δ 8.19 (d, J = 8.3 Hz, 2H),
7.50 (d, J = 8.1 Hz, 2H), 2.56 (s, 3H); 13C NMR (125 MHz, CS2-
DMSO-d6) (all 4C unless indicated) δ 145.54 (1C, aryl C), 145.36,
145.20, 145.11, 145.05 (2C), 144.58, 144.23, 144.04 (2C), 143.96,
143.36, 143.21, 143.16, 142.85 (2C), 142.24, 141.94, 141.43, 140.98,
135.89 (1C, aryl C), 130.17 (2C, aryl C), 128.62 (2C, aryl C), 79.95
(2C, sp3-C of C60), 21.95 (1C).
1
3e: H NMR (500 MHz, CS2-DMSO-d6) δ 4.47−4.53 (m, 4H),
1.56 (t, J = 7.1 Hz, 6H); 13C NMR (125 MHz, CS2-DMSO-d6) (all 4C
unless indicated) δ 145.38 (d, J3,C−P = 4.4 Hz), 145.27, 145.13, 144.90,
144.86 (2C), 144.53, 144.33, 144.00 (2C), 143.90, 143.17, 143.13,
142.80 (2C), 142.21, 142.09, 141.21, 140.86, 78.69 (d, J2,C−P = 5.8 Hz,
sp3-C of C60, 2C), 64.93 (d, J2,C−P = 6.4 Hz, 2C), 16.65 (d, J3,C−P = 6.0
Hz, 2C);
3g (brown solid, mp >300 °C): 1H NMR (500 MHz, CS2-CDCl3) δ
4.19 (br, 2H), 3.93 (br, 2H), 3.85 (br, 2H), 3.81 (br, 2H); 13C NMR
(125 MHz, CS2-CDCl3) (all 4C unless indicated) δ 155.51 (1C, C
O), 145.36, 145.25, 145.03, 144.98 (2C), 144.63, 144.50, 144.13 (2C),
144.11, 143.93 (2C), 143.20, 143.17, 142.94, 142.29, 142.23, 141.14,
140.57, 80.59 (2C, sp3-C of C60); UV−vis (CHCl3) λmax/nm (log ε)
256 (5.19), 325 (4.64), 423 (3.39), 483 (3.23), 686 (2.75); FT-IR
(KBr) ν/cm−1 2918, 2849, 1686, 1424, 1424, 1273, 1232, 1184, 1116,
1048, 903, 728, 573, 526; HRMS (MALDI-TOFMS) m/z [M + H]+
calcd for C65H9N2O2 849.0664, found 849.0667.
1
3h (brown solid, mp >300 °C): H NMR (500 MHz, CS2-CDCl3)
δ 4.48 (t, J = 6.8 Hz, 2H), 1.83 (quint, J = 7.1 Hz, 2H), 1.52 (sext, J =
7.5 Hz, 2H), 1.01 (t, J = 7.4 Hz, 3H); 13C NMR (125 MHz, CS2-
DMSO-d6) (all 4C unless indicated) δ 156.02 (1C, CO), 145.26,
145.18, 144.90, 144.83 (2C), 144.59, 144.51, 144.05 (2C), 143.86,
143.82, 143.25, 143.21, 142.84 (2C), 142.30, 142.28, 141.15, 140.08,
81.11 (2C, sp3-C of C60), 68.14 (1C), 31.16 (1C), 19.41 (1C), 13.90
(1C); UV−vis (CHCl3) λmax/nm (log ε) 257 (5.10), 325 (4.52), 422
(3.33), 482 (3.20), 686 (2.73); FT-IR (KBr) ν/cm−1 2920, 2850,
1741, 1510, 1427, 1402, 1225, 1183, 1058, 729, 526; HRMS (MALDI-
TOFMS) m/z M+ calcd for C65H9NO2 835.0633, found 835.0640.
D
dx.doi.org/10.1021/jo402079m | J. Org. Chem. XXXX, XXX, XXX−XXX

The Journal of Organic Chemistry
Note
4 (mixed with 2h, brown solid, mp >300 °C): 1H NMR (500 MHz,
CS2-DMSO-d6) δ 8.01 (d, J = 8.2 Hz, 2H), 7.44 (d, J = 8.1 Hz, 2H),
2.56 (s, 3H); 13C NMR (125 MHz, CS2-DMSO-d6, with Cr(acac)3 as
relaxation reagent) (all 2C unless indicated) δ 163.65 (1C, NC−O),
148.22, 147.36 (1C), 146.97 (1C), 145.52, 145.50, 145.31, 145.23,
145.16, 144.80, 144.58, 144.41, 144.32, 144.16, 143.82, 143.75, 143.43,
142.82, 141.88, 141.84, 141.77, 141.46, 141.39, 141.36, 141.23, 141.08,
140.87, 139.39, 138.61, 137.24, 135.03, 96.26 (1C, sp3-C of C60), 87.97
(1C, sp3-C of C60), 71.61 (1C), 30.55 (1C), 18.97 (1C), 13.50 (1C);
HRMS (MALDI-TOFMS) m/z M+ calcd for C65H9NO2 835.0633,
found 835.0623.
ACKNOWLEDGMENTS
■
We are grateful for financial support from the National Natural
Science Foundation of China (Nos. 20902039, 21202011, and
21272236), and the Priority Academic Program Development
of Jiangsu Higher Education Institutions.
REFERENCES
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6a: H NMR (500 MHz, CS2-CDCl3) δ 8.00 (d, J = 7.4 Hz, 2H),
7.73 (t, J = 7.6 Hz, 2H), 7.66 (t, J = 7.4 Hz, 1H), 5.07 (s, 2H); 13C
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145.08, 144.79, 144.76, 144.72, 144.34, 144.15, 143.73, 143.16, 143.12,
142.88, 142.58, 142.52, 142.39 (1C), 141.94, 141.61, 141.58, 141.00,
140.76 (1C), 140.72, 140.67, 140.60, 140.39, 139.78, 139.11 (1C),
139.08, 136.36 (aryl C), 127.97 (4C, aryl C), 127.67 (4C, aryl C),
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* Supporting Information
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Figures giving H and 13C NMR spectra of the products and
́
́
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figures and a table giving results of theoretical calculations. This
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substrates, some unidentified precipitates generated from starting
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consumption of raw materials and a low yield of product.
AUTHOR INFORMATION
■
Corresponding Authors
*E-mail for C.-B.M.: estally@yahoo.com.
*E-mail for H.-T.Y.: yht898@yahoo.com.
Notes
(12) Gunduz, T.; Tast
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The authors declare no competing financial interest.
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