Synthesis of New Cyclopentenofullerenes Containing a Norbornene Fragment

Article abstract of DOI:10.1134/S1070428019090033

Endic acid imides were synthesized by direct fusion of endic anhydride with various amino acids. Further transformations of the resulting acids gave new 2,3-dienoic acids containing a norbornene fragment. Triphenylphosphine-catalyzed [3+2]-cycloaddition of the latter to fullerene C₆₀ afforded the corresponding cyclopentenofullerenes.

Full text of DOI:10.1134/S1070428019090033

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2019, Vol. 55, No. 9, pp. 1280–1286. © Pleiades Publishing, Ltd., 2019.
Russian Text © The Author(s), 2019, published in Zhurnal Organicheskoi Khimii, 2019, Vol. 55, No. 9, pp. 1359–1366.
Synthesis of New Cyclopentenofullerenes
Containing a Norbornene Fragment
I. M. Sakhautdinova and A. F. Mukhametyanovaa*
a Ufa Institute of Chemistry, Ufa Federal Research Center, Russian Academy of Sciences,
Ufa, Bashkortostan, Russia
*e-mail: afmhim@bk.ru
Received February 8, 2019; revised March 28, 2019; accepted April 12, 2019
Abstract—Endic acid imides were synthesized by direct fusion of endic anhydride with various amino acids.
Further transformations of the resulting acids gave new 2,3-dienoic acids containing a norbornene fragment.
Triphenylphosphine-catalyzed [3+2]-cycloaddition of the latter to fullerene C60 afforded the corresponding
cyclopentenofullerenes.
Keywords: endic anhydride, norbornene, amino acids, imides, fullerene, cyclopentenofullerenes.
DOI: 10.1134/S1070428019090033
Fullerene C60 and its many derivatives possess
a very high ability to trap free radicals. Experiments in
animals showed that these compounds increase resis-
tance to oxidative stress and inhibit neurodegenerative
processes, which may reduce the risk of Parkinson’s
and Alzheimer’s diseases [1, 2]. Interest in the chem-
istry of compounds containing a norbornene (bicyclo-
[2.2.1]hept-2-ene) fragment is determined by diverse
biological activity of derivatives of commercially
available bicyclo[2.2.1]hept-5-ene-endo-2,3-dicarbox-
ylic (endic) acid anhydride (1). In particular, numerous
imides obtained from anhydride 1 exhibit psychotropic
and antidepressant activity and are used as anti-
arrhythmic, antipyretic, sedative, and anti-inflam-
matory drugs [3, 4].
The goal of the present work was to synthesize new
fullerene C60 conjugates by phosphine-catalyzed
[3+2]-cycloaddition of 2,3-dienoates derived from
endic anhydride. For this purpose, endic acid imides
3a–3e and 5a–5d were prepared by direct fusion of
endic anhydride (1) with amino acids 2a–2e and 4a–
4d, respectively (Scheme 1). Further treatment of acids
3a–3e and 5a–5d in succession with oxalyl chloride
and triethylamine gave the corresponding ketenes
Scheme 1.
O
O
O
OH
O
( )n
N
O
+
H2N
( )n
OH
O
O
1
1
2a–2e
3a–3e
n = 1 (a), 2 (b), 3 (c), 4 (d), 5 (e).
O
O
OH
O
+
N
H2N
OH
R
R
O
4a–4d
5a–5d
R = Me (a), i-Pr (b), i-Bu (c), PhCH2 (d).
1280

SYNTHESIS OF NEW CYCLOPENTENOFULLERENES
1281
Scheme 2.
O
O
O
OMe
(1) (COCl)2, CH2Cl2
(2) Et3N
Ph3P=CHCOOMe
CH2Cl2
·
O
·
( )n–1
( )n–1
N
3a–3e
N
O
O
6a–6e
n = 1 (a), 2 (b), 3 (c), 4 (d), 5 (e).
O
O
O
COOMe
(1) (COCl)2, CH2Cl2
(2) Et3N
Ph3P=CHCOOMe
CH2Cl2
·
·
5a–5d
N
N
R
R
O
O
7a–7d
R = Me (a), i-Pr (b), i-Bu (c), PhCH2 (d).
which were subjected to Wittig olefination with methyl
2-(triphenyl-λ5-phosphanylidene)acetate in the pres-
ence of triethylamine to obtain new 2,3-dienoates 6a–
6e and 7a–7d containing a norbornene fragment
(Scheme 2).
reactions with electron-deficient alkenes, which lead
to the formation of unsaturated five-membered rings
[10–12]. By triphenylphosphine-catalyzed [3+2]-cy-
cloaddition of 6b–6e to fullerene as dipolarophile we
obtained in good yields new C60 monoadducts 8b–8e
which were readily soluble in organic solvents
(Scheme 3). Compounds 8b–8e were isolated by silica
gel column chromatography. We failed to obtain ful-
lerene adducts with esters 6a and 7a–7d, presumably
due to steric hindrances.
The structure of 6a–6e and 7a–7d was confirmed
1
by spectral data. In the H NMR spectra of these com-
pounds, protons of the allene fragment resonated in the
region δ 5.56–5.92 ppm; in the spectrum of glycine
derivative 6a, the corresponding signals were singlets
13
at δ 6.05 and 6.91 ppm. The C NMR spectra charac-
One-pot synthesis of 2,3-dienoates and good yields
of C60 conjugates via phosphine-catalyzed [3 +2]-
cycloaddition make the proposed approach promising
for the preparation of fullerene monoadducts. The
structure of the isolated compounds was confirmed
by a combination of spectral methods, including
two-dimensional HSQC and HMBC NMR experi-
ments (Fig. 1).
teristically displayed signals in the region δC 88.17–
96.06 ppm due to terminal carbons of the allene
fragment. In the spectra of α-substituted amino acid
derivatives 7a–7d, the signal of the =CR quaternary
carbon atom was located in a weaker field (δC >
105 ppm); the central allene carbon atom of 6a–6e and
7a–7d resonated at δC 208.69–212.54 ppm [5–8].
2,3-Dienoates activated by nucleophilic attack of
a phosphine on the central sp-carbon atom are success-
fully used as C3-building blocks [9] in cycloaddition
In summary, new fullerene C60 conjugates contain-
ing a norbornene fragment have been synthesized by
phosphine-catalyzed functionalization of the C60 core
Scheme 3.
4
O
8
O
MeO
O
5'
1'
4'
3'
3
7
O
OMe
1
N
PPh3, 110°C
2'
·
( )n–1
+ C60
( )n–1
O
N
O
6b–6e
8b–8e
8b, n = 2, 55%; 8c, n = 3, 40%; 8d, n = 4, 70%; 8e, n = 5, 80%.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019

SAKHAUTDINOV, MUKHAMETYANOVA
(a)
1282
7.67
(b)
H
5.31
H
H
H
O
O
H
H
H
C15
154.07
H
H
H
163.88
C10, 41.81
52.36
C11
H
H
3.93H
O 136.61
56.05
72.28
O
C79
H
C13
77.05
Fig. 1. 1H–13C HMBC correlations in the cyclopentene fragment of molecule 8b: (a) C15, C79; (b) C11.
with 2,3-dienoates. The obtained adducts are readily
soluble in organic solvents, which extends the scope of
their further transformations, in particular their use as
monomers.
7a-H), 4.12 s (2H, 2-H), 6.08 s (2H, 5-H, 6-H), 8.73 s
(1H, OH). 13C NMR spectrum, δC, ppm: 38.98 (C2′),
44.99 (C3a, C7a), 46.11 (C4, C7), 52.25 (C8), 134.67 (C5,
C6), 170.15 (C1′), 177.94 (C1, C3). Found, %: C 59.72;
H 5.00; N 6.35. C11H11NO4. Calculated, %: C 59.73;
H 5.01; N 6.33. M 221.21.
EXPERIMENTAL
3-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)propanoic acids (3b). Yield
1.84 g (79%), yellow thick oily material. IR spectrum,
ν, cm–1: 1229, 1462, 1680, 1738, 3163. 1H NMR spec-
trum (CDCl3), δ, ppm (J, Hz): 1.56 d and 1.73 d (1H
each, 8-H, J = 8.7), 2.54 t (2H, 2′-H, J = 8.7), 3.29 s
(2H, 3a-H, 7a-H), 3.39 s (2H, 4-H, 7-H), 3.65 t (2H,
3′-H, J = 7.5), 6.09 s (2H, 5-H, 6-H), 10.08 s (1H,
The IR spectra were recorded on a Shimadzu IR
Prestige-21 Fourier transform spectrophotometer
1
13
from samples dispersed in mineral oil. The H and C
NMR spectra were measured on a Bruker AM 500
spectrometer at 500.13 and 125.76 MHz, respectively,
using tetramethylsilane as internal standard. The prog-
ress of reactions was monitored by TLC on Sorbfil
PTSKh-AF-A plates; spots were visualized under UV
light, by treatment with iodine vapor, and by spraying
with a solution of ninhydrin or 4-methoxybenzalde-
hyde, followed by heating at 100–120°C. The mass
spectra were recorded on a Shimadzu LCMS-2010EV
instrument (atmospheric pressure chemical ionization).
The melting points were determined with a Boetius hot
stage. Column chromatography was performed using
silica gel (Chemapol) with a grain size of 40 to
100 μm. The elemental analyses were obtained with
a Euro EA 3000 CHNS analyzer.
13
OH). C NMR spectrum, δC, ppm: 31.76 (C3′), 33.63
(C2′), 44.91 (C3a, C7a), 45.65 (C4, C7), 52.15 (C8),
134.38 (C5, C6), 175.92 (C1′), 177.57 (C1, C3). Found,
%: C 61.28; H 5.60; N 5.93. C12H13NO4. Calculated,
%: C 61.27; H 5.57; N 5.95. M 235.08.
4-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)butanoic acid (3c). Yield
0.057 g (75%), yellow thick oily material. IR spectrum
(mineral oil), ν, cm–1: 725, 1229, 1571, 1681, 1736,
1
1762, 3294. H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 1.47 d and 1.61 d (1H each, 8-H, J = 8.7),
1.69 m (2H, 3′-H), 2.17 m (2H, 2′-H), 3.18 s (2H,
3a-H, 7a-H), 3.32 m (4H, 4-H, 4′-H, 7-H), 6.02 m (2H,
5-H, 6-H), 11.1 s (1H, OH). 13C NMR spectrum, δC,
ppm: 22.84 (C3′), 31.22 (C2′), 37.63 (C4′), 44.79 (C3a,
C7a), 45.62 (C4, C7), 52.18 (C8), 134.4 (C5, C6), 176.85
(C1′), 177.83 (C1, C3). Found, %: C 62.66; H 6.09;
N 5.63. C13H15NO4. Calculated, %: C 62.64; H 6.07;
N 5.62. M 249.26.
Compounds 3a–3e and 5a–5d (general proce-
dure). A mixture of 10 mmol of endic anhydride (1)
and 10 mmol of amino acid 2a–2e or 4a–4d was
thoroughly ground in a porcelain mortar and was then
heated for 1 h at 150°C on an oil bath. After cooling to
room temperature, the mixture was dissolved in pure
acetone, and the product was isolated by silica gel
column chromatography using anhydrous acetone as
eluent.
2-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)acetic acid (3a). Yield 1.39 g
(63%), white crystals, mp 139–141°C. IR spectrum, ν,
5-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)pentanoic acid (3d). Yield
1.78 g (68%), white crystals, mp 117–119°C. IR spec-
trum, ν, cm–1: 720, 1230, 1551, 1692, 1713, 3435.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.42–
1.56 m (4H, 3′-H, 4′-H, 8-H), 1.70 d (1H, 8-H, J =
1
cm–1: 1233, 1377, 1461, 1709, 1746, 3180. H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 1.57 d and 1.74 d
(1H each, 8-H, J = 8.6), 3.39 s (4H, 3a-H, 4-H, 7-H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019

SYNTHESIS OF NEW CYCLOPENTENOFULLERENES
1283
8.8), 2.31 t (2H, 2′-H, J = 7.3), 3.22 s (2H, 3a-H,
7a-H), 3.31 t (2H, 5′-H, J = 7.4), 3.35 s (2H, 4-H,
7-H), 6.06 s (2H, 5-H, 6-H), 10.64 s (1H, OH).
13C NMR spectrum, δC, ppm: 21.80 (C3′), 27.03 (C4′),
33.31 (C2′), 37.78 (C5′), 44.84 (C3a, C7a), 45.68 (C4,
C7), 52.22 (C8), 134.42 (C5, C6), 177.9 (C1, C3), 178.93
(C1′). Found, %: C 63.89; H 6.54; N 5.33. C14H17NO4.
Calculated, %: C 63.87; H 6.51; N 5.32. M 263.29.
2-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)-4-methylpentanoic acid (5c).
Yield 2.61 g (94%), light yellow crystals, mp 109–
111°C. IR spectrum, ν, cm–1: 720, 1228, 1462, 1562,
1680, 1747, 3280. 1H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.84 m (6H, CH3), 1.32 m (1H, 4′-H), 1.51 d
(1H, 8-H, J = 8.7), 1.69 d (1H, 8-H, J = 8.8), 1.75 m
and 1.94 m (1H each, 3′-H), 3.26 s (2H, 3a-H, 7a-H),
3.35 s (2H, 4-H, 7-H), 4.57 m (1H, 2′-H), 6.04 s (2H,
6-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)hexanoic acid (3e). Yield
2.07 g (75%), yellow oil. IR spectrum, ν, cm–1: 725,
13
5-H, 6-H), 10.53 s (1H, OH). C NMR spectrum, δC,
ppm: 20.82 (C1″), 23.01 (C5′), 24.62 (C4′), 36.43 (C3′),
44.87 (C3a, C7a), 45.90 (C4, C7), 46.01 (C2′), 52.67 (C8),
134.76 (C5, C6), 174.12 (C1′), 177.28 (C1, C3). Found,
%: C 65.00; H 6.89; N 5.25. C15H19NO4. Calculated,
%: C 64.97; H 6.91; N 5.05. M 263.29.
1
1227, 1552, 1695, 1731, 3273. H NMR spectrum
(CDCl3), δ, ppm (J, Hz): 1.19–1.57 m (6H, 3′-H, 4′-H,
5′-H, 8-H), 1.66 d (1H, 8-H, J = 8.7), 2.23 t (2H, 2′-H,
J = 7.3), 3.17 s (2H, 3a-H, 7a-H), 3.24 t (2H, 6′-H, J =
7.4 Hz), 3.31 s (2H, 4-H, 7-H), 6.03 s (2H, 5-H, 6-H),
2-[1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl]-3-phenylpropanoic acid (5d).
Yield 2.49 g (80%), white crystals, mp 152–154°C. IR
spectrum, ν, cm–1: 721, 1224, 1456, 1684, 1752, 3251.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.4 d (1H,
8-H, J = 8.6), 1.57 d (1H, 8-H, J = 8.5), 3.10 s (2H,
3a-H, 7a-H), 3.22 s (2H, 4-H, 7-H), 3.37 m (2H, 3′-H),
5.01 m (1H, 2′-H), 5.68 s (2H, 5-H, 6-H), 7.1–7.26 m
(5H, C6H5), 10.36 s (1H, OH). 13C NMR spectrum, δC,
ppm: 33.50 (C3′), 44.85 (C3a, C7a), 45.82 (C4, C7),
52.11 (C8), 52.48 (C2′), 126.91 (Cp), 128.57 (Cm),
129.01 (Co), 134.24 (C5, C6), 136.14 (Ci), 173.29 (C1′),
177.14 (C1, C3). Found, %: C 69.46; H 5.52; N 4.48.
C18H17NO4. Calculated, %: C 69.44; H 5.50; N 4.50.
M 263.29.
13
10.98 s (1H, OH). C NMR spectrum, δC, ppm: 24.12
(C4′), 26.18 (C3′), 27.35 (C5′), 33.77 (C2′), 37.99 (C6′),
44.8 (C3a, C7a), 45.61 (C4, C7), 52.15 (C8), 134.33 (C5,
C6), 177.95 (C1, C3), 178.51 (C1′). Found, %: C 64.98;
H 6.93; N 5.03. C15H19NO4. Calculated, %: C 64.97;
H 6.91; N 5.05. M 277.32.
2-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)propanoic acid (5a). Yield
1.72 g (73%), white crystals, mp 144–146°C. IR spec-
trum, ν, cm–1: 736, 1223, 1463, 1674, 1743, 3286.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.56 d and
1.67 d (1H each, 8-H, J = 8.5), 1.36 d (3H, C3′H3, J =
6.9), 3.28 s (2H, 3a-H, 7a-H), 3.36 s (2H, 4-H, 7-H),
4.62 m (1H, 2′-H), 6.06 s (2H, 5-H, 6-H), 10.53 s (1H,
13
OH). C NMR spectrum, δC, ppm: 14.21 (C3′), 44.96
Esters 6a–6e and 7a–7d (general procedure). Acid
3a–3e or 5a–5d, 1 g, was dispersed in 10 mL of
anhydrous methylene chloride, 5 equiv of oxalyl
chloride was added, and the mixture was left over-
night. The solvent and excess oxalyl chloride were
evaporated on a rotary evaporator, and the residue
(acid chloride) was used without further purification.
An equimolar amount of triethylamine was added
dropwise to a solution of 2-(triphenyl-λ5-phosphanyli-
dene)acetate in methylene chloride, the resulting
solution was cooled to –5°C, and a cold solution of
N-substituted amino acid chloride was slowly added
dropwise. The mixture was stirred for 2 h, the solvent
was distilled off, and the product was isolated from the
residue by silica gel column chromatography on silica
gel using petroleum ether–ethyl acetate (4:1) as eluent.
(C3a, C7a), 45.77 (C4, C7), 47.04 (C2′), 52.11 (C8),
134.46 (C5, C6), 174.14 (C1′), 176.90 (C1, C3). Found,
%: C 61.25; H 6.00; N 5.93. C12H13NO4. Calculated,
%: C 61.27; H 5.57; N 5.95. M 235.24.
2-(1,3-Dioxo-1,3,3a,4,7,7a-hexahydro-2H-4,7-
methanoisoindol-2-yl)-3-methylbutanoic acid (5b).
Yield 1.89 g (72%), white crystals, mp 107–109°C. IR
spectrum, ν, cm–1: 721, 1193, 1213, 1404, 1512, 1676,
1
1708, 3225. H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.74 d (3H, CH3, J = 6.9), 0.96 d (3H, CH3,
J = 6.7), 1.54 d (1H, 8-H, J = 8.5), 1.72 d (1H, 8-H, J =
9.0), 2.46 m (3H, C3′H3), 3.29 s (2H, 3a-H, 7a-H),
3.35 s (2H, 4-H, 7-H), 4.22 d (1H, 2′-H, J = 8.0),
6.09 s (2H, 5-H, 6-H), 10.8 s (1H, OH). 13C NMR
spectrum, δC, ppm: 19.36 (C4′), 20.76 (C5′), 27.75 (C3′),
44.88 (C3a, C7a), 45.91 (C4, C7), 52.67 (C8), 57.64 (C2′),
134.93 (C5, C6), 173.01 (C1′), 177.39 (C1, C3). Found,
%: C 63.89; H 6.49; N 5.35. C14H17NO4. Calculated,
%: C 63.87; H 6.51; N 5.32. M 263.29.
Methyl 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)buta-2,3-dienoate (6a).
Yield 0.53 g (45%), yellow oil. IR spectrum, ν, cm–1:
719, 1170, 1380, 1456, 1598, 1704. 1H NMR spectrum
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019

SAKHAUTDINOV, MUKHAMETYANOVA
1284
(CDCl3), δ, ppm (J, Hz): 1.51 d (1H, 8-H, J = 8.9),
1.69 d (1H, 8-H, J = 8.8), 3.29 s (2H, 3a-H, 7a-H),
3.36 s (2H, 4-H, 7-H), 3.68 s (3H, OCH3), 6.05 s (1H,
4′-H), 6.09 s (2H, 5-H, 6-H), 6.91 s (1H, 2′-H).
13C NMR spectrum, δC, ppm: 45.24 (C3a, C7a), 45.88
(C4, C7), 52.16 (OCH3), 52.31 (C8), 91.31 (C4′), 96.06
(C2′), 134,56 (C5, C6), 164.43 (C1′), 174.14 (C1, C3),
210.13 (C2′). Found, %: C 64.84; H 5.08; N 5.42.
C14H13NO4. Calculated, %: C 64.86; H 5.05; N 5.40.
M 259.26.
(C5, C6), 164.44 (C1′), 177.68 (C1, C3), 212.23 (C3′).
Found, %: C 67.78; H 6.38; N 4.67. C17H19NO4.
Calculated, %: C 67.76; H 6.36; N 4.65. M 301.34.
Methyl 8-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)octa-2,3-dienoate (6e).
Yield 0.5 g (50%), transparent oil. IR spectrum, ν,
cm–1: 724, 1162, 1263, 1398, 1437, 1698, 1763, 1959.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.31–
1.43 m (6H, 6′-H, 7′-H, 8′-H), 1.48 d and 1.68 d (1H
each, 8-H, J = 8.6), 2.08 m (2H, 5′-H), 3.19 s (2H,
3a-H, 7a-H), 3.34 s (2H, 4-H, 7-H), 3.68 s (3H,
OCH3), 5.52 m (2H, 2′-H, 4′-H), 6.03 s (2H, 5-H, 6-H).
13C NMR spectrum, δC, ppm: 25.75 (C6′), 26.85 (C7′),
26.97 (C5′), 37.92 (C8′), 44.85 (C3a, C7a), 45.67 (C4,
C7), 51.98 (OCH3), 52.20 (C8), 88.17 (C2′), 94.86 (C4′),
134.40 (C5, C6), 166.51 (C1′), 177.52 (C1, C3), 212.28
(C3′). Found, %: C 68.58; H 6.73; N 4.46. C18H21NO4.
Calculated, %: C 68.55; H 6.71; N 4.44. M 315.36.
Methyl 5-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)penta-2,3-dienoate (6b).
Yield 1.12 g (96%), transparent oil. IR spectrum, ν,
cm–1: 728, 1172, 1336, 1389, 1413, 1704, 1722, 2104.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.46 d
(1H, 8-H, J = 8.9), 1.67d (1H, 8-H, J = 8.8), 3.18 s
(2H, 3a-H, 7a-H), 3.34 s (2H, 4-H, 7-H), 3.67 s (3H,
OCH3), 4.01 m (2H, 6′-H), 5.52 m (1H, 3′-H), 5.62 m
(1H, 5′-H), 6.06 s (2H, 5-H, 6-H). 13C NMR spectrum,
δC, ppm: 35.35 (C5′), 45.03 (C3a, C7a), 45.74 (C4, C7),
52.08 (OCH3), 52.12 (C8), 89.96 (C4′), 90.36 (C2′),
134.46 (C5, C6), 165.38 (C1′), 176.79 (C1, C3), 212.54
(C3′). Found, %: C 65.90; H 5.53; N 5.15. C15H15NO4.
Calculated, %: C 65.92; H 5.53; N 5.13. M 273.28.
Methyl 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)penta-2,3-dienoate (7a).
Yield 0.47 g (40%), transparent oil. IR spectrum, ν,
1
cm–1: 721, 1157, 1417, 1568, 1722, 1742. H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 1.26 d (3H, CH3,
J = 7.0), 1.51 d (1H, 8-H, J = 8.7), 1.74 d (1H, 8-H,
J = 8.8), 3.28 s (2H, 3a-H, 7a-H), 3.43 s (2H, 4-H,
7-H), 3.68 s (3H, OCH3), 4.58 m (1H, 2′-H), 6.12 s
(2H, 5-H, 6-H). 13C NMR spectrum, δC, ppm: 14.21
(C3′), 45.28 (C3a, C7a), 45.93 (C4, C7), 52.24 (OCH3),
52.24 (C8), 88.74 (C2′), 110.79 (C4′), 134.50 (C5, C6),
166.96 (C1′), 176.83 (C1, C3), 208.69 (C3′). Found, %:
C 65.94; H 5.55; N 5.15. C15H15NO4. Calculated, %:
C 65.92; H 5.53; N 5.13. M 273.28.
Methyl 6-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)hexa-2,3-dienoate (6c).
Yield 0.91 g (87%), thick yellow oil. IR spectrum, ν,
cm–1: 726, 1164, 1262, 1397, 1436, 1498, 1767, 1962.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.12 m
(2H, 6′-H), 1.44 d (1H, 8-H, J = 8.7), 1.61 d (1H, 8-H,
J = 7.3), 2.17 m (2H, 5′-H), 3.24 s (2H, 3a-H, 7a-H),
3.34 s (2H, 4-H, 7-H), 3.58 s (3H, OCH3), 5.46 m (2H,
2′-H, 4′-H), 5.96 s (2H, 5-H, 6-H). 13C NMR spectrum,
δC, ppm: 25.80 (C5′), 35.94 (C6′), 45.71 (C3a, C7a),
45.62 (C4, C7), 52.05 (OCH3), 52.36 (C8), 89.29 (C2′),
91.87 (C4′), 134.34 (C5, C6), 165.93 (C1′), 177.47 (C1,
C3), 212.31 (C3′). Found, %: C 66.87; H 5.99; N 4.90.
C16H17NO4. Calculated, %: C 66.89; H 5.96; N 4.88.
M 287.31.
Methyl 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-
2H-4,7-methanoisoindol-2-yl)-5-methylhexa-2,3-
dienoate (7b). Yield 0.48 g (48%), yellow oil. IR
spectrum, ν, cm–1: 722, 1170, 1377, 1469, 1593, 1708.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.97 d
(3H, 6′-H, J = 6.8), 1.01 d (3H, 7′-H, J = 7.0), 1.53 d
(1H, 8-H, J = 8.9), 1.72 d (1H, 8-H, J = 8.8), 2.73 m
(1H, 5′-H), 3.29 s (2H, 3a-H, 7a-H), 3.41 s (2H, 4-H,
7-H), 3.72 s (3H, OCH3), 5.92 m (1H, 2′-H), 6.13 s
(2H, 5-H, 6-H). 13C NMR spectrum, δC, ppm: 19.95
(C6′, C7′), 28.70 (C5′), 45.30 (C3a, C7a), 45.97 (C4, C7),
52.21 (OCH3), 52.23 (C8), 94.17 (C2′), 113.55 (C4′),
134.72 (C5, C6), 164.59 (C1′), 175.73 (C1, C3), 209.80
(C3′). Found, %: C 67.78; H 6.33; N 4.67. C17H19NO4.
Calculated, %: C 67.76; H 6.36; N 4.65. M 301.34.
Methyl 7-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-2H-
4,7-methanoisoindol-2-yl)hepta-2,3-dienoate (6d).
Yield 1.03 g (90%), transparent oil. IR spectrum, ν,
cm–1: 728, 1162, 1263, 1398, 1439, 1688, 1763, 1975.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 1.51–
1.61 m (4H, 6′-H, 7′-H), 1.62 d (1H, 8-H, J = 8.7),
1.71 d (1H, 8-H, J = 7.3), 2.08 m (2H, 5′-H), 3.23 s
(2H, 3a-H, 7a-H), 3.36 s (2H, 4-H, 7-H), 3.71 s (3H,
OCH3), 5.58 m (2H, 2′-H, 4′-H), 6.03 s (2H, 5-H, 6-H).
13C NMR spectrum, δC, ppm: 24.87 (C6′), 25.82 (C7′),
26.79 (C5′), 44.90 (C3a, C7a), 45.71 (C4, C7), 52.02
(OCH3), 52.24 (C8), 88.57 (C2′), 94.32 (C4′), 134.42
Methyl 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-
2H-4,7-methanoisoindol-2-yl)-6-methylhepta-2,3-
dienoate (7c). Yield 0.42 g (35%), yellow oil. IR
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019

SYNTHESIS OF NEW CYCLOPENTENOFULLERENES
1285
spectrum, ν, cm–1: 727, 1163, 1386, 1437, 1684, 1710.
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.71 m
(6H, 7′-H, 8′-H, J = 6.8), 1.41 m (2H, 8-H, 6′-H),
1.53 d (1H, 8-H, J = 9.0), 1.95 m (1H, 6′-H), 2.02 m
(2H, 5′-H), 3.14 s (2H, 3a-H, 7a-H), 3.21 s (2H, 4-H,
7-H), 3.54 s (3H, OCH3), 5.69 m (1H, 2′-H), 5.93 s
(2H, 5-H, 6-H). 13C NMR spectrum, δC, ppm: 20.79
(C7′, C8′), 24.30 (C6′), 36.18 (C5′), 45.40 (C3a, C7a),
45.92 (C4, C7), 52.02 (OCH3), 52.30 (C8), 92.40 (C2′),
106.34 (C4′), 134.50 (C5, C6), 164.23 (C1′), 176.26 (C1,
C3), 210.86 (C3′). Found, %: C 69.26; H 7.06; N 4.24.
C18H21NO4. Calculated, %: C 69.28; H 7.04; N 4.25.
M 329.39.
(OCH3), 52.68 (C8), 55.23 (OCH3), 72.22 (C2′), 72.27
(C1′), 128.57, 128.68, 131.80, 131.88, 134.29, 134.46,
134.71, 135.05 (C5, C6), 135.58, 135.69, 136.55,
136.67, 139.35, 139.41, 139.81, 140.44, 141.61,
141.72, 141.83, 141.89, 141.94, 142.25, 142.46,
142.67, 142.72, 142.73, 142.79, 143.11, 143.13,
144.33, 144.46, 144.50, 144.57, 145.20, 145.29 (C4′),
145.35, 145.44, 145.53, 145.63, 145.89, 145.90,
146.06, 146.16, 146.26, 146.29, 146.32, 146.39,
147.29, 147.41, 148.08 (C5′), 150.46, 150.52, 150.77,
156.14, 163.90 (5′-C=O), 177.53 (C1, C3). Found, %:
C 90.58; H 1.72; N 1.41. C75H15NO4. Calculated, %:
C 90.56; H 1.70; N 1.39. M 1007.95.
Methyl 3′-{2-[1,3-dioxo-1,3,3a,4,7,7a-tetrahydro-
2H-4,7-methanoisoindol-2-yl]ethyl}-3′H-cyclopenta-
[1,9](C60-Ih)[5,6]fullerene-5′-carboxylate (8c). Yield
Methyl 4-(1,3-dioxo-1,3,3a,4,7,7a-hexahydro-
2H-4,7-methanoisoindol-2-yl)-5-phenylpenta-2,3-
dienoate (7d). Yield 0.54 g (51%), white crystals,
mp 89–91°C. IR spectrum, ν, cm–1: 717, 1162, 1269,
1349, 1456, 1710. 1H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 1.41 d (1H, 8-H, J = 8.7), 1.56 d (1H, 8-H, J =
8.8), 3.16 s (2H, 3a-H, 7a-H), 3.25 s (2H, 4-H, 7-H),
3.37 m (2H, 3′-H), 3.76 s (3H, OCH3), 5.51 m (1H,
2′-H), 5.93 s (2H, 5-H, 6-H), 7.1–7.26 (5H, C6H5).
13C NMR spectrum, δC, ppm: 36.16 (C5′), 45.09 (C3a,
C7a), 45.82 (C4, C7), 51.88 (OCH3), 52.37 (C8), 93.00
(C2′), 105.91 (C4′), 126.09 (Cp), 128.29 (Cm), 129.27
(Co), 134.11 (C5, C6), 135.61 (Ci), 164.41 (C1′), 175.34
(C1, C3), 211.13 (C3′). Found, %: C 72.17; H 5.51;
N 4.03. C21H19NO4. Calculated, %: C 72.19; H 5.48;
N 4.01. M 349.38.
1
0.056 g (40%). H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 1.74 d (1H, 8-H, J = 8.5), 1.91 d (1H, 8-H, J =
9.0), 2.33 m and 2.68 m (1H each, NCH2), 3.21 s (2H,
4-H, 7-H), 3.33 m (2H, 3′-CH2), 3.52 s (2H, 3a-H,
7a-H), 3.55 m (1H, 3′-H), 3.72 s (3H, OCH3), 6.09 s
(2H, 5-H, 6-H) , 7.26 m (1H, 4′-H). 13C NMR spec-
trum, δC, ppm: 25.78 (NCH2), 36.96 (3′-CH2), 45.03
(C4, C7H), 45.93 (C3a, C7aH), 52.16 (OCH3), 52.52
(C8), 54.69 (C3″H3), 76.22 (C2′), 77.24 (C1′), 128.46,
128.56, 131.20, 132.07, 132.15, 133.93, 134.41,
134.53, 134.62, 134.79, 134.95, 135.95 (C5, C6),
135.56, 135.95, 136.14, 139.28, 139.40, 139.83,
140.15, 141.57, 141.65, 141.91, 142.02, 142.16,
142.24, 142.43, 142.63, 142.68, 142.73, 143.07,
143.10, 144.41, 144.47, 144.51, 145.14, 145.27,
145.47, 145.59, 145.92, 145.99, 146.12, 146.21,
146.29, 146.32, 146.39, 146.71 (C4′), 147.25, 147.38,
148.22 (C5′), 150.54, 150.82, 152.03, 156.49, 164.08
(5′-C=O), 177.68 (C1, C3). Found, %: C 90.54; H 1.72;
N 1.37. C76H17NO4. Calculated, %: C 90.56; H 1.70;
N 1.39. M 1007.95.
Cyclopentenofullerenes 8b–8e (general proce-
dure). Fullerene C60, 100 mg (0.14 mmol), was pre-
liminarily dissolved in 35 mL of toluene, the solution
was kept for 12 h, a solution of 0.14 mmol of ester 6b–
6e in 5 mL of toluene (compounds 6b–6e were dis-
solved at room temperature) was added, and an equi-
molar amount of triphenylphosphine was then added.
The mixture was refluxed for 12 h with stirring on
a magnetic stirrer (300 rpm), and the product was
isolated by flash chromatography using petroleum
ether–ethyl acetate (4:1) as eluent.
Methyl 3′-{3-[1,3-dioxo-1,3,3a,4,7,7a-tetrahydro-
2H-4,7-methanoisoindol-2-yl]propyl}-3′H-cyclo-
penta[1,9](C60-Ih)[5,6]fullerene-5′-carboxylate (8d).
Yield 0.1 g (70%). 1H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 1.51 m (2H, 3′-CH2CH2), 1.57 d (1H, 8-H, J =
7.4), 1.72 d (1H, 8-H, J = 9.0), 2.02 m and 2.48 m (1H
each, NCH2), 3.36 s (2H, 4-H, 7-H), 3.37 m (2H,
3′-CH2), 3.54 s (2H, 3a-H, 7a-H), 3.71 s (3H, OCH3),
4.62 m (3′-H), 6.07 s (2H, 5-H, 6-H), 7.65 m (1H,
4′-H). 13C NMR spectrum, δC, ppm: 24.89, 26.81,
32.63, 45.64 (C4, C7), 45.77 (C3a, C7a), 52.27 (OCH3),
52.68 (C8), 57.06, 76.22 (C2′), 77.24 (C1′), 128.46,
128.56, 131.20, 132.07, 132.15, 133.93, 134.41,
134.53, 134.62, 134.79, 134.95, 135.95 (C5, C6),
Methyl 3′-{[1,3-dioxo-1,3,3a,4,7,7a-tetrahydro-
2H-4,7-methanoisoindol-2-yl]methyl}-3′H-cyclo-
penta[1,9](C60-Ih)[5,6]fullerene-5′-carboxylate (8b).
1
Yield 0.071 g (55%). H NMR spectrum (CDCl3), δ,
ppm (J, Hz): 1.71 d (1H, 8-H, J = 8.5), 1.91 d (1H,
8-H, J = 9.0), 3.49 s (2H, 4-H, 7-H), 3.58 s (2H, 3a-H,
7a-H), 3.78 s (3H, OCH3), 4.39 d and 4.41 d (1H each,
3′-CH2, J = 5.0), 5.03 m (1H, 3′-H), 6.38 s (2H, 5-H,
6-H), 7.56 m (1H, 4′-H). 13C NMR spectrum, δC, ppm:
42.26 (3′-CH2), 45.26 (C4, C7), 46.04 (C3a, C7a), 52.42
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019

SAKHAUTDINOV, MUKHAMETYANOVA
1286
135.56, 135.95, 136.14, 139.28, 139.40, 139.83,
140.15, 141.57, 141.65, 141.91, 142.02, 142.16,
142.24, 142.43, 142.63, 142.68, 142.73, 143.07,
143.10, 144.37, 145.25 (C4′), 145.88, 146.07, 147.22,
147.29, 147.99, 148.11 (C5′), 150.49, 150.86, 156.72,
163.98 (5′-C=O), 177.57 (C1, C3). Found, %: C 90.51;
H 1.88; N 1.39. C77H19NO4. Calculated, %: C 90.49;
H 1.87; N 1.37. M 1021.98.
CONFLICT OF INTERESTS
The authors declare the absence of conflict of
interests.
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2H-4,7-methanoisoindol-2-yl]butyl}-3′H-cyclo-
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6. Sakhautdinov, I.M., Gumerov, A.M., Batyrshin, I.R.,
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Heterocycles, 2014, vol. 89, p. 641. doi 10.3987/COM-
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Zakiryanova, O.V., and Yunusov, M.S., Chem. Nat.
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8. Sakhautdinov, I.M., Gumerov, A.M., Malikova, R.N.,
Fatykhov, A.A., and Yunusov, M.S., Chem. Nat.
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1
Yield 0.136 g (80%). H NMR spectrum (CDCl3), δ,
ppm (J, Hz): 1.22 s (2H, 3′-CH2), 1.50 m (2H,
NCH2CH2), 1.66 d (1H, 8-H, J = 7.4), 1.71 d (1H, 8-H,
J = 9.0), 2.12 m and 2.58 m (1H each, 3′-CH2CH2),
3.27 s (2H, 4-H, 7-H), 3.39 m (2H, NCH2), 3.56 s (2H,
3a-H, 7a-H), 3.70 s (3H, OCH3), 5.24 m (1H, 3′-H),
6.02 s (2H, 5-H, 6-H), 7.62 m (1H, 4′-H). 13C NMR
spectrum, δC, ppm: 19. 87 (3′-CH2), 20. 02
(3′-CH2CH2), 29.26 (NCH2CH2), 32.47 (NCH2), 44.88
(C4, C7), 45.70 (C3a, C7a), 52.27 (OCH3), 53.50 (C8),
69.47 (OCH3), 76.22 (C2′), 77.24 (C1′), 94.54, 120.71,
128.54, 128.64, 131.71, 132.07, 132.44, 133.47,
134.09, 134.42, 134.53, 134.62, 134.79, 134.95,
135.95 (C5, C6), 135.56, 135.95, 136.14, 139.28,
139.40, 139.83, 140.15, 141.57, 141.65, 141.91,
142.02, 142.16, 142.24, 142.43, 142.63, 142.68,
142.73, 143.07, 143.10, 144.37, 145.25 (C4′), 145.88,
146.07, 147.22, 147.29, 147.99, 148.11 (C5′), 150.49,
150.86, 156.72, 166.30 (5′-C=O), 177.68 (C1, C3).
Found, %: C 90.45; H 2.06; N 1.34. C78H21NO4. Cal-
culated, %: C 90.43; H 2.04; N 1.35. M 1021.98.
9. Modern Allene Chemistry, Krause, N. and
ACKNOWLEDGMENTS
Hashmi, A.S.K., Eds., Weinheim: Wiley, 2004.
10. Ikuma, N., Inaba, S., Kokubo, K., and Oshima, T.,
Chem. Commun., 2014, vol. 50, p. 581. doi 10.1039/
C3CC45783D
The spectral studies were performed using the
facilities of the “Chemistry” joint center, Ufa Institute
of Chemistry, Russian Academy of Sciences.
11. Sakhautdinov, I.M., Malikova, R.N., Akchurina, O.V.,
Petrova, S.F., and Yunusov, M.S., Lett. Org. Chem.,
FUNDING
2017,
vol.
14,
p.
575.
doi
10.2174/
1570178614666170614091621
This study was performed in the framework of
research program “Synthesis of Biologically Active
Heterocyclic and Terpenoid Compounds” (state
registry no. AAAA-A17-117011910025-6).
12. Sakhautdinov, I.M., Malikova, R.N., Nugumanov, T.R.,
Biglova, Yu.N., Atangulov, A.B., and Yunusov, M.S.,
Chem. Nat. Compd., 2018, vol. 54, p. 481. doi 10.1007/
s10600-018-2384-1
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 55 No. 9 2019