N-heterocyclic carbenes: IX. Oxidative esterification of aromatic aldehydes with arylboronic acids catalyzed by N-heterocyclic carbenes

Article abstract of DOI:10.1134/S1070428015010145

Aromatic aldehydes reacted with arylboronic acids under catalysis by N-heterocyclic carbene and oxic conditions to produce phenol esters.

Full text of DOI:10.1134/S1070428015010145

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2015, Vol. 51, No. 1, pp. 86–90. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © M.S. Denisov, A.A. Gorbunov, V.A. Glushkov, 2015, published in Zhurnal Organicheskoi Khimii, 2015, Vol. 51, No. 1, pp. 89–93.
N-Heterocyclic Carbenes: IX.* Oxidative Esterification
of Aromatic Aldehydes with Arylboronic Acids
Catalyzed by N-Heterocyclic Carbenes
M. S. Denisov, A. A. Gorbunov, and V. A. Glushkov
Institute of Technical Chemistry, Ural Branch, Russian Academy of Sciences,
ul. Akad. Koroleva 3, Perm, 614013 Russia
e-mail: m189@mail.ru
Received July 30, 2014
Abstract—Aromatic aldehydes reacted with arylboronic acids under catalysis by N-heterocyclic carbene and
oxic conditions to produce phenol esters.
DOI: 10.1134/S1070428015010145
Esterification with the aid of N-heterocyclic
carbenes (NHCs) is now a widely recognized synthetic
method of organocatalysis [2–4]. We have found no
data on the use of NHCs in esterification reactions in
the Russian scientific literature, but examples of NHC-
catalyzed transesterification have been reported [5].
The goal of the present work was to determine the
scope of application of oxidative esterification.
Esterification of aldehydes with phenols catalyzed
by NHCs via intramolecular redox reaction has recent-
ly been reported. These reactions are typical of al-
dehydes containing oxidizing groups, such as α-halo
aldehydes [6, 7], 2,3-epoxy aldehydes [8], and α,β-un-
saturated aldehydes [9]. Later it was shown that not
only electron-withdrawing group in the substrate but
also atmospheric oxygen can act as oxidant in NHC-
catalyzed esterification, which made it possible to ex-
tend the series of aldehydes capable of reacting in this
way [10, 11]. However, such aerobic esterification
turned out to be inapplicable to phenols. An alternative
route is the synthesis of phenol esters from arylboronic
acids [12]. For this purpose, palladium complexes with
NHCs were used as catalyst. The procedure ensured
preparation of phenol esters from aromatic aldehydes
and arylboronic acids under oxic conditions, but the
yields were low. Gois et al. [13, 14] succeeded in
raising the yield to 92% by replacing palladium(II) by
iron(III). As shown subsequently in [15, 16], iron is
not necessary to catalyze the reaction since N-hetero-
cyclic carbenes themselves are active as organo-
catalysts.
We have synthesized 1-naphthyl and 4-tolyl esters
in 25–63% yields by oxidative esterification, i.e., by
NHC-catalyzed reaction of 4-methylphenyl- or
naphthalen-1-ylboronic acid with aromatic aldehydes
(Scheme 1). Taking into account published data
[15, 16], as NHC catalyst we selected 1,3-dimesityl-
4,5-dihydroimidazol-2-ylidene which was generated
in situ from 1,3-dimesityl-4,5-dihydroimidazolium
chloride [17] by the action of cesium carbonate. The
reaction mechanism was discussed previously [15, 16];
Scheme 2 shows a simplified version.
Scheme 1.
Cl– (10 mol %)
N
Mes
Mes
OH
B
O
O
O2, Cs2CO3 (1.5 equiv), PhMe, 50°C, 3 h
+
R1
OH
R2
H
R2
OR1
1a–1h, 2a, 2b
1, R1 = 4-MeC6H4, R2 = pyridin-2-yl (a), pyridin-3-yl (b), pyridin-4-yl (c), 2-thienyl (d), PhCH=CH (e), 3,4-(MeO)2C6H3 (f),
3,4,5-(MeO)3C6H2 (d), ferrocenyl (h); 2, R1 = 1-naphthyl, R2 = pyridin-3-yl (a), ferrocenyl (b).
* For communication VIII, see [1].
86

N-HETEROCYCLIC CARBENES: IX.
87
Scheme 2.
Cl–
N
Mes
Mes
O
Cs2CO3
Ar'
Ar
O
N
ArCHO
B(OH)3
Mes
Mes
··
N
N
Mes
Mes
Mes
Mes
OB(OH)2
OH
OAr'
Ar
Ar
OH
O2
N
Mes
Mes
Ar'B(OH)2
OH
O
Ar
O
B
OH
Ar'
OH
Different pyridinecarbaldehydes were reacted with
4-methylphenylboronic acid. The position of the
heteroatom with respect to the aldehyde group did not
affect the reactivity, and the conversion of isomeric
pyridine-2-, -3-, and -4-carbaldehydes was about ~90%
(according to the GC/MS data). Pyridinecarbaldehydes
may be regarded as electron-deficient. There are
published data, according to which electron-deficient
aldehydes are less reactive in oxidative esterification
[15, 16, 18], while the opposite was stated in [14]. We
have not revealed a statistically significant difference
in the reactivities of electron-deficient and electron-
rich aldehydes. The yields of the corresponding esters
from thiophene-2-carbaldehyde, 3,4-dimethoxybenzal-
dehyde, and 3,4,5-trimethoxybenzaldehyde (98, 100,
and 85%, respectively) were comparable with those
obtained in the reactions with pyridinecarbaldehydes
(92, 90, 89%). 3,4-Dimethoxybenzaldehyde turned out
to be the most reactive. In the reaction with thiophene-
2-carbaldehyde we isolated 22% of 1,2-dithienyl-
ethane-1,2-dione as by product. Cinnamaldehyde and
ferrocenecarbaldehyde also reacted with arylboronic
acids in the presence of NHC; in the latter case, the
temperature should be raised to 70°C. Among the
examined aldehydes, only vanillin and salicylaldehyde
failed to react. Taking into account high reactivity of
3,4-dimethoxybenzaldehyde, we presumed that the
presence of a phenolic hydroxy group makes vanillin
and salicylaldehyde non-reactive.
As stated in [13, 14, 16], steric hindrances are
essential for reactions with arylboronic acids. To verify
this statement we examined the reactions of pyridine-
3-carbaldehyde and ferrocenecarbaldehyde with naph-
thalen-1-ylboronic acid and revealed no reduction of
the reactivity. Naphthalen-1-yl ferrocenecarboxylate
was synthesized by us for the first time.
In summary, we have developed a simple prepara-
tive procedure for the synthesis of aryl arenecarbox-
ylates and estimated its application scope.
EXPERIMENTAL
The IR spectra were recorded on a Bruker IFS 66ps
spectrometer with Fourier transform from samples
1
dispersed in mineral oil. The H and 13C NMR spectra
were recorded from solutions in CDCl3 on a Varian
Mercury Plus 300 instrument at 300 and 75 MHz, re-
spectively, using hexamethyldisiloxane (1H) or solvent
signals as reference. The melting points were deter-
mined on a PTP melting point apparatus. The products
were isolated by column chromatography on Silicagel
60 (Alfa Aesar, 0.032–0.070 mm) using petroleum
ether–ethyl acetate [gradient elution, 20:1 to 1:1 (1b,
1c), to 3:1 (1a, 2a), to 5:1 (1f), to 10:1 (1g, 1h, 2b);
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

DENISOV et al.
88
3
2.37 s (3H, Me), 7.09 d (2H, 2′-H, 6′-H, J = 8.4 Hz),
7.23 d (2H, 3′-H, 5′-H, 3J = 8.4 Hz), 7.53 d.d (1H, 5-H,
3J = 7.5, 4.8 Hz), 8.44 d (1H, 4-H, 3J = 7.5 Hz), 8.84 d
(1H, 6-H, J = 4.8 Hz), 9.39 s (2-H). Mass spectrum, m/z
(Irel, %): 213 (15) [M]+·, 107 (10) [TolO]+, 106 (100)
[PyCO]+, 78 (46) [Py]+, 77 (10) [Py – H]+, 51 (15).
20:1 (1d, 1e)]. The purity of the isolated compounds
was checked by GC/MS on an Agilent Technologies
6890N/5975B GC/MS system (HP-5MS capillary
column, 30000×0.25 mm; injector temperature 260°C,
oven temperature programming at a rate of 20 to
40 deg/min; carrier gas helium, flow rate 1 mL/min;
electron impact, 70 eV).
4-Methylphenyl pyridine-4-carboxylate (1c) was
synthesized from 0.062 mL of pyridine-4-carbaldehyde
and 68 mg of 4-methylphenylboronic acid. Yield
60 mg (56%; 89%, GC/MS), white crystals, mp 69–
71°C [22], Rf 0.55 (petroleum ether–ethyl acetate,
1:1). IR spectrum, ν, cm–1: 1743, 1410, 1325, 1272,
1218, 1196, 1171, 1098, 1085, 1063, 1025, 880, 848,
4-Methylphenylboronic acid and naphthalen-1-yl-
boronic acid were synthesized as described in [19].
General procedure for the synthesis of esters 1
and 2. A mixture of 17.1 mg (0.05 mmol) of 1,3-bis-
(2,4,6-trimethylphenyl)-4,5-dihydro-3H-imidazol-
1-ium chloride, 244 mg (0.75 mmol) of Cs2CO3,
0.65 mmol of the corresponding aldehyde, 0.5 mmol of
arylboronic acid, and 5 mL of toluene was stirred for
3 h at 50°C (at 70°C in the synthesis of 1h). When the
reaction was complete, a sample of the reaction mix-
ture was withdrawn, dried over MgSO4, diluted with
methylene chloride to a product concentration of
~1 mg/mL, and analyzed by GC/MS. The solvent was
distilled off from the reaction mixture on a rotary
evaporator, and the residue was purified by column
chromatography.
1
830, 751, 670, 510. H NMR spectrum, δ, ppm: 2.37 s
(3H, Me), 7.09 d (2H, 2′-H, 6′-H, J = 8.4 Hz), 7.23 d
3
3
(2H, 3′-H, 5′-H, J = 8.4 Hz), 8.01 d.d (2H, 3-H, 5-H,
3J = 4.8, J = 1.5 Hz), 8.85 d (2H, 2-H, 6-H, J =
4.8 Hz). Mass spectrum, m/z (Irel, %): 213 (18) [M]+·,
107 (13) [TolO]+, 106 (100) [PyCO]+, 79 (6) [PyH]+,
78 (52) [Py]+, 77 (13) [Py – H]+, 51 (24), 50 (7).
4
3
4-Methylphenyl thiophene-2-carboxylate (1d)
was synthesized from 0.061 mg of thiophene-2-carbal-
dehyde and 68 mg of 4-methylphenylboronic acid.
Yield 126 mg (62%; 98%, GC/MS), yellow powder,
mp 77–83°C (published data [23]: mp 85–87°C),
Rf 0.55 (petroleum ether–ethyl acetate, 7:3). IR spec-
trum, ν, cm–1: 3108, 3099, 3090, 3080, 1713, 1648,
1609, 1595, 1525, 1313, 1255, 1224, 1210, 1197,
1165, 1102, 1083, 1063, 1022, 954, 866, 854, 841,
4-Methylphenyl pyridine-2-carboxylate (1a) was
synthesized from 0.062 mL of pyridine-2-carbaldehyde
and 68 mg of 4-methylphenylboronic acid. Yield
61 mg (58%; 92% according to GC/MS), gray crystals,
mp 76–79°C [20], Rf 0.56 (petroleum ether–ethyl
acetate, 1:1). IR spectrum, ν, cm–1: 1750, 1665, 1580,
1508, 1303, 1278, 1236, 1189, 1167, 1113, 1072, 1047,
1017, 993, 879, 817, 805, 750, 701, 687, 618, 514.
1H NMR spectrum, δ, ppm: 2.36 s (3H, Me), 7.12 d
1
820, 792, 744, 698, 663, 636, 567, 517, 500. H NMR
spectrum, δ, ppm: 2.34 s (3H, Me), 7.07 d (2H, Harom),
7.13 d.d (1H, 4-H, 3J = 5.1, 3.6 Hz), 7.18 d (2H, Harom),
7.61 d.d (1H, 3-H, 3J = 5.1, 4J = 1.2 Hz), 7.94 d.d (1H,
3
5-H, J = 3.6, J = 1.2 Hz). 13C NMR spectrum, δC,
ppm: 20.84, 121.25, 127.92, 129.91, 133.01, 133.28,
134.48, 135.55, 148.32, 160.70. Mass spectrum, m/z
(Irel, %): 218 (10) [M]+·, 112 (6) [(C4H3S)CO + 1]+, 111
(100) [(C4H3S)CO]+, 83 (6) [C4H3S]+, 77 (6).
3
4
(2H, 2′-H, 6′-H, J = 8.4 Hz), 7.22 d (2H, 3′-H, 5′-H,
3
4
3J = 8.4 Hz), 7.55 d.d.d (1H, 5-H, J = 10.5, 7.8, J =
3
4
1.2 Hz), 7.91 d.d.d (1H, 4-H, J = 7.8, 7.8, J =
3
1.5 Hz), 8.27 d (1H, 3-H, J = 7.8 Hz), 8.84 d.d (1H,
6-H, 3J = 7.8, 4J = 1.5 Hz). Mass spectrum, m/z (Irel, %):
213 (1) [M]+·, 170 (7) [PyTol + 1]+, 169 (58) [PyTol]+,
107 (7) [TolO]+, 106 (31) [PyCO]+, 79 (10) [PyH]+, 78
(100) [Py]+, 77 (14) [Py – H]+, 52 (7), 51 (18).
4-Methylphenyl (2E)-3-phenylprop-2-enoate (1e)
was synthesized from 0.082 mL of cinnamaldehyde
and 68 mg of 4-methylphenylboronic acid. Yield
29 mg (25%; 81%, GC/MS), gray powder, mp 84–
86°C (published data [24]: mp 84–85°C), Rf 0.50
(petroleum ether–ethyl acetate, 7:3). IR spectrum, ν,
cm–1: 3063, 1731, 1651, 1635, 1615, 1593, 1576, 1557,
1506, 1496, 1332, 1308, 1278, 1198, 1179, 1166, 1138,
1102, 1027, 1016, 991, 974, 945, 860, 846, 812, 759,
705, 678, 578, 527, 507, 486, 435. 1H NMR spectrum,
δ, ppm: 2.34 s (3H, Me), 6.61 d (β-CH=, 3J = 16.2 Hz),
4-Methylphenyl pyridine-3-carboxylate (1b) was
synthesized from 0.060 mL of pyridine-3-carbaldehyde
and 68 mg of 4-methylphenylboronic acid. Yield
66 mg (62%; 90%, GC/MS), white crystals, mp 64–
65°C (published data [21]: mp 62–63°C), Rf 0.38
(chloroform–ethyl acetate, 1:1). IR spectrum, ν, cm–1:
1729, 1688, 1589, 1507, 1422, 1323, 1279, 1248,
1194, 1161, 1127, 1093, 1077, 1037, 1018, 971, 941,
1
3
3
876, 758, 702, 687, 524. H NMR spectrum, δ, ppm:
7.04 d (2H, Harom, J = 8.4 Hz), 7.19 (2H, Harom, J =
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

N-HETEROCYCLIC CARBENES: IX.
89
8.4 Hz), 7.39–7.41 m (3H, Harom), 7.55–7.58 m (2H,
(100) [FcCO]+, 211 (6) [FcCO – 2]+, 200 (6), 186 (7)
[Fc + 1]+, 185 (48) [Fc]+, 129 (30), 128 (11) [CpCp]+,
121 (23) [FeCp]+, 77 (7), 56 (11) [Fe]+.
3
Harom), 7.85 d (α-CH=, J = 16.2 Hz). Mass spectrum,
m/z (Irel, %): 238 (3) [M]+·, 132 (10) [PhCHCHCO + 1]+,
131 (100) [PhCHCHCO]+, 103 (30) [PhCHCH]+,
77 (24) [Ph]+.
Naphthalen-1-yl pyridine-3-carboxylate (2a) [28]
was synthesized from 0.061 mL of pyridine-3-carbal-
dehyde and 86 mg of naphthalen-1-ylboronic acid.
Yield 72 mg (58%; 100%, GC/MS), brown viscous
liquid, Rf 0.17 (petroleum ether–ethyl acetate, 7:3). IR
spectrum, ν, cm–1: 3057, 1742, 1674, 1590, 1576,
1508, 1420, 1390, 1327, 1273, 1256, 1224, 1194,
1155, 1098, 1064, 1039, 1018, 871, 793, 770, 700,
590, 559, 508, 418. 1H NMR spectrum, δ, ppm: 7.38 d
4-Methylphenyl 3,4-dimethoxybenzoate (1f) was
synthesized from 108 mg of 3,4-dimethoxybenzalde-
hyde and 68 mg of 4-methylphenylboronic acid. Yield
85 mg (62%; 100%, GC/MS), gray crystals, mp 125–
131°C [25], Rf 0.32 (petroleum ether–ethyl acetate,
7:3). IR spectrum, ν, cm–1: 3017, 1725, 1600, 1509,
1416, 1350, 1290, 1272, 1248, 1217, 1195, 1189, 1168,
1143, 1102, 1086, 1023, 962, 945, 916, 879, 863, 825,
787, 769, 757, 738, 632, 517, 502. 1H NMR spectrum,
δ, ppm: 2.35 s (3H, Me), 3.93 s (3H, OMe), 3.94 s
3
(1H, 2′-H, J = 7.5 Hz), 7.39–7.53 m (4H, 3′-H, 5-H,
3
6′-H, 7′-H), 7.79 d (1H, 4′-H, J = 8.4 Hz), 7.88–
3
7.91 m (2H, 4-H, 5′-H), 8.56 d.d (1H, 8′-H, J = 8.1,
4J = 1.8 Hz), 8.91 m (1H, 6-H), 9.54 s (1H, 2-H). Mass
spectrum, m/z (Irel, %): 249 (21) [M]+ ·, 115 (21)
[indene]+·, 107 (6) [PyCO + 1]+, 106 (100) [PyCO]+,
78 (39) [Py]+, 51 (11).
3
(3H, OMe), 6.91 d (1H, 5-H, J = 8.4 Hz), 7.06 d
3
3
(2H, Harom, J = 8.4 Hz), 7.19 d (2H, Harom, J =
4
8.4 Hz), 7.65 d (1H, 2-H, J = 2.1 Hz), 7.83 d.d (1H,
3
4
6-H, J = 8.4, J = 2.1 Hz). Mass spectrum, m/z
(Irel, %): 272 (6) [M]+·, 166 (10) [(MeO)2C6H3CO + 1]+,
165 (100) [(MeO)2C6H3CO]+, 137 (6) [(MeO)2C6H3]+,
79 (7), 77 (8).
Naphthalen-1-yl ferrocenecarboxylate (2b) was
synthesized from 139 mg of ferrocenecarbaldehyde
and 86 mg of naphthalen-1-ylboronic acid. Yield
112 mg (63%; 77%, GC/MS), red crystals, mp 92–
94°C, Rf 0.58 (petroleum ether–ethyl acetate, 7:3). IR
spectrum, ν, cm–1: 3099, 3077, 1732, 1680, 1633,
1599, 1575, 1413, 1351, 1274, 1258, 1224, 1154,
1105, 1054, 1038, 1027, 1011, 970, 961, 915, 897,
866, 824, 783, 767, 759, 668, 627, 606, 596, 561, 541,
4-Methylphenyl 3,4,5-trimethoxybenzoate (1g)
was synthesized from 128 mg of 3,4,5-trimethoxy-
benzaldehyde and 68 mg of 4-methylphenylboronic
acid. Yield 68 mg (45%; 77%, GC/MS), gray crystals,
mp 85–88°C (published data [26]: mp 88–89°C),
Rf 0.43 (petroleum ether–ethyl acetate, 7:3). IR spec-
trum, ν, cm–1: 1727, 1587, 1507, 1415, 1337, 1230,
1215, 1189, 1169, 1159, 1129, 1031, 1020, 1003, 943,
928, 915, 866, 844, 824, 786, 773, 758, 696, 503.
1H NMR spectrum, δ, ppm: 2.36 s (3H, Me), 3.93 s
1
527, 505, 482, 459, 451, 422. H NMR spectrum, δ,
ppm: 4.33 s (5H, Fc), 4.51 m (2H, Fc), 5.06 m (2H,
3
Fc), 7.35 d (1H, 2-H, J = 7.8 Hz), 7.48–7.53 m (3H,
3
3-H, 6-H, 7-H), 7.73 d (1H, 4-H, J = 8.1 Hz), 7.86 m
3
(9H, OMe), 7.07 d (2H, Harom, J = 8.4 Hz), 7.16 d
(1H, 5-H), 8.05 m (1H, 8-H). 13C NMR spectrum, δC,
ppm: 69.99, 70.64, 70.72, 71.97, 118.16, 121.23,
125.44, 125.62, 126.25, 126.37, 127.13, 128.01,
134.67, 146.63, 170.34. Mass spectrum, m/z (Irel, %):
357 (8) [M + 1]+·, 356 (37) [M]+·, 264 (10) [M – TolH]+,
214 (14) [FcCO + 1]+, 213 (100) [FcCO]+, 211 (6)
[FcCO – 2]+, 207 (7), 198 (15) [FcCH]+, 185 (41) [Fc]+,
129 (28) [CpCpH]+, 128 (8) [CpCp]+, 121 (17) [FeCp]+,
115 (17) [indene]+·, 56 (7) [Fe]+. Found, %: C 70.87;
H 4.52. C21H16FeO2. Calculated, %: C 70.81; H 4.53.
M 356.20.
3
(2H, Harom, J = 8.4 Hz), 7.44 s (2H, Harom). Mass
spectrum, m/z (Irel, %): 302 (6) [M]+ ·, 196 (11)
[(MeO)3C6H2CO + 1]+, 195 (100) [(MeO)3C6H2CO]+,
77 (7).
4-Methylphenyl ferrocenecarboxylate (1h) was
synthesized from 139 mg of ferrocenecarbaldehyde
and 68 mg of 4-methylphenylboronic acid. Yield
135 mg (45%; 85%, GC/MS), red crystals, mp 93–
94°C (published data [27]: mp 90–94°C), Rf 0.43
(petroleum ether–ethyl acetate, 7:3). IR spectrum, ν,
cm–1: 1732, 1273, 1215, 1192, 1163, 1097, 1022, 1016,
1000, 911, 860, 829, 815, 783, 764, 505, 485. 1H NMR
spectrum, δ, ppm: 2.35 s (3H, Me), 4.28 s (5H, Fc),
The authors thank engineer I.A. Borisova for re-
cording the IR spectra, leading engineer O.A. Maioro-
1
va for recording the H and 13C NMR spectra, and
4.46 m (2H, Fc), 4.94 m (2H, Fc), 7.04 d (2H, Harom
,
researcher E.V. Baigacheva for performing elemental
analyses. This study was performed under financial
support by the Russian Foundation for Basic Research
(project no. 14-03-31168-mol-a).
3
3J = 8.4 Hz), 7.19 d (2H, Harom, J = 8.4 Hz). Mass
spectrum, m/z (Irel, %): 321 (15) [M + 1]+·, 320 (69)
[M]+·, 228 (21) [FcCO2]+, 214 (14) [FcCO + 1]+, 213
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015

DENISOV et al.
15. Arde, P., Ramanjaneyulu, B.T., Reddy, V., Saxena, A.,
90
REFERENCES
and Anand, R.V., Org. Biomol. Chem., 2012, vol. 10,
1. Denisov, M.S., Usatykh, I.S., Gorbunov, A.A., Maio-
rova, O.A., and Glushkov, V.A., Russ. J. Org. Chem.,
2014, vol. 50, p. 705.
2. Sarkar, S.D., Biswas, A., Samanta, R.C., and Studer, A.,
Chem. Eur. J., 2013, vol. 19, p. 4664.
3. Knappke, C.E.I., Imami, A., and Wangelin, A.J.,
p. 848.
16. Meng, J.-J., Gao, M., Wei, Y.-P., and Zhang, W.-Q.,
Chem. Asian J., 2012, vol. 7, p. 872.
17. Arduengo, A.J. III, Krafczyk, R., Schmutzler, R.,
Craig, H.A., Goerlich, J.R., Marshall, W.J., and Unver-
zagt, M., Tetrahedron, 1999, vol. 55, p. 14523.
ChemCatChem, 2012, vol. 4, p. 937.
18. Xin, Y.-C., Shi, S.-H., Xie, D.-D., Hui, X.-P., and
4. Nair, V., Menon, R.S., Biju, A.T., Sinu, C.R., Paul, R.R.,
Jose, A., and Sreekumar, V., Chem. Soc. Rev., 2011,
vol. 40, p. 5336.
5. Korotkikh, N.I., Saberov, V.Sh., Glinyanaya, N.V.,
Marichev, K.A., Kiselyov, A.V., Knishevitsky, A.V.,
Rayenko, G.F., and Shvaika, O.P., Chem. Heterocycl.
Compd., 2013, vol. 49, p. 19.
6. Reynolds, N.T., Alaniz, J.R., and Rovis, T., J. Am.
Chem. Soc., 2004, vol. 126, p. 9518.
7. Reynolds, N.T. and Rovis, T., J. Am. Chem. Soc., 2005,
vol. 127, p. 16406.
Xu, P.-F., Eur. J. Org. Chem., 2011, p. 6527.
19. Washburn, R.M., Levens, E., Albright, C.F., and
Billig, F.A., Org. Synth., 1959, vol. 39, p. 3.
20. Taylor, R.R.R. and Batey, R.A., J. Org. Chem., 2013,
vol. 78, p. 1404.
21. Letso, R.R., Bauer, A.J., Lunn, M.R., Yang, W.S.,
and Stockwell, B.R., ACS Chem. Biol., 2013, vol. 8,
p. 914.
22. Bhavsar, M.D. and Shah, B.M., Man-Made Textiles
India, 1989, vol. 32, p. 55.
23. Lee, C.K., Yu, J.S., and Lee, H.-J., J. Heterocycl. Chem.,
8. Chow, K.Y.-K. and Bode, J.W., J. Am. Chem. Soc.,
2004, vol. 126, p. 8126.
2002, vol. 39, p. 1207.
24. Palermo, V., Ruiz, D.M., Autino, J.C., Vázquez, P.G.,
and Romanelli, G.P., Pure Appl. Chem., 2012, vol. 84,
p. 529.
9. Chan, A. and Scheidt, K.A., Org. Lett., 2005, vol. 7,
p. 905.
10. Maki, B.E. and Scheidt, K.A., Org. Lett., 2008, vol. 10,
p. 4331.
11. Liu, Y.-K., Li, R., Yue, L., Li, B.-J., Chen, Y.-C., Wu, Y.,
and Ding, L.-S., Org. Lett., 2006, vol. 8, p. 1521.
12. Qin, C., Wu, H., Chen, J., Liu, M., Cheng, J., Su, W.,
and Ding, J., Org. Lett., 2008, vol. 10, p. 1537.
13. Rosa, J.N., Reddy, R.S., Candeias, N.R., Cal, P.M.S.D.,
and Gois, P.M.P., Org. Lett., 2010, vol. 12, p. 2686.
25. Auricchio, S., Citterio, A., and Sebastiano, R., J. Org.
Chem., 1990, vol. 55, p. 6312.
26. Tozatti, C.S.S., Khodyuk, R.G.D., Silva, A.O.,
Santos, E.A., and Lima, M.S.A.D.P., Quím. Nova, 2012,
vol. 35, p. 1758.
27. Hür, D., Ekti, S.F., and Dal, H., J. Organomet. Chem.,
2010, vol. 695, p. 1031.
28. Badgett, C.O. and Woodward, C.F., J. Am. Chem. Soc.,
14. Reddy, R.S., Rosa, J.N., Veiros, L.F., Caddick, S., and
Gois, P.M.P., Org. Biomol. Chem., 2011, vol. 9, p. 3126.
1947, vol. 69, p. 2907.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 51 No. 1 2015