Hydroarylation of Alkynes with Phenols in the Presence of Gallium Complexes of a Labile N-Ligand: Synthesis of Chromenes

Article abstract of DOI:10.1002/ejoc.201500680

In the presence of (dpp-bian)Ga-Ga(dpp-bian) (1) and [dpp-bian(Ph)C=C(H)]Ga-Ga[(H)C=C(Ph)dpp-bian] (2) {dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene}, phenylacetylene reacts with 1-naphthol to give 2-(1-phenylvinyl)naphthalen-1-ol (3). In

Full text of DOI:10.1002/ejoc.201500680

FULL PAPER
DOI: 10.1002/ejoc.201500680
Hydroarylation of Alkynes with Phenols in the Presence of Gallium Complexes
of a Labile N-Ligand: Synthesis of Chromenes
Mikhail V. Moskalev,[a] Arkadiy M. Yakub,[a] Alexander G. Morozov,[a]
Evgenii V. Baranov,[a] Olga V. Kazarina,[a] and Igor L. Fedushkin*[a]
Dedicated to Professor Nikolay S. Zefirov on occasion of his 80th anniversary
Keywords: Alkynes / N ligands / Ligand effects / Gallium / Hydroarylation / Oxygen heterocycles
In the presence of (dpp-bian)Ga–Ga(dpp-bian) (1) and [dpp-
bian(Ph)C=C(H)]Ga–Ga[(H)C=C(Ph)dpp-bian] (2) {dpp-bian
= 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene}, phen-
ylacetylene reacts with 1-naphthol to give 2-(1-phenylvinyl)-
naphthalen-1-ol (3). In solution in the presence of complexes
1 or 2, compound 3 undergoes further dimerization to give
2-[4-methyl-2,4-diphenyl-3,4-dihydro-2H-benzo[h]chromen-
2-yl]naphthalen-1-ol (C36H28O2), whose diastereomers 4 and
5 were isolated in crystalline form. Diastereomer 4 is the ki-
netically favored product, which, however, undergoes con-
version into diastereomer 5 in solution at elevated tempera-
ture. The structures of 4 and 5 were determined by single-
crystal X-ray analysis. The catalytic activity of complexes 1
and 2 in the hydroarylation reactions of phenylacetylene and
some other alkynes with different arenes has been investi-
gated. By the reaction of phenylacetylene with 3,5-di-tert-
butylphenol,
5,7-di-tert-butyl-4-methyl-2,4-diphenyl-4H-
chromene (7) has been prepared for the first time.
Introduction
centered reactivity. The first one involves single-electron
transfer from the dpp-bian dianion to the substrate to give
either complexes with a dpp-bian radical anion,[4] or com-
plexes with a C(imine)-substituted[4d,5] amido-imino ligand.
The second one involves a HOMO–LUMO interaction be-
tween the metal complex and the substrate. This latter
mode of reactivity also gives complexes with C(imine)-sub-
stituted amido-imino ligands. An illustrative example of
this could be the addition of alkynes to group 13 metal
complexes,[6] as for instance, to digallane (dpp-bian)Ga–
Ga(dpp-bian) (1) (Scheme 1).[6a,6c]
In the beginning of the 1990s, Elsevier and van Asselt
reported the first metal complexes of 1,2-bis(arylimino)ace-
naphthenes (bians).[1] Subsequent studies led to the prepa-
ration of robust late-transition-metal catalysts based on bi-
ans for olefin polymerization.[2] With few exceptions, in the
transition-metal complexes reported to date, the bians act
as neutral chelating ligands. One of the most popular li-
gands of this family is 1,2-bis[(2,6-diisopropylphenyl)-
imino]acenaphthene (dpp-bian). In the beginning of the
2000s, we reported a stepwise reduction of dpp-bian with
sodium metal to give the dpp-bian tetraanion.[3] Since the
reduction process is completely reversible, the dpp-bian can
be assigned to a group of redox-active ligands (e.g., ortho-
benzoquinones).
A major research interest of our group is the application
of redox-active complexes of “redox-inactive” metal ions
(e.g., Mg2+, Ca2+, Ga3+, Al3+, etc.) for organic synthesis.
We have shown that main-group metal complexes of the
dpp-bian dianion (bis-amido metal species) show reactivit-
ies that can be compared with those of complexes of redox-
active transition metals. Main-group metal complexes of
the noninnocent dpp-bian ligand show two types of ligand-
[a] G. A. Razuvaev Institute of Organometallic Chemistry, Russian
Academy of Sciences,
Tropinina 49, 603950 Nizhny Novgorod, Russia
E-mail: igorfed@iomc.ras.ru
http://iomc.ras.ru
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201500680.
Scheme 1. Addition of alkynes to complex (dpp-bian)Ga–Ga(dpp-
bian) (1).
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In 2012, we demonstrated that compound 1 has a high more quickly, and gives product 3 in a good yield already
catalytic activity in the hydroamination of alkynes with pri- within a few hours. However, at elevated temperatures prod-
mary aromatic amines.[6c] The corresponding imines were uct 3 undergoes further transformation (vide infra).
obtained with yields up to 99%. The reaction between 1-
aminonaphthalene and phenylacetylene in the presence of
compound 1 (2 mol-%) gives two products, i.e., N-naphthyl-
1-phenylethan-1-imine and 2-(1-phenylvinyl)naphthalen-1-
amine (1:1 molar ratio), as a result of hydroamination and
hydroarylation processes. With 1-aminoanthracene, phenyl-
acetylene reacts in the presence of digallane 1 to give exclu-
sively 2-(1-phenylvinyl)anthracen-1-amine as the product of
Scheme 2. Arylation of phenylacetylene with 1-naphthol in the
hydroarylation of phenylacetylene. To determine whether
complexes 1 and 2 are able to catalyze the addition of other
aromatic substrates to alkynes, we have studied the reac-
tions of phenylacetylene with naphthols. The results ob-
tained, together with data on some other tests of the cata-
lytic activity of 1 and 2, are described in this paper.
presence of compound 2.
To follow the progress of the formation of compound 3,
we monitored the reaction by NMR spectroscopy in C6D6
at 90 °C. The 1H NMR spectra of the starting mixture
(phenylacetylene + 1-naphthol) as well as compound 3 are
shown in Figure 1.
The single resonances at δ = 5.00 and 2.77 ppm arise
from the OH and HCϵC groups, respectively. After a reac-
tion time of 1 h, a new set of signals started to grow. The
Results and Discussion
The hydroarylation of alkynes with arenes in the pres- new signals at δ = 5.51 and 5.70 ppm correspond to the
ence of transition-metal catalysts has been well reviewed.[7] diastereotopic protons on the carbon–carbon double bond,
We have found that compound 2 serves as a catalyst for the and the signal at δ = 6.00 ppm arises from the OH group
reaction between 1-naphthol and phenylacetylene: at 45 °C of product 3. After a reaction time of 1 h, the conversions
within 20 d hydroarylation product 3 was obtained in 70% of the starting materials were 3 and 30% in the presence of
yield (Scheme 2). At 90 °C, the reaction proceeds much complexes 1 and 2, respectively. We believe that the differ-
Figure 1. 1H NMR spectra (293 K, 200 MHz, C6D6) of a mixture of phenylacetylene + 1-naphthol (top), and product 3 (bottom) isolated
from hexane. The resonances at δ = 1.75–0.50 ppm correspond to light petroleum in the sample.
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Hydroarylation of Alkynes with Phenols
ence in the reaction rates can be explained by a partial de-
composition of complex 1 during the course of the reaction
with 1-naphthol, before the interaction of complex 1 with
phenylacetylene took place. The best yield of the product 3
(70%) was observed after 2.5 h. Only three examples of the
formation of compound 3 in the presence of a catalyst have
been reported. Thus, with heterogeneous catalyst FeAl-
KIT-5,[8] compound 3 was obtained in 73% yield after 6 h
at 80 °C. The formation of compound 3 in 70% yield has
also been achieved in the presence of GaCl3 (10 mol-%,
110 °C).[9] Furthermore, compounds 1 and 2 are more
active than the gallium dithiocarbamate complex (dpp-
bian)Ga(S2CNMe2); in the presence of 2 mol-% of the latter
compound at 85 °C, product 3 was obtained in 40% yield
after 7 h.[6e] The application of organogallium complexes in
molecular catalysis has recently been reviewed.[10]
NMR monitoring of the progress of the formation of
product 3 in the presence of 2 as catalyst revealed that after
70% conversion of a mixture 1-naphthol + phenylacetylene
into product 3, a subsequent reaction began to take place.
After a further 24 h, the signals of compound 3 had almost
completely disappeared, and a new spectrum had appeared.
Figure 2. Enantiomeric pairs of compounds 4 and 5 present in the
unit cells.
Diastereomers 4 and 5 were characterized by 1H and 13
C
Among other signals, this spectrum had singlet signals at δ NMR spectroscopy. The 1H NMR spectra of compounds 4
= 1.43, 1.62, 8.98, and 9.15 ppm. Analysis of the spectrum and 5 are shown in Figure 3. The methyl groups at C-4 in
allowed us to conclude that compound 3 exists as two tau- 4 and 5 (see Figures 4 and 5) give rise to signals at δ = 1.51
tomers (Scheme 3) that can react with each other.
and 1.82 ppm, respectively. Due to the chiral atoms C-2 and
C-4, the protons at C-3 become diastereotopic and produce
doublets (4: δ = 3.43 and 3.14 ppm; 5: δ = 3.46 and
3.25 ppm). The coupling constants for the protons at C-3
in 4 and 5 are 0.58 and 0.44 Hz, respectively. The aromatic
protons in 4 and 5 lie in the range δ = 8.65–7.00 and 9.85–
6.75 ppm, respectively.
The molecular structures of 4 (Figure 4) and 5 (Figure 5)
were determined by single-crystal X-ray analysis. The crys-
tal data and structure refinement details for 4 and 5 are
presented in Table 1. Both compounds crystallized in the
centrosymmetric space group P21/c: their unit cells consist
in each case of two enantiomeric pairs. As expected, the
heterocycles in 4 and 5 are not flat. Atoms O-1, C-4, C-5,
and C-6 are almost perfectly positioned in one plane,
whereas atoms C-2 and C-3 deviate from this plane in op-
posite directions. For instance, in compound 5, atoms C-2
and C-3 deviate from the plane O-1–C-4–C-5–C-6 by 0.28
and 0.44 Å, respectively.
Scheme 3. Tautomerization of compound 3.
After the full conversion of compound 3, diastereomeric
compounds 4 and 5 were isolated from the reaction mixture
and were separated from each other by column chromatog-
raphy. Crystallization from light petroleum/benzene (4:1)
gave crystalline 4 and 5 in 16 and 8% yields, respectively.
Compounds 4 and 5 are the result of [4+2] cycloaddition
reactions between 3 and 3a (Scheme 4).
In compound 5, the planes of the phenyl rings are almost
parallel; the distance between their ipso-carbon atoms is
3.13 Å. This value is significantly shorter than the in-
terplane distance in graphite (3.35 Å). All the cycles (except
the heterocycles) in 4 and 5 are flat, thus indicating their
aromaticity. The hydrogen bonds O-2–H···O-1 in com-
pounds 4 and 5 are 1.90(1) and 1.76(2) Å, respectively.
We also investigated whether the formation of products
4 and 5 from compound 3 could occur without a catalyst
(such as complexes 1 and 2). We found that in benzene,
compound 3 remained unchanged at ambient temperature,
Scheme 4. Formation of compounds 4 and 5.
In the X-ray crystal structures (vide infra) of compounds as well as after heating (90 °C) for several hours. In con-
4 and 5, both enantiomers are present in the unit cell in trast, in the presence of complexes 1 and 2 at 90 °C, com-
each case. These are shown in Figure 2.
pound 3 was converted into products 4 and 5. For instance,
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I. L. Fedushkin et al.
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1
Figure 3. H NMR spectra (293 K, 400 MHz, CDCl3) of diastereomeric 4 (top) and 5 (bottom).
Figure 5. Molecular structure of compound 5. Selected bond
lengths [Å]: C-2–C-3 1.526(1), C-3–C-4 1.556(1), C-4–C-5 1.516(1),
C-5–C-6 1.367(1), C-6–O-1 1.384(1), O-1–C-2 1.465(1).
Figure 4. Molecular structure of compound 4. Selected bond
lengths [Å]: C-2–C-3 1.537(1), C-3–C-4 1.553(1), C-4–C-5 1.526(1),
C-5–C-6 1.370(1), C-6–O-1, 1.385(1), O-1–C-2 1.461(1).
with 2 mol-% of complex 2 at 90 °C in benzene, compound ratio of 4:1. Heating of this mixture for 72 h led to the epi-
3 gives 4 and 5 in 96% overall yield within 70 min (Fig- merization of 4 into 5 to give an almost equimolar mixture
ure 6). The mixture formed contained 4 and 5 in a molar of 4 and 5 (Figure 7). Similar results were obtained using
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Hydroarylation of Alkynes with Phenols
Table 1. Crystal data and structure refinement details for 4 and 5.
Compound
4
5
Formula
C36H28O2·C6H6
C36H28O2
Mw
570.69
492.58
Crystal system
Space group
a [Å]
monoclinic
monoclinic
P21/c
P21/c
17.7241(3)
16.6716(15)
b [Å]
10.61575(13)
9.9920(9)
c [Å]
16.6993(2)
15.1808(13)
β [°]
107.7804(15)
99.825(2)
V [Å]
2991.96(7)
2491.8(4)
Z
4
4
ρcalcd. [gm–3]
1.267
1.313
μ [mm–1]
0.076
0.080
F(000)
1208
1040
Crystal size [mm]
θmin/θmax [°]
Index ranges
Total reflections
Unique reflections
Rint
0.40ϫ0.40ϫ0.10
0.28ϫ0.19ϫ0.08
2.935/27.994
2.451/27.999
–23 Յ h Յ 23, –14 Յ k Յ 14, –22 Յ l Յ 22
–22 Յ h Յ 22, –13 Յ k Յ 13, –20 Յ l Յ 20
53989
28682
7195
5999
0.0370
0.0608
GOF on F2
Max/min transmission
Data/restraints/parameter
Final R indices [IϾ2σ(I)]
R indices (all data)
Largest diff. peak/hole [eÅ–3]
1.008
1.034
1.0000/0.9967
7195/0/402
0.9890/0.8852
5999/0/348
R1 = 0.0397, wR2 = 0.1057
R1 = 0.0507, wR2 = 0.1116
0.363/–0.230
R1 = 0.0486, wR2 = 0.1098
R1 = 0.0774, wR2 = 0.1182
0.354 /–0.207
complex 1 as catalyst. In benzene at 90 °C, the conversion 3, diastereomers 4 and 5 were present in the reaction mix-
of compound 3 into products 4 and 5 was 94% after 5 h. ture in a 2:1 molar ratio. After 77 h, the ratio 4/5 had
Within 0.7 h of mixing complex 1 (2 mol-%) and compound changed to 5:4 (Figure 8).
Figure 6. Kinetics of the formation of products 4 and 5 from com-
pound 3 in benzene at 90 °C in the presence of 2 mol-% of complex
2.
Figure 7. Kinetics of the epimerization of diastereomer 4 into dia-
stereomer 5 at 90 °C in benzene in the presence 2 mol-% of complex
2.
Figure 8. Extracts of the 1H NMR spectra of mixtures of diastereomers 4 and 5 after 0.7 h (top) and 77 h (bottom) after mixing of
complex 1 (2 mol-%) with compound 3 in benzene at 90 °C.
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Obviously, 4 is the kinetically more favorable isomer, Chromenes may show bistability that can be influenced by
whereas diastereomer 5 is thermodynamically more stable. external stimuli.[11] Furthermore, they constitute an impor-
Also, the formation of 5 from 4 probably occurs through tant class of scaffolds that are found in many natural prod-
cleavage of the heterocycle in 4 to give the starting material ucts. Compounds related to 4 and 5 have been obtained
(i.e., 3). This was confirmed by the fact that compound 3 using AuIII catalysts.[12] On the other hand, 1,3-disubsti-
was always present in the reaction mixtures in a small tuted 3H-benzo[f]chromenes have been prepared by cou-
amount (3–6%). Chromenes 4 and 5 are rather unique. pling of the three components naphthol, alkyne, and aro-
matic or aliphatic aldehyde in the presence of iron(III)
hydrogensulfate[13] or gallium(III) chloride.[14]
Table 2. Test of the catalytic activity of complexes 1 (Entries 11 and
12) and 2 (Entries 1–10) in the reactions of alkynes with aromatic
Thus, we have found that complexes 1 and 2 serve well
as catalysts for the hydroarylation of phenylacetylene with
1-naphthol. In order to obtain more insight into the hy-
droarylation process, we tested complexes 1 and 2 as cata-
lysts in the reactions of other aromatic compounds with
phenylacetylene, 1-hexyne, and 2-hexyne. The results of
these tests are summarized in Table 2.
compounds (NMR experiments, [D6]benzene, 90 °C).
We found that complex 2 catalyzes the reaction between
phenylacetylene and 2-naphthol: the hydroarylation prod-
uct (i.e., 6) was obtained in high yield. Unlike product 3,
compound 6 is stable, and it did not undergo further con-
version, even in the presence of the catalyst. The catalytic
activity of compound 2 in the reaction between 2-naphthol
and phenylacetylene is comparable with the activities of
other catalysts reported for this reaction.[8,9,15]
According to NMR spectroscopy, phenylacetylene re-
acted with 4-tert-butylphenol to give, in the beginning, the
hydroarylation product. Furthermore, similarly to the reac-
tion of phenylacetylene with 1-naphthol, signals due to the
nonequivalent protons of the CH2 group appeared in the
Scheme 5. Reaction of 3,5-di-tert-butylphenol with phenylacetylene
in the presence of complex 2.
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Hydroarylation of Alkynes with Phenols
3.9 mmol), and benzene (15 mL) were placed in a Schlenk flask
(50 mL). The flask was filled with nitrogen (99.995%), and the mix-
ture was heated at reflux at 45 °C. After 20 d, silica gel was added
to the reaction mixture. The mixture was dried in vacuo, and puri-
fied by column chromatography (light petroleum/ethyl acetate, 9:1).
Volatile products were evaporated from the extract at room tem-
perature. Compound 3 (0.51 g, 70%) was isolated as a brown oily
liquid. The 1H NMR spectrum of isolated 3 corresponds to that
reported in the literature.[9] 1H NMR (200 MHz, CDCl3, 25 °C): δ
= 8.27 (d, J = 3.5 Hz, 1 H, CH arom), 7.80 (d, J = 3.1 Hz, 1 H,
NMR spectrum. Unfortunately, we failed to isolate the indi-
vidual products of this reaction. The reaction of 3,5-di-tert-
butylphenol with phenylacetylene in the presence of com-
plex 2 first gave the hydroarylation product and then re-
sulted in the [4+2] cycloaddition product. However, in con-
trast to the reaction with 1-naphthol, the cycloaddition
product eliminated 3,5-di-tert-butylphenol to give 4H-
benzopyran 7 (Scheme 5), which was isolated by column
chromatography and characterized by NMR spectroscopy.
The hydroarylation of phenylacetylene with phenol or CH arom), 7.55–7.3 (m, 8 H, CH arom), 7.26 (s, 1 H, CH arom),
6.0 [d, J = 1.1 Hz, 1 H, HC=C(Ph)], 5.85 (s, 1 H, OH), 5.53 [d, J
= 1.1 Hz, 1 H, HC=C(Ph)] ppm.
benzoic acid in the presence of complex 2 did not proceed,
probably due to the destruction of complex 2 by these rea-
gents. Complex 2 did not catalyze the reactions between
(2R,4R)/(2S,4S)-2-[4-Methyl-2,4-diphenyl-3,4-dihydro-2H-benzo-
phenylacetylene and substrates that do not contain C–H [h]chromen-2-yl]naphthalen-1-ol (4): Phenylacetylene (0.8 g,
7.85 mmol) and compound 2 (85 mg, 6.0 mmol) were added to an
ampoule containing naphthalen-1-ol (0.73 g, 5.06 mmol). Benzene
(4 mL) was then added, and the ampule was sealed. The mixture
was heated at 90 °C. After 16 h, silica gel was added to the resulting
solution. The mixture was dried in vacuo, and then it was eluted
with light petroleum/benzene (9:1). Volatile products were evapo-
rated from the extract at ambient temperature. The residual solid
was recrystallized from light petroleum/benzene (4:1) to give com-
pound 4 (0.2 g, 16%) as pale yellow crystals. M.p. 129–131 °C. IR
bonds in a position ortho to the OH group (Table 1, En-
tries 5 and 6). In the presence of complex 2, phenylacetylene
was also unreactive towards anisole, 1-methoxynaphthol,
and 4-bromotoluene. Furthermore, the internal alkyne 2-
hexyne was inert towards 1-naphthol, whereas 1-hexyne re-
acted with 1-naphthol to give a mixture of products that
could not be separated. Nevertheless, the NMR spectrum
of the reaction mixture contained a set of signals that sug-
gest the formation of the [4+2] cycloaddition product.
(Nujol): ν = 3429 (m), 3053 (w), 1962 (w), 1943 (w), 1813 (w), 1636
˜
(w), 1600 (w), 1575 (m), 1510 (w), 1493 (m), 1460 (s), 1377 (s), 1342
(m), 1291 (m), 1261 (m), 1235 (w), 1218 (m), 1197 (m), 1159 (m),
1121 (m), 1079 (m), 1070 (m), 1061 (m), 1027 (m), 996 (w), 977
(m), 952 (m), 937 (w), 915 (w), 905 (w), 883 (m), 860 (w), 853 (w),
822 (w), 802 (s), 792 (m), 782 (w), 767 (m), 759 (m), 743 (s), 721
Conclusions
We have found that gallium complexes with the function-
ally labile (redox-active) bis-amido ligand dpp-bian serve
well as catalysts for the hydroarylation of terminal alkynes,
(s), 699 (s), 614 (w), 592 (w), 575 (m), 567 (m), 536 (w), 523 (w), 500
1
primarily phenylacetylene. The product of the reaction be- (w), 477 (w), 467 (w) cm–1. H NMR (200 MHz, CDCl3, 20 °C): δ
= 8.50 (s, 1 H, OH), 8.49 (d, J = 6.0 Hz, 1 H, CH arom), 8.18 (d,
J = 9.0 Hz, 1 H, CH arom), 7.86 (d, J = 7.8 Hz, 1 H, CH arom),
7.64 (m, 3 H, CH arom), 7.42 (m, 5 H, CH arom), 7.26 (m, 3 H,
CH arom), 7.09 (m, 7 H, CH arom), 7.01 (d, J = 8.5 Hz, 1 H, CH
arom), 3.43 (d, J = 14.5 Hz, 1 H, CH2), 3.14 (d, J = 14.5 Hz, 1 H,
CH2), 1.51 (s, 3 H, CH3) ppm. 13C NMR (200 MHz, CDCl3,
20 °C): δ = 30.0, 39.8, 49.3, 84.7, 118.7, 121.1, 121.6, 121.7, 122.5,
133.0, 124.2, 125.0, 125.5, 126.0, 126.1, 126.5, 126.5,126.6, 126.8,
126.9, 127.3, 127.5, 128.0, 128.4, 133.5, 133.9, 143.2, 146.5, 149.6,
150.6 ppm.
tween phenylacetylene and 1-naphthol-2-(1-phenylvinyl)-
naphthalen-1-ol (3), undergoes further catalytic transforma-
tion to give chiral chromenes. The hydroarylating reagents
are limited to non-acidic aromatic derivatives and to sub-
strates that do not have substituents in the position ortho
to the OH group.
Experimental Section
General Remarks: Compounds 1 and 2 are sensitive to oxygen and
moisture. Therefore, all manipulations involving their preparation
or their use as catalysts were carried out under vacuum or under
nitrogen, using glass ampoules, Schlenk flasks, and NMR tubes.
Benzene (Vekos) and [D6]benzene (Aldrich) were dried with so-
dium/benzophenone at ambient temperature and distilled under
vacuum immediately before use into the reaction ampoule or into
the NMR tube. The solvents light petroleum (OOO Novye Tekhno-
logii; boiling range 40–70 °C), ethyl acetate (Vekos), and n-hexane
(Acros) were used as received. IR spectra were recorded with an
FSM-1201 spectrometer. 1H NMR spectra were recorded with
Bruker DPX-200 and Bruker Avance III 400 spectrometers. 1-
Naphthol (Khimreaktiv) was recrystallized from hexane and sub-
limed in vacuo. Phenylacetylene (Aldrich) was distilled at reduced
pressure (79 °C/122 Torr). 1-Hexyne (Aldrich) and 2-hexyne (Ald-
rich) were used as received. Diimine dpp-bian,[16] and the com-
plexes (dpp-bian)Ga–Ga(dpp-bian) (1)[17] and [dpp-bian-
(PhC=CH)Ga–Ga(HC=CPh)dpp-bian] (2)[6a] were prepared ac-
cording to literature procedures.
(2S,4R)/(2R,4S)-2-[4-Methyl-2,4-diphenyl-3,4-dihydro-2H-benzo-
[h]chromen-2-yl]naphthalen-1-ol (5): Compound 5 was prepared by
a method similar to that described for 4. After column chromatog-
raphy, the product was crystallized from light petroleum/benzene
(4:1) to give compound 5 (0.1 g, 8%) as colorless crystals. M.p.
200–202 °C. IR (Nujol): ν = 3470 (m), 3059 (w), 1962 (w), 1943
˜
(w), 1813 (w), 1636 (w), 1600 (w), 1573 (m), 1509 (w), 1493 (m),
1460 (s), 1397 (w), 1377 (s), 1304 (w), 1283 (m), 1261 (m), 1235
(w), 1221 (m), 1200 (m), 1157 (m), 1121 (m), 1082 (m), 1063 (m),
1027 (w), 1007 (w), 971 (w), 956 (m), 935 (w), 909 (w), 879 (m),
866 (w), 807 (s), 786 (w), 762 (m), 748 (s), 722 (m), 700 (s), 677
(m), 617 (w), 604 (w), 576 (m), 558 (m), 526 (w), 513 (w), 493 (w),
1
468 (w) cm–1. H NMR (200 MHz, CDCl3, 20 °C): δ = 8.78 (s, 1
H, OH), 8.50 (d, J = 8.1 Hz, 1 H, CH arom), 8.31 (d, J = 5.2 Hz,
1 H, CH arom), 7.88 (d, J = 7.6 Hz, 1 H, CH arom), 7.73–6.75 (m,
19 H, CH arom), 3.46 (d, J = 8.0 Hz, 1 H, CH2), 3.25 (d, J =
8.0 Hz, 1 H, CH2), 1.82 (s, 3 H, CH3) ppm. 13C NMR (200 MHz,
CDCl3, 20 °C): δ = 32.5, 39.6, 48.2, 85.3, 119.1, 121.3, 121.6, 122.3,
122.8, 123.4, 124.4, 125.3, 125.4, 126.0, 126.4, 126.6, 126.6, 126.7,
2-(1-Phenylvinyl)naphthalen-1-ol (3): Naphthalen-1-ol (0.432 g, 126.9, 126.9, 127.1, 127.3, 127.8, 128.0, 133.6, 134.2, 140.6, 146.5,
3 mmol), complex 2 (45 mg, 0.031 mmol), phenylacetylene (0.4 g, 148.7, 150.7 ppm.
Eur. J. Org. Chem. 2015, 5781–5788
© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
5787

I. L. Fedushkin et al.
FULL PAPER
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2-(1-Phenylvinyl)naphthalen-1-ol (6): Under air, naphthalen-2-ol
(0.14 g, 1.0 mmol) was placed in an NMR tube. Then, under vac-
uum, compound 2 (15 mg, 0.01 mmol), phenylacetylene (0.1 g,
1.0 mmol), and [D6]benzene (0.5 mL) were added to this tube. The
tube was sealed, and the mixture was heated at 90 °C. The forma-
tion of compound 6 was monitored by NMR spectroscopy. 1H
NMR (200 MHz, CDCl3, 25 °C): δ = 7.84–7.81 (m, 1 H, CH arom),
7.79–7.76 (m, 1 H, CH arom), 7.57–7.49 (m, 1 H, CH arom), 7.41–
7.26 (m, 8 H, CH arom), 6.34 [d, J = 1.1 Hz, 1 H, HC=C(Ph)],
5.62 (s, 1 H, OH), 5.53 [d, J = 1.1 Hz, 1 H, HC=C(Ph)] ppm. The
NMR spectrum listed above is identical with that reported in the
literature.[9] After 20 h at 90 °C, the conversion of the reagents
reached 99%.
5,7-(Di-tert-butyl)-4-methyl-2,4-diphenyl-4H-chromene (7): Under
air, 3,5-di-tert-butylphenol (0.21 g, 1.0 mmol) was placed in an
NMR tube. Then, under vacuum, compound 2 (15 mg, 0.01 mmol),
phenylacetylene (0.1 g, 1.0 mmol) and [D6]benzene (0.5 mL) were
added to this tube. The tube was sealed, and the mixture was heated
at 90 °C. The formation of compound 7 was monitored by NMR
spectroscopy. According to the NMR spectroscopic data, the yield
of compound 7 reached 95% after 46 h. Compound 7 (0.17 g, 80%)
was isolated by column chromatography using light petroleum/
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1
benzene (9:1). H NMR (200 MHz, CDCl3, 20 °C): δ = 7.50 (d, J
= 6.4 Hz, 2 H, CH arom), 7.30–7.15 (m, 8 H, CH arom), 6.96 (s,
1 H, CH arom), 6.90 (s, 1 H, CH arom), 5.95 (s, 1 H, CH), 1.78
(s, 3 H, CH3), 1.29 (s, 9 H, CH3), 0.82 (s, 9 H, CH3) ppm.
Single-Crystal X-ray Structure Determination: The X-ray data for
4 and 5 were collected at 100 K with Agilent Xcalibur E and Bruker
D8 QUEST diffractometers, respectively, with monochromated
Mo-Kα radiation (λ = 0.71073 Å) using the ω-scan technique. The
structures were solved by direct methods and were refined on F2
using SHELXTL.[18] SCALE3 ABSPACK[19] (for 4) and SAD-
ABS[20] (for 5) were used to perform area-detector scaling and ab-
sorption corrections. All non-hydrogen atoms in 4 and 5 were
found from Fourier syntheses of electron density, and were refined
anisotropically. Hydrogen atoms were placed in calculated posi-
tions and were refined using the “riding model” with Uiso(H) =
1.2Ueq of their parent atoms [or Uiso(H) = 1.5Ueq for the hydrogen
atoms in CH3 groups]. The H atoms of the OH groups in 4 and 5
were located from Fourier synthesis and refined isotropically. A
solvent molecule of benzene was found in the crystal of 4. CCDC-
1402892 (for 4) and -1402893 (for 5) contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from the Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.
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Acknowledgments
This work was supported by the Russian Science Foundation (pro-
ject no. 14-13-01063).
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Received: May 27, 2015
Published Online: July 31, 2015
5788
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© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2015, 5781–5788