Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Br?nsted acids. NMR and DFT study of these cations and their reactions

Article abstract of DOI:10.3762/bjoc.14.268

In strong Br?nsted acids (CF₃SO₃H, FSO₃H, D₂SO₄), (arysulfonyl)allenes (ArSO₂-CR¹=C=CR²R³) and (arylsulfinyl)allenes (ArSO-CR¹=C=CR²R³) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their deprotonation with a stereoselective formation of (arysulfonyl)butadienes (for instance, ArSO₂-CR¹=C-C(Me)=CH₂, for R² = R³ = Me, yields of 87-98%). Reactions of (arysulfonyl)allenes in the system TfOH (0.1 equiv)-HFIP (hexafluoropropan-2-ol) followed by hydrolysis give rise to allyl alcohols (ArSO₂-CR¹=CH-C(OH)R²R³, yields of 78-99%). Reflux of solutions of (arysulfonyl)allenes in the presence of TfOH (1 equiv) in 1,2-dichlorobenzene leads to the cyclization into thiochromene 1,1-diox-ides in high yields. Under the action of TfOH or AlX₃ (X = Cl, Br) followed by hydrolysis of reaction mixtures, (arylsulfinyl)allenes give allyl alcohols (ArSO₂-CR¹=CH-C(OH)R²R³). Plausible reaction mechanisms have been proposed for all studied reactions.

Full text of DOI:10.3762/bjoc.14.268

Generation of 1,2-oxathiolium ions from (arysulfonyl)- and
(arylsulfinyl)allenes in Brønsted acids. NMR and
DFT study of these cations and their reactions
Stanislav V. Lozovskiy1, Alexander Yu. Ivanov2, Olesya V. Khoroshilova1
and Aleksander V. Vasilyev*1,3,§
Full Research Paper
Open Access
Address:
Beilstein J. Org. Chem. 2018, 14, 2897–2906.
1Department of Organic Chemistry, Institute of Chemistry, Saint
Petersburg State University, Universitetskaya nab., 7/9, Saint
Petersburg, 199034, Russia, 2Center for Magnetic Resonance,
Research Park, St. Petersburg State University, Universitetskiy pr.,
26, Saint Petersburg, Petrodvoretz, 198504 , Russia and 3Department
of Chemistry, Saint Petersburg State Forest Technical University,
Institutsky per., 5, Saint Petersburg, 194021, Russia
doi:10.3762/bjoc.14.268
Received: 08 August 2018
Accepted: 07 November 2018
Published: 22 November 2018
Associate Editor: T. P. Yoon
Email:
© 2018 Lozovskiy et al.; licensee Beilstein-Institut.
License and terms: see end of document.
Aleksander V. Vasilyev* - aleksvasil@mail.ru
* Corresponding author
§ Tel.: 07 812 670 93 52; fax: 07 812 670 93 90
Keywords:
(arylsulfinyl)allenes; (arylsulfonyl)allenes; butadienes; 1,2-oxathiolium
ions; thiochromene 1,1-dioxides
Abstract
In strong Brønsted acids (CF3SO3H, FSO3H, D2SO4), (arysulfonyl)allenes (ArSO2–CR1=C=CR2R3) and (arylsulfinyl)allenes
(ArSO–CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of
NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their
deprotonation with a stereoselective formation of (arysulfonyl)butadienes (for instance, ArSO2–CR1=C–C(Me)=CH2, for
R2 = R3 = Me, yields of 87–98%). Reactions of (arysulfonyl)allenes in the system TfOH (0.1 equiv)–HFIP (hexafluoropropan-2-ol)
followed by hydrolysis give rise to allyl alcohols (ArSO2–CR1=CH–C(OH)R2R3, yields of 78–99%). Reflux of solutions of
(arysulfonyl)allenes in the presence of TfOH (1 equiv) in 1,2-dichlorobenzene leads to the cyclization into thiochromene 1,1-diox-
ides in high yields. Under the action of TfOH or AlX3 (X = Cl, Br) followed by hydrolysis of reaction mixtures,
(arylsulfinyl)allenes give allyl alcohols (ArSO2–CR1=CH–C(OH)R2R3). Plausible reaction mechanisms have been proposed for all
studied reactions.
Introduction
Allenes are widely explored in organic synthesis for the con- transformations. For instance, addition of such allenes to
struction of various molecules [1-7]. In particular, arylsulfonyl Michael acceptors leading to terminal acetylenes has been
(ArSO2) allenes are usefull building blocks in miscellaneous recently shown [8]. These allenes give rise to pyrrolidines [9],
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pyrroles [10], chromenes [11], benzoazepinones [12], The reaction between proparylic alcohols and arylsulfanyl chlo-
macrolides [13], and some other carbo- and heterocycles rides followed by acetylene–allene rearrangement was used to
[14-16]. It should be specially emphasized that many com- prepare (arylsulfinyl)allenes 1 according to the literature
pounds containing SO2 groups are drugs, such as, dapson [17], procedure [24,25]. The latter were in situ oxidized to (arylsul-
oxicams [18], or amisulpride [19]. Substantial contribution in fonyl)allenes 2 (see X-ray structure of 2h in Figure 1). Allenes
this area was made by Harmata et al. [20-24]. However, to the 1a,b were specially isolated to compare their reactivity with
best of our knowledge, electrophilic reactions of (aryl- allenes 2.
sulfonyl)allenes have not been widely studied yet. It has been
shown by Ma et al. that ArSO2-allenes take part into halogeno- The main goals of this work were the investigation of reactions
hydroxylation (Hal = I, Br) or addition–elemination of bromine of sulfur-containing allenes 1 and 2 under electrophilic activa-
(forming bromobutadienes) with high stereoselectivity [25,26]. tion with Brønsted or Lewis (super)acids, and the study on
Apart from that, reactions of sulfur containing allenes were cationic intermediates of these reactions by means of NMR and
studied in acidic media [27,28]. Despite promising results, there DFT calculations.
was no further research in this area.
Results and Discussion
Based on our recent work on transformations of phosphono- First, the behavior of allenes 1a,b and 2a–h in Brønsted acids
allenes under the action of strong Brønsted or Lewis (TfOH, D2SO4) was studied by means of NMR (Table 1).
acids [29-32], we undertook a special study on reactions of Dissolving these allenes in TfOH or D2SO4 directly in NMR
(arylsulfonyl)allenes 2a–j and (arylsulfinyl)allenes 1a,b tubes at room temperature gave intensively colored red solu-
(Scheme 1).
tions of cationic species, which were stable for a long time.
Scheme 1: (Arylsulfinyl)allenes 1 and (arylsulfonyl)allenes 2 used in this study.
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Figure 1: X-ray crystal structures of compounds 2h (CCDC 1843276), 3e (CCDC 1843277), 5c (CCDC 1580895), 7b (CCDC 1843239); ellipsoid
contours of probability levels are 50%.
Table 1: Selected 1H and 13C NMR data for cations Aa,b and Ba–h, P1, P2 derived at the protonation of the corresponding allenes at room tempera-
ture in TfOH and D2SO4.
initial allene
cation
acid
1H NMR, δ, ppm
13C NMR, δ, ppm
H3
H4
C3
C4
C5
1a
1b
2a
TfOH 6.85 d (J = 5.7 Hz) 7.47 d (J = 5.7 Hz)
TfOH 6.83 d (J = 6.1 Hz) 7.51 d (J = 6.1 Hz)
TfOH 7.16 d (J = 6.2 Hz) 8.05 d (J = 6.2 Hz)
117.2
117.2
121.0
150.2
150.6
158.7
112.4
Aa
Ab
Ba
112.8
112.0
2b
TfOH 7.17 d (J = 6.0 Hz) 8.07 d (J = 6.0 Hz)
122.4
159.6
113.0
Bb
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Table 1: Selected 1H and 13C NMR data for cations Aa,b and Ba–h, P1, P2 derived at the protonation of the corresponding allenes at room tempera-
ture in TfOH and D2SO4. (continued)
2c
TfOH 7.12 d (J = 6.2 Hz) 8.01 d (J = 6.2 Hz)
121.3
157.1
110.2
Bc
Bd
2d
2d
TfOH
–
–
7.95 s
109.9
109.0
153.0
153.0
112.7
113.0
D2SO4
–
Bd-d
2e
2f
TfOH
TfOH
–
–
7.91
8.02
123.4
115.6
122.6
154.1
154.1
157.7
110.0
119.3
114.7
Be
Bf
2 isomers in a ratio of 5:1a
2g
TfOH 7.11 d (J = 6.2 Hz) 8.02 d (J = 6.2 Hz)
Bg
120.9
and
157.9
and
112.8
and
2h
TfOH
–
8.35 and 8.09
120.7
157.1
112.2
Bh
P1
Data from
ref. [30]
TfOH
TfOH
–
–
7.78 d (JHP = 28 Hz)
7.84 d (JHP = 46 Hz)
102.0
96.0
164.3
169.1
103.6
102.8
Data from
ref. [32]
P2
aNMR data for major isomer.
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The NMR data, including 1H, 13C, DEPT, COSY, and HSQC a large positive charge 0.25 e, which should make this carbon a
spectra (see Supporting Information File 1), demonstrated un- highly reactive electrophilic center. Another electrophilic center
ambiguously that compounds 1a,b and 2a–h underwent cycliza- is the sulfur atom, which also bears a large positive charge
tion into the corresponding ions Aa,b and Ba–h via protonation (1.21–2.06 e). Apart from that, the atomic coefficient of contri-
(deuteration for D2SO4, Bd-d) of the central carbon allenic triad bution in the LUMO for sulfur is much higher than for C5.
followed by nucleophilic attack of oxygen of the SO2 group (for Thus, the electrophilic reactivity of sulfur may be explained by
Ba–h) or SO group (for Aa,b) onto the carbocationic center. both charge and orbital control. Also, ortho-carbons in the phe-
The similar cyclization was observed for phosphonoallenes (see nyl group bear a negative charge −0.17 to −0.16 e; this means
P1, P2, Table 1) by us previously [30,32]. A new signal of the that intramolecular cyclization on these atoms is possible.
attached proton H4 at δ 8.05–6.83 ppm range appeared in
1H NMR spectra of species A, B. The comparison of 13C NMR To conclude the study on electronic characteristics of 1,2-
spectra of oxathiolylium A, B and oxaphospholium P1, P2 ions oxathiolylium ions A, B by means of NMR and DFT calcula-
shows that for the former species the signal of carbon C5 is tions, one should expect that these species may react in several
about 10–15 ppm downfield shifted relatively the same signal in pathways. First, they may undergo nucleophilic attack on sulfur
the cations P1, P2 (Table 1). This reveals that carbon C5 bears a or on carbon C5, due to a high positive charge on it. Another
rather large positive charge in cations A, B. For dication Bh, pathway may be an electrophilic cyclization at the ortho-car-
different signals were detected for quaternary carbons C5 and bon in the S-phenyl ring.
C5', and vinyl carbons C4 and C4', etc., that, probably, indi-
cates formation of two diastereomers (one meso-form and one Then, the preparative reactions of allene 2a under the action of
pair of enantiomers) due to the stereogenic sulfur centers.
different electrophilic reagents were conducted. Transformat-
ions of 2a using an excess of various Brønsted acids followed
In the case of the cation Bf, the signals of two isomers were by aqueous quenching of the reaction mixture are shown in
found in the spectra in a ratio of 5 to 1. These isomers appear Table 3. These reactions resulted in the formation of three dif-
due to cis-, trans-orientation of t-Bu and ArS groups in the five- ferent products, Z-3a, Z-4a and 5a, depending on the reaction
membered ring.
conditions. At room temperature in CF3SO3H or H2SO4 for a
short time, 10 min or 1 h, respectively, butadiene Z-3a and
To the best of our knowledge, this is one of the first examples alcohol Z-4a were formed (Table 3, entries 1 and 3). Increasing
of full NMR characterization of such broad series of cyclic the reaction temperature to 60 °C and the time to 8 h in
sulfur containing cations Aa,b and Ba–h. Allenes 2i,j did not CF3SO3H led to the formation of thiochromene 1,1-dioxide 5a
react with acids at room temperature, however, they react with (Table 3, entry 2). Decreasing the reaction temperature down to
TfOH at higher temperature (see below).
−60 °C in FSO3H with work-up of the superacidic reaction
solution with a low nucleophilic medium (frozen aqueous HCl
To estimate the charge distribution in species Aa, Ba we carried at −60 °C) gave almost quantitatively butadiene Z-3a with a
out DFT calculations (Table 2). The calculations confirm the small admixture of its E-isomer (Table 3, entry 4). Weaker
experimental NMR data (Table 1) and prove that C5 does have acids, CF3CO2H or aqueous HCl, did not activate allene 2a, no
Table 2: Selected electronic characteristics of cations Aa, Ba generated from allenes 1a, 2a, correspondingly (DFT calculations).
cation
q(S)a e
q(C3)a e
q(C4)a e
q(C5)a e
q(Co-Ph)a e
kLUMOb %
S
C3 C4 C5 ∑CPh (ortho + para + ipso)
1.21
2.06
−0.38
−0.43
−0.13
−0.10
0.25
0.25
−0.17
−0.16
35
4
0
2
1
38
47
Aa
Ba
11 14 25
aNatural charges. bContribution of atomic orbital into the molecular orbital.
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Table 3: Reactions of allene 2a under the action of various Brønsted acids.
entry
reaction conditions
temperature, °C
reaction products, yield, %
acid (equiv)
time
Z-3a
Z-4a
5a
1
2
3
4
5
6
TfOH (40)
rt
10 min
8 h
18
81
–
–
TfOH (40)
60
rt
–
40
–
H2SO4 (40)
FSO3H (40)a
CF3CO2H (40)b
HClaq (40)b
1 h
20
20
–
−60
50
rt
1 h
90 (+ E-3a, 9%)
–
24 h
24 h
–
–
–
–
–
–
aWork-up with frozen aqueous HCl at −60 °C. bQuantitative recovery of starting 2a.
reactions took place (Table 3, entries 5 and 6). Apart from that, Z-3a. The predominant formation of the Z-isomer of 3a may
Lewis acids of various strength (AlCl3, AlBr3, FeCl3, CeCl3, reveal that cation Ba undergoes deprotonation and recycliza-
BF3-Et2O, In(OTf)3) were found to be ineffective for this trans- tion, rather than species C. Quenching of species Ba with water
formation, no reactions of allenes 2 occurred with them.
(high nucleophilicity) affords alcohol Z-4a. The formation of
compound 4a in exclusively Z-configuration may indicate that
Taking into account the data on the formation of cations B cation Ba reacts with H2O in SN2 manner, keeping in mind that
(Table 1), their electronic characteristics (Table 2), and reac- carbon C5 in Ba possesses a large positive charge (see data in
tions of allene 2a in Brønsted acids (Table 3), one may propose Table 1 and Table 2). An alternative mechanism of the forma-
a plausible mechanism for the transformation of 2a (Scheme 2). tion of alcohol 4a includes the attack of H2O on the sulfur elec-
Protonation of the allene system gives cation C, which is trophilic center giving intermediate D, which is rearranged into
cyclized into stable species Ba. Upon work-up of the acidic alcohol Z-4a. Preparation of sulfur heterocycle 5a at high reac-
reaction solution, the fate of the cation Ba strongly depends on tion temperature (Table 3, entry 2) shows that the intramolecu-
the nucleophilicity of the quenching medium. Under the condi- lar cyclization to the ortho-carbon of phenyl ring occurs, most
tions of low nucleophilic work-up with aqueous HCl (Table 3, probably, through cation C (Scheme 2). And this reaction has a
entry 4), the deprotonation takes place leading to butadiene high activation barrier, analogously to the similar cyclization of
Scheme 2: Plausible reaction mechanisms of transformations of allene 2a in Brønsted acids.
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phosphonoallenes to the corresponding phosphonoheterocycles scribed recently [23]. Herein, we have developed a novel metal-
[30].
free approach for the synthesis of cis-isomers of 3.
We decided to achieve the selective formation of each of these Then, we tried to get selectively products of the nucleophilic
different products, butadienes 3, adducts with nucleophiles 4, attack onto cations B (like structure Z-4a in Scheme 2) by
and thiochromene 1,1-dioxides 5, from allenes 2. The prepara- quenching of the acidic reaction solutions (in TfOH) with
tion of compounds 3a–h was done by the following method various nucleophiles (water, methanol, benzene, acetonitrile).
(Scheme 3). Reactions of 2a–h were carried out in CH2Cl2 with But, in all cases, these reactions were unselective. For instance,
1 equivalent of TfOH to generate the corresponding cations for allene 2a, mixtures of butadiene Z-3a and alcohol Z-4a were
Ba–h. Then, the reaction mixture was cooled down to −35 °C obtained. To overcome this obstacle we decided to use
and quenched under very mild and low nucleophilic conditions 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which was known to
with frozen aqueous HCl at −60 °C, that finally led quantitative- form the corresponding ether for further substitution reactions
ly to butadienes 3a–h (see X-ray structure of 3e in Figure 1). [33]. Indeed, the use of HFIP and a catalytic amount of TfOH
Worth noting, that compounds 3a–h have strictly cis-configura- (0.1 equiv) followed by hydrolysis allowed to achieve an exclu-
tion of SO2Ar group and a vinyl substituent at C2 carbon. It sive formation of allyl alcohols Z-4a,b and E-4c from allenes
should be mentioned that palladium-catalyzed isomerization of 2a,b,d, respectively, in high yields (Scheme 4). The most prob-
such (arylsulfonyl)allenes 2 into trans-butadienes 3 was de- ably, this reaction proceeds through intermediate formation of
Scheme 3: Selective formation of butadienes 3a–h from allenes 2a–h.
Scheme 4: Reactions of allenes 2 in the system HFIP/TfOH followed by interaction with nucleophiles leading to allyl alcohols 4.
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ethers E from the corresponding species B. The ethers E are tions, that there was a [6,7]-shift of the methyl group in the
hydrolyzed to compounds 4. Reactions of allenes 2 with other thiochromene system of 5b obtained from allene 2c, which, at
nucleophiles (methanol, benzene, acetonitrile) led to the forma- first, should give 6-methyl substituted thiochromene. This shift
tion of complex mixtures of reaction products. It must be noted is caused by the action of superacid at high reaction tempera-
that no reaction proceeded in HFIP without TfOH.
ture. Phenyl-substituted allenes 2e,f did not afford the corre-
sponding thiochromenes, due to oligomerization under the harsh
The assignment of the cis-configuration of the ArSO2 group and reaction conditions. Other allenes 2g,h gave the corresponding
the C3-substituent in compounds 3 and 4 was based on the low heterocycles 5 in very poor yields (<4%, by GC–MS and
spin–spin interaction constant of 8.0–11.8 Hz between the vinyl 1H NMR data).
protons in the 1H NMR spectrum (see Supporting Information
File 1) and on comparison with the known trans-isomers of 3 As it was mentioned above, unsubsituted allenes 2i,j did not
[23].
react with TfOH at room temperature (see discussion on NMR
of cations B, Table 1). Under the heating in TfOH at 100 °C for
Compounds Z-3a and Z-4a could be interconverted in acids 0.5 h, these allenes afforded (arylsulfonyl)acetones 6a,b, which
through species Ba (Scheme 2). Thus, both Z-3a and Z-4a give may be formed under the hydrolysis of the formed vinyl triflates
cation Ba upon dissolving in TfOH. Then, a different quenching F (Scheme 6).
of solution of the cation affords Z-3a (Scheme 3) or Z-4a
(Scheme 5). Heating of the solution of Ba leads to 5a (see Finally, in this study, we carried out reactions of (aryl-
Scheme 5).
sulfinyl)allenes 1a,b under superelectrophilic activation with
TfOH or AlX3 (X = Cl, Br). The corresponding cations Aa,b
generated from 1a,b in TfOH were subjected to quenching with
various nucleophiles followed by hydrolysis (Scheme 7). In all
the cases, allyl alcohols 7a,b were isolated (see X-ray structure
of 7b in Figure 1). The same alcohols were obtained in reac-
tions of 1a,b with AlX3 (X = Cl, Br) after the hydrolysis of
reaction solutions. In these reactions, presumably, intermediate
Scheme 5: Formation of thiochromene 1,1-dioxides 5a–c from allenes
2a,c,d.
The exclusive formation of thiochromene 1,1-dioxides 5a–c
was obtained by running the reaction of 2a,c,d with 1 equiva-
lent of CF3SO3H at high temperature (reflux in ortho-dichloro-
benzene at 144 °C) for 2 h (Scheme 5, see X-ray structure of 5c
in Figure 1). It was found by H,H-NOESY and COSY correla-
Scheme 7: Reactions of (aryl-sulfinyl)allenes 1a,b under superelec-
trophilic activation.
Scheme 6: Formation of (arylsulfonyl)acetones 6a,b from allenes 2h,j in TfOH (100 °C, 0.5 h) followed by hydrolysis of superacidic reaction solutions.
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6. Back, T. G.; Clary, K. N.; Gao, D. Chem. Rev. 2010, 110, 4498–4553.
doi:10.1021/cr1000546
adducts G, which are formed upon interaction of species Aa,b
with nucleophiles, are easily hydrolazible and give rise to alco-
hols 7a,b.
7. Yu, S.; Ma, S. Angew. Chem., Int. Ed. 2012, 51, 3074–3112.
doi:10.1002/anie.201101460
8. Martzel, T.; Lohier, J.-F.; Gaumont, A.-C.; Brière, J.-F.; Perrio, S.
Adv. Synth. Catal. 2017, 359, 96–106. doi:10.1002/adsc.201600929
9. Lin, T.-Y.; Zhu, C.-Z.; Zhang, P.; Wang, Y.; Wu, H.-H.; Feng, J.-J.;
Zhang, J. Angew. Chem., Int. Ed. 2016, 55, 10844–10848.
doi:10.1002/anie.201605530
Conclusion
Transformations of (arylsulfonyl)- and (arylsulfinyl)allenes
under the action of the Brønsted superacid TfOH, or strong
Lewis acids AlX3 (X = Cl, Br) have been studied. Under elec-
trophilic conditions, these allenes form the corresponding 1,2-
oxathiolium ions, which have been studied by NMR and DFT
calculations. Depending on electrophilic activator, reaction
conditions (temperature, time), and nucleophilicity of media for
quenching of solutions of 1,2-oxathiolium ions, these species
may undergo various transformations leading to the selective
formation of one of the reaction products: conjugated dienes,
allyl alcohols, or thiochromene 1,1-dioxides. These reactions
open new opportunities for organic synthesis based on electro-
philic activation of sulfur containing allenes.
10.Undeela, S.; Thadkapally, S.; Nanubolu, J. B.; Singarapu, K. K.;
Menon, R. S. Chem. Commun. 2015, 51, 13748–13751.
doi:10.1039/c5cc04871k
11.Kumar, A.; Thadkapally, S.; Menon, R. S. J. Org. Chem. 2015, 80,
11048–11056. doi:10.1021/acs.joc.5b02324
12.Mo, D.-L.; Wink, D. J.; Anderson, L. L. Chem. – Eur. J. 2014, 20,
13217–13225. doi:10.1002/chem.201403268
13.Xiong, Z.; Hale, K. J. Org. Lett. 2016, 18, 4254–4257.
doi:10.1021/acs.orglett.6b02002
14.Mukai, C.; Kobayashi, M.; Kubota, S.; Takahashi, Y.; Kitagaki, S.
J. Org. Chem. 2004, 69, 2128–2136. doi:10.1021/jo035729f
15.Mukai, C.; Yamashita, H.; Hanaoka, M. Org. Lett. 2001, 3, 3385–3387.
doi:10.1021/ol0101842
16.Mukai, C.; Ukon, R.; Kuroda, N. Tetrahedron Lett. 2003, 44,
1583–1586. doi:10.1016/s0040-4039(03)00067-4
17.Zhu, Y. I.; Stiller, M. J. J. Am. Acad. Dermatol. 2001, 45, 420–434.
doi:10.1067/mjd.2001.114733
Supporting Information
Supporting Information File 1
18.Xu, S.; Rouzer, C. A.; Marnett, L. J. IUBMB Life 2014, 66, 803–811.
doi:10.1002/iub.1334
Copies of 1H and 13C NMR spectra of compounds and
cations, X-ray data, and data of DFT calculations.
[https://www.beilstein-journals.org/bjoc/content/
supplementary/1860-5397-14-268-S1.pdf]
19.Noble, S.; Benfield, P. CNS Drugs 1999, 12, 471–483.
doi:10.2165/00023210-199912060-00005
20.Denmark, S. E.; Harmata, M. A.; White, K. S. J. Org. Chem. 1987, 52,
4031–4042. doi:10.1021/jo00227a017
21.Harmata, M.; Cai, Z.; Huang, C. Org. Synth. 2011, 88, 309–316.
doi:10.15227/orgsyn.088.0309
Acknowledgements
22.Tata, R. R.; Hampton, C. S.; Harmata, M. Adv. Synth. Catal. 2017, 359,
1232–1241. doi:10.1002/adsc.201600986
This work was supported by Russian Scientific Foundation
(grant no. 18-13-00008). Spectral studies were performed at
Center for Magnetic Resonance, Center for Chemical Analysis
and Materials Research, and Research Center for X-ray Diffrac-
tion Studies of Saint Petersburg State University, Saint Peters-
burg, Russia.
23.Hampton, C. S.; Harmata, M. Org. Lett. 2014, 16, 1256–1259.
doi:10.1021/ol500259m
24.Hampton, C. S.; Harmata, M. J. Org. Chem. 2016, 81, 4807–4822.
doi:10.1021/acs.joc.6b00880
25.Ma, S.; Ren, H.; Wei, Q. J. Am. Chem. Soc. 2003, 125, 4817–4830.
doi:10.1021/ja034039q
26.Zhou, C.; Fu, C.; Ma, S. Tetrahedron 2007, 63, 7612–7616.
doi:10.1016/j.tet.2007.05.039
ORCID® iDs
Stanislav V. Lozovskiy - https://orcid.org/0000-0001-7035-0557
Alexander Yu. Ivanov - https://orcid.org/0000-0002-4228-1248
Aleksander V. Vasilyev - https://orcid.org/0000-0003-3628-1492
27.Zhou, C.; Fang, Z.; Fu, C.; Ma, S. J. Org. Chem. 2009, 74, 2887–2890.
doi:10.1021/jo802755k
28.Fang, Z.; Zhou, C.; Fu, C.; Ma, S. Org. Biomol. Chem. 2010, 8,
4554–4561. doi:10.1039/c0ob00007h
29.Bogachenkov, A. S.; Dogadina, A. V.; Boyarskiy, V. P.; Vasilyev, A. V.
Org. Biomol. Chem. 2015, 13, 1333–1338. doi:10.1039/c4ob02269f
30.Bogachenkov, A. S.; Dogadina, A. V.; Boyarskaya, I. A.;
Boyarskiy, V. P.; Vasilyev, A. V. Org. Biomol. Chem. 2016, 14,
1370–1381. doi:10.1039/c5ob02143j
References
1. Krause, N.; Hashmi, A. S. K., Eds. Modern Allene Chemistry;
Wiley-VCH: Weinheim, 2004; Vol. 1 and 2.
doi:10.1002/9783527619573
2. Brummond, K. M.; DeForrest, J. E. Synthesis 2007, 795–818.
doi:10.1055/s-2007-965963
31.Lozovskiy, S. V.; Bogachenkov, A. S.; Dogadina, A. V.; Vasilyev, A. V.
Tetrahedron Lett. 2016, 57, 3167–3170.
3. Bates, R. W.; Satcharoen, V. Chem. Soc. Rev. 2002, 31, 12–21.
doi:10.1039/b103904k
doi:10.1016/j.tetlet.2016.06.026
32.Lozovskiy, S. V.; Ivanov, A. Y.; Bogachenkov, A. S.; Vasilyev, A. V.
ChemistrySelect 2017, 2, 4505–4510. doi:10.1002/slct.201700637
33.Trillo, P.; Baeza, A.; Nájera, C. J. Org. Chem. 2012, 77, 7344–7354.
doi:10.1021/jo301049w
4. Ma, S. Aldrichimica Acta 2007, 40, 91–102.
5. Hassan, H. Curr. Org. Synth. 2007, 4, 413–439.
doi:10.2174/157017907782408798
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