Interaction of 1,3λ4δ2,2,4-benzodithiadiazines with neutral and charged S-electrophiles: SCl2, C6F5SCl, and NS2+

Article abstract of DOI:10.1007/s10593-020-02760-y

[Figure not available: see fulltext.] Reactions of 1,3λ⁴δ²,2,4-benzothiadiazines with SCl₂, C₆F₅SCl, and [NS₂][SbF₆] leading to 1,2,3-benzodithiazolium salts (Herz salts) were in

Full text of DOI:10.1007/s10593-020-02760-y

DOI 10.1007/s10593-020-02760-y
Chemistry of Heterocyclic Compounds 2020, 56(7), 968–972
Interaction of 1,3λ4δ2,2,4-benzodithiadiazines with neutral
+
and charged S-electrophiles: SCl2, C6F5SCl, and NS2
Alexander Yu. Makarov1*, Irina Yu. Bagryanskaya1, Vladimir V. Zhivonitko2
1 N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences,
9 Akademika Lavrentieva Ave., Novosibirsk 630090, Russia; е-mail: makarov@nioch.nsc.ru
2 NMR Research Unit, Faculty of Science, University of Oulu,
P. O. Box 3000, Oulu 90014, Finnland
Translated from Khimiya Geterotsiklicheskikh Soedinenii,
2020, 56(7), 968–972
Submitted April 30, 2020
Accepted May 22, 2020
Reactions of 1,3λ4δ2,2,4-benzothiadiazines with SCl2, C6F5SCl, and [NS2][SbF6] leading to 1,2,3-benzodithiazolium salts (Herz salts)
were investigated. The relative rate of reaction with SCl2 significantly depends on the nature of the substituent and its position in the
carbocycle. Halogen substituents Cl, Br, and I slow down the reaction, especially if located closely to the heterocycle (positions 5 and 8).
In the case of C6F5SCl and R = H, chlorination of the carbocycle and opening of the heterocycle also takes place with the formation of
7-chloro-1,3λ4δ2,2,4-benzothiadiazine аnd C6F5–S–N=S=N–Ar (Ar = 2-Cl-6-F5C6SC6H3), respectively. In the reaction with NS2 , along
+
with contraction of the heterocycle, also its expansion occurs with the formation of 1,2,4λ4δ2,3,5-benzotrithiadiazepine.
Keywords: benzodithiazolium salts, 1,3,2,4-benzothiadiazines, 1,2,4,3,5-benzotrithiadiazepine, dithionitronium, pentafluorobenzene-
sulfenyl chloride, sulfur dichloride, sulfur-nitrogen heterocycles, tetrasulfur tetranitride.
1,3λ4δ2,2,4-Benzothiadiazines 1 (the indices λ and δ are
omitted below) are relatively little studied 12π-electron, i.e.,
formally antiaromatic, compounds which are stable at
normal conditions. Their heteroatom reactivity is high,
diverse, and largely unpredictable,1–7 the ring contraction
being the most typical kind. In particular, the reaction with
SCl2 leads to 1,2,3-benzodithiazolium salts 2 (Herz salts),
which is the mildest method for their synthesis, allowing to
obtain also otherwise unaccessible derivatives;2c,3 the
reaction with Ph3P leads to iminophosphoranes Ph3P=N–R
(R = 1,2,3-benzodithiazol-2-yl);1,4 thermolysis and photo-
lysis of dilute solutions produces 1,2,3-benzodithiazolyls
(Herz radicals) 3.1,3,5 At high concentrations, the
thermolysis leads both to ring contraction toward 1,2,3-di-
thiazole or 1,2,5-thiadiazole ring and to ring expansion
toward 1,2,4,3,5-trithiadiazepine and 1,3,2,4,7-dithiatri-
azepine ring.1,6 The addition of H2O causes opening of the
heterocycle.4b,7
purpose of spectroscopic investigation, including reaction
mechanism study, it is convenient to generate Herz radicals
3 from compounds 1.1,3,5
The key intermediate of photolysis and likely also
thermolysis of compounds 1 is singlet nitrenoid 4 detected
under conditions of matrix isolation.5с,10 It has been
assumed that it also takes part in reaction of compounds 1
with PPh3 and SCl2 by oxidative imination of the P and S
atoms of those reactants (Scheme 1).1,2c Isomerization of
compounds 1 into intermediate 4 requires energy the source
of which can be the interaction of the low-lying vacant
Scheme 1
Herz salts 2 are preparative precursors of Herz radicals 3
which are stable π-radicals, and they can in some cases be
isolated separately and used as structural blocks in the
design and synthesis of molecular semiconductors and
magnetics.8 Recently, they have found application in the
synthesis of polycyclic sulfur-nitrogen π-systems with
intense absorption in the near-infrared range.9 For the
0009-3122/20/56(7)-0968©2020 Springer Science+Business Media, LLC
968

Chemistry of Heterocyclic Compounds 2020, 56(7), 968–972
Figure 1. The effect of substituent in the carbocycle on the rate of reaction of compunds 1a–e with SCl2.
1
π-МО with the lone electron pair of phosphorus or sulfur
atoms.2c In this context, compounds 1 act as Lewis acids,
but PPh3 и SCl2 have the role of Lewis bases.
of compound 1j (identified by Н NMR spectroscopy)2b
and opening of the heterocycle leading to the formation of
compound 6 (Scheme 2), the structure of which has been
established using X-ray structural investigation (Fig. 2) are
also observed. However, the low quality of crystals
(R 0.17) prevents the discussion of bond lengths and
valence angle values.
The results of reactions with other compounds,
including sulfur compounds, is difficult to predict. The
formation of new types of compounds, including new
precursors of 1,2,3-benzodithiazolyl radicals, can be
expected. In particular, the exchange of Cl atoms for
organic groups in iminosulfurane 5 was expected to
stabilize the latter, so that it would be possible to isolate
such compounds and study their properties.
Scheme 2
In the present work, the study of reactions of compounds
1 with SCl2 is carried forward and other S-electrophiles,
+
C6F5SCl and [NS2][SbF6], are used for the first time. NS2
cation possesses high and diverse reactivity. However, its
reactions with heterocyclic compounds have been investi-
gated only to a limited extent.11
Previously it was found, using the method of competing
reactions, that for derivatives of compound 1а, containing
halogens (I, Br) in 6 and 8 positions, the relative rate of
their reaction with SCl2 depends on the position of halogen:
8-isomers react more slowly.2с In the present work, the
effect of the nature and position of substituents on the
relative rate of this reaction is studied using the same
method. The processes taking place in the reaction mixture
are complex and not entirely understood.2с Therefore, it is
possible to establish only qualitative relationships which
nevertheless are important for the understanding the
reactivity of 1,3,2,4-benzothiadiazines 1 and development
of methods for their synthesis.
Figure 2. Molecular structure of compound 6 with atoms
represented as thermal vibration ellipsoids of 50% probability.
It was found that compounds 1b (5-Br) and 1e (8-Br)
interact with SCl2 at approximately equal rates which are
significantly slower than in the case of compounds 1c
(6-Br) and 1d (7-Br) the reaction rates of which, too, have
similar values. Compound 1а reacts faster than compounds
1c,d (Fig. 1). Compound 1f (8-Cl) is also more inert toward
SCl2 than its isomer compound 1g (6-Cl), while between
compounds 1h (8-СН3) and 1i (6-СН3) such difference is
not observed. Therefore, Cl, Br, and I atoms have
deactivating effect which becomes weaker with increasing
their distance from the heterocycle, which corresponds to
their inductive effect.
The deactivating effect of Cl, Br, I atoms better
corresponds to the role of compounds 1 as nucleophiles,
rather than Lewis acids. Meanwhile it can be not excluded
that intermediate 4 also can act as nucleophile, since its
stable analog Ph3S≡N is known to have such property.12
The reaction of compound 1а with С6F5SCl leads to salt
2а and (C6F5S)2 as the main products. In addition to that,
the chlorination of compound 1a leading to the formation
The reaction of compound 1а with С6F5SCl proceeds
slower than with SCl2, while (C6F5)2Sn (n = 1,* 2) do not
interact with compound 1а under these conditions. This
speaks against the hypothesis about the reactions of
compounds 1 with XSCl (X = Cl, С6F5) as oxidative
imination of the S atom by nitrenoid 4 and in favor of the
role of the latter reagents as S-electrophiles: the transition
from X = Cl to X = С6F5 should not decrease the ability of
the S to to be iminated, yet it decreases its electrophilicity;
compounds (C6F5)2Sn (n = 1, 2) also should be amenable to
imination, but they are not electrophiles. Still one further
cause of different reactivity of the reagents under
discussion is the presence or absence of a good leaving
group in their molecules, namely Cl atom, the elimination
* In the present work, (C6F5)2S was synthesized by a new method using
reaction of C6F5MgBr with (SN)4. Although this method does not have
significant advantages over those described before,13 it is of interest to
note that formation of organic sulfides in reaction of (SN)4 with Grignard
reagents was not observed previously.14
969

Chemistry of Heterocyclic Compounds 2020, 56(7), 968–972
of which is necessary for conversion of the starting
spectrum of the reaction mixture of compound 1a with
[NS2][SbF6] was acquired on a Bruker DRX-500 (36 МHz)
spectrometer. 19F NMR spectra were acquired on Bruker
DRX-500 (471 MHz) and Bruker WP200-SY (188 МHz)
spectrometers. Chemical shift reference was TMS (for 1Н and
13С nuclei), liquid NH3 (for 14N nuclei), С6F6 (for 19F nuclei).
High-resolution mass spectra were recorded on a Finnigan
MAT MS-8200 spectrometer (ionization by electron impact
at 70 eV). Electronic absorption spectra in UV and visible
range were recorded on a Hewlett Packard 8453
spectrometer.
compounds into the final products.
Introduction of the С6F5S substituent into the carbocycle
of compound 6, which requires the C–S bond cleavage in
either substrate or reagent, as well as substitution of Н
atom by Cl atom (taking place also upon formation of
compound 1j) are difficult to explain by electrophilic or
nucleophilic substitution reactions. It can be suggested that
radical cation of compound 1а participates in the process,
having been previously detected by ESR spectroscopy
during electrochemical oxidation of compound 1а.15
The reaction of compound 1а with [NS2][SbF6] leads to
products of both ring contraction and ring expansion –
1,2,3-benzodithiazolium (2а) and 1,2,4,3,5-benzotrithia-
diazepine (7), as well as (SN)4 (Scheme 3). The formation
of these compounds can be explained by electrophilic
All described experiments were performed in absolute
solvents under stirring in Ar atmosphere. Reagents were
added dropwise. Solvents were evaporated under reduced
pressure.
Compounds 1a–e,2а,с 1j,2b mixtures of compounds 1f and
1g, 1h and 1i2b and C6F5SCl17 were obtained in accordance
with the methods described earlier. Salt [NS2][SbF6]18 was
generously gifted by Dr. K. V. Shuvaev.
+
attack of cation NS2 at N-2 atom of the substrate (in
+
+
contrast to NО2 , the reaction center of NS2 ion is S, not
N atom)11а with subsequent bifurcation of the reaction path
toward the elimination of either NS+ or (SN)2 further
dimerizing into (SN)4 (Scheme 3). It should be noted that
the yield of compound 7 in this reaction (20%) is twice as
high as in a previously published method of its synthesis
(10%).16
Competing reactions of 1,3,2,4-benzothiadiazines 1
with SCl2. A solution of SCl2 (10 mg, 0.1 mmol) in CH2Cl2
(0.2 ml) was added to a solution of 1:1 mixture of
compounds 1b and 1c, 1b and 1e, 1c and 1d, 1c and 1a, 1f
and 1g, 1h and 1i (0.2 mmol) in CH2Cl2 (1.5 ml). After
30 min, the solution was filtered, the filtrate was
evaporated to dryness, the residue was sublimated in vacuo.
Scheme 3
1
According to H NMR spectrum, compound 1g was absent
in the sublimate; in other cases the ratio of compounds was
as follows: 1b:1c > 10; 1b:1e = 1:1; 1c:1d = 1:1; 1c:1a = 2:1;
1h:1i = 1:1.
Interaction of 1,3,2,4-benzothiadiazine (1a) with
С6F5SCl, synthesis of compound 6. Compound 1a (84 mg,
0.5 mmol) in CH2Cl2 (1.5 ml) was added within 20 min to a
solution of C6F5SCl (118 mg, 0.5 mmol) in CH2Cl2
(1.5 ml). After 1 week, the yellow fine crystalline
precipitate of salt 2a was filtered off. The filtrate was
evaporated to dryness, the residue was separated by column
chromatography on silica gel (eluent
C6F5SSC6F5 and compound 6 were isolated.
–
hexane).
1,2,3-Benzodithiazolium chloride (2а). Yield 30 mg
(32%), light-brown crystals, mp 145–160°С (decomp.). The
1H NMR spectrum matched a published one.19
In summary, contraction, expansion, and opening of the
heterocycle take place in the investigated reactions of
1,3,2,4-benzothiadiazines with S-electrophiles. The
transformation of antiaromatic 1,3,2,4-dithiadiazine hetero-
cycle into aromatic 1,2,3-dithiazolium is the most typical
process. It is energetically favorable, which is the obvious
driving force of the reaction. The reaction mechanisms are
complex and require additional experimental and,
especially, theoretical study because of the obvious
difficulties of the experimental approach. Nevertheless, the
obtained data allow to state that compounds XSCl (X = Cl,
С6F5) in reactions with 1,3,2,4-benzothiadiazines act as
electrophiles rather than Lewis bases.
2-Chloro-6-[(pentafluorophenyl)sulfanyl]-N-({[(penta-
fluorophenyl)sulfanyl]imino}-λ4-sulfanylidene)aniline
(6). Yield 10 mg (3.5%), orange crystals, mp 126–129°С.
UV spectrum (pentane), λmax, nm (log ε): 432 (3.85), 361
1
(3.73), 223 (4.43). Н NMR spectrum (500 МHz, СDCl3),
δ, ppm: 7.31 (1H, dd, J = 8.0 J = 1.0, H Ar); 6.97 (1H, t,
J = 8.0, H Ar); 6.79 (1H, d, J = 8.0, H Ar). 13C NMR
spectrum (СDCl3), δ, ppm: 139.3; 131.2; 127.9 (CH);
127.1; 126.1 (CH); 126.5 (CH); signals of С6F5 groups
were not detected due to their low intensity. 19F NMR
spectrum (471 МHz, СDCl3), δ, ppm (J, Hz): 32.3 (2F, d,
J = 19.0); 31.1 (2F, d, J = 20.0); 14.7 (1F, tt, J = 21.0,
J = 4.0); 13.1 (1F, t, J = 21.0); 3.19–3.04 (2F, m); 2.90–
3.03 (2F, m). Found, m/z: 567.8987 [M]+. C18H3ClF10N2S3.
Calculated, m/z: 567.8987.
Experimental
1H NMR spectra were acquired on Bruker DRX-500
(500 MHz) and Bruker WP200-SY (200 МHz)
spectrometers, and 13C NMR spectra were acquired on a
Bruker DRX-500 (126 MHz) spectrometer. 14N NMR
Decafluorodiphenyl disulfide. Yield 40 mg (40%), pale-
yellow crystals, mp 49–50°С (mp 50–51°С20).
970

Chemistry of Heterocyclic Compounds 2020, 56(7), 968–972
evolution of gas and preceding sublimation of crystals with
Identification of 7-chloro-1,3,2,4-benzothiadiazine
a characteristic shape).
(1j) as a product of interaction of 1,3,2,4-benzothia-
diazine (1a) with C6F5SCl. C6F5SCl (2.11 g, 0.009 mol)
was added to a solution of compound 1a (0.50 g, 0.003 mol)
in CH2Cl2 (5 ml). After 2 days, the solution was filtered,
the filtrate was evaporated, the residue was sublimated
X-ray structure investigation of compound 6 was
carried out at 20°С on a Bruker P4 single crystal
diffractometer with a graphite monochromator using MoKα
radiation. The structure was solved by the direct method
and refined with the full-matrix least-squares anisotropic
(isotropic for H atoms) approximation using the SHELXL-
97 software.23 The positions of the H atoms were localized
geometrically. The crystal was a thin (0.01–0.02 mm)
elongated plate. The experiment was carried out up to 2θ
45°, since at larger angles all reflections were of zero
intensity. The high R value (0.17) has possibly to do with
the fact that the crystal was an aggregate, although the twin
law was not established. The complete crystallographic
information on compound 6 has been deposited at the
Cambridge Crystallographic Data Center (deposit CCDC
1999877).
1
in vacuo (80°С, 2 Torr). The main signals in the Н NMR
spectrum of the green sublimate (1.12 g) matched
those of compound 1j,2b while the main signals in the
19F NMR spectrum matched those of decafluorodiphenyl
sulfide.20а
Decafluorodiphenyl disulfide. A solution of C6F5Br
(9.88 g, 40 mmol) in THF (20 ml) during 30 min was
added to a refluxing suspension of Mg turnings (0.96 g,
40 mmol), activated by I2, in THF (80 ml). Almost all Mg
was dissolved within 30 min. Freshly recrystallized (SN)4
(1.84 g, 10 mmol) was added to the reaction mixture in
small portions. After 1.5 h, the mixture was cooled with ice
water and a solution of Br2 (3.20 g, 20 mmol) in THF
(15 ml) was gradually added. After 30 min, the mixture
was filtered, the solvent was evaporated, and the residue
was extracted with boiling hexane (4×30 ml). The
combined extract was evaporated, the residue was sub-
limated and recrystallized from hexane. The sublimation
and recrystallization was repeated to obtain decafluoro-
diphenyl sulfide. Yield 3.18 g (48%), slightly yellow
crystals, mp 86–88°С (mp 85–86°С13c). The 19F NMR
spectrum matched a published one.21
Interaction of 1,3,2,4-benzothiadiazine (1а) with
(C6F5)2Sn (n = 1, 2). Compound 1a (84 mg, 0.5 mmol) and
(C6F5)2Sn (n = 1, 2) (183 or 199 mg, 0.5 mmol) were
dissolved in CDCl3 (0.7 ml). 1Н and 19F NMR spectra were
recorded right after the mixing and after keeping for
15 days at room temperature. Only signals of starting
compounds were observed in the spectra.
Authors thank the Collective Use Chemistry Service Center
of the Siberian Branch of the Russian Academy of Sciences
for the instrumental measurements and A. V. Zibarev for
discussion of the results and useful suggestions.
References
1. Blockhuys, F.; Gritsan, N. P.; Makarov, A. Yu.; Tersago, K.;
Zibarev, A. V. Eur. J. Inorg. Chem. 2008, 655.
2. (a) Cordes, A. W.; Hojo, M.; Koenig, H.; Noble, M. C.;
Oakley, R. T.; Pennington, W. T. Inorg. Chem. 1986, 25,
1137. (b) Bagryanskaya, I. Yu.; Gatilov, Yu. V.; Makarov, A. Yu.;
Maksimov, A. M.; Miller, A. O.; Shakirov, M. M.; Zibarev, A. V.
Heteroat. Chem. 1999, 10, 113. (c) Makarov, A. Yu.;
Bagryanskaya, I. Yu.; Gatilov, Yu. V.; Mikhalina, T. V.;
Shakirov, M. M.; Shchegoleva, L. N.; Zibarev, A. V.
Heteroat. Chem. 2001, 12, 563.
3. (a) Gritsan, N. P.; Kim, S. N.; Makarov, A. Yu.; Chesnokov, E. N.;
Zibarev, A. V. Photochem. Photobiol. Sci. 2006, 5, 95.
(b Makarov, A. Yu.; Kim, S. N.; Gritsan, N. P.;
Bagryanskaya, I. Yu.; Gatilov, Yu. V.; Zibarev, A. V.
Mendeleev Commun. 2005, 15, 14.
4. (a) Zibarev, A. V.; Gatilov, Yu. V.; Bagryanskaya, I. Yu.;
Maksimov, A. M.; Miller, A. O. Chem. Commun. 1993, 298.
(b) Makarov, A. Yu.; Zhivonitko, V. V.; Makarov, A. G.;
Zikirin, S. B.; Bagryanskaya, I. Yu.; Bagryansky, V. A.;
Gatilov, Yu. V.; Irtegova, I. G.; Shakirov, M. M.;
Zibarev, A. V. Inorg. Chem. 2011, 50, 3017. (c) Grayfer, T. D.;
Makarov, A. Yu.; Bagryanskaya, I. Yu.; Irtegova, I. G.;
Gatilov, Yu. V.; Zibarev, A. V. Heteroat. Chem. 2015, 26,
42.
Interaction of 1,3,2,4-benzothiadiazine (1a) with
[NS2][SbF6]. [NS2][SbF6] salt (166 mg, 0.52 mmol) was
added in small portions to a solution of compound 1a
(89 mg, 0.52 mmol) in CH2Cl2 (40 ml). After 16 h, the
black precipitate (78 mg) was filtered off and washed on
the filter with CH2Cl2. The filtrate was evaporated, the
residue was dissolved in CDCl3 (62 mg of black substance
1
remained), and NMR spectra were recorded. The Н NMR
spectrum corresponded to a 1:3 mixture of compounds 1a2a
and 7,16 in the 14N NMR spectrum, beside signals of
compounds 1a2с and 7,16 an intensive signal at 125 ppm
was observed corresponding to (SN)4.22 Signals of cations
of salt 2a were absent in the spectra. Chromatography on
silica gel (eluent PhH–heptane, 1:1, with addition of 1%
EtOAc) separated compound 7 and (SN)4. The insoluble in
CDCl3 black substance was dissolved in CF3CO2H and
1Н NMR spectrum was recorded containing signals of
cations of salt 2a and NH4+ in 12:1 molar ratio.
5. (a) Gritsan, N. P.; Makarov, A. Yu.; Zibarev, A. V. Appl.
Magn. Reson. 2011, 41, 449. (b) Shuvaev, K. V.; Bagryansky, V. A.;
Gritsan, N. P.; Makarov, A. Yu.; Molin, Yu. N.; Zibarev, A. V.
Mendeleev Commun. 2003, 13, 178. (c) Gritsan, N. P.;
Bagryansky, V. A.; Vlasyuk, I. V.; Molin, Yu. N.;
Makarov, A. Yu.; Platz, M. S.; Zibarev, A. V. Russ. Chem.
Bull., Int. Ed. 2001, 50, 2064. [Izv. AN, Ser. Khim. 2001,
1973.] (d) Vlasyuk, I. V.; Bagryansky, V. A.; Gritsan, N. P.;
Molin, Yu. N.; Makarov, A. Yu.; Gatilov, Yu. V.;
Shcherbukhin, V. V.; Zibarev, A. V. Phys. Chem. Chem.
Phys. 2001, 3, 409.
1,2,4λ4δ2,3,5-Benzotrithiadiazepine (7). Yield 19.3 mg
(18%, 20% considering the incomplete conversion of
1
compound 1a), red crystals, mp 27–28°С. The H NMR
spectrum matched a published one.16
6. Zhivonitko, V. V.; Makarov, A. Yu.; Bagryanskaya, I. Yu.;
Gatilov, Yu. V.; Shakirov, M. M.; Zibarev, A. V. Eur.
J. Inorg. Chem. 2005, 4099.
Tetrasulfur tetranitride ((SN)4). Yield 4.5 mg (9%),
оrange crystals, mp 180–190°С (decomposes with
971

Chemistry of Heterocyclic Compounds 2020, 56(7), 968–972
7. Makarov, A. Yu.; Bagryanskaya, I. Yu.; Gatilov, Yu. V.;
15. Vasilieva, N. V.; Irtegova, I. G.; Gritsan, N. P.; Shundrin, L. A.;
Lonchakov, A. V.; Makarov, A. Yu.; Zibarev, A. V.
Mendeleev Commun. 2007, 17, 161.
16. Makarov, A. Yu.; Shakirov, M. M.; Shuvaev, K. V.;
Bagryanskaya, I. Yu.; Gatilov, Yu. V.; Zibarev, A. V. Chem.
Commun. 2001, 1774.
17. Sartori, P.; Golloch, A. Chem. Ber. 1970, 103, 3936.
18. Cameron, T. S.; Mailman, A.; Passmore, J.; Shuvaev, K. V.
Inorg. Chem. 2005, 44, 6524.
19. (a) Makarov, A. Yu.; Blockhuys, F.; Bagryanskaya, I. Yu.;
Gatilov, Yu. V.; Shakirov, M. M.; Zibarev, A. V. Inorg.
Chem. 2013, 52, 3699. (b) Akulin, Yu. I.; Gel'mont, M. M.;
Strelets, B. Kh.; Éfros, L. S. Chem. Heterocycl. Compd. 1978,
14, 733. [Khim. Geterotsikl. Soedin. 1978, 912.]
20. (a) Neil, R. J.; Peach, M. E. J. Fluor. Chem. 1971/72, 1, 257.
(b) Robson, P.; Stacey, M; Stephens, R; Tatlow, J. C.
J. Chem. Soc. 1960, 4754.
21. Chambers, R. D.; Cunningham, J. A.; Spring, D. J.
Tetrahedron 1968, 24, 3997.
Shakirov, M. M.; Zibarev, A. V. Mendeleev Commun. 2003, 13, 19.
8. Volkova, Yu. M.; Makarov, A. Yu.; Pritchina, Е. А.;
Gritsan, N. P.; Zibarev, A. V. Mendeleev Commun. 2020, 30,
385.
9. Makarov, A. Yu.; Volkova, Yu. M.; Shundrin, L. A;
Dmitriev, A. A.; Irtegova, I. G.; Bagryanskaya, I. Yu.;
Shundrina, I. K.; Gritsan, N. P.; Beckmann, J.; Zibarev, A. V.
Chem. Commun. 2020, 56, 727.
10. Gritsan, N. P.; Pritchina, E. A.; Bally, T.; Makarov, A. Yu.;
Zibarev, A. V. J. Phys. Chem. A 2007, 111, 817.
11. (a) Parsons, S.; Passmore, J. Acc. Chem. Res. 1994, 27,
101. (b) Decken, A.; Mailman, A.; Mattar, S. M.;
Passmore, J. Chem. Commun. 2005, 2366. (c) Decken, A.;
Mailman, A.; Passmore, J. Chem. Commun. 2009, 6077.
12. Yoshimura, T. Rev. Heteroat. Chem. 2000, 2, 101.
13. (a) Chambers, R. D.; Cunningham, J. A.; Pyke, D. A.
Tetrahedron 1968, 24, 2783. (b) Furin, G. G.; Terentyrva, Т. V.;
Yakobson, G. G. Izv. SO AN SSSR, Ser. Khim. 1972, 78.
(c) Belf, L. J.; Buxton, M. W.; Fuller, G. J. Chem. Soc. 1965,
3372.
22. Passmore, J.; Schriver, M. J. Inorg. Chem. 1988, 27 , 2749.
23. Sheldrick, G. M. SHELX-97, Programs for Crystal Structure
Analysis (Release 97.2); Goettingen University: Goettingen,
1997.
14. Mataka, S.; Takahashi, K.; Yamamoto, H.; Tashiro, M.
J. Chem. Soc., Perkin Trans. 1 1980, 2417.
972