A novel structural type of conformationally fixed, mixed phosphonium-iodonium ylides based on phenoxaphosphinine

Article abstract of DOI:10.1007/s11172-020-3034-x

A synthetic approach to a novel type of phosphonium and mixed phosphonium-iodonium ylides containing a conformationally fixed phosphonium fragment is developed. New representatives of these families of chemical compounds based on cyclic phenoxaphosphinine

Full text of DOI:10.1007/s11172-020-3034-x

Russian Chemical Bulletin, International Edition, Vol. 69, No. 12, pp. 2333—2339, December, 2020
2333
A novel structural type of conformationally fixed,
mixed phosphonium-iodonium ylides based on phenoxaphosphinine
A. S. Nenashev, D. S. Vinogradov, A. V. Mironov, and T. A. Podrugina
Department of Chemistry, M. V. Lomonosov Moscow State University,
Build. 3, 1 Leninskie Gory, 119991 Moscow, Russian Federation.
E-mail: anton.nenashev@chemistry.msu.ru
A synthetic approach to a novel type of phosphonium and mixed phosphonium-iodonium
ylides containing a conformationally fixed phosphonium fragment is developed. New represen-
tatives of these families of chemical compounds based on cyclic phenoxaphosphinine were
synthesized. One compound was structurally characterized by single-crystal X-ray diffraction.
Based on the 1H NMR data, one can state that phosphonium ylide exists in solution in the form
of two geometric isomers even at room temperature. This is indicative of pronounced double-
bond character of the bond between the ylide carbon atom and the stabilizing carbomethoxy
group.
Keywords: mixed ylides, phosphonium ylides, phosphonium-iodonium ylides, phenoxa-
phosphinine, cyclic phosphines.
Among a great variety of ylides, mixed phosphonium-
iodonium ylides hold a specific place owing to unique
synthetic potential originating from two onium fragments
and a mesomeric acceptor at the carbanion
The most widely used and the best described cyclic
phosphines include phosphole and its benzo analogue,
viz., 5-phenyl-5H-benzo[b]phosphindole (or 5-phenyl-
5H-dibenzophosphole) where the phosphorus atom is
a constituent of the five-membered ring. Recently,
such structures have attracted increasing attention as
promising organic ligands with unique optical and elec-
tronic properties.11 Systems with the phosphorus atom
included in the six-membered ring, e.g., 10-phenyl-
10H-phenoxaphosphinine (1), are much less studied.
At present, the 1,4-oxaphosphinine ligands and more
complex organic structures containing this fragment
are used in homogeneous catalysis as bulky phosphine
ligands.12—15
center (structure I). Nevertheless, they still
remain the least studied representatives of
this large class of chemical compounds.
During the last two decades we have car-
ried out systematic studies on the synthesis and properties
of mixed phosphonium-iodonium ylides. In particular, we
have for the first time demonstrated that they can enter
into heterocyclization reactions with compounds con-
taining both С≡N (see Refs 1, 2) and С≡С bonds (see
Refs 3—10) to give heterocyclic systems (Scheme 1).
This work is a continuation of our research on the
synthetic potential of mixed phosphonium-iodonium
ylides. Here we report on a previously unknown structural
modification of a mixed ylide where the phosphonium
moiety adopts a fixed conformation. The synthesis was
carried out using 10-phenyl-10H-phenoxaphosphinine 1
as the starting substrate.
Scheme 1
Compound 1 was synthesized in 25% yield following
a classical scheme, viz., by ortho-dilithiation of diphenyl
ether followed by the reaction of the dilithium derivative
with dichlorodiphenylphosphine16 (Scheme 2).
Phosphonium salt 2 was obtained by alkylation of 1
with methyl bromoacetate. The 1H NMR spectrum of
compound 2 exhibits a characteristic doublet of methylene
group with a spin-spin coupling constant 2JН,P of 14.2 Hz.
Ylide 3 was obtained by the reaction of salt 2 with sodium
methoxide (Scheme 3).
Mixed ylides with the phosphonium fragment based
on cyclic phosphine derivatives still remain unknown.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2333—2339, December, 2020.
1066-5285/20/6912-2333 © 2020 Springer Science+Business Media LLC

Nenashev et al.
2334
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
Scheme 2
Scheme 4
1
i. Ether, hexane, 0 С; ii. –78 C.
Scheme 3
a polar medium. An analysis of the bond lengths showed
that this structure is characterized by delocalization of the
-electron density in the P(1)—C(1)C(2)=O(2) fragment
with predominant contribution for the P(1)—C(1) bond
(1.685—1.687 Å) rather than the С(1)—С(2) bond
(1.422—1.427 Å). From these bond length intervals it fol-
lows that the change in the type of the isomer does not
lead to significant redistribution of the -electron density.
In particular, the С=О bond length changes from 1.212
to 1.222 Å. A scan of the potential energy surface along
the Р(1)—С(1)—С(2)—О(2) coordinate showed that,
owing to a small contribution of -bonding to the
С(1)—С(2) bond, the barrier to rotation about this bond
is 10.5 kcal mol–1. The maximum energy value was ob-
tained for the structure with a torsion angle of 101.6. The
С(1)—С(2) bond length varied only slightly (from 1.42 to
1.44 Å) on scanning.
Phosphorane 3 was oxidized by (diacetoxyiodo)ben-
zene in methanol to phosphonium-iodonium ylide 4
(Scheme 5). Usually, crystalline mixed ylides contain
counterions with no nucleophilic properties. Ylide 4 can
be stabilized by adding HBF4 and HPF6 to the reaction
mixture to give compounds 4a and 4b, respectively. Note
that precipitation of 4а occurs within a few minutes (the
yield is 48%) while ylide 4b precipitates immediately (the
yield is 56%). The presence of the BF4– and PF6– coun-
terions in the mixed ylides was proved by IR spectroscopy
and by 19F and 31P NMR spectroscopies (for PF6–). The
1H NMR spectrum of the carbomethoxy-substituted mixed
ylide 4 exhibits a characteristic broadening of the signal
of the methoxy group.18 It follows that this signal is a super-
position of signals from two geometric isomers similar to
those of ylide 3; however, the barrier to rotation about the
bond formed by the ylide carbon atom and the carboxyl group
at room temperature is almost overcome. A similar picture
was observed earlier for mixed phosphonium-iodonium
ylides19 and products of their nucleophilic substitution.18
Our previous studies revealed that crystalline mixed
phosphonium-iodonium ylides are stable and slowly de-
The carbon—carbon bond in the ylides stabilized by
mesomeric acceptor substituents has partial double bond
character. Various stereoisomers of stabilized ylides were
1
detected at −40 C by H, 13C, and 31P NMR spectro-
scopies.17 The NMR spectra of ylide 3 demonstrate the
presence of two geometric isomers even at room tem-
perature. Two doublets at  2.77 and 2.96 in the 1H NMR
spectrum correspond to proton at the ylide carbon atom
while two singlets at  3.20 and 3.54 correspond to the
methoxy group (Fig. 1). The structure of compound 3 can
be described by a number of resonance forms (Scheme 4),
and the presence of two isomers in solution suggests the
predominant contributions of structures 3B and 3C.
To obtain additional information on the structure of
ylide 3, we carried out quantum chemical calculations at
the PBE1PBE/dev-2-TZVP level of the density functional
theory (DFT). Full geometry optimization of the Е- and
Z-isomers with the P(1)—C(1)C(2)=O(2) torsion angle
equal to –1.8 and 178.4, respectively, showed that their
energies are comparable (Fig. 2). According to calcula-
tions, the energy of the former isomer is 1 kcal mol–1 lower
than that of the latter; however, taking account of the
higher dipole moment of the Z-isomer (6.2 D vs. 4.16 D),
one can assume that both isomers have equal energies in

Novel type of phosphonium-iodonium ylides
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
2335
24.69
24.01
3.54
3.20
2.99
2.93
2.73 2.79
2.00
1.01
0.54
0.25

3.70 3.60 3.50 3.40 3.30 3.20 3.10 3.00 2.90 2.80 2.70
Fig. 1. A fragment of the 1H NMR spectrum of compound 3.
O(2)
С(1)
O(3)
O(1)
O(2)
O(3)
O(1)
С(2)
P(1)
С(2)
P(1)
С(1)
E
Z
Fig. 2. Е- and Z-isomers of 3: a general view (obtained from PBE1PBE/def-2-TZVp calculations).
Scheme 5
in solution; the process proceeds faster on UV irradiation
(Scheme 6).
Scheme 6
compose in solvents by homolytic dissociation of the C—I
bond resulting in corresponding phosphonium salts.20—22
Taking ylide 4a as an example, we demonstrated that
the novel conformationally fixed phosphonium-iodonium
ylides are also transformed to salts on long-term standing
The structure of the phosphonium salt 5 was confirmed
by single-crystal X-ray diffraction (Fig. 3, Tables 1 and 2).

Nenashev et al.
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Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
O(2)
С(33)
С(3)
С(1)
С(32)
С(34)
С(2)
O(3)
С(31)
С(35)
С(12)
С(36)
P(1)
С(13)
С(14)
C(11)
С(22)
С(21)
С(16)
C(26)
C(25)
C(23)
C(24)
С(15)
O(1)
Fig. 3. Molecular structure of phosphonium cation in salt 5.
Table 2. Selected bond angles () in com-
pound 5
The central ring in the cation is almost planar. The
maximum deviation of the Р(1) atom from the plane where
other atoms lie, is 0.12 Å. The P(1)—C(1) bond (1.791(4) Å)
is much longer than the corresponding bond in the E- and
Z-isomers 3 (see above). The C(16)—O(1) and C(26)—O(1)
bond lengths are close (1.361(4) vs. 1.368(4) Å), being
almost equal to the average bond lengths in xanthenes.
By and large, the most important bond lengths and bond
angles in the cation of salt 5 are close to those in 10-methyl-
10-phenyl-10H-phenoxaphosphonium bromide23 and
10-(4-bromobenzyl)-10-phenyl-10H-phenoxaphospho-
nium bromide.24
Summing up, we developed a synthetic approach to
a novel type of phosphonium and mixed phosphonium-
iodonium ylides containing a conformationally fixed
phosphonium fragment. Based on the 1H NMR data, one
can state that phosphonium ylide 3 exists in solution in
the form of two geometric isomers even at room tem-
perature. This is indicative of pronounced double-bond
Angle
/deg
C(1)—P(1)—C(11)
C(11)—P(1)—C(21)
C(11)—P(1)—C(31)
C(21)—P(1)—C(31)
P(1)—C(11)—C(16)
P(1)—C(21)—C(26)
C(11)—C(16)—O(1)
C(21)—C(26)—O(1)
C(16)—O(1)—C(26)
110.93(15)
103.81(14)
110.91(14)
110.79(14)
120.6(2)
120.5(2)
124.8(3)
124.9(2)
124.8(2)
character of the bond between the ylide carbon atom and
the stabilizing carbomethoxy group.
Experimental
Quantum chemical calculations were carried out within the
framework of dispersion corrected DFT using the PBE0 func-
tional,25 the def-2-TZVP basis set, and the Gaussian09 pro-
gram.26 Geometry optimization was performed taking account
of empirical dispersion correction to the total energy27 with the
D3 damping function by Becke and Johnson.28
Table 1. Selected interatomic distances (d) in compound 5
Bond
d/Å
Bond
d/Å
P(1)—C(1)
1.791(4)
1.757(3)
1.763(3)
1.786(3)
1.400(4)
1.391(4)
1.393(5)
1.361(4)
C(21)—C(22)
C(21)—C(26)
C(25)—C(26)
C(26)—O(1)
C(1)—C(2)
C(2)—O(2)
C(2)—O(3)
C(3)—O(2)
1.392(4)
1.387(5)
1.388(5)
1.368(4)
1.504(5)
1.306(5)
1.180(5)
1.453(8)
1Н, 13С, and 31Р NMR spectra were recorded on Bruker
АМ-400 and Agilent 400-MR spectrometers, both operating at
400, 100, and 162 MHz, respectively. The solvent signals were
used as internal references, viz., δ 7.26 (CDCl3) and δ 2.49
(DMSO-d6) for 1Н and δ 77.1 (CDCl3) and δ 39.5 (DMSO-d6)
for 13C; 85% H3PO4 was used as external reference for 31P.
Infrared spectra were recorded on a Thermo Scientific Nicolet
IR200 FT IR spectrometer equipped with an attenuated total
P(1)—C(11)
P(1)—C(21)
P(1)—C(31)
C(11)—C(12)
C(11)—C(16)
C(15)—C(16)
C(16)—O(1)

Novel type of phosphonium-iodonium ylides
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
2337
reflection (ATR) accessory with a ZnSe crystal. The angle of
incidence was 45 and the spectral resolution was 4 cm–1. A total
of 20 scans were collected.
methoxide was added, white precipitate disappeared. The reac-
tion mixture was stirred for 1 h, methanol was removed at reduced
pressure at room temperature, and the residue was dissolved in
methylene chloride (5 mL). The sodium bromide residue was
separated from the solution of ylide 3 by filtering, and filter-
washed with methylene chloride (35 mL). The filtrate was
concentrated at reduced pressure at room temperature. The yield
High-resolution electrospray ionization (ESI) mass spectra
were recorded on an Agilent LC/MSD 1100 SL instrument with
atmospheric pressure ESI (AP-ESI) in the positive ion mode
(ion trap mass analyzer). Conditions: drying gas (nitrogen) tem-
perature 300 C; drying gas feed rate 12 L min–1, ion source
voltage 5000 V, capillary voltage 150 V, acetonitrile as solvent.
Chromatography. Chromatographic separation was performed
using columns filled with MN Kieselgel 60 silica gel (0.04—
0.063 mm//230—400 mesh ASTM).
was 0.43 g (89%), beige-colored crystals, m.p. 130—132 C.
2
1Н NMR (CDCl3), δ: 2.77, 2.96 (both d, 1 H, PCH, JH,P
=
2
= 23.5 Hz, JH,P = 24.7 Hz); 3.20, 3.54 (both s, 3 H, Me);
7.20—8.00 (m, 13 H, Harom). 13C NMR (CDCl3), δ: 27.39, 28.87
(both d, CH, 1JC,P = 136.7 Hz; 1JC,P = 129.0 Hz); 49.25, 49.51
10-Phenyl-10H-phenoxaphosphinine16 (1). Glassware was
dried in a vacuum oven. The synthesis was carried out in a dry
argon atmosphere. Diphenyl ether (12.32 g, 0.072 mol) was dis-
solved in dry hexane—diethyl ether mixture (1 : 1 v/v, a total
volume of 360 mL) and freshly distilled TMEDA (25.9 mL,
0.174 mol) was added. The reaction mixture was cooled to 0 C
and 2.5 М BunLi in hexane (69.5 mL, 0.174 mol) was added
dropwise with stirring. The mixture was stirred for 8 h at room
temperature, cooled to –78 C, and dichlorodiphenylphosphine
(14.7 mL, 0.109 mol) was added dropwise. The reaction mixture
was stirred for 10 h at room temperature, distilled water (150 mL)
was added, then extracted with ether (350 mL), washed with
saturated aqueous NaCl solution (70 mL), and dried over an-
hydrous Na2SO4. The solvent was removed at reduced pressure,
the residue was chromatographed on silica gel using petroleum
ether as eluent and then recrystallized from hot petroleum ether.
(both s, OMe); 109.55 (d, Cipso, JC,P = 92.5 Hz); 118.03 (d,
1
JC,P = 5.7 Hz); 124.13 (d, JC,P = 11.8 Hz); 128.60 (d,
JC,P = 12.4 Hz); 131.00 (d, JC,P = 10.3 Hz); 131.14 (d,
JC,P = 7.2 Hz); 131.59 (d, JC,P = 2.8 Hz); 133.35 (s); 156.27 (s)
(Carom); 171.05, 171.18 (both s, C—O–).31P NMR (CDCl3), δ:
–12.61, –11.63. IR, ν/cm–1: 1622 (COOMe). High-resolution
ESI mass spectrum: found m/z 349.0983 [M + H]+; calculated
for C21H17O3P 349.0988.
Synthesis of phosphonium-iodonium ylides 4a,b. To a solution
of ylide 3 (0.21 g, 0.6 mmol) in methanol (1 mL) cooled to 0 С,
a solution of (diacetoxyiodo)benzene (0.19 g, 0.6 mmol) in
methanol (1.5 mL) was added, the temperature of the reaction
mixture being maintained at 0 C. The reaction mixture was
stirred for 1 h. Then, a 50% aqueous HBF4 solution (0.79 mL,
0.6 mmol) (for mixed ylide 4a) or a 60% HPF6 solution (0.09 mL,
0.6 mmol) (for ylide 4b) was added, the temperature being main-
tained at 0 C. The solution was stirred for 1 h, diethyl ether
(1.5 mL) was added, and stirred for an additional 1 h. The pre-
cipitate was filtered off, washed with diethyl ether (32 mL), and
dried in air.
1
The yield was 5.00 g (25%), white crystals. Н NMR (CDCl3),
δ: 7.15 (tt, 2 H, Harom, JH,H = 7.4 Hz, JH,H = 1.3 Hz); 7.22
(m, 7 H, Harom); 7.39 (ddd, 2 H, Harom
,
3JH,P = 8.8 Hz,
4
3JH,H = 7.1 Hz, JH,H = 1.7 Hz); 7.52 (ddd, 2 H, Harom
,
3
4
3JH,P = 10.4 Hz, JH,H = 7.5 Hz, JH,H = 1.7 Hz). 31P NMR
[2-Methoxy-2-oxo-1-(10-phenyl-10H-10λ5-phenoxaphos-
phinine-10-ylidene)ethyl](phenyl)iodonium tetrafluoroborate (4a).
The yield was 48%, white crystals, decomp. at 125—127 C.
1H NMR (DMSO-d6), δ: 3.51 (br.s, 3 H, OMe); 7.39—7.71
(m, 15 H, Harom); 7.76 (t, 1 H, Harom, J = 7.6 Hz); 7.84 (t, 2 H,
Harom, J = 8.0 Hz). 13C NMR (DMSO-d6), δ: 52.65 (s, OMe);
(CDCl3), δ: – 54.37.
10-(2-Methoxy-2-oxoethyl)-10-phenyl-10H-phenoxaphos-
phonium bromide (2). To a solution of 10-phenyl-10H-phenoxa-
phosphinine 1 (0.64 g, 2.3 mmol) in acetonitrile (3 mL),
methyl bromoacetate (0.23 mL, 2.4 mmol) was added. The
mixture was stirred on heating (80 C) for 2 h. The precipitate
was filtered off, washed with acetonitrile (32 mL), then with
diethyl ether (2 mL), and dried at room temperature. The yield
was 0.63 g (63%), white crystals, m.p. 130—132 С. 1Н NMR
(DMSO-d6), δ: 3.49 (s, 3 H, ОСН3); 5.33 (d, 2 H, CH2COOMe,
2JР,Н = 14.2 Hz); 7.52—7.60 (m, 2 H, Harom); 7.66—7.72 (m, 2 H,
Harom); 7.73—7.79 (m, 2 H, Harom); 7.84—7.90 (m, 1 H, Harom);
106.59 (d, Cipso
,
1JC,P = 95.4 Hz); 119.42 (d, JC,P = 6.1 Hz);
119.84 (d, JC,P = 3.1 Hz); 124.50 (d, Cipso
,
1JC,P = 101.5 Hz);
125.71 (d, JC,P = 11.4 Hz); 130.17 (d, JC,P = 13.0 Hz); 131.66
(s, Carom); 131.76 (s, Carom); 132.38 (d, JC,P = 6.1 Hz); 132.78
(s, Carom); 133.12 (d, JC,P = 11.4 Hz); 134.36 (d, JC,P = 3.0 Hz);
136.34 (d, JC,P = 1.5 Hz); 155.85 (d, JC,P = 2.3 Hz); 167.41
(d, C=O, 2JC,P = 15.3 Hz). 19F NMR (DMSO-d6), δ: –148.30
7.94—8.05 (m, 6 H, Harom). 13C NMR (DMSO-d6), δ: 30.98
[
11BF4]–, –148.25 [10BF4]–. 31P NMR (DMSO-d6), δ: –2.99.
1
(d, CH2, JC,P = 50.6 Hz); 53.20 (s, OMe); 98.15 (d, Cipso
1JC,P = 92.7 Hz); 119.31 (d, JC,P = 6.1 Hz); 121.05 (d, Cipso
,
,
IR, ν/cm–1: 1600 (COOMe); 1060, 1030 (BF4–). High-resolution
ESI mass spectrum: found m/z 551.0264 [M]+; calculated for
C27H21IO3P 551.0268.
1JC,P = 97.1 Hz); 125.78 (d, JC,P = 11.8 Hz); 130.16 (d,
JC,P = 14.2 Hz); 132.24 (d, JC,P = 7.7 Hz); 133.36 (d,
JC,P = 12.4 Hz); 135.38 (d, JC,P = 2.6 Hz); 137.56 (s, Carom);
[2-Methoxy-2-oxo-1-(10-phenyl-10H-10λ5-phenoxaphos-
phinine-10-ylidene)ethyl](phenyl)iodonium hexafluorophosphate
(4b). The yield was 56%, white crystals, decomp. at 129—131 С.
1H NMR (DMSO-d6), δ: 3.51 (br.s, 3 H, OMe); 7.39—7.71
(m, 15 H, Harom); 7.76 (t, 1 H, Harom, J = 7.6 Hz); 7.84 (t, 2 H,
Harom, J = 8.0 Hz). 13C NMR (DMSO-d6), δ: 52.65 (s, OMe);
155.73 (s, Carom); 165.15 (d, C=O, JC,P = 3.7). 31P NMR
2
(DMSO-d6), δ: –8.96. IR, ν/cm–1: 1720 (COOMe). High-
resolution ESI mass spectrum: found m/z 349.0985 [M]+; cal-
culated for C21H18O3P+ 349.0988.
Methyl-2-(10-phenyl-10H-10λ5-phenoxaphosphinine-10-
ylidene) acetate (3). To a solution of phosphonium salt 2 (0.60 g,
1.4 mmol) in anhydrous methanol (4 mL), a solution of sodium
methoxide (0.076 g, 1.4 mmol) in anhydrous methanol (1 mL)
was added gradually, the temperature of the reaction mixture
being maintained at 0—5 С. As the whole amount of sodium
106.59 (d, Cipso
,
1JC,P = 95.4 Hz); 119.42 (d, JC,P = 6.1 Hz);
1JC,P = 101.5 Hz);
119.84 (d, JC,P = 3.1 Hz); 124.50 (d, Cipso
,
125.71 (d, JC,P = 11.4 Hz); 130.17 (d, JC,P = 13.0 Hz); 131.66
(s, Carom); 131.76 (s, Carom); 132.38 (d, JC,P = 6.1 Hz); 132.78
(s, Carom); 133.12 (d, JC,P = 11.4 Hz); 134.36 (d, JC,P = 3.0 Hz);
136.34 (d, JC,P = 1.5 Hz); 155.85 (d, JC,P = 2.3 Hz); 167.41

Nenashev et al.
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Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
2
(d, C=O, JC,P = 15.3 Hz). 19F NMR (DMSO-d6), δ: –70.16
(d, 1JF,P = 711.1 Hz). 31P NMR (DMSO-d6), δ: –144.24 (sep-
tet, 1JF,P = 711.6 Hz), –2.97. IR, ν/cm–1: 1610 (COOMe); 840,
830 (PF6–). High-resolution ESI mass spectrum: found m/z
597.0475 [M]+; calculated for C32H23IO2P 597.0475.
6. E. D. Matveeva, T. A. Podrugina, M. A. Taranova, A. M.
Ivanova, R. Gleiter, N. S. Zefirov, J. Org. Chem., 2012,
77, 5770.
7. E. D. Matveeva, T. A. Podrugina, M. A. Taranova, E. Yu.
Melikhova, R. Gleiter, N. S. Zefirov, Tetrahedron, 2013,
69, 7395.
8. E. D. Matveeva, T. A. Podrugina, M. A. Taranova, D. S.
Vinogradov, R. Gleiter, N. S. Zefirov, J. Org. Chem., 2013,
78, 11691.
9. E. D. Matveeva, D. S. Vinogradov, T. A. Podrugina, T. D.
Nekipelova, A. V. Mironov, R. Gleiter, N. S. Zefirov, Eur. J.
Org. Chem., 2015, 7324.
10-(2-Methoxy-2-oxoethyl)-10-phenyl-10H-phenoxaphos-
phonium tetrafluoroborate (5). A solution of ylide 4a (0.05 g,
0.078 mmol) in 5 mL of acetonitrile (HPLC) in a quartz tube in
dry argon atmosphere was irradiated with a mercury lamp
(λ = 365 nm) for 2 h. The ylide conversion was 100%, as deter-
mined analyzing the reaction mixture by 31P NMR spectroscopy.
After two days, colorless crystals formed on the tube wall. A crys-
tal was picked up and characterized by X-ray diffraction. Other
crystals were characterized by 31P NMR spectroscopy. 31P NMR
(CDCl3), δ: –9.14.
10. T. D. Nekipelova, M. A. Taranova, E. D. Matveeva, V. A.
Kuz´min, N. S. Zefirov, Kinet. Catal. (Engl. Transl.), 2015,
56, 403.
X-ray diffraction study of phosphonium salt 5. At 295 К:
crystals of 5, C21H18BF4O3P, are colorless, monoclinic, space
group P21/n, a = 8.7197(15), b = 22.203(5), c = 11.1958(18) Å,
11. V. Iaroshenko, S. Mkrtchyan, Organophosphorus Chemistry:
From Molecules to Applications, Ed. V. Iaroshenko, Wiley,
Weinheim, 2019, p. 296.
12. R. P. J. Bronger, J. P. Bermon, J. Herwig, P. C. J. Kamer,
P. W. N. M. van Leeuwen, Adv. Synth. Catal., 2004, 346, 789.
13. E. Zuidema, P. E. Goudriaan, B. H. Swennenhuis, P. C.
Kamer, P. W. N. M. van Leeuwen, M. Lutz, A. L. Spek,
Organometallics, 2010, 29, 1210.
14. M. J.-L. Tschan, E. J. García-Suárez, Z. Freixa, H. Launay,
H. Hagen, J. Benet-Buchholz, P. W. Leeuwen, J. Am. Chem.
Soc., 2010, 132, 6463.
15. O. Jacquet, N. D. Clément, C. Blanco, M. M. Belmonte,
J. Benet-Buchholz, P. W. Leeuwen, Eur. J. Org. Chem.,
2012, 4844.
16. D. L. Dodds, M. D. K. Boele, G. P. F. van Strijdonck, J. G.
de Vries, P. W. N. M. van Leeuwen, P. C. J. Kamer, Eur. J.
Inorg. Chem., 2012, 1660.
17. M. M. Kayser, K. L. Hatt, D. L. Hooper, Can. J. Chem.,
1991, 69, 1929.
18. E. D. Matveeva, T. A. Podrugina, Y. K. Grishin, A. S. Pav-
lova, N. S. Zefirov, Russ. J. Org. Chem., 2007, 43, 201.
19. E. D. Matveeva, T. A. Podrugina, Y. K. Grishin, V. V. Tka-
chev, V. V. Zhdankin, S. M. Aldoshin, N. S. Zefirov, Russ. J.
Org. Chem., 2003, 39, 536.
20. I. I. Levina, O. N. Klimovich, D. S. Vinogradov, T. A.
Podrugina, D. S. Bormotov, A. S. Kononikhin, O. V. De-
ment´eva, I. N. Senchikhin, E. N. Nikolaev, V. A. Kuzmin,
T. D. Nekipelova, J. Phys. Org. Chem., 2018, 31, 3844.
21. E. D. Matveeva, T. A. Podrugina, A. S. Pavlova, A. V.
Mironov, A. A. Borisenko, R. Gleiter, N. S. Zefirov, J. Org.
Chem., 2009, 74, 9428.
β = 105.174(13), V = 2092.0(7) Å3, Z = 4 (Z´ = 1), dcalc
=
= 1.384 g cm–3, M = 436.1, (Сu-K) = 16.68 cm–1, F(000) = 896.
The intensities of 2600 reflections were measured on a CAD-4
diffractometer at 298 К ((Cu-K) = 1.54178 Å, /-scan,
 < 50) and 2136 independent reflections (Rint = 0.0220) were
used for structure refinement. The absorption correction was
applied empirically. The transmission factor (min/max) was
0.816/1.000, the  range was from 2 to 50, the h, k, l index
ranges were as follows: –8  h  8, –2  k  22, and 0  l  11;
structure refinement based on |F 2|. The structure was solved by
the direct method using the SIR2002 software package29 and
successive electron density syntheses. The difference Fourier
synthesis of the electron density revealed pronounced maxima
in the vicinity of the boron atom, which was interpreted as the
second position of the BF4 group. Positions of all hydrogen atoms
were calculated geometrically and refined using the riding
model. Structure refinement on F2 was carried out in the
hkl
anisotropic approximation for the non-hydrogen atoms and in
the isotropic approximation for the hydrogen atoms. The final
R-index values for 5: R1 = 0.0478 (based on Fhkl for 1883 reflec-
tions with I > 2(I)), wR2 = 0.1550, GOOF = 1.10. Calculations
were carried out using the JANA 2000 software package.30
A complete set of structural data for compound 5 was deposited
at the Cambridge Crystallographic Data Centre (CCDC
1987446).
This work was financially supported by the Russian
Foundation for Basic Research (Project No. 18-33-01039).
22. T. A. Podrugina, A. S. Pavlova, D. S. Vinogradov, M. V.
Shuvalov, I. D. Potapov, I. I. Levina, A. V. Mironov,
R. Gleiter, Russ. Chem. Bull., 2019, 68, 284.
References
23. S. V. Toldov, N. L. Kostenko, V. K. Bel´skii, N. K. Skvortsov,
V. O. Reikhsfel´d, J. Gen. Chem. USSR (Engl. Transl.), 1990,
60, 1120.
24. D. W. Allen, I. W. Nowell, P. E. Walker, Phosphorus, Sulfur
Relat. Elem., 1979, 7, 309.
25. J. P. Perdew, M. Ernzerhof, K. Burke, J. Chem. Phys., 1996,
105, 9982; DOI: 10.1063/1.472933.
26. M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria,
M. A. Robb, J. R. Cheeseman, G. Scalmani, V. Barone, G. A.
Petersson, H. Nakatsuji, X. Li, M. Caricato, A. Marenich,
J. Bloino, B. G. Janesko, R. Gomperts, B. Mennucci, H. P.
Hratchian, J. V. Ortiz, A. F. Izmaylov, J. L. Sonnenberg,
D. Williams-Young, F. Ding, F. Lipparini, F. Egidi, J. Goings,
1. E. D. Matveeva, T. A. Podrugina, A. S. Pavlova, A. V.
Mironov, N. S. Zefirov, Russ. Chem. Bull., 2008, 57, 2237.
2. E. D. Matveeva, T. A. Podrugina, A. S. Pavlova, A. V. Miro-
nov, R. Gleiter, N. S. Zefirov, Eur. J. Org. Chem., 2009, 2323.
3. E. D. Matveeva, T. A. Podrugina, A. S. Pavlova, A. V.
Mironov, A. A. Borisenko, R. Gleiter, N. S. Zefirov, J. Org.
Chem., 2009, 74, 9428.
4. E. D. Matveeva, R. Gleiter, N. S. Zefirov, Russ. Chem. Bull.,
2010, 59, 488.
5. E. D. Matveeva, T. A. Podrugina, M. A. Taranova, A. A.
Borisenko, A. V. Mironov, R. Gleiter, N. S. Zefirov, J. Org.
Chem., 2011, 76, 566.

Novel type of phosphonium-iodonium ylides
Russ. Chem. Bull., Int. Ed., Vol. 69, No. 12, December, 2020
2339
B. Peng, A. Petrone, T. Henderson, D. Ranasinghe, V. G.
Zakrzewski, J. Gao, N. Rega, G. Zheng, W. Liang, M. Hada,
M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishida,
T. Nakajima, Y. Honda, O. Kitao, H. Nakai, T. Vreven,
K. Throssell, J. A. Montgomery, Jr., J. E. Peralta, F. Ogliaro,
M. Bearpark, J. J. Heyd, E. Brothers, K. N. Kudin, V. N.
Staroverov, T. Keith, R. Kobayashi, J. Normand, K. Ragha-
vachari, A. Rendell, J. C. Burant, S. S. Iyengar, J. Tomasi,
M. Cossi, J. M. Millam, M. Klene, C. Adamo, R. Cammi,
J. W. Ochterski, R. L. Martin, K. Morokuma, O. Farkas,
J. B. Foresman, D. J. Fox, Gaussian 09, Revision D.01,
Gaussian, Inc., Wallingford CT, 2016.
28. S. Grimme, S. Ehrlich, L. Goerigk, J. Comp. Chem., 2011,
32, 1456; DOI: 10.1002/jcc.21759.
29. M. C. Burla, M. Camalli, B. Carrozzini, G. Cascarano, C.
Giacovazzo, G. Polidori, R. Spagna, J. Appl. Cryst., 2003,
36, 1103.
30. V. Petricek, M. Dusek, L. Palatinus, JANA 2000. Structure
Determination Software Programs, Institute of Physics, Praha,
Czech Republic, 2000.
Received February 28, 2020;
in revised form August 20, 2020;
accepted August 27, 2020
27. S. Grimme, J. Antony, S. Ehrlich, H. Krieg, J. Chem. Phys.,
2010, 132, 154104; DOI: 10.1063/1.3382344.