Reactions of phenylenedioxytrihalophosphoranes with arylacetylenes: 5. Regiochemistry of the reaction of 2,2,2-trichloro-5-chlorocarbonylbenzo[d]-1,3, 2-dioxaphosphole with phenylacetylene. Synthesis and three-dimensional structures of 6-alkylaminocarbonyl-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine derivatives

Article abstract of DOI:10.1023/B:RUCB.0000024850.10750.b9

2,2,2-Trichloro-5-chlorocarbonylbenzo[d]-1,3,2-dioxaphosphole was prepared for the first time by the reaction of protocatechuic acid with phosphorus pentachloride or trichloride followed by chlorination. According to the results of NMR spectroscopy, the reaction of this phosphole with phenylacetylene gave rise to 2,5-dichloro- and 2,8-dichloro-6-chlorocarbonyl-2-oxo-4-phenylbenzo[e]- 1,2-oxaphosphorinines as the major products. The molecular and supramolecular structures of their stable derivatives, viz., 2-tert-butylamino-6-tert- butylaminocarbonyl-5-chloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine and isopropylammonium 8-chloro-6-isopropylaminocarbonyl-2-oxo-4-phenylbenzo[e]-1,2- oxaphosphorinin-2-oate, respectively, were established by X-ray diffraction analysis.

Full text of DOI:10.1023/B:RUCB.0000024850.10750.b9

194
Russian Chemical Bulletin, International Edition, Vol. 53, No. 1, pp. 194—212, January, 2004
Reactions of phenylenedioxytrihalophosphoranes with arylacetylenes
5.* Regiochemistry of the reaction of 2,2,2ꢀtrichloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ
1,3,2ꢀdioxaphosphole with phenylacetylene. Synthesis and threeꢀdimensional structures
of 6ꢀalkylaminocarbonylꢀ2ꢀoxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorinine derivatives
V. F. Mironov,ꢀ A. A. Shtyrlina, A. T. Gubaidullin, A. V. Bogdanov, I. A. Litvinov,
N. M. Azancheev, Sh. K. Latypov, R. Z. Musin, and Yu. Ya. Efremov
A. E. Arbuzov Institute of Organic and Physical Chemistry,
Kazan Research Center of the Russian Academy of Sciences,
8 ul. Akad. Arbuzova, 420088 Kazan, Russian Federation.
Fax: +7 (843 2) 75 2253. Еꢀmail: mironov@iopc.knc.ru
2,2,2ꢀTrichloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ1,3,2ꢀdioxaphosphole was prepared for the first
time by the reaction of protocatechuic acid with phosphorus pentachloride or trichloride
followed by chlorination. According to the results of NMR spectroscopy, the reaction of this
phosphole with phenylacetylene gave rise to 2,5ꢀdichloroꢀ and 2,8ꢀdichloroꢀ6ꢀchlorocarbonylꢀ
2ꢀoxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorinines as the major products. The molecular and
supramolecular structures of their stable derivatives, viz., 2ꢀtertꢀbutylaminoꢀ6ꢀtertꢀbutylꢀ
aminocarbonylꢀ5ꢀchloroꢀ2ꢀoxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorinine and isopropylammoꢀ
nium 8ꢀchloroꢀ6ꢀisopropylaminocarbonylꢀ2ꢀoxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorininꢀ
2ꢀoate, respectively, were established by Xꢀray diffraction analysis.
Key words: phenylacetylene, phosphorus(V) chlorides, 1,3,2ꢀdioxaphospholes, regioꢀ
chemistry of the reaction, benzophosphorinines, chlorination, ipsoꢀsubstitution of oxygen.
Scheme 1
P,P,PꢀTrihalobenzo[d]ꢀ1,3,2ꢀdioxaphospholes are
typical representatives of derivatives containing the
pentacoordinated phosphorus atom, viz., phosphoranes,
which can readily react with compounds containing C=O,
C=C, or C=N double bonds to yield products in which
the coordination number of the phosphorus atom can
remain unchanged, increase, or decrease.2 If the reaction
gives rise to the phosphoryl group, these transformations
can be assigned to nonclassical Arbuzov reactions.2
Arylacetylenes react with P,P,Pꢀtrihalobenzo[d]ꢀ1,3,2ꢀ
dioxaphospholes in an unusual way. Earlier, we have demꢀ
onstrated3 that the reactions of P,P,Pꢀtrichlorobenzo[d]ꢀ
1,3,2ꢀdioxaphosphole (1) with arylacetylenes afforded
benzo[e]ꢀ1,2ꢀoxaphosphorinine derivatives (2), which are
phosphorusꢀcontaining analogs of the natural heterocyꢀ
clic compound coumarin (Scheme 1). Under mild condiꢀ
tions, the latter reaction involves the ipsoꢀsubstitution of
the O atom, the formation of the P—C and P=O bonds,
and regioselective chlorination of the phenylene fragment
at the para position with respect to the endocyclic O atom
of the oxaphosphorinine heterocycle.
In the presence of a halogen atom in the benzo fragꢀ
ment of the starting phosphole 3, the second halogen
atom is introduced at the ortho position with respect to
the first halogen atom and at the para position with reꢀ
spect to the O atom of the annelated O,P heterocycle
(Scheme 2, compound 4).4
Scheme 2
* For Part 4, see Ref. 1.
X = Cl, Br
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 186—202, January, 2004.
1066ꢀ5285/04/5301ꢀ0194 © 2004 Plenum Publishing Corporation

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
195
If positions 5 and 6 in benzophosphole (5) are occuꢀ
pied by Br atoms, the insertion of the third halogen (chloꢀ
rine) atom does not take place, and the reaction produces
compound 6 (the reaction proceeds with elimination of
the chlorine molecule) (Scheme 3). However, this reacꢀ
tion is also accompanied by partial ipsoꢀsubstitution with
the replacement of the bromine atom by the chlorine
atom (compound 7).5
uct 8 in moderate yields. The reactions were accompaꢀ
nied by chlorination of the carboxy group to form the
chlorocarbonyl group. Since the molecule cannot contain
simultaneously the free carboxy group and the phosꢀ
phorane fragment with three P—Cl bonds,6 the reaction
was carried out in the presence of a twoꢀfold excess of
PCl3 or PCl5.
Trichlorophosphole 8 is thermally stable and can be
distilled in vacuo. The EI mass spectrum of benzoꢀ
phosphole 8 shows the molecular ion peak [M]•+ at
m/z 306. The precisely measured mass of the [M]•+ ion
(305.8577) agrees well with the ion mass (305.8574) calꢀ
culated from the elemental composition C7H3Cl4O3P.
The first step of the fragmentation of molecule 8 under
electron impact involves the detachment of the Cl atom
from the phosphorus atom. This process is responsible for
the presence of the ion peak [M – Cl]•+ at m/z 271 with
the highest intensity. The peak at m/z 201 belongs, apparꢀ
ently, to the ion obtained as a result of loss of three Cl
atoms detached from the P atom. The structure of
benzophosphole 8 was confirmed also by 13C NMR specꢀ
troscopy (see the Experimental section). The signals of
the C atoms of the benzo fragment were interpreted takꢀ
ing into account the para and ortho effects of deshielding
of the chlorocarbonyl substituent. The C(4) and C(7)
atoms are easily distinguishable from the C(4a) and C(7a)
atoms also based on the multiplicities of the correspondꢀ
ing signals (for the C(4a) and C(7) atoms, the multiplets
have a smaller number of lines).
Scheme 3
Results and Discussion
The aim of the present study was to examine the possiꢀ
bility of extending the aboveꢀdescribed reaction to more
complex benzophosphole derivatives containing a residue
of the natural compound, viz., protocatechuic acid. To
prepare 2,2,2ꢀtrichloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ1,3,2ꢀ
dioxaphosphole (8), we investigated the following two
approaches (Scheme 4): phosphorylation of protocatꢀ
echuic acid with phosphorus trichloride to form derivaꢀ
tive 9 followed by chlorination (path A) and phosphorylaꢀ
tion directly with phosphorus pentachloride (path B). Both
approaches appeared to be efficient and gave rise to prodꢀ
The reaction of benzophosphole 8 with phenylaceꢀ
tylene proceeded readily in a solution in CH2Cl2 at 20 °C
(Scheme 5). After 4 h, the 31P{1H} NMR spectrum of the
reaction mixture shows three singlets at δP1 16.0, δP2 16.1,
and δP3 –14.7 in a ratio of 5 (δ and δ 2) : 1 (δ 3). In the
1
P
P
P
31P NMR spectrum, all three singlets turn into doublets
2
with the constants JP,CH = 24—25 Hz (δP and δ 2) and
1
P
37.5 Hz (δP3). Since the signals at δ and δP are close
1
2
P
together, it is impossible to determine the ratio between
them from the 31P or 31P{1H} NMR spectra. However, we
succeeded in determining this ratio from the H NMR
Scheme 4
1
spectrum (400 MHz), in which the integral intensity ratio
of the signals at δ 6.49 and 6.57 appearing as doublets with
similar constants (2JP,CH = 24.2 and 25.6 Hz) is 1 : 2. The
2
doublet at low field (δ 7.36) with the constant JP,CH
=
37.6 Hz belongs to a compound characterized by δP
.
3
Taking into account the chemical shifts of the protons, it
can be concluded that the reaction afforded three comꢀ
pounds containing the P—CH=C fragment. Based on the
chemical shifts δP1, δP2, and δP3, the first two signals can
be assigned to compounds bearing the phosphoryl group
and the third signal can be assigned to a derivative conꢀ
taining the pentacoordinated P atom. According to the
13C{1H} and 13C NMR spectroscopic data (Table 1) for
the reaction mixture, which was kept in vacuo at 0.05 Torr
to remove volatile impurities at a temperature of no higher

196
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
Scheme 5
than 20 °C, these compounds are benzophosphole 10 (δP
and isomeric benzooxaphosphorinines 11 and 12 (δP
)
This allowed us to more reliably assign the key signals to
phosphorane 10, because this compound is thermally unꢀ
stable and undergoes ambiguous disproportionation proꢀ
cesses, which are, apparently, analogous to the transforꢀ
mations of 2,2ꢀdichloroꢀ2ꢀ(2ꢀphenylethenꢀ1ꢀyl)benzo[d]ꢀ
1,3,2ꢀdioxaphosphole.7 Because of a small amount of
compound 10, we failed to unambiguously interpret these
processes. The signals corresponding to this compound
disappear after heating, which is reflected in the specꢀ
trum. The highꢀfield regions of the 13C NMR spectrum
3
2
and δP1). Therefore, the reaction of benzophosphole 8
with phenylacetylene follows two pathways, viz., the clasꢀ
sical electrophilic addition at the double bond (see
Scheme 5, path A) and the path B involving the formation
of benzooxaphosphorinines 11 and 12.
To establish the structures of these compounds, we
recorded the 13C NMR spectra of the reaction mixture
before heating and after its heating in vacuo at 150 °C.
Table 1. Parameters of the 13C{1H} and 13C NMR spectra of compounds 11 and 12 in CDCl3
Atom
δ (J/Hz)
11
12
C(3)
C(4)
C(4a)
120.66 (d [dd], JP,C(3) = 157.2, JH,C(3) =172.6) {120.46 (d)}
154.94 (s [m]) {155.03 (s)}
116.16 (d [dd], JP,C(3) = 153.2, JH,C(3) = 171.8)
154.93 (s [m])
123.02 (d [dd], JP,C(4a) = 18.2, JH(3),C(4a) = 8.6)
122.79 (d [dddd], JP,C(4a) = 18.7, JH(3),C(4a) = 9.0,
JH(8),C(4a) = 4.9—5.0, JH(7),C(4a) = 1.6) {122.75 (d)}
133.43 (d [br.d], JH(7),C(5) = 8.0, JP,C(5) = 1.1) {133.26 (d)}
133.40 (d [br.d], JH(8),C(6) = 10.3, JP,C(6) = 2.4) {133.50 (d)}
133.95 (s [d], JH,C(7) = 169.2) {134.34 (s)}
118.68 (d [dd], JH,C(8) = 171.3, JP,C(8) = 7.4) {118.73 (d)}
153.99 (d [ddd], JH(7),C(8a) = 12.2, JP,C(8a) = 10.2,
JH(8),C(8a) = 3.8) {159.99 (d)}
C(5)
C(6)
C(7)
C(8)
C(8a)
130.92 (s [dd], JH,C(5) = 169.9, JH(7),C(5) = 6.6)
129.67 (s [br.s])
134.31 (s [dd], JH,C(7) = 171.8, JH(5),C(7) = 6.9—7.0)
125.95 (d [br.d], JP,C(8) = 7.7)
151.88 (d [ddd], JP,C(8a) = 9.4, JH(7),C(8a) = 9.1,
JH(5),C(8a) = 9.1)
C(9)
138.50 (d [br.dtd], JP,C(9) = 19.6, JH(11),C(9) = 8.1,
JH(3),C(9) = 6.9) {138.55 (d)}
135.80 (d [dtd], JP,C(9) = 20.4, JH(11),C(9) = 7.1,
JH(3),C(9) = 6.6)
C(10),
C(14)
C(11),
C(13)
C(12)
126.46 (s [ddd], JH,C(10) = 160.6, JH(12),C(10)
JH(14),C(10) = 6.8—7.0) {126.45 (s)}
128.89 (s [br.dm], JH,C(11) = 161.6, JH(13),C(11) = 5.0—6.5)
{128.88 (s)}
129.68 (s [dt], JH,C(12) = 161.6, JH(10),C(12) = JH(14),C(12) = 7.5)
{129.66 (s)}
=
128.07 (s [br.ddd], JH,C(10) = 160.4, JH(12),C(10)
JH(14),C(10) = 6.7—6.9)
129.04 (s [dd], JH,C(11) = 163.4, JH(13),C(11) = 6.7)
=
130.35 (s [dt], JH,C(12) = 161.0, JH(10),C(12)
JH(14),C(12) = 7.3)
=
C(15)
164.07 (s [d], JH(7),C(15) = 5.1) {164.15 (s)}
165.44 (s [dd], JH(5),C(15) = JH(7),C(15) = 5.3)
Note. Here and in Table 2, the types of the signals in the 13C NMR spectrum are given in brackets, the chemical shifts and the types of
the signal in the 13C NMR spectrum of a pure sample of 11 are given in braces.

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
C(8) 11
197
C(3)
11
C(3)
C(7)
12
C(4)
10
10
120
117
114
111
δ
Fig. 1. Fragment of the highꢀfield region of the 13C NMR spectrum of a mixture of compounds 10—12 prepared by the reaction of
benzophosphole 8 with phenylacetylene (before heating).
1
has signals of the C(4) (δ 113.97) and C(7) (δ 111.0)
atoms (Fig. 1) of phosphorane 10 with the multiplicities
characteristic of the trisubstituted benzene ring (ddd
(dd) and constants (1JP,C(9) = 202.0 Hz and JH,C(9)
=
168.8 Hz) of this resonance are consistent with those
observed for the chemically similar compound, viz.,
2,2ꢀdichloroꢀ2ꢀ(2ꢀphenylethenꢀ1ꢀyl)benzo[d]ꢀ1,3,2ꢀdiꢀ
oxaphosphole.7 The assignment of all other C atoms is
unreliable because of overlapping of the signals of oxaꢀ
phosphorinines 11 and 12.
3
3
(1JH,C(4) = 168.7 Hz, JP,C(4) = 16.4 Hz, JH(6),C(4)
=
6.8 Hz) and dd (1JH,C(7) = 169.2 Hz, 3JP,C(7) = 12.5 Hz)).
On the whole, these multiplicities are analogous to those
observed for the corresponding signals of the starting
phosphole 8. Figure 2 presents fragments of the lowꢀfield
region of the 13C{1H} NMR spectrum (see Fig. 2, a) and
the 13C NMR spectra (see Fig. 2, b—d) of a mixtures of
the resulting compounds (10—12). As can be seen from
Fig. 2, the signals of the C atoms of the corresponding
compounds are wellꢀresolved, which facilitates their inꢀ
terpretation. The signal of the C(8) atom of the chloroꢀ
The EI mass spectrum measured directly for the reacꢀ
tion mixture consisting of compounds 11 and 12 has only
one molecular ion peak [M]•+. Its precisely measured
mass is 371.9281, which is in good agreement with
the value calculated from the elemental composition
C15H8Cl3O3P, i.e., both compounds, apparently, contain
the Cl atom in the benzo fragment. The first step of fragꢀ
mentation of both compounds under electron impact inꢀ
volves detachment of the Cl atom from the phosphorus
atom giving rise to a peak at m/z 337 [M – Cl]•+, which
has the maximum height in the mass spectrum. The cleavꢀ
age of the P—O and P—C bonds in the phosphorinine
ring results in an ion with m/z 274. This process is accomꢀ
panied by migration of one H atom to the neutral fragꢀ
ment to form an ion with m/z 273. For the aboveꢀmenꢀ
tioned ions, the relative intensities of the peaks associated
with the presence of isotopes correspond to those calcuꢀ
lated from the molecular formulas of the ions. The presꢀ
ence of other fragmentation ions with small m/z (see the
Experimental section) is, apparently, attributed to further
successive fragmentation of these ions under electron imꢀ
pact. Therefore, the mass spectra show clear evidence for
carbonyl substituent in compound 10 is observed at low
3
field (δ 166.19, ddd, JH(6),C(8)
=
3JH(4),C(8) = 5.3 Hz,
4JH(7),C(8) = 1.0 Hz). This region of the spectrum shows
also the resonances of the C(7a) atom (δ 150.31, ddd,
3
3JH(6),C(7a) = 11.1 Hz, JH(4),C(7a) = 5.7 Hz, 2JH(7),C(7a)
=
2
2.7 Hz, JP,C(7a) = 0 Hz) and the C(4a) atom (δ 142.48,
ddd, JH(7),C(4a) = 5.7 Hz, JH(4),C(4a) = 3.3 Hz,
4JH(6),C(4a) = 1.2 Hz, JP,C(4a) = 0 Hz). The C(10)
3
2
2
and C(11) atoms come into resonance at δ 142.47 (m,
2JP,C(10) = 9.5 Hz) and δ 134.96 (m, 3JP,C(11) = 23.6 Hz),
respectively. It should be noted that the value of the conꢀ
stant 3JP,C(11) is indicative of the trans arrangement of the
phosphorane fragment and the Ph substituent, i.e., of the
Е configuration of the substituted ethene. The resonance
of the C(9) atom is observed at δ 128.76. The multiplicity

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Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
C(15)
C(8a)
11
C(15)
c
d
C(8)
12
3JH(7),C(15)
12
3JH(5),C(15)
3JH(7),C(15)
3JH(4),C(8)
3JH(6),C(8)
10
3JH(7),C(8a)
3JP,C(8a)
3JH(5),C(8a)
C(4)
166.2
165.6
165.0
164.4
δ
11
b
11 C(8a)
3JH(7),C(8a)
a
C(8a)
3JP,C(8a)
2JH(8),C(8a)
11
C(9)
11
C(9)
C(9)
C(11)
C(8a)
12
10
C(4)
12
10
12
C(7a)
C(3a)
10
10
152
148
144
140
136
δ
Fig. 2. Fragments of the lowꢀfield region of the 13C{1H} NMR spectrum (a) and the 13C NMR spectra (b—d) of a mixture of
compounds 10—12 prepared by the reaction of benzophosphole 8 with phenylacetylene (before heating).
the formation of two benzooxaphosphorinines containing
three Cl atoms.
C(7) atoms bear H atoms (for the aromatic nuclei, the
vicinal constant JH,C is larger than the geminal conꢀ
3
The 13C NMR spectroscopic data (see Table 1) unamꢀ
biguously demonstrate that the Cl atom is introduced into
the phenylene fragment (rather than into the phenyl subꢀ
stituent) at position 4 of the heterocycle. The presence of
the only doublet of doublets at high field (δC 118.75)
indicates that the C(8) atom in the major isomer (comꢀ
pound 11) bears the proton, whereas this atom in the
minor isomer (compound 12) is bound to the Cl atom.
The multiplicity of the signal of C(8) (see Fig. 1) is eviꢀ
dence for the presence of the substituent at position 6
stant7). By contrast, the spectrum of isomer 11 shows this
signal as a doublet, which indicates that the Cl atom is
bound to either the C(5) or C(7) atom. In the spectra of
compounds 2, 4, 6, and 7, the resonance of the analogous
C(7) atom bearing the Cl atom is observed at rather low
field (δ 136—138),3,4 whereas the signal of the C(5)(Cl)
atom in the spectra of 4ꢀarylꢀ2,5,6,7,8ꢀpentachloroꢀ2ꢀ
oxobenzo[e]ꢀ1,2ꢀoxaphosphorinines is present in the reꢀ
gion of δ 131—132 due to shielding by the aryl substituent
at position 4.8,9 It should be noted that both the multiꢀ
3
3
3
2
(i.e., the constant JH(6),C(8) is absent). The fact that the
plicities and the constants JH,C, JP,C, and JH,C of the
signals of the C(4a) atom (see Fig. 2, b, c) are also consisꢀ
tent with the structures of 1,2,3,4ꢀ and 1,2,4,6ꢀtetraꢀ
substituted benzenes 11 and 12, respectively. Taking into
account these data, it can be concluded that the Cl atom
in major isomer 11 is attached to the C(5) atom. The
question as to the position of the Cl atom in the pheꢀ
nylene ring can also be solved by 1H NMR spectroscopy.
If the Cl atom is located at position 5, the H(7) and H(8)
protons would appear as either an AX or AB spin system.
signal of the C(8a) atom in both compounds 11 and 12
appears at lower field compared to those in benzooxaꢀ
phosphorinines 2, 4, 6, and 7 3—5 is indicative of the
presence of the chlorocarbonyl substituent in the para poꢀ
sition with respect to the C(8a) atom. The difference in
the multiplicity of the signals of the C(15) atoms in isoꢀ
mers 11 and 12 at low field (see Fig. 2, d) is very informaꢀ
tive. In the spectrum of isomer 12, this signal appears as a
doublet of doublets, which is evidence that the C(5) and

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
199
1
Actually, the H NMR spectrum (250 MHz) of the reacꢀ
Two forms differ in the orientation of the substituents at
tion mixture shows signals corresponding to the resoꢀ
the asymmetric P atom (axial and equatorial orientations).
For each of these forms, two conformers can occur due to
rotation of the substituent about the C(6)—CO bond.
Each form is presented in Fig. 3 by one of enantiomers.
Below, we consider in detail only two most stable conforꢀ
mations, viz., 11a and 11b.
In all four forms, the conformation of the heterocyclic
fragment can be described as a boat with the P(2) and
C(3) atoms deviating from the plane of the fragment. The
presence of the bulky groups (ClC(O), Cl, or Ph) leads to
a substantial distortion of the geometry of the aromatic
fragment from the usual planar structure. The selected
calculated dihedral angles describing the conformation of
the heterocycle and the chlorocarbonyl substituent for
major conformer 11a are as follows:
3
nance of an AMX system (δ 8.11 (dd, H(7), JH(7),H(8)
=
=
3
8.8 Hz, 5JP,H(7) = 1.6 Hz); δ 7.42 (dd, H(8), JH(7),H(8)
8.8 Hz, 4JP,H(8) = 0.8 Hz)). This spectrum has also signals
belonging to the protons of the benzo fragment of comꢀ
4
pound 12 (at δ 7.95 (br.d, H(5), JH(7),H(5) = 2.2 Hz);
4
5
8.30 (dd, H(7), JH(7),H(5) = 2.2 Hz, JP,H(7) = 1.8 Hz)),
which confirm the presence of the H atoms at the C(5)
and C(7) atoms.
Because of the complexity of the spectra associated
with the presence of three compounds in the reaction
mixture, we also calculated the chemical shifts of the
compounds under study by quantumꢀchemical methods.
The modern calculation methods can be successfully used
for complex organic compounds containing C, H, N, and
O atoms (see, for example, the studies10—18). In the present
investigation, we calculated the 1H and 13C chemical shifts
of benzooxaphosphorinines 11 and 12 by the GIAO
B3LYP/6ꢀ31G(d) method for geometries optimized at
the HF/6ꢀ31G level of theory. To our knowledge, this
approach has not previously been used for systems conꢀ
taining the P atom in the ring and several polar substituꢀ
ents. A complication of the electronic structures of comꢀ
pounds, which is associated with the introduction of heavy
atoms, such as P and Cl, as well as with the conformaꢀ
tional inhomogeneity, makes calculations more difficult.19
The preliminary results of these calculations are given
below. The detailed data will be published elsewhere. The
absolute values of shielding were calculated and the chemiꢀ
cal shifts were assigned relative to the signal of Me4Si
calculated under the identical conditions.
Cl—C(15)—C(6)—C(7) 142.0°,
Cl(5)—C(5)—C(4a)—C(4) –166.6°,
C(5)—C(4a)—C(4)—C(3) 25.7°,
P(2)—C(3)—C(4)—C(4a) –5.3°,
C(4)—C(3)—P(2)—O(1) –22.0°,
C(3)—P(2)—O(1)—C(8a) 38.3°,
P(2)—O(1)—C(8a)—C(4a) –26.1°,
O(1)—C(8a)—C(4a)—C(4) 10.0°,
O(1)—C(8a)—C(4a)—C(5) –7.7° .
On the whole, the calculated chemical shifts for the
aboveꢀgiven conformers of compound 11 correlate well
with the experimental data (except for two points), and
the dependence is nearly linear (Fig. 4, a, b). The theoꢀ
retical values of the 13C chemical shifts are somewhat
underestimated, which is typical of this method. This efꢀ
fect has been observed earlier11 for compounds containꢀ
ing C, H, O, and N atoms and is, apparently, associated
with either limitations of the method used for calculations
of chemical shifts or with the fact that the experimental
data are obtained in solutions, whereas calculations are
carried out for the gas phase. The exceptions are the
chemical shifts of the C(4) and C(3) atoms, for which
deviations are as high as 13—14 and 6 ppm, respectively.
For compound 11, the geometry optimization revealed
four forms (Fig. 3) corresponding to the energy minima.
Cl
Cl
O
O
O
Cl
Cl
Cl
O
a
b
Cl
δ
δ
calc
calc
y = 1.1453x – 23.893
R2 = 0.9372
y = 1.1116x – 19.324
R2 = 0.9375
11a (0)
11b (0.72)
160
160
O
O
O
C(4)
C(3)
140
120
140
120
Cl
Cl
Cl
Cl
Cl
O
Cl
120
140
δ
120
140
δ
exp
exp
11c (1.73)
11d (2.47)
Fig. 4. Correlation between the calculated and experimental
chemical shifts of the C atoms in major conformers 11a (a)
and 11b (b).
Fig. 3. Main forms of compound 11 (the relative energies in
kcal mol–1 (HF/6ꢀ31G) are given in parentheses).

200
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
Cl
It is quite possible that this discrepancy results from either
a notꢀtooꢀ"good" optimized geometry determined within
the framework of the method used (which is not suffiꢀ
ciently correct to describe Period III elements, such as P
and Cl), or limitations of the model used for calculations
of the chemical shifts.
a
O
O
Cl
Cl
A comparison of the experimental chemical shifts with
the calculated data on four conformers shows that the
best agreement is observed for the conformer with the
minimum energy. According to the results of calculaꢀ
tions, the orientation of the substituent at the P atom has
the most pronounced effect on the chemical shift of the
C(3) atom and, to some extent, on that of the C(4) atom.
The change in the orientation of the substituent at the
C(6) atom has also a predictable effect on the chemical
shifts of the C(7), C(5), and C(15) atoms, i.e., the chemiꢀ
cal shifts δC can serve as a spectroscopic test for the idenꢀ
tification of fine conformational details of such strucꢀ
tures.
Cl
b
Cl
O
O
Cl
Rotational isomerism about the C(6)—C(15) bond has
an appreciable effect on the chemical shifts of the vicinal
protons of the aromatic fragment. Thus, the difference
between the chemical shifts calculated for the conformer
with the cis orientation of the Cl atoms has a minimum
value (0.19 ppm), whereas this difference for the conꢀ
formers with the trans orientation of these atoms may be
as large as 0.84 ppm, which is close to the experimental
value (0.67 ppm). The chemical shifts of the protons of
the cyclic fragment are also wellꢀreproduced for the geꢀ
ometry corresponding to the major conformer. The folꢀ
lowing correlations between the calculated and experiꢀ
mental chemical shifts of the protons for two orientations
of the substituent at the C(6) atom were obtained (conforꢀ
mations 11a and 11b): y = 1.2837x – 2.5851, R2 = 0.9999
(11a) and y = 0.8843x + 0.1494, R2 = 0.9098 (11b).
Calculations for compound 12 were carried out for the
conformer with the axial orientation of the Cl atom at the
phosphorus atom. The rotation about the C(6)—C(15)
bond gives rise to two conformations with virtually equal
energies (the difference is 0.007 kcal mol–1). According
to the results of calculations, the conformation of the
heterocycle can be described as a boat, which is more
flattened compared to that observed in the heterocycle of
compound 11 (due, apparently, to the absence of a close
contact between the sterically overcrowded groups)
(Fig. 5). It should also be noted that the aromatic fragꢀ
ment of the molecule is not deformed.
Fig. 5. Structure of the major conformer of compound 12 as
viewed from the phenyl substituent (a) and the P atom (b).
δ
calc
y = 1.0673x – 13.473
R2 = 0.9478
160
140
120
C(8)
C(6)
140
120
160
δ
exp
Fig. 6. Correlation between the experimental and calculated
chemical shifts of the C atoms for compound 12.
valuable for the identification of the structure, because
attempts to obtain a correlation with the experimental
data within the framework of any other hypothetical strucꢀ
ture led to an obvious disagreement with calculations.
For protons, a good correlation was also obtained:
y = 1.2961x – 2.6782, R2 = 0.9905.
The results of calculations of the 13C chemical shifts
for the optimized geometry are also in good agreement
with the experimental data for most of the C atoms
(Fig. 6). A substantial disagreement between the experiꢀ
mental and calculated data is observed for the C(8) atom,
and a somewhat smaller discrepancy is observed for C(6).
The best correspondence was obtained for the C(3) atom.
Nevertheless, the observed agreement is diagnostically
Hence, the reaction of chlorocarbonylꢀsubstituted
phosphole 8, unlike those of unsubstituted phosphole 1
and monohalogenꢀsubstituted derivatives 3 and 5, with
phenylacetylene follows two pathway. The first path is
similar to the reaction of PCl5 with phenylacetylene and
involves the electrophilic addition to the triple bond of
acetylene with retention of coordination of the P atom.
The second path involves the formation of the heteroꢀ

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
201
Scheme 6
cyclic benzo[e]ꢀ1,2ꢀoxaphosphorinine system accompaꢀ
nied by regioselective ipsoꢀsubstitution of the O atom,
which is in the meta position with respect to the chloroꢀ
carbonyl group, in the starting phosphole giving rise to
the C—C bond. The process is attended with chlorination
of the phenylene substituents in the ortho and meta posiꢀ
tions with respect to this group. Apparently, these results
can be explained within the framework of the general
scheme of the process proposed earlier.3 As the first step,
the reaction involves the formation of the π complex A of
phenylacetylene (as Lewis base) with benzophosphole 8
(as Lewis acid) (Scheme 6). Then, this complex is transꢀ
formed into the structure B with charge separation, which
is converted into more stable quinoid phospholene C.
Earlier,20 we have described the formation of analoꢀ
gous compounds as final products in the phenanthreneꢀ
quinone—phosphorus trichloride—arylacetylene system.
λ5ꢀPhospholenes analogous to the intermediate C can
be in equilibrium with a quasiphosphonium structure of
the type D.21 The structure D is analogous to a quasiꢀ
phosphoniumꢀtype intermediate produced in the Arbuzov
reaction and is further transformed into vinylphosphonate
E containing the nonclassical carbocation, whose reacꢀ
tion with the chloride anion can follow two pathways
(1 and 2). Both directions of the attack of the chloride
anion are accompanied by cyclization giving benzoꢀ
oxaphosphorinines 11 and 12.
carbonyl substituent. The stability of the structure B proꢀ
vides the exclusive formation of compounds 11 and 12,
which are derivatives of the same bicyclic system.
The reaction is accompanied by elimination of HCl,
which can add to the starting phenylacetylene giving rise
to chlorostyrene. Taking into account the experimental
data,3—5 bubbling with argon can be used. In this case, the
major portion of HCl is purged from the reaction mixture.
As a result, the ratio between the starting reagents
(phosphole : phenylacetylene) can be decreased from 1 : 2
to 1 : 1.2.
The major isomer was isolated from a mixture of 11
and 12. The fact that this isomer has the structure of
benzooxaphosphorinine 11, was confirmed by 1H, 31P
(see the Experimental section), and 13C NMR spectroꢀ
scopy (see Table 1; the chemical shifts of a pure sample
are given in braces). Interestingly, the spectrum of the
pure sample has the resonance of C(6) at lower field comꢀ
pared to that of C(5), whereas the reverse pattern is obꢀ
served in the 13C NMR spectrum of the reaction mixture,
in which the signal of the C(5) atom appears at higher
field. This is, presumably, attributed to the fact that in the
13C NMR spectroscopic study of the reaction mixture,
the concentration of phosphorusꢀcontaining compounds
in CDCl3 is higher, which, in turn, influences the hinꢀ
dered rotation of the phenyl group about the C(4)—C(9)
bond. In the 13C NMR spectra, like in the 1H NMR
spectra (25 °C), the signals of the carbon atoms and proꢀ
tons belonging to the phenyl fragment are substantially
broadened.
In the context of this
scheme, the regiochemistry of
the reaction can be explained
by the fact that the key interꢀ
mediate B is much more
stable than its isomer F due to
more efficient delocalization
of the negative charge on the
O atom by the paraꢀchloroꢀ
Compound 11 was transformed into hydrolytically
more stable amide 13 by treatment with tertꢀbutylamine
(Scheme 7). Compound 13 gradually precipitated from
diethyl ether. This compound can easily be recrystallized
from acetone to form a solvate with the latter. This fact
1
was established by IR (ν(C=O) = 1713 cm–1), H NMR

202
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
the spectrum in CD3CN, the protons of the ButNH group
bound to the P atom are observed as a doublet with the
Scheme 7
4
constant JP,H = 0.6 Hz. In the 31P NMR spectrum in
acetone, the signal of the phosphorus nucleus appears as a
doublet of doublets (2JP,CH = 20.3 Hz, 2JP,NH = 10.0 Hz).
The spectrum of compound 13, unlike that of comꢀ
pound 11, shows a signal of the C(3) atom bound to the
P atom at lower field (δC 124.37).
Quantumꢀchemical calculations analogous to those
described above were carried out for the molecule of comꢀ
pound 13. According to these calculations, the structure
with the axial orientation of the O atom at the P atoms is
∼2 kcal mmol–1 more favorable than the structure with
the equatorial orientation of this substituent (Fig. 7). This
fact is consistent with the Xꢀray diffraction data considꢀ
ered below.
(δ 2.09), and 13C NMR spectroscopy (Table 2). Comꢀ
pound 13 is amide rather than phosphonate, which was
unambiguously confirmed by the 13C NMR spectrum in
which the signals of the C atoms of the tertꢀbutylamino
group bound to the P(2) atom are observed as doublets
2
3
with the constants JP,C = 2.6 Hz and JP,C = 4.4 Hz. In
The rotation of the substituent at the C(6) atom gives
rise to two stable conformers with the cis and trans orienꢀ
tations of the carbonyl and phosphoryl groups. The energy
1
the H NMR spectrum, the signal of the amide proton of
the PNH fragment also appears as a doublet (2JP,H
=
9.9 Hz). The spectral pattern depends on the solvent,
particularly, for the proton of the PNH fragment. For
example, in going from DMSOꢀd6 to CD3CN (with a
small additive of DMSOꢀd6), the signal of this proton is
shifted upfield (from 5.35 to 4.81 ppm, respectively). In
difference between the conformers is 0.5 kcal mmol–1
,
the conformer with the trans orientation of the C=O group
being more favorable.
On the whole, the calculated 13C chemical shifts corꢀ
relate well with the experimental data (Fig. 8). However,
Table 2. Parameters of the 13C{1H} and 13C NMR spectra of compounds 13 and 16 in DMSOꢀd6
Atom
δ (J/Hz)
13*
16**
C(3)
C(4)
124.37 (d [dd], JP,C(3) = 158.6, JH,C(3) = 164.1)
152.54 (s [m], JH(10),C(4) = 4.5—4.7,
JH(3),C(4) = 3.3—3.5)
122.75 (d [dd], JP,C(3) = 164.9, JH,C(3) = 157.2)
144.63 (s [br.m])
C(4a)
123.26 (d [ddd], JP,C(4a) = 16.3, JH(3),C(4a) = 9.2,
JH(8),C(4a) = 6.8)
123.20 (d [dd], JP,C(4a) = 15.4, JH(3),C(4a) = 8.7)
C(5)
C(6)
C(7)
C(8)
C(8a)
137.25 (s [d], JH(7),C(5) = 8.0)
131.02 (d [br.d], JH(8),C(6) = 11.5, JP,C(6) = 1.7)
130.73 (s [d], JH,C(7) = 166.6)
119.64 (d [br.dd], JH,C(8) = 167.6, JP,C(8) = 5.9)
153.75 (d [ddd], JH(7),C(8a) = 11.7, JP,C(8a) = 8.3,
JH(8),C(8a) = 4.0—4.3)
125.26 (s [dd], JH,C(5) = 163.4, JH(7),C(5) = 7.4)
126.65 (s [br.s])
126.49 (s [dd], JH,C(7) = 166.4, JH(5),C(7) = 7.3)
121.30 (d [dd], JP,C(8) = 5.7, JH(7),C(8) = 5.1—5.2)
149.76 (d [ddd], JH(7),C(8a) = JH(5),C(8a) = 6.5—6.8,
JP,C(8a) = 6.4)
C(9)
142.54 (d [m], JP,C(9) = 16.9)
138.70 (d [dm], JP,C(9) = 16.9, JH(11),C(9) = 7.8,
JH(3),C(9) = 7.0)
C(10), C(14)
128.13 (s [dm], JH,C(10) = 160.1)
126.92 (s [dm], JH,C(10) = 161.2, JH(12),C(10)
JH(14),C(10) = 6.5—6.8)
=
C(11), C(13)
C(12)
129.62 (s [dd], JH,C(11) = 161.1, JH(13),C(11) = 4.8)
127.18 (s [dd], JH,C(11) = 161.4, JH(13),C(11) = 7.7)
129.48 (s [dt], JH,C(12) = 161.2, JH(10),C(12)
JH(14),C(12) = 7.5)
=
126.82 (s [dt], JH,C(12) = 160.2, JH(10),C(12)
JH(14),C(12) = 7.8)
=
C(15)
167.13 (s [dd], JH(7),C(15) = 3.1, JHCN = 3.1)
164.15 (s [d], JH(7),C(15) = 5.1)
1
3
* The solvate with acetone; 13C NMR of the (CH3)3C(16)NH fragment, δ: 28.98 (s [qm], CH3, JH,C = 126.7 Hz, JH,C
=
=
3.5—4.0 Hz); 52.67 (s [m], C(16)). 13C NMR of the (CH3)3C(20)NH fragment: 32.16 (d [qm], CH3, 1JH,C = 126.5 Hz, 2JP,C
4.4 Hz, JH,C = 3.7—4.0 Hz); 53.08 (d [m], C(20), JP,C = 2.6 Hz). 13C NMR of the (CH3)2C=O fragment: 30.94 (s [br.q],
3
2
CH3, 1JH,C = 126.3 Hz); 207.29 (s [sept], C=O, 2JH,C = 6.3 Hz).
** 13C NMR of the (CH3)2C(16)HNH fragment, δ: 20.63 (s [br.qm], CH3, 1JH,C = 126.3 Hz, JH,C = 3.7 Hz); 41.65 (s [dm],
2
C(16), JH,C = 142.9 Hz, JH,NC = 4.4 Hz, JH,CC = 3.6—3.7 Hz). 13C NMR of the (CH3)2C(19)HN+ fragment: 18.88
1
2
2
(s [br.qm], CH3, 1JH,C = 127.4 Hz); 39.89 (s [dm], C(19), 1JH,C = 140.5 Hz).

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
203
deviation of the calculated chemical shift of the C(5)
atom from the experimental value and the situation with
the C atoms bound to the Cl atom in the aboveꢀconsidꢀ
ered compounds 11 and 12 have, apparently, a common
nature, whereas a slight disagreement for the C(6), C(7),
and C(15) atoms is, presumably, caused by hydrogen
bonding with the solvent (acetone or DMSO) or the forꢀ
mation of dimers in solutions. This is indirectly conꢀ
firmed also by calculations of the 1H chemical shifts,
according to which the protons of NH should come into
resonance at substantially higher field (at δ 4.36 (C(6)NH)
and 1.79 (P(2)NH)), whereas the experimental resonanses
are observed at δ 7.81 and 5.35, respectively. This downꢀ
field shift by more than 3 ppm is, apparently, indicative of
the formation of hydrogenꢀbonded dimers.
O
P
N
N
Cl
O
Fig. 7. Structure of the major conformer of compound 13.
δ
calc
On the whole, the calculated chemical shifts correlate
well with the experimental data. The maximum deviaꢀ
tions are observed for the C atoms directly bound to the
Cl atom (C(5) in compound 11 and C(8) in comꢀ
pound 12), and smaller discrepancies are observed for the
carbon atoms bound to the P atom (C(3)). On the one
hand, this is, apparently, attributed to the fact that the
method used for geometry optimization is inapplicable to
systems containing Group III elements22 (for example,
the calculated C—Cl bond lengths are in the range of
1.811—1.813 Å, whereas the corresponding bond lengths
determined by Xꢀray diffraction study are in the range of
1.743—1.747 Å 23). An analogous disagreement is also
observed for the P—C bond length. On the other hand,
this discrepancy may result from limitations of the method
used for estimations of the chemical shifts in such sysꢀ
tems.19 For example, trial calculations of the 13C chemiꢀ
cal shifts for the structure with the fixed C—Cl bond
length (1.73 Å) gave a much better correlation with
the experimental data (the chemical shift decreases by
5.4 ppm). Therefore, a comparison of the chemical shifts
provides a reliable criterion for the identification of not
only the structure but also of the conformation.
a
160
120
80
y = 0.9496x + 0.5824
R2 = 0.9918
40
40
80
120
δ
exp
δ
calc
b
160
140
120
y = 1.0224x – 9.552
R2 = 0.9284
C(15)
C(5)
C(7)
C(6)
The structure of the solvate of compound 13 with
acetone was established by Xꢀray diffraction analysis. The
overall view of molecule 13 in the crystal is shown in
Fig. 9. The selected bond lengths, bond angles, and torꢀ
sion angles are given in Table 3.
120
140
160
δ
exp
The heterocycle of molecule 13 contains two
planar fragments, viz., O(1)C(8a)C(4a)C(4) and
P(2)C(3)C(4)C(4a); the dihedral angle between these
fragments is 20.0(3)°. The C(3) and P(2) atoms of the
heterocycle deviate from the O(1)C(8a)C(4a)C(4) plane
in the same direction by –0.367(4) and –0.887(1) Å,
respectively. The O(1) and C(8a) atoms of the heteroꢀ
cycle deviate from the P(2)C(3)C(4)C(4a) fragment also
in the same direction by 0.811(3) and 0.487(4) Å respecꢀ
tively. Therefore, the oxaphosphorine ring in molecule 13
adopts a distorted boat conformation, which is less flatꢀ
Fig. 8. Correlation between the experimental and calculated
chemical shifts of the C atoms for the trans conformation of
compound 13: the overall correlation (a) and the lowꢀfield reꢀ
gion (b).
like in the aboveꢀconsidered cases, there are some disꢀ
crepancies. In particular, there is a noticeable disagreeꢀ
ment between the calculated and experimental shifts of
the C(5) atom and an incomplete agreement for the C(6)
and C(7) atoms. The chemical shift of the C(15) atom is
somewhat underestimated. It should be noted that the

204
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
H(261)
C(26)
H(221)
H(2)
C(25)
O(3)
O(2)
O(1)
C(24)
H(251)
H(8)
C(22)
H(171)
H(231)
C(23)
P(2)
C(8)
C(8a)
C(7)
N(2)
C(21)
H(1)
C(18)
C(17)
C(20)
C(6)
H(181)
N(1)
C(16)
C(19)
H(191)
C(5)
C(4a)
C(3)
C(15)
H(3)
C(4)
H(211)
O(15)
C(9)
Cl(5)
C(14)
C(13)
C(10)
C(11)
C(12)
Fig. 9. Geometry of molecule 13 (solvate with acetone) in the crystal.
Table 3. Selected bond lengths (d), bond angles (ω), and torsion angles (τ) in amide 13 and salt 16
Bond
d/Å
Angle
ω/deg
16
Angle
τ/deg
13
16
13
13
16
P(2)—O(1) 1.625(3) 1.635(3) O(1)—P(2)—O(2)
P(2)—O(2) 1.460(3) 1.474(4) O(1)—P(2)—C(3)
P(2)—C(3) 1.762(4) 1.771(5) O(2)—P(2)—C(3)
O(1)—C(8a) 1.383(5) 1.371(5) P(2)—O(1)—C(8a)
113.8(2) 105.8(2) O(2)—P(2)—O(1)—C(8a)
99.3(2) 100.5(2) C(3)—P(2)—O(1)—C(8a)
115.9(2) 111.5(2) O(1)—P(2)—C(3)—C(4)
120.5(2) 119.4(3) O(1)—P(2)—C(3)—H(3)
78.4(3)
–45.4(3)
160.3(3)
44.2(3)
28.9(4) –25.9(4)
–154 148.5(4)
–93.3(4) –137.7(4)
84.2(4) 36.7(5)
31.2(5) –36.9(5)
O(15)—C(15) 1.222(5) 1.242(5) C(15)—N(1)—C(16) 125.6(4) 121.8(3) O(2)—P(2)—C(3)—C(4)
N(1)—C(15) 1.336(6) 1.348(5) P(2)—C(3)—C(4)
N(1)—C(16) 1.467(6) 1.472(5) P(2)—C(3)—H(3)
C(3)—C(4) 1.357(5) 1.349(6) C(4)—C(4a)—C(5)
121.4(3) 122.0(3) O(2)—P(2)—C(3)—H(3)
118 124.4(3) P(2)—O(1)—C(8a)—C(4a)
125.8(3) 121.2(4) P(2)—O(1)—C(8a)—C(8)
–149.5(3)
144.3(3)
–1.6(6)
177.0(3)
C(3)—H(3)
1.11 1.113(4) C(4)—C(4a)—C(8a) 119.8(3) 120.9(4) C(16)—N(1)—C(15)—O(15) –4.7(7)
177.8(4)
C(4)—C(4a) 1.467(5) 1.484(5) O(15)—C(15)—N(1) 124.8(4) 122.8(4) C(16)—N(1)—C(15)—C(6)
C(4a)—C(5) 1.409(5) 1.380(6) O(15)—C(15)—C(6) 120.0(4) 122.0(3) C(15)—N(1)—C(16)—C(17) –176.3(4) –158.9(4)
C(4a)—C(8a) 1.402(5) 1.409(6) N(1)—C(15)—C(6) 115.1(4) 115.2(4) C(15)—N(1)—C(16)—C(18)
C(4)—C(9) 1.493(5) 1.482(6) N(1)—C(16)—C(17) 104.9(4) 107.5(4) C(3)—C(4)—C(4a)—C(5)
C(5)—C(6) 1.375(6) 1.391(5) N(1)—C(16)—C(18) 109.7(4) 110.8(4) C(9)—C(4)—C(4a)—C(5)
67.1(6)
155.4(4) –162.8(4)
–30.8(6)
77.1(5)
17.8(6)
16.8(6)
C(6)—C(7) 1.385(6) 1.396(6) C(17)—C(16)—C(18) 108.7(5) 113.1(4) C(3)—C(4)—C(4a)—C(8a) –25.5(6)
C(6)—C(15) 1.517(6) 1.492(6) C(5)—C(4a)—C(8a) 114.4(3) 118.0(4) C(9)—C(4)—C(4a)—C(8a)
148.3(4) –162.5(4)
128.7(4) –128.6(4)
C(7)—C(8) 1.368(6) 1.370(6) C(3)—C(4)—C(4a)
C(8)—C(8a) 1.384(6) 1.385(6) C(3)—C(4)—C(9)
C(9)—C(10) 1.397(6) 1.399(5) C(4a)—C(4)—C(9)
C(9)—C(14) 1.376(6) 1.379(6) C(4a)—C(5)—C(6)
C(10)—C(11) 1.379(6) 1.398(7) C(5)—C(6)—C(7)
119.9(3) 119.8(4) C(3)—C(4)—C(9)—C(10)
118.9(4) 120.5(4) C(3)—C(4)—C(9)—C(14)
120.9(3) 119.7(3) C(4a)—C(4)—C(9)—C(10) –45.2(6)
123.4(4) 121.8(4) C(4a)—C(4)—C(9)—C(14)
118.6(4) 119.4(4) C(7)—C(6)—C(15)—O(15) –75.7(5)
–46.8(6)
46.7(6)
50.7(5)
139.3(4) –133.9(4)
151.6(4)
30.0(6)
C(11)—C(12) 1.366(8) 1.360(7) C(5)—C(6)—C(15) 122.5(4) 118.2(4) C(5)—C(6)—C(15)—O(15)
C(12)—C(13) 1.364(8) 1.392(7) C(7)—C(6)—C(15) 118.9(4) 122.4(3) C(5)—C(6)—C(15)—N(1)
102.0(5)
–80.3(5) –148.6(4)
101.9(5) 29.7(5)
C(13)—C(14) 1.389(7) 1.385(8) C(6)—C(7)—C(8)
120.7(4) 119.3(4) C(7)—C(6)—C(15)—N(1)
C(16)—C(17) 1.544(8) 1.508(6) O(1)—C(8a)—C(4a) 120.9(3) 121.5(4)
C(16)—C(18) 1.528(7) 1.495(7) O(1)—C(8a)—C(8) 116.3(3) 118.5(4)

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
205
tened than those in the compounds described earlier.3—5
This is reflected in the direction of deviations of the O(2)
and N(2) atoms, which are located on one side of the
O(1)C(8a)C(4a)C(4) plane at distances of –2.324(3) and
–0.288(3) Å, respectively, from this plane. In structurally
similar 6ꢀchloroꢀ2ꢀmorpholinoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀ
oxaphosphorinine (14),3
This rotation is, presumably, caused by steric repulsion
between the C(15) and Cl atoms. Molecule 13 contains
one more planar (within 0.015(4) Å) fragment, viz.,
C(6)C(15)N(1)C(16); the deviations of the O(15) and
C(17) atoms from this plane are very small (–0.059(3)
and 0.086(7) Å, respectively). Hence, the overall
C(6)C(15)(O(15))N(1)C(16)C(17) sixꢀmembered fragꢀ
ment can be considered as a planar moiety. This structure
is favorable because of the efficient amide n—π conjugaꢀ
tion and the minimum steric interactions with the Me
groups of the But substituent. The N(1) atom has a
trigonalꢀplanar configuration (the sum of the bond
angles at this atom is 359.5(4)°). The dihedral angle
between the planes of the C(6)C(15)N(1)C(16) and
C(4a)C(5)C(6)C(7)C(8)C(8a) fragments is 80.6(2)°. The
C(5) and C(7) atoms virtually symmetrically deviate
from the C(6)C(15)N(1)C(16) plane (by 1.162(4) and
–1.171(4) Å, respectively). Hence, conjugation between
the carbonyl group and the benzene ring in molecule 13 is
impossible, but there is conjugation between the lone elecꢀ
tron pair of the N atom and the C=O bond. The observed
shortening of the N(1)—C(15) bond and elongations of
the C(15)=O(15) and C(6)—C(15) bonds are consistent
with this assumption. The phenyl substituent at the C atom
of the heterocycle at position 4 is twisted with respect to
the P(2)C(3)C(4)C(4a) plane; the dihedral angle between
these planes is large (132.7(1)°).
In the crystals of compound 13, the molecules are
linked by various types of short intermolecular contacts.
Analysis of these interactions reveals supramolecular isomꢀ
erism in the crystal, i.e., the formation of different types
of supramolecular structures depending on the type of the
contacts. For example, the classical N(2)—H(2)...O(2´)
hydrogen bonds (1 – x, –y, 1 – z) (d(H(2)...O(2´)) =
2.09 Å, N(2)—H(2)...O(2´) = 174°) give rise to centroꢀ
symmetrical dimers (Fig. 10), each molecule 13 being
linked to one acetone molecule through a hydrogen bond
(d(H(1)...O(3)), 1.91 Å; N(1)—H(1)...O(3), 175°). The
H(3) and H(14) protons of the initial molecule are inꢀ
volved in a bifurcate C—H...O hydrogen bond with
the O(15″) atom of the carbonyl group of another molꢀ
these atoms deviate from
the
aboveꢀmentioned
plane in opposite direcꢀ
tions by smaller distances
(O(2), by –2.12(1) Å;
N(2), by 0.12(1) Å). These
atoms in molecules 13 deꢀ
viate from another plane,
viz., P(2)C(3)C(4)C(4a), in opposite directions (the same
situation is observed in the structure of 14) by –1.303(3)
(O(2)) and 0.983(3) Å (N(2)) (in compound 14, these
deviations are –1.28(1) (O(2)) and 1.12 Å (N(2))). The
larger deviations of the O(2) atom are indicative of its
axial orientation, whereas the N(2) atom is in the equatoꢀ
rial position.
The P(2)—O(1) bond in molecule 13 (1.625(3) Å) is
somewhat elongated, which may be caused by the reverse
anomeric effect (interaction between the lone electron
pair of the N(2) atom and the antibonding orbital of the
endocyclic O(1)—P(2) bond). This effect is favored by
the virtually eclipsed conformation along the P(2)—N(2)
bond (the O(2)—P(2)—N(2)—C(20) torsion angle is
169.8(4)°). The N(2) atom has a trigonalꢀplanar configuꢀ
ration (the sum of the bond angles at this atom is
359.8(3)°). It should be noted that the attachment of the
bulky ButNH substituent at the P(2) atom has virtually no
effect on the bond angles at the P atom (these angles are
close to those in the structure of 14). The exocyclic
O(2)—P(2)—N(2) (111.3(2)°) and O(2)—P(2)—C(3)
(115.9(2)°) bond angles are larger than the endocyclic
O(1)—P(2)—C(3) bond angle (99.3(2)°).
The presence of the Cl atom at C(5), the Ph substituꢀ
ent at C(4), and the tertꢀbutylaminocarbonyl group at
position 6 leads to repulsions between these substituꢀ
ents resulting in an increase in the C(4a)—C(5)—C(6)
(123.4(4)°), C(4)—C(4a)—C(5) (125.8(3)°), and
C(5)—C(6)—C(15) (122.5(4)°) bond angles compared to
the ideal value for the sp2ꢀhybridized atom. Compound
13 contains 1,2,3,4ꢀtetrasubstituted benzene as the benzo
fragment. Steric repulsions between the substituents lead
also to deviations of the O(1), C(4), and Cl atoms from
the plane of the benzene ring in opposite directions by
–0.160(3), +0.226(4), and –0.210(1) Å, respectively. The
deviation of the C(15) atom is very small (–0.040(5) Å).
Nevertheless, the carbonyl group is substantially
twisted with respect to the plane of the benzene ring
(O(5)—C(15)—C(6)—C(7) torsion angle is –75.7(5)°).
ecule (1
+ x, y, z) (d(H(3)...O(15″)), 2.36 Å;
C(3)—H(3)...O(15″), 147°; and d(H(14)...O(15″)),
2.50 Å; C(14)—H(14)...O(15″), 141°). As a result,
the molecules in the crystal are linked in ribbonꢀlike
infinite chains along the crystallographic axis 0x
(Fig. 11), because each molecule of the dimer is inꢀ
volved in two such contacts (both as a donor and an
acceptor). In the crystal, there are also interactions of
C—H...π and π...π types. Taking into account two differꢀ
ent types of intermolecular contacts, the crystal structure
of 13 can be described as a 1Dꢀtype supramolecular strucꢀ
ture rather than as a structure consisting of 0D dimers.
On the whole, the molecular packing in the crystal can

206
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
O(3)
H(1)
H(2´)
N(1)
O(15)
O(2)
O(1)
H(2)
O(2´)
N(2)
H(3)
H(14)
Fig. 10. Formation of dimers in the crystal of compound 13. Only protons involved in hydrogen bonding are shown.
Fig. 11. Molecular packing of compound 13 in the crystal projected along the crystallographic axis 0x.
be represented as follows. A parallel packing of such ribꢀ
bonꢀlike structures forms a layer parallel to the x0z plane
of the crystal, so that the Ph substituents of the adjacent
chains in the layer are in contact with each other. The
next layer is rotated with respect to this layer by 90°, the
But substituents and the acetone molecules forming a
pseudolayer.
with the structure of the salt. The spectroscopic data were
interpreted taking into account the aboveꢀdescribed specꢀ
tra of compounds 11 and 12. The absence of the spinꢀspin
coupling of the P atom with the C atoms of the CH and
Me groups of the PriNH fragment is indicative of the
absence of the P—NH bond, i.e., the amidophosphonate
fragment rather than the amide group C(O)NHCHMe2 is
subjected to hydrolysis. The IR spectrum of compound 16
shows a band belonging to vibrations of the amide group
(ν(NC=O) = 1634 cm–1).
The structure of salt 16 was unambiguously estabꢀ
lished by Xꢀray diffraction analysis. The threeꢀdimenꢀ
sional structures of the anion and cation of salt 16 in the
crystal are shown in Fig. 12. The selected geometric paꢀ
rameters (bond lengths, bond angles, and torsion angles)
are given in Table 3. The heterocycle in molecule 16, like
that in the structure of 13, has two planar fragments, viz.,
O(1)C(8a)C(4a)C(4) and P(2)C(3)C(4)C(4a); the diꢀ
After separation of the major portion of benzooxaꢀ
phosphorinine 11, the filtrate was thoroughly dried in
vacuo and treated with isopropylamine. Then less soluble
isopropylamide 15 was isolated (Scheme 8). The latter
was readily hydrolyzed in the course of crystallization
from DMSO to give salt 16 (see the Experimental section).
In the 31P NMR spectrum of compound 16 (DMSOꢀd6),
the signal of the P atom appears as a doublet with the
2
constant JP,CH, i.e., spinꢀspin coupling with the proton
of the NH group is not manifested. The results of 1H and
13C NMR spectroscopy (see Table 2) are also consistent

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
207
Scheme 8
deviations indicate that the oxaphosphorine ring adopts a
distorted boat conformation. This conformation of the
heterocycle in 16, like that in the structure of 13, is less
flattened (the deviations of the aboveꢀmentioned atoms
from the above two planar fragments are larger) comꢀ
pared to that observed in benzophosphorinines studied
earlier.3—5 Correspondingly, the exocyclic O(2) and
O(3) atoms deviate more substantially from the
O(1)C(8a)C(4a)C(4) plane (by –0.241(4) and
2.264(3) Å, respectively). These atoms deviate from the
P(2)C(3)C(4)C(4a) plane by –0.917(4) and 1.384(3) Å,
respectively. The deviations of the O(2) and O(3) atoms
are indicative of their equatorial and axial positions, reꢀ
spectively. The P(2)O(2)O(3) fragment bears a negaꢀ
tive charge (i.e., this fragment is an anion). This leads
to an elongation and equalization of the P(2)—O(2)
(1.474(4) Å) and P(2)—O(3) (1.485(3) Å) bonds comꢀ
pared to the P(2)=O(2) bond in 4ꢀ(4ꢀbromophenyl)ꢀ6ꢀ
chloroꢀ2ꢀhydroxybenzo[e]ꢀ1,2ꢀoxaphosphorinine (17)
(1.468(6) Å).3 Nevertheless, in spite of delocalization of
the negative charge in the P(2)O(2)O(3) fragment, the
P(2)—O(2) and P(2)—O(3) bond lengths are slightly difꢀ
ferent. This may be associated, first, with the different
positions of the O atoms in the ring (the O(3) and O(2)
atoms are in the axial and equatorial positions, respecꢀ
tively) and, second, with the different hydrogen bonds
involving these atoms as acceptors.
hedral angle between these planes is 17.4(3)°. The C(3)
and P(2) atoms of the heterocycle deviate from the former
plane by 0.396(5) and 0.821(1) Å, respectively, i.e., are
located on the same side of this plane. The O(1) and
C(8a) atoms of the heterocycle deviate from the latter
plane also in the same direction (by –0.718(3) and
–0.335(4) Å, respectively). The deviations of these atoms
in the same direction and the different values of these
The O(2)P(2)O(3) bond angle (119.6(3)°) in 16 is
larger than that in molecule 17 (112.2(3)°). The endocyclic
C(12)
C(13)
C(11)
H(211)
C(10)
C(21)
C(19)
C(14)
O(15)
H(191)
H(201)
C(20)
H(212)
C(9)
H(5)
H(3)
H(16)
C(4)
H(23)
H(4)
H(171)
C(5)
C(4a)
C(17)
H(21)
O(4)
C(6)
C(3)
P(2)
N(2)
H(22)
O(3)
C(16)
C(15)
N(1)
H(1)
H(182)
H(4a)
C(18)
H(172)
C(7)
H(7)
O(2)
C(8a)
O(1)
H(181)
C(8)
Cl(8)
Fig. 12. Geometry of the crystal hydrate of compound 16 in the crystal.

208
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
P(2)—O(1) bond in salt 16 (1.635(3) Å), like that in comꢀ
pound 13, is somewhat longer than that in compound 17
(1.593(6) Å), and, vice versa, the O(1)—C(8a) bond
(1.371(5) Å) is shorter (in
compound 17, 1.40(1) Å). The
endocyclic P(2)—C(3) bond is
also somewhat elongated
(1.771(5) Å; cf. 1.753(9) Å in
molecule 17). These changes
in the bond lengths in molꢀ
H(1)
O(1)
Cl(8)
O(2)
O(3)
H(4)
N(1)
O(15)
P(2)
H(23)
O(4)
H(22)
O(3)
P(2)
N(2)
H(21)
O(2)
Cl(8)
ecule 16 may be indicative of
partial σ—π delocalization of the negative charge from
the exocyclic O atoms to the endocyclic O(1)—P(2) and
C(3)—P(2) bonds as well as of the efficient conjugation
between the lone electron pairs of the O(1) atom and
the electronꢀwithdrawing benzo fragment (bearing the
paraꢀchlorocarbonyl substituent). Salt 16 contains not
only the Ph ring but also the virtually planar fiveꢀmemꢀ
bered C(6)C(15)(O(15))N(1)C(16) fragment; the dihedral
angle between this fragment and the benzene ring is
30.8(2)°, which does not exclude conjugation of this fragꢀ
ment with the benzene ring. The N(1) atom has a trigoꢀ
nalꢀplanar configuration (the sum of the bond angles
at this atom is 360.0(4)°). The C(6)—C(15) bond
length (1.492(6) Å) is smaller than that in compound 13
(1.517(6) Å), which is also consistent with a more effiꢀ
cient conjugation of the carbonyl group with the aromatic
system in salt 16. The dihedral angle between the planes
of the Ph substituent and the P(2)C(3)C(4)C(4a) fragꢀ
ment is rather large (49.3(2)°), which decreases the possiꢀ
bility of conjugation between these fragments.
In the crystals of this compound, the molecules are
linked through various intermolecular contacts involving
both classical hydrogen bonds and weak C—H...N and
O(1)
Fig. 13. Formation of a tetramer in the crystal of compound 16.
Only protons involved in hydrogen bonding are shown.
C—H...π intermolecular interactions. It should be noted
that this compound crystallizes with a water molecule of
solvation. In the crystal, this water molecule occupies a
special position and is also involved in hydrogen bonding.
The parameters of the strongest interactions (hydrogen
bonds) in the crystal structure are given in Table 4.
The crystal structure of compound 16 is characterized
by the formation of centrosymmetrical hydrogenꢀbonded
tetramers involving two anionꢀcation pairs (Fig. 13). The
water molecule also participates in stabilization of the
tetramer. The H atoms of the water molecule are involved
in bifurcate hydrogen bonds with the O atoms of the
phosphoryl groups of molecules 16 adjacent to the tetꢀ
ramer. In addition, each anion is involved in two hydroꢀ
gen bonds (both as a donor and acceptor) between the
H(1) proton of the amino group and the carbonyl O(15)
atom giving rise to an infinite chain along the crystalloꢀ
graphic axis 0z (Fig. 14). As a result, the tetramers are
Table 4. Parameters of the hydrogen bonds in the crystal strucꢀ
ture of compound 16 (D is a donor and A is an acceptor)
DH...A Bond
D—H H...A
D...A
Angle
D—H...A
/deg
Å
N(1)—H(1)...O(15)#1
N(2)—H(21)...O(3)#2
O(4)—H(4)...O(2)#3
N(2)—H(22)...O(2)#3
N(2)—H(23)...O(3)
C(5)—H(5)...O(15)
C(16)—H(16)...O(15)
1.00
1.09
1.09
0.98
0.98
1.12
1.18
1.96
1.76
1.91
1.80
1.93
2.50
2.69
2.69
2.70
2.93
2.890(4)
2.760(5)
2.944(4)
2.759(5)
2.857(6)
—
153
150
156
163
155
—
—
—
157
124
N(1)
H(1)
—
—
O(15)
O(1)
C(12)—H(12)...O(15)#4 1.07
Cl(8)
C(18)—H(183)...Cg(2)
C(17)—H(172)...Cg(3)
0.98
1.08
3.621(6)
3.644(6)
P(2)
O(3)
O(2)
Note. Symmetry operations: #1 x, –y, 1/2 + z; #2 –x, y, 1/2 – z;
#3 x, 1 – y, –1/2 + z; #4 1/2 – x, 1/2 + y, 1/2 – z. Cg(2) is the
center of gravity of the fused benzene ring; Cg(3) is the center of
gravity of the Ph substituent.
Fig. 14. Fragment of an infinite chain of the hydrogenꢀbonded
molecules in the crystal of compound 16.

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
209
Fig. 15. Molecular packing of compound 16 in the crystal containing pseudochannels formed by chlorine atoms (Cl atoms are
represented by large circles). The projection along the crystallographic axis 0z.
(400 (1H), 162.0 (31P), 100.6 MHz (13C)), and Bruker CXPꢀ100
linked to each other to form finally a twoꢀdimensional
(36.48 MHz (31P)) instruments in DMSOꢀd6 (45 °C) or CDCl3,
CD3CN (25 °C). The chemical shifts are given in the δ scale
supramolecular structure in the crystal.
Interestingly, the molecular packing in the crystal,
which can be described as a packing of parallel hydrogenꢀ
with respect to Me4Si using signals of the residual protons of the
deuterated solvent or carbon nuclei of DMSO or CHCl3 (1H and
bonded layers along the direction 0z results in localizaꢀ
13C) as the internal standard or H3PO4 as the external standard.
tion of regions with the Cl atoms and the formation of
The IR spectra were measured on a Vectorꢀ22 (Bruker) Fourierꢀ
pseudochannels (Fig. 15). The packing coefficient of this
transform spectrometer in Nujol mulls or KBr pellets. The EI
structure is not high (64.6%). The calculations demonꢀ
strated that the unit cell has cavities with a total volume of
149 Å3. One would expect that the crystals of comꢀ
pound 16, which have such a special direction, could
exhibit substantial anisotropy of the physical properties.
To summarize, it was demonstrated that 2,2,2ꢀtriꢀ
chloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ1,3,2ꢀdioxaphosꢀ
phole (8) rather readily reacts with arylacetylenes to give
the benzo[e]ꢀ1,2ꢀoxaphosphorinine heterocyclic system.
The unusual feature of this reaction is the introduction of
the Cl atom at the ortho position with respect to either the
O atom or the C atom of the annelated oxaphosphorinine
heterocycle. Apparently, this reaction is common to phosꢀ
phorylated derivatives of oꢀdihydroxyarenes. However, in
each particular case, the regiochemistry of the process is
determined by the nature of the substituents in the arene
fragment. This problem calls for further investigation.
mass spectra were obtained on a MATꢀ212 (Finnigan) instruꢀ
ment; the energy of ionizing electrons was 70 eV. The masses
were precisely determined by fitting to the reference peaks of
perfluorokerosene. The temperature of the ion source was 120 °C.
The samples were introduced into the ion source using a diꢀ
rect inlet system. The temperature of the evaporator tube was
100 °C. The massꢀspectrometric data were processed using the
MASPEC 2 system program.
Ab initio quantum calculations were carried out using the
GAUSSIAN98 program package24 on a computer cluster at the
A. E. Arbuzov Institute of Organic and Physical Chemistry of
the Kazan Research Center of the Russian Academy of Sciences
consisting of nine Compaq Alpha DS10L workstations (Alphaꢀ
264ꢀ466MHz/256 Mb/10 Gb) and an Alpha DS20E workstation
(2*Alphaꢀ264ꢀ667MHz/512 Mb/20 Gb) with 100 Mbps Fast
Ethernet system. All molecular geometries were optimized at the
HF/6ꢀ31G level of theory. The absolute values of shielding were
calculated by the DFT/GIAO (density functional theory/gaugeꢀ
including atomic orbital) method with the 6ꢀ31G(d) basis set
and the B3LYP functional. Calculations were carried out for the
isolated molecule in the gas phase without regard for the solvent
effects. The chemical shifts are given relative to the signal of
Me4Si calculated in the identical conditions.
Experimental
1
The H, 13C, 13C{1H}, 31P, and 31P{1H} NMR spectra were
2ꢀChloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ1,3,2ꢀdioxaphosphole
(9). A mixture of PCl3 (13.7 g, 0.1 mol) and protocatechuic acid
recorded on Bruker WMꢀ250 (250 MHz (1H)), Bruker MSLꢀ400

210
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Mironov et al.
(5 g, 0.032 mol) was heated with stirring for 2 h. Then the
reaction mixture was distilled off. Benzophosphole 9 was isoꢀ
lated in a yield of 1.6 g (21%) as a colorless viscous liquid, b.p.
89—90 °C (0.8 Torr). 31P NMR (CH2Cl2): δP 179.8. Found (%):
Cl, 30.05. C7H3Cl2O3P. Calculated (%): Cl, 29.96.
was kept at 0—5 °C for 2—3 days, after which it partially crystalꢀ
lized. The crystals were washed with a 10 : 1 light petroꢀ
leum—CH2Cl2 mixture and dried in vacuo to prepare compound
11 in a yield of 2.2 g (29.4%), m.p. 136—138 °C. 31P NMR
2
(CDCl3): δ 17.0 (d, JP,CH = 25.3 Hz). 1H NMR (400 MHz,
P
2
2,2,2ꢀTrichloroꢀ5ꢀchlorocarbonylbenzo[d]ꢀ1,3,2ꢀdioxaphosꢀ
phole (8). A. Phosphorus pentachloride (32.7 g, 0.157 mol) susꢀ
pended in benzene (50 mL) was placed in a threeꢀneck flask
equipped with a stirrer and a reflux condenser. Then benzene
(150 mL) was added, and protocatechuic acid (9.7 g, 0.06 mol)
was gradually added portionwise with stirring at 20 °C (for
40 min). The reaction mixture was stirred for 1 h and the benꢀ
zene was distilled off under atmospheric pressure. The residue
was kept in vacuo (12 Torr) at 120 °C until distillation of POCl3
and sublimation of excess PCl5 ceased and then distilled.
Benzophosphole 8 was isolated in a yield of 10.9 g (56.2%) as a
viscous yellowish liquid, b.p. 129—130 °C (0.5 Torr). Found (%):
Cl, 46.18. C7H3Cl4O3P. Calculated (%): Cl, 46.1. MS*,
m/z (Irel (%)): 312 (2.0), 311 (0.63), 310 (8.8), 309 (1.0), 308
(18.7), 307 (1.7), 306 [M]•+ (14.6), 273 (100.0), 201 (14.7), 119
(24.4), 107 (34.1), 79 (45.7), 63 (32.4), 47 (16.0), 36 (15.7),
35 (4.5). 31P NMR (CDCl3): δP –23.5. 13C NMR (signals in the
13C{1H}) NMR spectrum are given in brackets (CDCl3)), δ:
CDCl3), δ: 6.58 (d, PCH, JP,CH = 25.5 Hz); 7.24—7.25 and
7.43—7.45 (both br.m, Ph); 7.43 (dd, H(8), 3JH(7),H(8) = 8.8 Hz,
4JP,H(8) = 0.8 Hz); 8.10 (dd, H(7), 3JH(7),H(8) = 8.8 Hz, 5JP,H(7)
=
1.6 Hz). After separation of the crystals of compound 11, the
residue was kept at 150 °C to remove volatile impurities. Then
the resulting glassy amberꢀcolored compound (4.8 g) was cooled
and used for the synthesis of amide 16.
2ꢀtertꢀButylaminoꢀ6ꢀtertꢀbutylaminocarbonylꢀ5ꢀchloroꢀ2ꢀ
oxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorinine (13). tertꢀButylꢀ
amine (3.5 mL, 0.069 mol) was added to a solution of compound
11 (2.0 g, 0.005 mol) in CH2Cl2 (20 mL) by bubbling through a
capillary with a stream of argon. The reaction mixture was kept
for 2 h and then the solvent and an excess of the amine were
removed in vacuo (12 Torr). The glassy yellowish residue was
mixed with dry diethyl ether (25 mL), which led to dissolution
of the glassy compound to form a white precipitate. The resultꢀ
ing mixture was kept for 5—8 h to achieve better coagulation of
the precipitate. The latter was filtered off, washed with diethyl
ether, dried in vacuo (12 Torr), treated with water (рH 8.0)
(3×10—15 mL) to dissolve tertꢀbutylammonium hydrochloride,
and dried in air. Compound 13 was obtained in a yield of 1.9 g
(79.2%). 1H NMR (400 MHz, CD3CN + 10% DMSOꢀd6), δ:
1.30 (s, C(17)H3, C(18)H3, C(19)H3); 1.31 (d, C(21)H3,
1
3
110.64 (dd [d], C(7), JH,C(7) = 170.6 Hz, JP,C(4) = 17.0 Hz);
1
3
113.49 (ddd [d], C(4), JH,C(4) = 170.7 Hz, JP,C(4) = 19.6 Hz,
3JH(6),C(4) = 6.7 Hz); 127.73 (br.d [br.s], C(5), JH(7),C(5)
8.4 Hz); 128.75 (dd [s], C(6), JH,C(6) = 170.7 Hz, JH(4),C(6)
5.9 Hz); 141.53 (dd [s], C(4a), 3JH(7),C(4a) = 7.0 Hz, 2JH(4),C(4a)
4.9 Hz); 148.15 (ddd [s], C(7a), JH(6),C(7a) = 11.4 Hz,
3JH(4),C(7a) = 6.7 Hz, JH(7),C(7a) = 2.9 Hz); 165.89 (dd [s],
COCl, JH(6),C = JH(4),C = 5.0—5.4 Hz).
3
=
=
=
1
3
3
C(22)H3, C(23)H3, 4JP,H = 0.6 Hz); 4.81 (br.d, PNH, 2JP,NH
=
2
2
8.5 Hz); 6.23 (d, PCH, JP,CH = 18.0 Hz); 7.08 (dd, H(8),
3
3
4
3JH(7),H(8) = 8.3 Hz, JP,H(8) = 0.6 Hz); 7.12 (br.s, CNH); 7.25
B. A cooled (from 0 to –10 °C) solution of chlorine (0.5 g,
0.07 mol) in CH2Cl2 (20 mL) was added dropwise with stirꢀ
ring to a solution of benzophosphole 9 (1.5 g, 0.006 mol)
in CH2Cl2 (5 mL) under argon at –20 °C. An excess of chloꢀ
rine was removed in vacuo (12 Torr). Tetrachlorobenzophosꢀ
phole 8 was obtained in a nearly quantitative yield. The resulting
solution of phosphorane 8 was used without additional purifiꢀ
cation.
Reaction of benzophosphole 8 with phenylacetylene. A soluꢀ
tion of phenylacetylene (2.93 g, 0.029 mol) in CH2Cl2 (5 mL)
(5—15 °C) was added dropwise with stirring to a solution of
benzophosphole 8 (5.9 g, 0.019 mol) in CH2Cl2 (20 mL) through
a thin capillary using a stream of dry argon. The reaction mixꢀ
ture was kept at 20 °C for 4 h and then the solvent was removed
in vacuo (12 Torr). According to the 31P NMR spectroscopic
data, a mixture of 2,5ꢀdichloroꢀ6ꢀchlorocarbonylꢀ2ꢀoxoꢀ4ꢀ
phenylbenzo[e]ꢀ1,2ꢀoxaphosphorinine (11), 2,8ꢀdichloroꢀ6ꢀ
chlorocarbonylꢀ2ꢀoxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorinine
(12) (∼83%), and 2,2ꢀdichloroꢀ2ꢀ(2ꢀchloroꢀ2ꢀphenylethenꢀ1ꢀ
yl)benzo[d]ꢀ1,3,2ꢀdioxaphosphole (10) (∼17%) was obtained.
MS of a mixture of isomers of 11 and 12, m/z (Irel (%)): 377
(0.7), 376 (5.3), 375 (2.5), 374 (16.0), 373 (3.7), 372 [M]•+
(16.5), 337 (100.0), 273 (6.3), 274 (3.0), 217 (8.0), 183 (10.5),
163 (15.8), 102 (15.3), 79 (11.6), 51 (15.0), 63 (10.5), 47 (7.6),
36 (8.9), 35 (1.1). The resulting mixture was kept in vacuo
(0.05 Torr) at 20 °C to remove volatile impurities. The residue
(dd, H(7), 3JH(7),H(8) = 8.3 Hz, 5JP,H(7) = 1.0 Hz); 7.23 and 7.33
(both m, Ph). After recrystallization from acetone, the solvate of
compound 13 with acetone was obtained in a yield of 1.3 g, m.p.
148—152 °C. Found (%): C, 62.27; H, 7.12; Cl, 7.11; N, 5.84.
C23H28ClN2O3P•C3H6O. Calculated (%): C, 61.84; H, 6.74;
Cl, 7.04; N, 5.55. IR (Nujol mull), ν/cm–1: 3336, 3227 (NH);
3066, 3033 (CH arom.); 1713 (C=O); 1663 (HNC=O); 1589,
1569, 1557 sh, 1538 (C=C arom., C=C); 1494, 1446, 1392,
1337, 1304, 1266, 1224—1228 (P=O), 1196 (POC), 1138,
1127, 1069, 1033, 978, 929, 907, 895, 877, 843, 830, 812, 796,
777, 758, 744, 696, 656, 596, 563, 550, 523, 500, 473, 461, 446,
2
412. 31P NMR (acetone): δ 8.4 (br.dd, JP,CH = 20.0 Hz,
P
2JP,NH = 10.0 Hz). 1H NMR (400 MHz, DMSOꢀd6), δ: 1.29 (s,
C(17)H3, C(18)H3, C(19)H3); 1.31 (s, C(21)H3, C(22)H3,
2
C(23)H3); 2.09 (s, acetone); 5.35 (br.d, PNH, JP,NH = 9.9);
6.37 (d, PCH, 2JP,CH = 20.2 Hz); 7.27 and 7.39 (both br.m, Ph);
3
4
7.30 (dd, H(8), JH(7),H(8) = 8.4 Hz, JP,H(8) = 0.5 Hz); 7.38
3
5
(dd, H(7), JH(7),H(8) = 8.4 Hz, JP,H(7) = 1.2 Hz); 7.81
(br.s, CNH).
Isopropylammonium 8ꢀchloroꢀ6ꢀisopropylaminocarbonylꢀ2ꢀ
oxoꢀ4ꢀphenylbenzo[e]ꢀ1,2ꢀoxaphosphorininꢀ2ꢀoate (16). After
separation of crystals of compound 11 (4.8 g), isopropylamine
(6 g) was added to the residue dissolved in benzene (20 mL). The
resulting mixture was kept for 8 h and washed with water with
рH 8.0. The benzene solution was concentrated in vacuo to oneꢀ
half of the initial volume. This solution was kept for 3—5 day,
after which a white precipitate of salt 16 (1.0 g) was obtained.
The precipitate was filtered off, dried, and recrystallized from
DMSO (crystals precipitated upon prolonged storage in air).
* The peaks of ions containing the most widespread isotopes are
given.

Reaction of benzodioxaphosphole with phenylacetylene Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
211
Salt 16 was obtained in a yield of 0.7 g, m.p. 227—230 °C.
Found (%): C, 56.87; H, 6.11; N, 6.32. C18H17ClNO4P•
•C3H10N•0.5H2O. Calculated (%): C, 56.48; H, 6.32; N, 6.27.
IR (KBr), ν/cm–1: 3445, 3280, 3063, 3032, 2967, 2931, 2767,
2645, 2104, 1634, 1603, 1548, 1594, 1447, 1382, 1328, 1289,
1241, 1169, 1106, 1077, 917, 878, 846, 816, 753, 703, 629, 567,
T. A. Zyablikova, R. Z. Musin, and V. I. Morozov,
Zh. Obshch. Khim., 2002, 72, 1868 [Russ. J. Gen. Chem.,
2002, 72 (Engl. Transl.)].
2. V. F. Mironov, R. A. Cherkasov, and I. V. Konovalova,
Zh. Obshch. Khim., 1996, 66, 422 [Russ. J. Gen. Chem., 1996,
66 (Engl. Transl.)].
3. V. F. Mironov, A. I. Konovalov, I. A. Litvinov, A. T.
Gubaidullin, R. R. Petrov, A. A. Shtyrlina, T. A. Zyablikova,
R. Z. Musin, N. M. Azancheev, and A. V. Il´yasov,
Zh. Obshch. Khim., 1998, 68, 1482 [Russ. J. Gen. Chem.,
1998, 68 (Engl. Transl.)].
539, 520, 481, 441. 31P NMR (DMSOꢀd6): δ –1.4 (br.d,
P
2JP,CH = 16.7 Hz). 1H NMR (250 MHz, DMSOꢀd6), δ: 1.07 (d,
NCCH3, 3JH,CH = 7.5 Hz); 1.15 (d, N+CCH3, 3JH,CH = 6.4 Hz);
3
3.26 (br.m, N+CH, JH,CH = 6.4 Hz); 4.01 (dsept, CHNC,
3
2
3JH,NH = 7.5 Hz, JH,CH = 7.5 Hz); 6.21 (d, PCH, JP,CH
=
16.7 Hz); 7.33 and 7.44 (both br.m, Ph); 7.56 (d, H(5),
4JH(5),H(7) = 1.7 Hz); 8.05 (br.s, H(7)); 8.27 (br.d, NHC,
3JH,NH = 7.5 Hz).
4. V. F. Mironov, I. A. Litvinov, A. A. Shtyrlina, A. T.
Gubaidullin, R. R. Petrov, A. I. Konovalov, N. M.
Azancheev, and R. Z. Musin, Zh. Obshch. Khim., 2000, 70,
1117 [Russ. J. Gen. Chem., 2000, 70 (Engl. Transl.)].
5. V. F. Mironov, R. R. Petrov, A. A. Shtyrlina, A. T.
Gubaidullin, I. A. Litvinov, R. Z. Musin, and A. I.
Konovalov, Zh. Obshch. Khim., 2001, 71, 74 [Russ. J. Gen.
Chem., 2001, 71 (Engl. Transl.)].
Xꢀray diffraction analysis of compounds 13 and 16 was carꢀ
ried out on an automated fourꢀcircle EnrafꢀNonius CADꢀ4
diffractometer at 20 °C (MoꢀKα radiation, λ(MoꢀKα) =
0.71073 Å). Crystals of the solvate of benzophosphorinine 13
with acetone are monoclinic. At 20 °C, a = 9.698(2) Å, b =
17.333(4) Å, c = 16.629(4) Å, β = 91.56(2)°, V = 2794(1) Å3,
Z = 4, dcalc = 1.20 g cm–3, space group P21/n. Crystals of salt 16
are monoclinic. At 20 °C, a = 36.96(1) Å, b = 13.881(2) Å, c =
6. J. Gloede, Z. Chem., 1982, 22, 126.
7. V. F. Mironov, R. R. Petrov, L. M. Burnaeva, and I. V.
Konovalova, Zh. Obshch. Khim., 1997, 67, 1400 [Russ. J. Gen.
Chem., 1997, 67 (Engl. Transl.)].
9.397(2) Å, β = 102.17(2)°, V = 4712.7(2) Å3, Z = 8, dcalc
=
1.28 g cm–3, space group C2/c. The unit cell parameters and
intensities of 6200 (13) and 4903 (16) reflections, of which
2797 (13) and 2283 (16) reflections were with I ≥ 2σ, were
measured at ∼20 °C (λ(MoꢀKα) = 0.71073 Å, graphite monoꢀ
chromator, ω/2θ (13) and ω scanning technique (16), θ ≤ 27.2°).
The intensities of three check reflections showed no decrease in
the course of Xꢀray data collection. Because of low values of the
coefficient (µ(Mo) = 2.22 and 2.58 cm–1, respectively), absorpꢀ
tion was ignored. The structures were solved by direct methods
using the SIR program25 and refined first isotropically and then
anisotropically. In the crystal structure of 16, the water molꢀ
ecule of crystallization occupies a special position on a twofold
axis. All H atoms were revealed from difference electron density
syntheses. Their contributions to the structure factors were taken
into account in the final steps of the leastꢀsquares refinement
with fixed positional and isotropic thermal parameters. The fiꢀ
nal values of the reliability factors were as follows: R = 0.053,
Rw = 0.060 based on 2536 independent reflections with F 2 ≤ σ in
the structure of 13 and R = 0.054, Rw = 0.064 based on 2045 inꢀ
dependent reflections with F2 ≤ 3σ in the structure of 16. All
calculations were carried out using the MolEN complex proꢀ
gram26 on an AlphaStation 200 computer. The atomic coordiꢀ
nates and thermal parameters were deposited with the Camꢀ
bridge Structural Database. Selected geometric parameters are
given in Table 3. The molecular structures were drawn and
intermolecular interactions were calculated with the use of the
PLATON program.27
8. A. Yu. Denisov and V. I. Mamatyuk, Spinꢀspinovoe
vzaimodeistvie 13C—13
C
i
13C—1H
v
spektrakh YaMR
and
organicheskikh soedinenii [SpinꢀSpin 13C—13
C
13C—1H Coupling in NMR Spectra of Organic Compounds],
Novosibirskii Institut Organicheskoi Khimii SO AN SSSR,
Novosibirsk, 1989, 366 pp. (in Russian).
9. V. F. Mironov, T. A. Baronova, A. I. Konovalov, N. M.
Azancheev, F. F. Alekseev, T. A. Zyablikova, and R. Z.
Musin, Zh. Org. Khim., 2002, 38, 1235 [Russ. J. Org. Chem.,
2002, 38 (Engl. Transl.)].
10. A. C. de Dios, J. Progr. Magn. Res. Spectrosc., 1996,
29, 229.aa
11. D. A. Forsyth and A. B. Sebag, J. Am. Chem. Soc., 1997,
119, 9483.
12. J. E. Rich, M. N. Manalo, and A. C. de Dios, J. Phys. Chem.
A, 2000, 104, 5837.
13. A. B. Sebag, C. J. Friel, R. N. Hanson, and D. A. Forsyth,
J. Org. Chem., 2000, 65, 7902.
14. G. A. Olah, G. K. S. Prakash, and G. Rasul, J. Am. Chem.
Soc., 2001, 123, 3308.
15. A. B. Sebag, D. A. Forsyth, and M. A. Plante, J. Org. Chem.,
2001, 66, 7967.
16. P. Rossi and G. S. Harbison, J. Magn. Reson., 2001, 151, 1.
17. M. S. Meier, H. P. Spielmann, R. G. Bergosh, and R. C.
Haddon, J. Am. Chem. Soc., 2002, 124, 8090.
18. R. M. Gomila, D. Quinonero, C. Rotger, C. Garau,
A. Frontera, P. Ballester, A. Costa, and P. M. Deya, Org.
Lett., 2002, 4, 399.
This study was financially supported by the Russian
Foundation for Basic Research (Project Nos. 03ꢀ03ꢀ
32542, 03ꢀ03ꢀ06559, and 02ꢀ03ꢀ32280).
19. C. van Wüllen, Phys. Chem. Chem. Phys., 2000, 2, 2137.
20. V. F. Mironov, T. A. Baronova, A. T. Gubaidullin, R. Z.
Musin, N. M. Azancheev, Sh. K. Latypov, A. B. Dobrynin,
F. F. Alekseev, I. A. Litvinov, and A. I. Konovalov, Dokl.
Akad. Nauk, 2002, 385, 196 [Dokl. Chem., 2002 (Engl.
Transl.)].
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Received July 25, 2003;
in revised form November 24, 2003