Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene. ipso-substitution of the tert-butyl group

Article abstract of DOI:10.1023/A:1011377231921

The reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene follows the mechanism of ipso-substitution of the tert-butyl group that is in para-position relative to the endocyclic O atom of the heterocycle, predomi

Full text of DOI:10.1023/A:1011377231921

Russian Chemical Bulletin, International Edition, Vol. 50, No. 4, pp. 693—696, April, 2001
693
Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-
dioxaphosphole with phenylacetylene.
ipso-Substitution of the tert-butyl group
V. F. Mironov,« R. R. Petrov, A. A. Shtyrlina, I. A. Litvinov, A. T. Gubaidullin,
E. N. Varaksina, and A. I. Konovalov
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. Å-mail: mironov@iopc.kcn.ru
The reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with
phenylacetylene follows the mechanism of ipso-substitution of the tert-butyl group that is in
para-position relative to the endocyclic O atom of the heterocycle, predominantly yielding
8-(tert-butyl)-2,6-dichloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (NMR data). The
structure of its hydrolysis product, 8-(tert-butyl)-6-chloro-2-hydroxy-2-oxo-4-phenylbenzo[e]-
1,2-oxaphosphorinine, was proved by X-ray diffraction analysis.
Key words: phenylacetylene, phosphorus(V) chlorides, benzo[e]-1,2-oxaphosphorinines,
ipso-substitution of the tert-butyl group, X-ray diffraction analysis.
Recently, we have shown that, unlike PCl5, phe-
nylenedioxytrichlorophosphorane reacts with aryl-
acetylene to give phosphorus-containing analogs of cou-
marin, namely, benzo[e]-1,2-oxaphosphorinine deriva-
tives in rather high yields.1,2 It was of interest to involve
trichlorophosphoranes with substituents in the benzene
ring in this reaction, since in this case it would be
possible to study the effect of the corresponding sub-
stituents on the reaction outcome and discuss possible
pathways for the formation of benzophosphorinines. In
the present work, we studied the reaction of the hitherto
meta-position relative to both tert-butyl groups as the
main process. In parallel, the tert-butyl group that is in
para-position relative to the O atom of the heterocycle
undergoes ipso-substitution (Scheme 1).
Scheme 1
But
But
3
4
3a
O
O
O
5
2
P
Ph
C CH
PCl3
Cl
1
unknown trichlorophosphorane
1 containing two
O
But
6
7a
Cl
tert-butyl groups with phenylacetylene.
7
Ph
1
2
Results and Discussion
H2O
17
Me3C
Compound 1 readily reacts with phenylacetylene in
CH2Cl2 with evolution of HCl resulting in a product
containing the Ð(Î)ÑÍ=Ñ fragment (31P and 1H NMR
data) in 55—65% yield, depending on the degree of
dilution. This product was isolated by crystallization
from CCl4, and its structure was established as benzo[e]-
1,2-oxaphosphorinine 2 based on the 13C NMR spectral
data (Table 1). Analysis of the NMR spectra shows that
compound 2 contains only one tert-butyl group, and the
fused benzene ring is tetrasubstituted. Based on the
spectroscopic data altogether and the results of our
previous publications,1,2 one can conclude that the Cl
atom is in para-position relative to the endocyclic O
atom of the phosphorinine heterocycle. Thus, the reac-
tion includes ipso-substitution for the O atom which is in
1
8a
2
O
O
7
8
P
OH
4
3
6
4a
Cl
5
11
12
13
14
3
This conclusion was completely confirmed by the
X-ray diffraction analysis of phosphonic acid 3, which is
a hydrolysis product of chlorophosphorinine 2. The
13Ñ NMR data for compound 3 and selected geometri-
cal parameters of its molecule are given in Tables 1
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 666—668, April, 2001.
1066-5285/01/5004-693 $25.00 © 2001 Plenum Publishing Corporation

694
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 4, April, 2001
Mironov et al.
Table 1. 31P, 13Ñ, and 13Ñ-{1H} NMR parameters for benzophosphorinines 2 and 3 (δ, J/Hz)a
Atom
2 (CH2Cl2 + 30% C6D6)
15.1 d (JÐÑÍ = 24.3)b
3 (DMSO-d6)
4.9 d (JÐÑÍ = 18)c
Ð
Ñ(3)
Ñ(4)
Ñ(4a)
Ñ(5)
115.3 d (dd, JÐÑ = 155, JÍÑ = 172)
156.9 d (m, JÐÑÑ = 2)
123.9 d (dd, JÐÑÑÑ = 18, JÍÑ(3)ÑÑ = 8)
127.8 s (dd, JÍÑ = 169, JÍÑ(7)ÑÑ = 5)
117.1 d (dd, JÐÑ = 169, JÍÑ = 164)
151.3 d (m, JÐÑÑ = 2)
124.3 d (dd, JÐÑÑÑ = 16, JÍÑ(3)ÑÑ = 8)
125.8 d (ddd, JÍÑ = 166, JÍÑ(7)ÑÑ = 6,
JÐÎÑÑÑ = 1)
126.5 d (br.m, JÐÎÑÑÑÑ = 1, JÍÑ(7)Ñ = 5,
JÍÑ(5)Ñ = 5, JÍÑ(3)ÑÑÑÑ = 1)
127.8 s (dd, JÍÑ = 165, JÍÑ(5)ÑÑ = 6)
141.6 d (m, JÐÎÑÑ = 6)
149.1 d (ddd, JÐÎÑ = 8, JÍÑÑÑ = 9,
JÍÑÑÑ = 10)
Ñ(6)
130.0 sd
Ñ(7)
Ñ(8)
Ñ(8a)
130.5 s (dd, JÍÑ = 164, JÍÑ(5)ÑÑ = 7)
142.8 d (m, JÐÎÑÑ = 7)
149.0 d (ddd, JÐÎÑ = 11, JÍÑ(7)ÑÑ = 9—10,
JÍÑ(5)ÑÑ = 9—10)
Ñ(11)
Ñ(12)
137.8 d (m, JÐÑÑÑ = 21)
138.6 d (ddt, JÐÑÑÑ = 19, JÍÑ(3)ÑÑ(12) = 6,
JÍÑ(13)CC = 6—7)
128.2 s (ddd, JÍÑ = 161, JÍÑ(14)CC = 7,
JÍÑ(16)CC = 6)
128.7 s (dd, JÍÑ = 162, JÍÑ(15)CC = 7)
128.8 s (dt, JÍÑ = 162, JÍÑ(12)CC = 6—7)
34.9 s (m, JÍÑÑ = 4, JÍÑÑÑ = 4)
29.4 s (qm, JÍÑ = 126, JÍÑÑÑ = 5)
128.5 s (br.ddd, JÍÑ = 160,
JÍÑ(14)CC = 6—7, JÍÑ(16)CC = 6—7)
129.1 s (dd, JÍÑ = 161, JÍÑ(15)CC = 6—7)
130.1 s (dt, JÍÑ = 161, JÍÑ(12)CC = 6—7)
35.5 s (m)
Ñ(13)
Ñ(14)
Ñ(17)
ÑÍ3
29.9 s (qm, JÍÑ = 127, JÍÑÑÑ = 4)
a The multiplicities of the 31P or 13C-{1H} and 13C signals (in parentheses) are indicated.
b In ÑÑl4.
c In DMSO.
d Overlap with a component of the signal for the Ñ(12) atom.
and 2, respectively. A spatial structure of the molecule in
crystal is shown in Fig. 1. Benzophosphorinine 3 con-
tains two planar fragments (O(1)C(8a)C(4a)C(4) and
P(2)C(3)C(4)C(4a)) at a dihedral angle of 11.4(1)°. The
heterocycle has a distorted boat conformation (the P(2)
and C(3) atoms deviate from the O(1)C(8a)C(4a)C(4)
plane by –0.5407(7) and –0.227(7) Å, respecti-
vely). Note a significant torsion angle between the
Table 2. Selected geometrical parameters of the molecule of benzophosphorinine 3
Bond
Cl(9)—C(6)
d/Å
Bond angle
ϕ/deg
Torsion angle
τ/deg
1.741(5)
1.585(3)
1.468(4)
1.514(5)
1.744(7)
1.397(5)
0.943(4)
0.981(6)
1.355(8)
1.477(7)
1.492(8)
1.396(7)
1.379(8)
1.378(9)
1.396(7)
1.531(9)
1.389(8)
1.505(9)
O(1)—P(2)—O(2)
O(1)—P(2)—O(3)
O(1)—P(2)—C(3)
O(2)—P(2)—O(3)
O(2)—P(2)—C(3)
O(3)—P(2)—C(3)
P(2)—O(1)—C(8a)
P(2)—O(3)—H(30)
P(2)—C(3)—C(4)
P(2)—C(3)—H(3)
C(3)—C(4)—C(4a)
C(3)—C(4)—C(11)
C(4)—C(4a)—C(8a)
O(1)—C(8a)—C(4a)
O(1)—C(8a)—C(7)
C(8a)—C(8)—C(17)
C(4)—C(11)—C(12)
C(8)—C(17)—C(18)
108.0(2)
105.9(2)
101.9(2)
115.2(2)
115.8(3)
108.8(3)
125.3(3)
111.0(4)
121.7(5)
118.7(5)
121.8(5)
119.1(5)
121.7(5)
119.5(5)
116.1(5)
123.6(5)
119.1(5)
111.6(5)
O(2)—P(2)—O(1)—C(8a)
O(3)—P(2)—O(1)—C(8a)
C(3)—P(2)—O(1)—C(6)
O(1)—P(2)—C(3)—C(4)
O(1)—P(2)—C(3)—H(3)
O(2)—P(2)—C(3)—C(4)
O(2)—P(2)—C(3)—H(3)
O(3)—P(2)—C(3)—C(4)
O(3)—P(2)—C(3)—H(3)
P(2)—O(1)—C(8a)—C(4a)
P(2)—O(1)—C(6)—C(7)
P(2)—C(3)—C(4)—C(4a)
P(2)—C(3)—C(4)—C(11)
H(3)—C(3)—C(4)—C(4a)
C(3)—C(4)—C(5)—C(8a)
C(3)—C(4)—C(5)—C(5)
C(11)—C(4)—C(4a)—C(8a)
C(11)—C(4)—C(4a)—C(5)
C(3)—C(4)—C(11)—C(12)
C(3)—C(4)—C(11)—C(16)
C(4)—C(4a)—C(6)—O(1)
C(8a)—C(8)—C(17)—C(18)
C(8a)—C(8)—C(17)—C(19)
C(8a)—C(8)—C(17)—C(20)
–155.7(5)
80.4(6)
–33.3(6)
19.2(6)
–156.2(5)
136.2(5)
–39.3(7)
–92.3(6)
92.3(6)
P(2)—O(1)
P(2)—O(2)
P(2)—O(3)
P(2)—C(3)
O(1)—C(8a)
O(3)—H(30)
C(3)—H(3)
C(3)—C(4)
C(4)—C(4a)
C(4)—C(11)
C(4a)—C(5)
C(4a)—C(8a)
C(7)—C(6)
C(7)—C(8)
C(8)—C(17)
C(8a)—C(8)
C(17)—C(18)
29.7(9)
–153.6(5)
–2.5(9)
177.5(4)
172.9(6)
–6.7(9)
170.9(6)
173.4(6)
–9.1(8)
–64.6(8)
113.2(7)
–5.8(9)
178.2(6)
–63.7(8)
58.6(8)
x
x

Synthesis of benzo[e]-1,2-oxaphosphorinines
Russ.Chem.Bull., Int.Ed., Vol. 50, No. 4, April, 2001
695
31P NMR (ÑÍ2Ñl2), δ: –29.2. 1H NMR (CCl4 + 30% C6D6),
δ: 1.25, 1.36 (both s, each 18 H, ÑÍ3); 6.88, 6.93 (both br.s,
each 2 H, ÑÍ). 13Ñ-{1H} NMR (CCl4 + 30% C6D6), δ: 29.94,
31.90 (both s, ÑÍ3); 34.85, 35.56 (both s, Ñquat); 106.62 (d,
Ñ(7), JÐÎÑÑ = 18.0 Hz); 118.12 (s, Ñ(5)); 134.59 (d, Ñ(4),
JÐÎÑÑ = 13.9 Hz); 139.17 (s, (Ñ(6)); 143.31 (s, Ñ(3à));
147.07 (s, Ñ(7à)).
Reaction of phosphorane 1 with phenylacetylene. Dry argon
was passed through a solution of phosphorane 1 (7.3 g, 0.02 mol)
in 50 mL of CH2Cl2, and a solution of phenylacetylene (4.5 mL,
0.04 mol) in 30 mL of CH2Cl2 was added dropwise at 5—10 °Ñ.
Hydrogen chloride evolved vigorously. The reaction mixture
was kept at 20 °Ñ for one day, and the solvent was removed.
Then, the excess of phenylacetylene and styryl chloride were
removed in vacuo (0.1 Torr). The residual light yellow viscous
glass was dissolved in ÑCl4 and kept for 3—5 days to give
8-(tert-butyl)-2,6-dichloro-2-oxo-4-phenylbenzo[e]-1,2-oxa-
phosphorinine (2) as a crystalline precipitate, which was filtered
off, washed with cold ÑCl4, and dried in vacuo. Yield 2.33 g
(31%), m.p. 196 °Ñ. Found (%): C, 59.07; Í, 4.88; P, 8.31;
Cl, 19.76. Ñ18H17Cl2O2P. Calculated (%): C, 58.85; Í, 4.63;
P, 8.44; Cl, 19.34. 1H NMR (CCl4 + 30% Ñ6D6), δ: 1.30 (s,
9 H, ÑÍ3); 5.84 (d, 1 H, Í(3), JÐÑÍ = 24.5 Hz); 6.76 (m, 2 H,
Ío); 6.96 (d, Í(5), JÍ(7)ÑÑÑÍ(5) = 2.7 Hz); 6.97, 7.02 (both m,
Cl(2)
C(6)
C(7)
C(8)
C(5)
C(18)
C(19)
C(15)
C(16)
C(14)
C(13)
C(17)
C(8A)
C(4A)
C(11)
C(4)
C(12)
C(20)
O(1)
P(2)
C(3)
H(3)
O(3)
O(2)
H(30)
Fig. 1. Structure of compound 3.
phenyl group and the O(1)C(8a)C(4a)C(4) plane
(Ñ(4a)—C(4)—C(11)—C(12) 115.4(6)°). The equatorial
O(2) atom and the axial Î(3)Í(3) group are located at
distances of 0.170(5) and –2.037(5) Å, respectively,
from the O(1)C(8a)C(4a)C(4) plane. The P(2)—O(2)
and P(2)—O(3) bond lengths are markedly different
(1.468(4) è 1.514(5) Å, respectively), which makes the P
atom chiral. The molecules of 3 crystallize in non-
centrosymmetric space group, i.e., they form enanti-
omers. The absolute configuration of the phosphorus
atom is RP. In general, structure 3 has standard geo-
metrical parameters.2
In crystal, the molecules are linked through hydrogen
bonds between the hydroxy and phosphoryl groups to
form infinite zigzag chains along the crystallographic ó
axis. The O(3)—H(3)...O(2´) (–x, 1/2 + y, –z) bond
parameters are as follow: the O(3)—H(3), O(3)...O(2´),
and H(3)...O(2´) distances are equal to 0.94, 2.514(5),
and 1.63 Å, respectively, and the O(3)—H(3)...O(2´)
angle is 155°.
each 4 Í, Íp, Hm, Í(5)); 7.28 (dd, 1 H, Í(7), JÍ(7)ÑÑÑÍ(5)
2.7 Hz, JÐÎÑÑÑÍ(7) = 1.5 Hz).
=
Chlorophosphorinine 2 was dissolved in 20 mL of dioxane
and treated with water (0.4 mL). Prolonged storage (>10 days)
of the reaction mixture in open air gave 8-(tert-butyl)-6-chloro-
2-hydroxy-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (3) as
a well-formed crystalline precipitate, which was filtered off,
washed with ether, and dried. Yield 2.0
g (90%), m.p.
212—214 °Ñ. Found (%): C, 62.12; Í, 5.19; P, 9.03; Cl, 10.07.
Ñ18H18ClO3P. Calculated (%): C, 61.97; Í, 5.16; P, 8.89;
Cl, 10.18. 1H NMR (CD3OD), δ: 1.46 (br.s, 9 H, ÑÍ3); 6.22
(d, 1 H, Í(3), JÐÑÍ = 18.8 Hz); 6.91 (d, 1 H, Í(5),
JÍ(7)ÑÑÑÍ(5) = 2.6 Hz); 7.30—7.31, 7.44—7.46 (both m,
each 5 H, Ph); 7.37 (dd, 1 H, Í(7), JÍ(7)ÑÑÑÍ(5) = 2.6 Hz,
JÐÎÑÑÑÍ(7) = 1.7 Hz). IR, ν/cm–1: 482, 517, 562, 580, 635,
700, 725, 765, 815, 822, 872, 888, 945, 998, 1000 sh, 1125,
1150, 1180, 1220, 1232 sh, 1270 (P=O); 1335, 1365, 1420, 1452,
1555 (C=C); 1590, 1600, 2130—2150 v.br, 2260—2290 v.br,
2500—2600 v.br.
X-Ray diffraction analysis of compound 3. The crystals of 3
are monoclinic, at 20 °Ñ
a = 9.8774(9), b = 5.942(1),
Experimental
c = 16.317(4) Å, β = 97.11(2)°, V = 854.1(3) Å3, Z = 2,
dcalc = 1.36 g cm–3, space group Ð21, Ñ18Í18ClÎ3P. The unit
cell parameters and the intensities of 1978 reflections (includ-
ing 1147 reflections with I ≥ 3σ) were measured on an
Enraf—Nonius CAD4 automated four-circle diffractometer
(λMo-Kα, graphite monochromator, ω/2θ scan mode, θ ≤ 26.9°).
1
Í, 13Ñ, 13Ñ-{1H}, 31Ð, and 31Ð-{1H} NMR spectra were
recorded on Bruker WM-250 (1Í, 250 MHz) and Bruker
MSL-400 instruments (31Ð, 162.0 MHz; 13Ñ, 100.6 MHz) in
DMSO-d6 at 45 °Ñ and in Ñ6D6—CCl4 (ÑÍ2Ñl2) at 32 °Ñ with
HMDS as the internal standard (1Í) and Í3ÐÎ4 as the external
standard (31Ð) or referenced to the residual protons or the
carbon nuclei of DMSO and Ñ6D6 (1H and 13C). IR spectra
were recorded on a Specord IR-75 instrument (suspensions in
Vaseline oil).
The intensities of three reference reflections were not decreased
during recording, and absorption correction (µ-Ìî 3.3 cm
–1
)
was not applied. The structure was solved by the direct method
with the SIR program3 and refined first in the isotropic and
then anisotropic approximations. The H atoms were located
from the difference electron-density map and included with
fixed coordinates and isotropic thermal parameters. To establish
the absolute structure and configuration of 3, we refined the
"direct" and inverted structures with consideration of abnormal
scattering by all non-hydrogen atoms. The discrepancy factors
are R = 0.04035 and Rw = 0.04440 for 1065 reflections from the
direct structure and R = 0.04039 and Rw = 0.04444 for the
inverted structure. According to the Hamilton test,4 the direct
structure corresponds to the absolute structure at a confidence
4,6-Bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxa-
phosphole (1). 3,5-Bis(tert-butyl)pyrocatechol (7 g, 0.032 mol)
was added portionwise with stirring to a suspension of PCl5
(26 g, 0.1247 mol) in 500 mL of benzene over 2 h. The reaction
mixture was heated to 50—60 °Ñ to bring the reaction to
completion. The solvent was removed under atmospheric pres-
sure, and the residue was distilled in vacuo. The yield of
phosphorane 1 was 7.33 g (65%), b.p. 139—141 °Ñ (0.1 Torr).
Found (%): Ñl, 30.04. C14H20Cl3O2P. Calculated (%): Ñl, 29.79.

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Russ.Chem.Bull., Int.Ed., Vol. 50, No. 4, April, 2001
Mironov et al.
level of 90%. The final residuals are R = 0.040 and Rw = 0.044
for 1065 independent reflections with F2 ≥ 3σ. All calculations
were performed with the MOLEN program package5 using an
AlphaStation 200 computer. Intermolecular interactions were
analyzed and structure 3 was constructed with the PLATON
program.6 The atomic coordinates were deposited with the
Cambridge Crystallographic Database.
Khim., 1997, 368 [Russ. Chem. Bull., 1997, 46, 355 (Engl.
Transl.)].
2. 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.)].
3. A. Altomare, G. Cascarano, Ñ. Giacovazzo, and D. Viterbo,
Acta Crystallogr., A, 1991, 47, 744.
4. W. C. Hamilton, Acta Crystallogr., 1965, 18, 502.
5. L. H. Straver and A. J. Schierbeek, MolEN. Structure Deter-
mination System, Nonius B. V., 1994, 1, 2.
This work was financially supported by the Russian
Foundation for Basic Research (Project Nos. 00-03-
32835 and 98-03-33266).
6. A. L. Spek, Acta Crystallogr., A, 1990, 46, 34.
References
1. V. F. Mironov, T. A. Zyablikova, I. V. Konovalova,
R. A. Musin, and M. G. Khanipova, Izv. Akad. Nauk, Ser.
Received July 28, 2000