A phospha-wittig route to 5-phosphaphenanthrene

Article abstract of DOI:10.1002/ejic.201100466

The reaction of tributylphosphane with a 7-(2′-formyl-2-biphenylyl) phosphanorbornadiene P-W(CO)₅ complex leads to the 5-phosphaphenanthrene P-W(CO)₅ complex via an intramolecular phospha-Wittig condensation. This complex is stable e

Full text of DOI:10.1002/ejic.201100466

FULL PAPER
DOI: 10.1002/ejic.201100466
A Phospha-Wittig Route to 5-Phosphaphenanthrene
Huaiqiu Wang,[a] Weining Zhao,[a] Yang Zhou,[a] Zheng Duan,*[a] and François Mathey*[a,b]
Keywords: Cycloaddition / Phosphorus heterocycles / Phospha-Wittig reaction
The reaction of tributylphosphane with a 7-(2Ј-formyl-2-bi-
phenylyl)phosphanorbornadiene P-W(CO)5 complex leads to
the 5-phosphaphenanthrene P-W(CO)5 complex via an intra-
molecular phospha-Wittig condensation. This complex is
stable enough for detection by 31P NMR spectroscopy but
cannot be isolated due to its high reactivity. It is trapped by
addition of MeOH or cycloaddition with 2,3-dimethylbutadi-
ene or a nitrileimine. The adducts were characterized by X-
ray crystal structure analysis.
Introduction
Results and Discussion
5-Phosphaphenanthrenes (phosphanthridines) are still a
Our starting point was the functional phosphole complex
very poorly studied class of compounds in spite of their 1 with a protected aldehyde functionality. It was prepared
interesting structure. Indeed, they can be viewed as stabi- from 2,2Ј-dibromobiphenyl[5] in three steps and 81% overall
lized all-carbon-substituted phosphaalkenes with a planar yield as shown in Equation (1).
core. The parent 5-phosphaphenanthrene was briefly men-
In spite of the steric bulk of the phosphorus substituent,
tioned as early as 1968 by Bickelhaupt[1] as an unstable spe- it proved possible to react complex 1 with neat dimethyl
cies, only characterized by UV spectroscopy and mass spec- acetylenedicarboxylate to obtain the corresponding 7-phos-
trometry. Sometime later, some of us synthesized the stable phanorbornadiene complex 2 [Equation (2)].
6-phenyl derivative.[2] The chemistry of these species re-
In the normal case, when the substituent at P is not
mains essentially unknown at the moment.[3] In view of this bulky, dimethyl acetylenedicarboxylate (DMAD) reacts on
state of affairs, we decided to investigate a new approach to the phosphole face opposite to tungsten. The 13C spectrum
5-phosphaphenanthrene based on the phospha-Wittig reac- of the product displays a Me-C resonance at ca. 138 ppm
tion.[4] In so doing, we highlight the phosphaalkene charac- with a strong JCP coupling of ca. 17 Hz and a MeO2C-C
ter of these species.
resonance at ca. 147 ppm with a weak JCP coupling of ca.
4–5 Hz.[6] In the present case, it is possible to detect the
MeO2C-C resonance at δ = 147.65 ppm with a strong JCP
coupling of 19.2 Hz. Thus, we suspect that the cycload-
dition has taken place on the same side as tungsten. An
interesting side product (compound 3) is also formed dur-
ing this synthesis. Its formula was established by a combina-
[a] Chemistry Department, International Phosphorus Laboratory,
Zhengzhou University,
Zhengzhou 450052, P. R. China
[b] Division of Chemistry & Biological Chemistry, School of
Physical & Mathematical Sciences, Nanyang Technological
University,
21 Nanyang Link, Singapore 637371
E-mail: duanzheng@zzu.edu.cn
fmathey@ntu.edu.sg
tion of NMR spectroscopy and mass spectrometry. The 13
C
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H. Wang, W. Zhao, Y. Zhou, Z. Duan, F. Mathey
FULL PAPER
All three adducts were obtained in good yields and char-
acterized by X-ray crystal structure analysis (see Figures 1,
2, and 3). The structure of the central six-membered phos-
phorus ring is remarkably insensitive to the type of reaction
performed with 5. The C–C bridge bond of the biphenyl
unit varies between 1.482 and 1.485 Å, the C–P–C intra-
cyclic angle varies between 96.9 and 97.8° and the phenyl
interplane angle within the biphenyl unit stays within the
range 26.44(7) to 28.58° (compound 8).
spectrum shows an O-CH resonance at δ = 84.50 ppm (JCP
= 37.2 Hz) and two OCH2 at 64.58 (JCP = 3.2 Hz) and
69.83 ppm (JCP = 3.6 Hz). The calculated exact mass is
602.9806 [M + Na+] vs. 602.9844 (found). The product re-
sults from the intramolecular insertion of the electrophilic
phosphanylidene formed via the collapse of the bridge of 2
into one of the O–C bonds of the dioxolane ring. This type
of reaction has never been reported before.[7] In spite of the
sensitivity of 2, we were then able to perform the un-
masking of the aldehyde under mild acidic conditions to
obtain 4 in very good yield. Following a protocol that we
had already used for the synthesis of other cyclic phos-
phaalkenes,[8] we then reacted 4 with tributylphosphane in
dichloromethane at room temperature. We detected the for-
Figure 1. X-ray crystal structure of MeOH adduct 6. Significant
distances [Å] and angles (°): O1–P1 1.607(4), P1–W1 2.4660(14),
P1–C7 1.819(5), P1–C13 1.822(5), C1–C7 1.510(8), C1–C6
1.396(7), C6–C8 1.484(8), C8–C13 1.404(7); C7–P1–C13 96.9(2).
Finally, this work highlights the high versatility of both
mation of the 5-phosphaphenanthrene complex 5 (δ31P = phosphanylidene and phospha-Wittig chemistries. Besides,
1
164.9 ppm, JPW = 267.3 Hz) but its reactivity precluded the tungstenpentacarbonyl complexation of 5-phos-
its isolation. We trapped it by reaction with methanol, 2,3- phaphenanthrene stabilizes it to a sufficient extent to allow
dimethylbutadiene, and a nitrileimine as shown in Equa- its use in a variety of high yield addition and cycloaddition
tion (3).
reactions. More chemistry can be envisaged.
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A Phospha-Wittig Route to 5-Phosphaphenanthrene
ium (2.2 m in hexane) were purchased from Alfa Aesar. Nuclear
magnetic resonance spectra were recorded with a Bruker 300 MHz
1
spectrometer operating at 300.13 MHz for H, 75.47 MHz for 13C,
and 121.495 MHz for 31P. Chemical shifts are expressed from in-
ternal TMS (1H and 13C) or external 85% H3PO4 (31P). All cou-
pling constants (J values) are reported in Hertz [Hz]. HRMS were
obtained with a Micromass Q-TOF mass spectrometer. Mass spec-
tra were recorded with a Bruker Esquire 3000 (Bruker Dalton, Ger-
many) ion trap mass spectrometer that interfaced an ESI source.
1-Phenyl-3,4-dimethylphosphole was prepared according to a pub-
lished procedure.[9]
2-Bromobiphenyl-2Ј-carbaldehyde: n-BuLi (5 mL, 2.2 m, 11 mmol)
in hexane was added to a solution of 2,2Ј-dibromobiphenyl (3.43 g,
11 mmol) in THF (70 mL) over a period of 10 min at –78 °C. Then,
a solution of N,N-dimethylformamide (2 mL, 25.8 mmol) in THF
(10 mL) was added over 10 min at –78 °C. The reaction mixture
was warmed to room temperature and stirred overnight. Then, it
was quenched with saturated aqueous NH4Cl solution and the sep-
arated organic layer was dried with MgSO4. After removal of the
solvent, the residue was chromatographed on silica gel. Elution
with a mixture of petroleum ether and ethyl acetate (95:5) afforded
the formyl derivative (colorless oil, 2.77 g, yield 97%). 1H NMR
(CDCl3): δ = 7.24–7.31 (m, 3 H), 7.35–7.38 (m, 1 H), 7.51–7.53 (m,
1 H), 7.59–7.67 (m, 2 H), 8.01–8.04 (m, 1 H), 9.79 (s, 1 H,
CHO) ppm. 13C NMR (CDCl3): δ = 123.83, 127.36, 127.47, 128.58,
129.86, 130.87, 131.61, 132.74, 133.61, 133.74, 138.85, 144.44,
191.44 ppm.
Figure 2. X-ray crystal structure of dimethylbutadiene adduct 7.
Significant distances [Å] and angles (°): P1–W1 2.519(3), P1–C6
1.820(12), P1–C18 1.824(10), P1–C24 1.836(11), C6–C11 1.425(16),
C11–C12 1.485(16), C12–C17 1.404(16), C17–C18 1.517(14); C6–
P1–C18 97.7(5).
Dioxolane Derivative of 2-Bromobiphenyl-2Ј-carbaldehyde: A solu-
tion of 2-bromobiphenyl-2Ј-carbaldehyde (5.2 g, 20 mmol), ethyl-
ene glycol (11 mL, 200 mmol), and p-toluenesulfonic acid monohy-
drate (380 mg, 2 mmol) in toluene was refluxed with water separa-
tion until total consumption of the starting aldehyde as monitored
by GC. After removal of toluene, the reaction mixture was ex-
tracted with diethyl ether and the organic layer was dried with
MgSO4. After evaporation of the solvent, the crude product was
chromatographed on silica gel. Elution with hexane/CH2Cl2 (3:1)
afforded the pure dioxolane derivative (5.78 g, yield 95%). 1H
NMR (CDCl3): δ = 3.74–3.88 (m, 2 H), 3.92–3.98 (m, 1 H), 4.03–
4.09 (m, 1 H), 5.51 (s, 1 H), 7.14–7.22 (m, 2 H), 7.29–7.32 (m, 2 H),
7.36–7.46 (m, 2 H), 7.62–7.70 (m, 2 H) ppm. 13C NMR (CDCl3): δ
= 65.27, 65.57, 101.59, 123.74, 126.54, 126.86, 128.29, 128.87,
129.08, 130.06, 131.86, 132.47, 135.41, 140.79, 140.82 ppm.
Phosphole Complex 1: To a THF (30 mL) solution of dioxolane
(608 mg, 2.2 mmol), nBuLi (1 mL, 2.2 m, 2.2 mmol) was added at
–78 °C. The reaction mixture was stirred at –78 °C for 10 min and
then a THF (5 mL) solution of 1-cyano-3,4-dimethylphosphole[10]
(301 mg, 2.2 mmol) was added. The mixture was warmed to room
temperature and stirred for 2 h. After removal of the solvent, the
residue was quickly chromatographed with CH2Cl2. After evapora-
tion of the solvent, the crude product (yellow viscous oil, 31P
NMR: δ = –4.8 ppm in CH2Cl2) was obtained and used without
further purification.
Figure 3. X-ray crystal structure of nitrileimine adduct 8. Signifi-
cant distances [Å] and angles (°): P1–W1 2.4853(10), P1–C6
1.841(30), P1–C7 1.846(3), P1–C31 1.825(30), C6–C20 1.497(5),
C20–C25 1.410(5), C25–C26 1.482(5), C26–C31 1.402(5); C6–P1–
C31 97.78(15).
Experimental Section
To a stirred solution of crude phosphole (672 mg, 2 mmol) in dry
THF (30 mL), a freshly prepared THF (20 mL) solution of W(CO)5-
(CH3CN) (803 mg, 2.2 mmol) was added. The reaction mixture
was stirred at 50 °C for 2 h. After evaporation of the solvent, the
residue was chromatographed on silica gel with petroleum ether/
CH2Cl2 (1:1) as eluent to give pure 1 (yellow crystal, 1.27 g, yield
General: All reactions were routinely performed under an inert at-
mosphere of nitrogen using standard Schlenk techniques and dry
deoxygenated solvents.
Dry CH2Cl2 was obtained by distillation from P2O5. THF was ob-
tained by distillation from Na/benzophenone. Silica gel (200–
300 mesh) purchased from Qing Dao Hai Yang Chemical Industry
Co. Ltd. was used for chromatographic separations. PBu3 was pur-
chased from Aladdin Chemistry Co. Ltd., DMAD and n-butyllith-
88% from the dioxolane). 31P NMR (CDCl3): δ = 9.1 (1JPW
=
1
207.1 Hz) ppm. H NMR (CDCl3): δ = 1.78 (s, 3 H, Me), 1.85 (s,
3 H, Me), 3.62–3.97 (m, 4 H, 2OCH2), 4.97 (d, JHP = 36.9 Hz, 1
2
2
H, =CH), 5.07 (s, 1 H, CH), 6.17 (d, JHP = 35.7 Hz, 1 H, =CH),
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H. Wang, W. Zhao, Y. Zhou, Z. Duan, F. Mathey
7.10–7.15 (m, 2 H), 7.21–7.39 (m, 4 H), 7.58–7.69 (m, 2 H) ppm. 43.2 Hz, Csp2), 196.69 (d, JCP = 7.6 Hz, cis-CO), 197.90 (d, JCP
FULL PAPER
=
13C NMR (CDCl3): δ = 16.79 (d, JCP = 11.5 Hz, CH3), 16.95 (d,
JCP = 11.3 Hz, CH3), 65.11 (s, OCH2), 65.42 (s, OCH2), 101.42 (s,
CH), 126.40 (s, Csp2), 127.46 (d, JCP = 14.7 Hz, Csp2), 127.62 (d,
JCP = 40 Hz, Csp2), 128.53–128.60 (3Csp2), 129.31 (d, JCP = 41.8 Hz,
Csp2), 129.62 (s, Csp2), 131.91 (d, JCP = 5.9 Hz, Csp2), 132.20 (d, JCP
= 37.5 Hz, Csp2), 133.33 (d, JCP = 18.3 Hz, Csp2), 136.42 (s, Csp2),
140.33 (d, JCP = 3.2 Hz, Csp2), 141.37 (d, JCP = 2.6 Hz, Csp2), 148.46
(d, JCP = 10.4 Hz, Csp2), 148.66 (d, JCP = 9.8 Hz, Csp2), 196.65 (d,
JCP = 6.5 Hz, cis-CO), 199.52 (d, JCP = 17.7 Hz, trans-CO) ppm.
The inequivalency of the two sides of the phosphole ring indicates
a blocked rotation of the substituent at phosphorus. MS (ESI): m/z
(%) = 683.0 ([M + Na]+). HRMS (ESI) calcd. for C26H21O7PW:
[M + Na]+, 683.0432; found m/z 683.0452.
28.0 Hz, trans-CO) ppm. MS (ESI): m/z (%) = 546.8 ([M + Na-
2CO]+). HRMS (ESI) calcd. for C20H13O7PW: [M
602.9806; found m/z 602.9844.
+
Na]+
Phosphanorbornadiene Complex 4: A solution of 2 (802 mg,
1 mmol), p-toluenesulfonic acid monohydrate (380 mg, 2 mmol),
and water (90 mg, 5 mmol) in CH2Cl2 (10 mL) was refluxed and
monitored by 31P NMR until the disappearance of 2. The solution
was extracted with CH2Cl2 (25 mL)/ H2O (20 mLϫ3) and the or-
ganic layer was dried with MgSO4. After evaporation of the sol-
vent, pure 4 (green crystals, 705 mg, yield 93%) was obtained after
recrystallization. 31P NMR (CDCl3):
δ = =
217.3 (1JPW
235.7 Hz) ppm. H NMR (CDCl3): δ = 0.98 (s, 3 H, Me), 1.33 (s,
3 H, Me), 2.57 (d, JCP = 0.9 Hz, 1 H, CH), 3.62 (d, 6 H, 2OMe),
1
2
2
Phosphanorbornadiene Complex 2: A mixture of 1 (1.32 g, 2 mmol)
3.98 (d, JCP = 1.5 Hz, 1 H, CH), 6.97–7.00 (m, 1 H), 7.20–7.62
and DMAD (2.4 mL, 20 mmol) was heated and stirred at 70 °C for (m, 6 H), 7.93–7.96 (m, 1 H), 9.60 (s, 1 H, CHO) ppm. 13C NMR
15 h in a sealed tube (the reaction cannot proceed completely). The
crude mixture was first chromatographed on silica gel with petro-
leum ether as eluent to get a mixture of 1, DMAD, and compound
3, and then the column was washed with CH2Cl2 to give the crude
product 2. After evaporation of the solvent, the mixture of 1,
DMAD, and compound 3 can be directly used for [4+2] cycload-
dition and the same procedure was repeated until complete con-
sumption of 1. The crude product 2 was collected and chromato-
graphed on silica gel with petroleum ether/CH2Cl2 (1:3) to give
pure 2 (yellow crystal, 816 mg, yield 51%). 31P NMR (CDCl3): δ
(CDCl3): δ = 15.24 (d, JCP = 1.7 Hz, Me), 15.60 (d, JCP = 2.0 Hz,
Me), 52.53 (s, 2OMe), 60.50 (d, JCP = 22.0 Hz, CH), 61.65 (d, JCP
= 19.2 Hz, CH), 128.42 (d, JCP = 8.8 Hz, Csp2), 128.54 (s, Csp2),
128.89 (s, Csp2), 129.261 (d, JCP = 14.3 Hz, Csp2), 129.26 (s, Csp2),
130.02 (s, Csp2), 133.64 (s, 2Csp2), 134.36 (s, Csp2), 135.80 (d, JCP
4.2 Hz, Csp2), 136.18 (d, JCP = 2.8 Hz, Csp2), 141.28 (d, JCP
3.5 Hz, Csp2), 141.29 (d, JCP = 15.1 Hz, Csp2), 142.56 (d, JCP
20.4 Hz, Csp2), 143.65 (d, JCP = 1.2 Hz, Csp2), 147.29 (d, JCP
19.5 Hz, Csp2), 163.89 (d, JCP = 2.1 Hz, COO), 165.19 (d, JCP
=
=
=
=
=
3.2 Hz, COO), 191.42 (s, CHO), 196.58 (d, JCP = 6.3 Hz, cis-CO),
198.31 (d, JCP = 25.7 Hz, trans-CO) ppm. Same inequivalency as
in 2. MS (ESI): m/z (%) = 780.9 ([M + Na]+). HRMS (ESI) calcd.
for C30H23O10PW: [M + Na]+, 781.0436; found m/z 781.0435.
1
= 219.7 (1JPW = 233.1 Hz) ppm. H NMR (CDCl3): δ = 1.28 (s, 3
H, Me), 1.51 (s, 3 H, Me), 2.71–2.73 (m, 1 H, CH), 3.81 (s, 6 H,
2OMe), 3.96–3.99 (m, 2 H), 4.12–4.13 (m, 1 H), 4.14–4.26 (m, 2
H), 5.42 (s, 1 H, 1CH), 7.34–7.54 (m, 5 H), 7.58–7.62 (m, 1 H),
7.68–7.71 (m, 1 H), 7.83–7.86 (m, 1 H) ppm. 13C NMR (CDCl3):
δ = 15.04 (d, JCP = 2.1 Hz, Me), 15.61 (d, JCP = 2.0 Hz, Me), 52.46
(s, 2OMe), 60.61 (d, JCP = 22.3 Hz, CH), 61.62 (d, JCP = 19.4 Hz,
CH), 65.23 (s, OCH2), 65.84 (s, OCH2), 100.94 (s, CH), 127.50 (d,
JCP = 9.1 Hz, Csp2), 127.72 (s, Csp2), 128.41 (d, JCP = 1.4 Hz, Csp2),
128.80 (s, Csp2), 128.97 (d, JCP = 14.4 Hz, Csp2), 129.01 (s, Csp2),
129.57 (d, JCP = 0.9 Hz, Csp2), 133.13 (d, JCP = 4.1 Hz, Csp2), 136.22
(s, Csp2), 136.84 (d, JCP = 3.9 Hz, Csp2), 138.22 (d, JCP = 2.7 Hz,
Csp2), 139.55 (d, JCP = 1.4 HZ, Csp2), 140.01 (d, JCP = 3.5 Hz, Csp2),
140.95 (d, JCP = 16.0 Hz, Csp2), 142.52 (d, JCP = 21.1 Hz, Csp2),
147.65 (d, JCP = 19.2 Hz, Csp2), 164.07 (d, JCP = 2.2 Hz, COO),
165.46 (d, JCP = 3.3 Hz, COO), 196.77 (m, JCP = 6.3 Hz, cis-CO),
198.68 (d, JCP = 25.5 Hz, trans-CO) ppm.
Methanol Adduct 6: To a well-stirred solution of 4 (379 mg,
0.5 mmol), PBu3 (122 mg, 0.6 mmol) was added quickly and the
solution was stirred for 3 h at room temperature. After the disap-
pearance of 4 (monitored by 31P NMR), MeOH (64 mg, 2 mmol)
was added and the mixture was stirred for another 2 h. The crude
mixture was chromatographed on silica gel with petroleum ether/
CH2Cl2 (4:1) as eluent to give 6 (colorless crystal, 194 mg, yield
70%). 31P NMR (CDCl3): δ = 108.0 (1JPW = 235.7 Hz) ppm. 1H
2
2
NMR (CDCl3): δ = 3.21 (d, JHH = 14.4 Hz, 1 H), 3.44 (d, JHP
=
2
2
12.3 Hz, 3 H, OMe), 4.04 (dd, JHP = JHH = 14.4 Hz, 1 H), 7.19–
7.34 (m, 3 H), 7.38–7.50 (m, 2 H), 7.57–7.63 (m, 2 H), 7.70–7.74
(m, 1 H) ppm. 13C NMR (CDCl3): δ = 37.59 (d, JCP = 24.3 Hz,
CH2), 54.33 (d, JCP = 9.4 Hz, OMe), 126.30 (d, JCP = 5.8 Hz, Csp2),
126.74 (d, JCP = 1.8 Hz, Csp2), 127.98 (d, JCP = 9.6 Hz, Csp2), 128.64
(d, JCP = 1.3 Hz, Csp2), 128.91 (s, Csp2), 129.29 (d, JCP = 1.7 Hz,
Csp2), 129.93 (d, JCP = 13.2 Hz, Csp2), 131.55 (d, JCP = 7.8 Hz, Csp2),
131.90 (d, JCP = 1.4 Hz, Csp2), 132.58 (d, JCP = 37.7 Hz, Csp2),
134.43 (d, JCP = 7.8 Hz, Csp2), 137.14 (d, JCP = 5.5 Hz, Csp2), 195.76
(d, JCP = 8.1 Hz, cis-CO), 199.05 (d, JCP = 25.8 Hz, trans-
CO) ppm. MS (ESI): m/z (%) = 536.8 ([M – Me]).
As in the case of 1, the two sides of 2 are inequivalent due to a
blocked rotation of the P-substituent. MS (ESI): m/z (%) = 825.1
([M + Na]+). HRMS (ESI) calcd. for C32H27O11PW: [M + Na]+,
825.0698; found m/z 825.0696. C32H27O11PW (802.38): calcd. C
47.90, H 3.39; found C 47.07, H 3.38.
Complex 3: After complete consumption of 1, the reaction mixture
was chromatographed on silica gel with petroleum ether/CH2Cl2
(2:1) to give the pure product 3: white crystals, 115 mg, yield 10%.
Dimethylbutadiene Adduct 7: To a solution of 4 (379 mg, 0.5 mmol),
PBu3 (122 mg, 0.6 mmol) was added quickly and the solution was
stirred for 3 h at room temperature. After the disappearance of 4
31P NMR (CDCl3): δ = 113.2 (1JPW = 283.2 Hz) ppm. 1H NMR
2
(CDCl3): δ = 4.08–4.28 (m, 3 H), 4.56–4.68 (m, 1 H), 5.38 (d, JHP (monitored by 31P NMR), 2,3-dimethyl-1,3-butadiene (164 mg,
= 11.1 Hz, 1 H), 7.39–7.44 (m, 2 H), 7.45–7.53 (m, 3 H), 7.55–7.63 2 mmol) was added and the mixture was stirred for another 2 h.
(m, 2 H), 7.69–7.73 (m, 1 H) ppm. 13C NMR (CDCl3): δ = 64.58 The crude mixture was chromatographed on silica gel with petro-
(d, JCP = 3.2 Hz, OCH2), 69.83 (d, JCP = 3.6 Hz, OCH2), 84.50 (d,
leum ether/CH2Cl2 (8:1) as eluent to give 7 (colorless crystal,
JCP = 37.2 Hz, CH), 122.62 (d, JCP = 5.5 Hz, Csp2), 126.95 (d, JCP 227 mg, yield 76%). 31P NMR (CDCl3): δ = –25.1 (1JPW
=
1
= 3.3 Hz, Csp2), 126.96 (d, JCP = 7.1 Hz, Csp2), 127.10 (d, JCP
5.8 Hz, Csp2), 128.35 (d, JCP = 7.6 Hz, Csp2), 128.50 (d, JCP
3.2 Hz, Csp2), 129.30 (d, JCP = 2.3 Hz, Csp2), 131.45 (d, JCP
1.3 Hz, Csp2), 131.97 (d, JCP = 6.6 Hz, Csp2), 132.03 (d, JCP
4.4 Hz, Csp2), 134.80 (d, JCP = 9.7 Hz, Csp2), 135.27 (d, JCP
=
=
=
=
=
235.5 Hz) ppm. H NMR (CDCl3): δ = 1.44 (s, 3 H, Me), 1.73 (s,
3 H, Me), 1.94–2.03 (m, 1 H), 2.18–2.33 (m, 1 H), 3.00 (s, 2 H),
3.07–3.13 (m, 1 H), 7.26–7.41 (m, 6 H), 7.65–7.73 (m, 2 H) ppm.
13C NMR (CDCl3): δ = 20.56 (s, CH3), 21.17 (d, JCP = 7.5 Hz,
CH3), 33.71 (d, JCP = 22.1 Hz, CH2), 36.29 (d, JCP = 5.1 Hz, CH2),
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A Phospha-Wittig Route to 5-Phosphaphenanthrene
36.51 (d, JCP = 28.0 Hz, CH), 120.39 (d, JCP = 8.2 Hz, Csp2), 126.20
can be obtained free of charge from The Cambridge Crystallo-
(d, JCP = 6.2 Hz, Csp2), 127.43 (d, JCP = 1.5 Hz, Csp2), 127.82 (d, graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
JCP = 7.2 Hz, Csp2), 128.26 (d, JCP = 7.2 Hz, Csp2), 128.46 (d, JCP
= 8.2 Hz, Csp2), 128.73 (d, JCP = 1.4 Hz, Csp2), 129.02 (s, Csp2),
130.17 (d, JCP = 36.2 Hz, Csp2), 130.23 (d, JCP = 1.5 Hz, Csp2),
Acknowledgments
130.47 (d, JCP = 8.2 Hz, Csp2), 133.79 (d, JCP = 9.9 Hz, Csp2), 136.25
(d, JCP = 2.8 Hz, Csp2), 137.18 (d, JCP = 5.7 Hz, Csp2), 196.22 (d,
The authors thank the National Natural Science Foundation of
China (NSFC) (grant number 21072179), the Scientific Research
Foundation for the Returned Overseas Chinese, Zhengzhou Uni-
versity, and Nanyang Technological University in Singapore for fi-
JCP = 7.1 Hz, cis-CO), 199.38 (d, JCP = 20.8 Hz, trans-CO) ppm.
MS (ESI): m/z = 568.9 ([M + Na – 2CO]+). C24H19O5PW (602.23):
calcd. C 47.87, H 3.18; found C 48.33, H 3.20.
nancial support of this work.
Nitrileimine Adduct 8: To a well-stirred solution of 4 (379 mg,
0.5 mmol), PBu3 (122 mg, 0.6 mmol) was added quickly and the
[1] P. de Koe, R. van Veen, F. Bickelhaupt, Angew. Chem. Int. Ed.
Engl. 1968, 7, 465.
[2] F. Nief, C. Charrier, F. Mathey, M. Simalty, Tetrahedron Lett.
solution was stirred for 3 h at room temperature. After the disap-
pearance of 4 (monitored by 31P NMR), N-phenylbenzohydraz-
1980, 21, 1441.
onoyl chloride[11] (126 mg, 0.55 mmol) was added and then a solu-
[3] Some chemistry has been described with the dithieno ana-
tion of Et3N (61 mg, 0.6 mmol) in CH2Cl2 (2 mL) was added drop-
wise to the mixture. The solution was stirred for another 2 h. After
removal of the solvent, the residue was chromatographed on silica
gel with petroleum ether/CH2Cl2 (3:1) as eluent to give 8 (light-
logues: N. H. Tran Huy, B. Donnadieu, F. Mathey, Organome-
tallics 2008, 27, 4005; correction: Organometallics 2008, 27,
4544.
[4] Review: S. Shah, J. D. Protasiewicz, Coord. Chem. Rev. 2000,
210, 181. Key publications: A. Marinetti, F. Mathey, Angew.
Chem. Int. Ed. Engl. 1988, 27, 1382; P. Le Floch, A. Marinetti,
L. Ricard, F. Mathey, J. Am. Chem. Soc. 1990, 112, 2407; S.
Shah, J. D. Protasiewicz, Chem. Commun. 1998, 1585.
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1983, 48, 5273.
[6] A. Marinetti, F. Mathey, J. Fischer, A. Mitschler, J. Chem. Soc.,
Chem. Commun. 1982, 667; A. Marinetti, F. Mathey, Organo-
metallics 1982, 1, 1488.
yellow crystals, 223 mg, yield 63%). 31P NMR (CDCl3): δ = 0.9
2
(1JPW = 247.2 Hz) ppm. 1H NMR (CDCl3): δ = 5.04 (d, JHP
=
6.9 Hz, 1 H, CH), 6.91–7.00 (m, 2 H), 7.01–7.05 (m, 1 H), 7.11–
7.16 (m, 2 H), 7.23–7.31 (m, 3 H), 7.33–7.53 (m, 6 H), 7.74–7.76
(d, 1 H), 7.79–7.83 (m, 1 H), 8.16–8.19 (d, 2 H) ppm. 13C NMR
(CDCl3): δ = 75.75 (d, JCP = 36.2 Hz, CH), 122.12 (s, 2Csp2), 125.09
(d, JCP = 5.2 Hz, Csp2), 125.28 (s, Csp2), 126.21 (d, JCP = 2.3 Hz,
Csp2), 127.06 (d, JCP = 30.1 Hz, Csp2), 127.85 (d, JCP = 4.6 Hz,
2Csp2), 127.92 (s, Csp2), 128.53 (s, Csp2), 128.70 (s, 2Csp2), 128.93 (s,
2Csp2), 129.14 (d, JCP = 5.0 Hz, Csp2), 129.17 (d, JCP = 4.6 Hz, Csp2),
[7] For reviews on the chemistry of phosphanylidenes, see: F. Ma-
they, N. H. Tran Huy, A. Marinetti, Helv. Chim. Acta 2001, 84,
2938; K. Lammertsma, M. J. M. Vlaar, Eur. J. Org. Chem.
2002, 1127.
129.81 (d, JCP = 11.8 Hz, Csp2), 130.83 (s, Csp2), 130.97 (d, JCP
1.4 Hz, Csp2), 133.52 (d, JCP = 19.6 Hz, Csp2), 134.48 (d, JCP
7.7 Hz, Csp2), 134.84 (d, JCP = 7.2 Hz, Csp2), 136.83 (d, JCP
2.2 Hz, Csp2), 141.91 (d, JCP = 6.5 Hz, Csp2), 145.54 (d, JCP
3.3 Hz, Csp2), 195.50 (d, JCP = 6.7 Hz, cis-CO), 197.67 (d, JCP
=
=
=
=
=
[8] A. Marinetti, P. Le Floch, F. Mathey, Organometallics 1991,
10, 1190.
[9] A. Breque, F. Mathey, P. Savignac, Synthesis 1981, 983.
[10] S. Holand, F. Mathey, Organometallics 1988, 7, 1796.
[11] P. S. Mukund, M. S. Levi, S. Takahiro, Adv. Synth. Catal. 2006,
348, 2371.
25.2 Hz, trans-CO) ppm. MS (ESI): m/z (%) = 737.0 ([M + Na]+).
CCDC-821260 (for 6), -821259 (for 7), and -821258 (for 8) contain
Received: May 3, 2011
the supplementary crystallographic data for this paper. These data
Published Online: September 2, 2011
Eur. J. Inorg. Chem. 2011, 4585–4589
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4589