Investigations of the synthesis of 1,2-diphosphinines

Article abstract of DOI:10.1021/om010682e

Several 1,2-disubstituted 3,6-bis(trimethylsilyl)-1,2-dihydro-1,2-diphosphinine complexes were prepared in a series of reactions starting from the palladium-catalyzed head-to-head dimerization of a 1-(2-ethoxycarbonylethyl)-2-trimethylsilylphosphirene W(CO)₅-complex. The P-CH₂CH₂CO₂Et bonds were cleaved by ^tBuOK in THF to give the corresponding P-anions. The most significant products were the PCl-P(CH₂CH₂CO₂Et) (4), PH-P(OH) (5), and PH-P(CH₂Ph) (8) complexes. The thermolysis of the P(CH₂Ph)-P(CH₂Ph) complex (9) led to the corresponding phosphole complex 11 by extrusion of one phosphorus unit. Apparently, the postulated aromatic 1,2-diphosphinines are able to evolve toward other products via low-energy pathways.

Full text of DOI:10.1021/om010682e

336
Organometallics 2002, 21, 336-339
In vestiga tion s of th e Syn th esis of 1,2-Dip h osp h in in es
Ngoc Hoa Tran Huy,* He´le`ne Vong, and Franc¸ois Mathey*
Laboratoire “He´te´roe´le´ments et Coordination”, UMR CNRS 7653, DCPH, Ecole Polytechnique,
91128 Palaiseau Cedex, France
Received J uly 31, 2001
Several 1,2-disubstituted 3,6-bis(trimethylsilyl)-1,2-dihydro-1,2-diphosphinine complexes
were prepared in a series of reactions starting from the palladium-catalyzed head-to-head
dimerization of a 1-(2-ethoxycarbonylethyl)-2-trimethylsilylphosphirene W(CO)5-complex. The
P-CH2CH2CO2Et bonds were cleaved by tBuOK in THF to give the corresponding P-anions.
The most significant products were the PCl-P(CH2CH2CO2Et) (4), PH-P(OH) (5), and PH-
P(CH2Ph) (8) complexes. The thermolysis of the P(CH2Ph)-P(CH2Ph) complex (9) led to the
corresponding phosphole complex 11 by extrusion of one phosphorus unit. Apparently, the
postulated aromatic 1,2-diphosphinines are able to evolve toward other products via low-
energy pathways.
In tr od u ction
described by our group.6 This observation gave us an
ideal starting point for our synthetic work. A phos-
phirene with a good leaving group at phosphorus (1) was
first synthesized as shown in Scheme 1. Phosphirene 1
was then dimerized in the presence of a palladium(0)
catalyst using our previous protocol. The 1,2-dihydro-
1,2-diphosphinine was mainly obtained as a bis-complex
(2), the mono-complex appearing only as a minor
byproduct (20% yield, 31P NMR δ -34.2 (P-W) and
Two recent theoretical studies have pointed out that
the presently unknown 1,2-diphosphinines (A) display
an aromatic stabilization energy of the same order of
magnitude as their known 1,3- (B) and 1,4-isomers
(C).1,2 In fact, both studies predict that the 1,2-isomer
is ca. 5-10 kcal mol-1 lower in energy than the
corresponding 1,3- and 1,4-species. Nonetheless, 1,2-
diphosphinines remain conspicuous by their absence
from the literature,3 and the authors of the first
theoretical study have suggested that inappropriate
synthetic procedures could be responsible for that
situation.1 In this report, we wish to present our own
attempts aimed at the synthesis of a 1,2-diphosphinine.
Since complexation by pentacarbonyltungsten is known
to increase the kinetic stability of PdP double bonds,4
we decided to work in the coordination sphere of
tungsten and to base our approach on the versatile
chemistry of electrophilic terminal phosphinidene com-
plexes [RP-W(CO)5].5
1
-88.6, J (P-P) ) 227 Hz) contrary to our earlier experi-
ments. We assume that the stereochemistry of the P2
unit of 2 is cis, as in our previous work, but this point
t
has not been confirmed. Treating 2 with 1 equiv of -
BuOK in THF induces a clean dealkylation to the
monoanion 3.7 The transformation was conveniently
followed by 31P NMR, where the resonance of 2 at ca. 3
ppm is quantitatively replaced by an AX system: δA
1
1
-30.4, J (P-P) ) 320 Hz, J (P-W) ) 227.4 Hz (P-CH2);
δX -116.6, J (P-W) ) 78.4 Hz (P-). The small direct
1
coupling between P- and tungsten confirms the pres-
ence of the negative charge.8 The next step of our
program involved the transformation of the P-anion 3
into the corresponding chlorophosphine. A preliminary
attempt with S2Cl2 gave poor yields of the corresponding
P-Cl compound 4. A report by Kovar, Rausch, and
Rosenberg9 on the transformation of 1,1′-dilithio- into
1,1′-dibromoferrocene by reaction with tosyl bromide led
us to investigate the reaction of 3 with tosyl chloride. A
clean transformation into 4 was observed in 77%
isolated yield. The most significant spectroscopic char-
acteristics for 4 are the 31P NMR data [δ (P-CH2) 22.2,
Resu lts a n d Discu ssion
A head-to-head dimerization of phosphirenes leading
to 1,2-dihydro-1,2-diphosphinines has been recently
(1) Colombet, L.; Volatron, F.; Maˆıtre, P.; Hiberty, P. C. J . Am.
Chem. Soc. 1999, 121, 4215.
(2) Priyakumar, U. D.; Sastry, G. N. J . Am. Chem. Soc. 2000, 122,
11173.
(3) As far as we know, the unsuccessful synthesis of a diphos-
phaphenanthrene is the only described attempt to prepare a 1,2-
diphosphaarene: van den Winkel, Y.; van der Laarse, J .; de Kanter,
F. J . J .; van der Does, T.; Bickelhaupt, F.; Smeets, W. J . J .; Spek, A.
L. Heteroat. Chem. 1991, 2, 17.
1
1J (P-W) ) 237 Hz, J (P-P) ) 173 Hz; δ (P-Cl) 107.1,
1J (P-W) ) 262 Hz] and the mass spectrum [(35Cl, 184W)
(6) Tran Huy, N. H.; Ricard, L.; Mathey, F. Chem. Commun. 2000,
1137.
(4) See, for example, the stabilization of dichlorodiphosphene Cl2P2:
Vogel, U.; Sto¨sser, G.; Scheer, M. Angew. Chem., Int. Ed. 2001, 40,
1443.
(5) Reviews: Mathey, F. Angew. Chem., Int. Ed. Engl. 1987, 27, 275.
Mathey, F. In Multiple Bonds and Low Coordination in Phosphorus
Chemistry; Regitz, M., Scherer, O. J ., Eds.; Thieme: Stuttgart, 1990;
p 38. Dillon, K. B.; Mathey, F.; Nixon, J . F. In Phosphorus: The Carbon
Copy; Wiley: Chichester, 1998; p 19.
(7) Base-catalyzed addition of secondary phosphines to activated
CdC double bonds is a classical reaction. The reverse reaction can be
observed whenever the resulting P-anion is somewhat stabilized, see
for example ref 11.
1
(8) For example: J (P-W) ) 68 Hz for [H2LiP-W(CO)5]: Nief, F.;
Mercier, F.; Mathey, F. J . Organomet. Chem. 1987, 328, 349.
(9) Kovar, R. F.; Rausch, M. D.; Rosenberg, H. Organomet. Chem.
Synth. 1970/1971, 1, 173.
10.1021/om010682e CCC: $22.00 © 2002 American Chemical Society
Publication on Web 12/20/2001

Synthesis of 1,2-Diphosphinines
Organometallics, Vol. 21, No. 2, 2002 337
Sch em e 1
Sch em e 2
m/z 903 (M - 5CO, 6%), 819 (M - 8CO, 9%), 763 (M -
10CO, 9%), 578 (M - 10CO - W, 65%), 543 (M - 10CO
- W - Cl, 100%)]. Complex 4 was then subjected to
protonation, it gives complex 8, which has a character-
istic 31P NMR spectrum: δ (P-H) -45.3, 1J (P-P) ) 121.8
Hz, 1J (P-H) ) 341.3 Hz; δ (PCH2Ph) -15.1 (CDCl3). The
mass spectrum of 8 (EI) shows a base peak at m/z 527,
which may correspond to the η6-1,2-diphosphinine-
W(CO)3 complex. However, the thermolysis of 8 under
vacuum at 170-200 °C gave disappointing results. After
45 min, a complex mixture of products was obtained.
The most interesting product of this mixture displays
a AX 31P spectrum: δA -56, δX + 295, J (AX) ) 51 Hz.
Apparently, this reactive molecule contains one dicoor-
dinate and one tricoordinate phosphorus atom and no
P-P bond. This suggests that the reaction pathway does
not involve the anticipated aromatization with loss of
toluene, but a 6π-cycloreversion creating two sp2-P
centers, followed by a 4π-electrocyclization retransform-
ing one of the sp2-centers into an sp3-phosphorus.10 After
filtration through Florisil in hexane, this species disap-
peared. The 31P NMR spectrum of the filtrate shows
singlets at +147.8, +120.8, and -86.7, plus a new AX
system: δA -81, δX -127, 1J (AX) ) 146.7 Hz, correspond-
ing to a P-P bonded species. The mass spectrum is very
similar to that of 8, except that the m/z 527 peak almost
disappears.
t
attack by BuOK. The first experiments were done at
-78 °C in THF with 1 equiv of base. We reasoned that
the nucleophilic substitution at the P-Cl bond would
be slow because of the steric hindrance at phosphorus
and that proton abstraction from the CH2CO2Et group
would be preferred. This is not the case. The initial
product of the reaction shows the following 31P NMR
1
characteristics: AX system, δA + 54, δB -3, J (P-P)
)
134 Hz. These data are not consistent with the forma-
tion of the expected P(Cl)-P- anion, but more in line
with a nucleophilic attack at P-Cl. Thus, we were
obliged to work with 2 equiv of tBuOK. At room
temperature, the reaction cleanly leads to a major
product having the following 31P NMR characteristics:
AX system, δA + 27, δX -129, 1J AX ) 170 Hz. An anionic
species is thus formed. Protonation at low temperature
then yields the PH-P(OH) derivative 5, which was
isolated in 54% yield. The 31P data of 5 are as follows:
1
1
δ (P-H) -32.8, J (P-P) ) 124.9 Hz, J (P-H) ) 344.7 Hz;
δ (P(OH)) 84.7 (THF).
In view of the high strength of the P-O bond, complex
5 represented a dead end. Thus, we were obliged to
change our strategy. Starting again from the anion 3,
we performed its benzylation giving complex 6 in
acceptable yield (Scheme 2).
To get more reliable information on the thermal
evolution of these 1,2-dihydro-1,2-diphosphinine com-
plexes, we transformed the monoanion 7 into the 1,2-
dibenzyl derivative 9. The thermolysis of 9 proved to
be cleaner than that of 8. After 8 min, the monitoring
Complex 6 was then dealkylated as previously. The
formation of the intermediate P(Bn)-P- monoanion (7)
was monitored by 31P NMR: AX system, δA + 19.4
(10) 1-Phosphadiene complexes are known to cyclize readily: Tran
Huy, N. H.; Ricard, L.; Mathey, F. Organometallics 1988, 7, 1791.
1
(P-CH2Ph), δB -102.6 (P-), J (P-P) ) 327 Hz. Upon

338 Organometallics, Vol. 21, No. 2, 2002
Tran Huy et al.
Sch em e 3
of the reaction mixture by 31P NMR showed the com-
sten (2). A solution of complex 1 (2 g, 3 mmol) and [Pd(PPh3)4]
(50 mg) in toluene (20 mL) was heated at 85 °C overnight.
After evaporation, the residue was chromatographed with 1:1
hexane/CH2Cl2 as the eluent. Complex 2 was isolated as yellow
crystals (1.2 g, 70%). 31P NMR (CDCl3): δ 2.6. 1H NMR (CDCl3):
δ 0.35 (s, SiMe3), 1.25 (t, CH3(Et)), 2.45, 2.70 (m, CH2), 4.17
(q, OCH2), 6.74 (pseudo t, ∑J (H-P) ) 30.2 Hz, ring CH). 13C
NMR (CDCl3): δ 1.64 (s, SiMe3), 14.36 (s, CH3(Et)), 26.01-
(pseudo t, ∑J (C-P) ) 34.8 Hz, CH2P), 31.83 (pseudo t, ∑J (C-P)
) 8.9 Hz, CH2CO), 61.76 (s, OCH2), 138.22 (s, C-SiMe3), 142.94
(pseudo t, ∑J (C-P) ) 15.5 Hz, ring CH), 171.05 (pseudo t, ∑J (C-P)
) 19.9 Hz, CO2), 196.60 (m, cis CO). MS: m/z 829 (M+ - 10CO
+ H, 4%), 543 (100%). Anal. Calcd for C30H38O14P2Si2W2: C,
32.51; H, 3.46. Found: C, 32.84; H, 3.62.
[1-Ch lor o-2-(2-eth oxyca r bon yleth yl)-3,6-bis(tr im eth yl-
silyl)-1,2-d ih yd r o-1,2-d ip h osp h in in e ]d e ca ca r b on yld i-
tu n gsten (4). Potassium tert-butoxide (0.1 g, 0.9 mmol) was
added to a solution of complex 2 (1 g, 0.9 mmol) in THF (10
mL) at room temperature. The solution turned deep red, and
the formation of the anion 3 was monitored by 31P NMR. Then
the solution was cooled to -50 °C, and a solution of tosyl
chloride (0.17 g, 0.9 mmol) in THF (3 mL) was added dropwise.
After stirring at room temperature, the solution was concen-
trated and the residue chromatographed with 1:1 hexane/CH2-
Cl2 as the eluent. Complex 4 was thus isolated (0.72 g, 77%).
31P NMR (CDCl3): δ 22.2 and 107.1, 1J (P-P) ) 172 Hz. 1H NMR
plete transformation of 9 into the monocomplex 10: δ
1
1
(P-W) -21.8, J (P-W) ) 230 Hz, J (P-P) ) 282.7 Hz; δ
(P-Bn) -79.0. Further heating led to a single compound
with a 31P resonance at +46.0 (CDCl3). A detailed
analysis demonstrated that this compound was the
phosphole complex 11. Both the 1H and 13C NMR
spectra demonstrate that the molecule is symmetrical,
and the mass spectrum indicates that one (Bn-P-
W(CO)5) unit has been lost. The reactions are depicted
in Scheme 3. It is tempting to propose as a first step of
this ring contraction a 6π-electrocyclic ring-opening
followed by a loss of benzylphosphinidene and a recy-
clization.
What can we conclude from this series of experiments
concerning the stability of 1,2-diphosphinines? It must
be stressed that we have used bulky [3,6-(Me3Si)2]
substitution and P-W(CO)5 complexation, which are
both known to provide kinetic stability to the PdP
double bond. Besides, the thermolytic approach is
especially adapted to the synthesis of highly reactive
molecules. Thus our negative results cannot be dis-
missed easily. We think that a low-energy pathway
probably allows the aromatic 1,2-diphosphinines to
evolve toward more stable products.
4
4
(CDCl3): δ 0.34 (d, J (H-P) ) 2.4 Hz, SiMe3), 0.38 (d, J (H-P)
)
5.1 Hz, SiMe3), 1.26 (t, CH3(Et)), 2.5-3.2 (m, CH2), 4.18 (q,
OCH2), 6.66 (ABXY, ring CH). 13C NMR (CDCl3): δ 1.15 (s,
Exp er im en ta l Section
1
SiMe3), 1.58 (s, SiMe3), 14.35 (s, CH3(Et)), 25.40 (dd, J (C-P)
)
2
2
23.4 Hz, J (C-P) ) 10.3 Hz, CH2P), 30.35 (d, J (C-P) ) 6.6 Hz,
All reactions were performed under an inert atmosphere
(nitrogen or argon). NMR spectra were measured on a Bruker
300 MHz multinuclear spectrometer. Chemical shifts are
expressed in ppm from internal TMS (1H and 13C) or external
85% H3PO4(31P); coupling constants are expressed in Hz. Mass
spectra (electron impact, unless otherwise noted) were mea-
sured at 70 eV by the direct inlet method. Elemental analyses
were performed at the Service de Microanalyse du CNRS, Gif
sur Yvette, France.
CH2CO), 61.61 (s, OCH2), 140.35 (s, C-SiMe3), 140.89 (d, 2J (C-P)
2
) 16.5 Hz, ring CH), 142.38 (d, J (C-P) ) 21.3 Hz, ring CH),
143.35 (d, 1J (C-P) ) 10.9 Hz, C-SiMe3), 171.24 (d, 3J (C-P) ) 20.5
Hz, CO2), 195.95 (d, 2J (C-P) ) 6.4 Hz, cis-CO), 196.46 (d, 2J (C-P)
) 6.0 Hz, cis-CO). MS: m/z 903 (M+ - 5CO) 6%), 543 (100%).
[1-H yd r oxy-3,6-b is(t r im e t h ylsilyl)-1,2-d ih yd r o-1,2-
d ip h osp h in in e]d eca ca r bon yld itu n gsten (5). Potassium
tert-butoxide (0.13 g, 1.2 mmol) was added to a solution of
complex 4 (0.63 g, 0.6 mmol) in THF (5 mL) at room temper-
ature. The red solution was then hydrolyzed with 3 N HCl at
-50 °C. After evaporation of the solvent, the product was
chromatographed with 1:1 hexane/CH2Cl2 as the eluent.
Complex 5 was isolated as a white powder (0.3 g, 54%). 31P
[1-(2-E t h oxyca r b on ylet h yl)-2-t r im et h ylsilylp h osp h i-
r en e]p en ta ca r bon yltu n gsten (1). A solution of the 7-phos-
phanorbornadiene precursor11 (5 g, 7.4 mmol) and an excess
of trimethylsilylacetylene (ca. 2.5 mL) in toluene (25 mL) was
refluxed at 110 °C for 20 h. After evaporation of the solvent,
the residue was chromatographed on silica gel with 5:3 hexane/
CH2Cl2 as the eluent. Phosphirene 1 was isolated as an oil
1
1
NMR (THF): δ -32.7, J (P-P) ) 124.9 Hz, J (P-H) ) 344.8 Hz,
(PH), 84.7 (P-OH). 1H NMR (CDCl3): δ -0.25 (s, SiMe3), 0.20
1
2
(s, SiMe3), 4.3 (br, OH), 5.53 (dd, J (H-P) ) 343.5 Hz, J (H-P)
)
1
(2.5 g, 62%). 31P NMR (1:1 CH2Cl2/hexane): δ -175.3, J (P-W)
19.7 Hz, PH), 6.5 and 6.8 (2m, CH ring). 13C NMR (CDCl3): δ
-0.66 (s, SiMe3), 0.66 (s, SiMe3), 133.38 (s, C-SiMe3), 140.84
(d, 2J (C-P) ) 16.5 Hz, ring CH), 142.86 (m, C-SiMe3 + ring CH),
) 272 Hz. 1H NMR (CDCl3): δ 0.29 (s, SiMe3), 1.22 (t, CH3-
(Et)), 1.88 (ABX, 1H, CH2), 2.10 (ABX, 1H, CH2), 4.10 (q,
2
OCH2), 8.82 (d, J (H-P) ) 25.2 Hz, ring H). 13C NMR (CDCl3):
2
2
195.96 (d, J (C-P) ) 6.3 Hz, cis-CO), 196.31 (d, J (C-P) ) 6.5
Hz, cis-CO), MS: m/z 927 (M+ + 3H, 18%), 700 (M+ - 8CO,
73%), 459 (100%). Anal. Calcd for C20H22O11P2Si2W2: C, 25.99;
H, 2.40. Found: C, 25.24; H, 2.54.
δ -1.36 (s, SiMe3), 14.38 (s, CH3(Et)), 30.31 (d, J (C-P) ) 2.5
1
Hz, CH2), 32.61 (d, J (C-P) ) 3.3 Hz, CH2), 141.71 (d, J (C-P)
)
16.8 Hz, ring CH), 144.68 (d, 1J (C-P) ) 37.0 Hz, ring C), 171.85
3
2
(d, J (C-P) ) 9.9 Hz, CO2), 196.40 (d, J (C-P) ) 8.2 Hz, cis-CO),
198.50 (d, J (C-P) ) 30.6 Hz, trans-CO). MS (184W): m/z 554
2
[1-Ben zyl-2-(2-eth oxyca r bon yleth yl)-3,6-bis(tr im eth yl-
silyl)-1,2-d ih yd r o-1,2-d ip h osp h in in e ]d e ca ca r b on yld i-
tu n gsten (6). Anion 3 was formed as indicated in the
synthesis of 4. An excess of PhCH2Br was added at -20 °C,
and the solution was stirred at room temperature for 1 h. The
product was purified by chromatography with 1:1 hexane/CH2-
Cl2 as the eluent. Complex 6 was isolated as a yellow powder
(M+, 11%), 526 (M+ - 2CO, 27%), 414 (M+ - 5CO, 100%). Anal.
Calcd for C15H19O7PsiW: C, 32.51; H, 3.46. Found: C, 32.85;
H, 3.51.
[1,2-Bis(2-e t h oxyca r b on yle t h yl)-3,6-b is(t r im e t h yl-
silyl)-1,2-dih ydr o-1,2-diph osph in in e]decacar bon ylditu n g-
1
(0.4 g, 46%). 31P NMR (CDCl3): δ 3.7 and 12.1, J (P-P) ) 152
(11) Espinosa-Ferao, A.; Deschamps, B.; Mathey, F. Bull. Soc. Chim.
Fr. 1993, 130, 695.
1
Hz. H NMR (CDCl3): δ 0.33 (s, SiMe3), 0.42 (s, SiMe3), 1.19

Synthesis of 1,2-Diphosphinines
Organometallics, Vol. 21, No. 2, 2002 339
(t, CH3(Et)), 1.8-2.6 (m, CH2CH2),), 3.6-4.15 (m, CH2Ph +
OCH2), 6.73 (m, ring CH), 7.33 (m, Ph). 13C NMR (CDCl3): δ
1.54 and 1.59 (2s, SiMe3), 14.08 (s, CH3(Et)), 24.93 (dd, J (C-P)
) 23.3 and 10.3 Hz, CH2P), 31.73 (s, CH2CO), 36.09 (m, CH2-
Ph), 61.06 (s, OCH2), 128.51(s)-129.36(s)-130.83(d)-133.00-
(s) (Ph), 137.82 (s, CSiMe3), 140.20 (s, CSiMe3), 142.30 (d,
Th er m olysis of Com p lex 9. The preparation of complex
9 from anion 7 was similar to that of complex 6 from anion 3.
Complex 9: 31P NMR (CDCl3): δ 20.6. 1H NMR (CDCl3): δ 0.41
(s, SiMe3), 3.81 (m, CH2Ph), 6.80 (pseudo t, ∑J (H-P) ) 28.6 Hz,
ring CH), 7.16 (m, Ph ortho), 7.26 (m, Ph). 13C NMR (CDCl3):
δ 0.0 (s, SiMe3), 34.09 (m, CH2Ph), 137.61 (s, CSiMe3), 141.02
(pseudo t, ∑J (C-P) ) 14.6 Hz, ring CH), 195.08 (m, cis-CO). MS:
m/z 1007 (M+ - 3 CO + H, 2.3%), 810 (M+ - 10 CO, 4.4%),
534 (M+ - 10 CO - W - PhCH3 , 67%), 91 (PhCH2, 100%).
Anal. Calcd for C34H34O10P2Si2W2: C, 37.52; H, 3.15. Found:
C, 37.46; H, 3.19.
2
2J (C-P) ) 18.4 Hz, ring CH), 142.87 (d, J (C-P) )18.6 Hz, ring
2
2
CH), 196.66 (d, J (C-P) ) 5.9 Hz, cis-CO), 196.86 (d, J (C-P)
)
5.8 Hz, cis-CO). Anal. Calcd for C32H36O12PSi2W2: C, 34.99; H,
3.30. Found: C, 34.91; H, 3.25.
[1-Ben zyl-3,6-bis(tr im eth ylsilyl)-1,2-dih ydr o-1,2-diph os-
p h in in e]d eca ca r bon yld itu n gsten (8). Potassium tert-bu-
toxide (90 mg, 0.8 mmol) was added to a solution of complex
6 (0.4 g, 0.4 mmol) in THF (5 mL). The solution turned deep
red. After a few minutes, the solution was hydrolyzed by 3 N
HCl at -50 °C. The product was purified by chromatography
with 2:1 hexane/CH2Cl2 as the eluent. Complex 8 was isolated
as a yellow powder (0.25 g, 63%). 31P NMR (CDCl3): δ -45.3,
[1-Ben zyl-2,5-bis(tr im eth ylsilyl)ph osph ole]pen tacar bon -
yltu n gsten (11). Complex 9 was thermolyzed in a Kugelrohr
apparatus under 10-2 Torr at 180-200 °C. The resulting
product was purified by chromatography with 4:1 hexane/CH2-
1
Cl2. 31P NMR (CDCl3): δ 46.0, J (P-W) ) 206 Hz. 1H NMR
2
(CDCl3): δ 0.23 (s, SiMe3), 3.64 (d, J (H-P) ) 5.1 Hz, CH2Ph),
1
1
1J (P-P) ) 122 Hz, J (P-H) ) 341 Hz (PH); -15.1 (PCH2Ph). H
NMR (CDCl3): δ 0.34 (s, SiMe3), 0.42 (s, SiMe3), 3.50 (m, 1H,
CH2Ph), 4.26 (m, 1H, CH2Ph), 5.52 (dd, 1J (H-P) ) 341 Hz, 2J (H-P)
) 17.5 Hz, PH), 6.86 (m, 2H, ring CH). 13C NMR (CDCl3): δ
-0.47 (s, SiMe3), 1.27 (s, SiMe3), 36.47 (dd, J (C-P) ) 18.6 and
7.9 Hz, CH2Ph), 128.24(s)-129.47(s)-130.21(d)-132.97(s) (Ph),
133.97 (s, CSiMe3), 135.40(s, CSiMe3), 142.17 (d, 2J (C-P) ) 21.2
6.85 (m, 2H, Ph), 7.08 (d, 3J (H-P) ) 35.5 Hz, ring CH), 7.15 (m,
3H, Ph). 13C NMR (CDCl3): δ -0.36 (s, SiMe3), 36.73 (d, 1J (C-P)
) 21 Hz, CH2Ph), 126.79(d)-127.56(d)-128.04(d) (CH(Ph)),
135.55 (d, 2J (C-P) ) 9.5 Hz, ipso C(Ph), 147.44 (d, 2J (C-P) ) 10.7
2
Hz, Câ), 155.71 (s, CR), 196.84 (d, J (C-P) ) 6.1 Hz, cis-CO),
2
197.58 (d, J (C-P) ) 18 Hz, trans-CO). MS: m/z 644 (M+ + 2H,
2
Hz, ring CH), 143.61 (d, J (C-P) ) 23.3 Hz, ring CH), 195.90
22%), 438 (100%). Anal. Calcd for C22H27O5PSi2W: C, 41.13;
H, 4.24. Found: C, 41.03; H, 4.25.
2
2
(d, J (C-P) ) 5.8 Hz, cis-CO), 196.13 (d, J (C-P) ) 6.3 Hz, cis-
CO). MS: m/z 1000 (M+ + 2H, 13%), 527 (100%). Anal. Calcd
for C27H28O10P2Si2W2: C, 32.48; H, 2.83. Found: C, 32.68; H,
2.83.
OM010682E