C-P and C-H Bond Activations and C-C Coupling in Bis-Phosphonium Salts Induced by Platinum(II) Complexes

Article abstract of DOI:10.1021/om0305465

The reaction of [Ph₃PCH₂-(E)-C(Me)=C(H)PPh ₃]Cl₂ (1b) with PtCl₂(NCPh)₂ (1:1 molar ratio) in refluxing 2-methoxyethanol gives the ortho-metalated complex [Pt(C₆H₃-3-Ph-2-PPh₂-C=C(Me)CH ₂PPh₂-κC,C,P)Cl] (3). The synthesis of complex 3 formally involves three C-H and one C-P bond activation and one C-C bond coupling. Complex 3 reacts with excess KBr or NaI to give, after halide metathesis, the complexes [Pt(C₆H₃-3-Ph-2-PPh ₂-C=C(Me)CH₂PPh₂-κC,C,P)X] (X = Br (4), I (5)). Complex 5 has been characterized by X-ray diffraction methods. The influences of several factors, such as the solvent, the platinum starting complex, and the bis-phosphonium salt, in the synthesis of 3 have been examined, and a plausible reaction mechanism for the synthesis of 3 is proposed. This mechanism is supported by the isolation of the Pt(IV) derivative [Pt(C ₆H₄-4-F){C₆H₃-5-F-2-P(p-FC ₆H₄)₂-C=C(Me)CH₂P(p-FC ₆H₄)₂-κC,C,P}Cl₂] (6), obtained by reaction of [(p-FC₆H₄)₃PCH ₂-(E)-C(Me)=C(H)P(p-FC₆H₄)₃]Cl ₂ (1f) with PtCl₂(NCPh)₂ in refluxing 2-methoxyethanol. Complex 3 reacts with AgClO₄ and neutral monodentate (L) and bidentate (L-L) ligands, giving the cationic derivatives [Pt(C₆H₃-3-Ph-2-PPh₂-C=C(Me)CH ₂PPh₂-κC,C,P)(L)](ClO₄) (L = NCMe (8), PPh₃ (9), pyridine (10), C≡N^tBu (11)) and [Pt(C ₆H₃-3-Ph-2-PPh₂-C=C(Me)CH₂PPh ₂-κC,C,P)(L-L-κP)](ClO₄) (L-L = Ph ₂PCH₂PPh₂ (12)). Complex 3 reacts with excess X₂ (Cl₂, I₂) to give the expected Pt(IV) derivatives [Pt(C₆H₃-3-Ph-2-PPh₂-C=C(Me)CH ₂PPh₂-κC,C,P)-(Cl)(X)₂] ((X)₂ = (Cl)₂ (13), (I)₂ (14)) through a typical oxidative addition process. Complex 14 has also been characterized by X-ray diffraction methods.

Full text of DOI:10.1021/om0305465

4910
Organometallics 2003, 22, 4910-4921
C-P a n d C-H Bon d Activa tion s a n d C-C Cou p lin g in
Bis-P h osp h on iu m Sa lts In d u ced by P la tin u m (II)
Com p lexes
Cecilia Gracia,† Gema Marco,† Rafael Navarro,*,† Pilar Romero,‡
Tatiana Soler,† and Esteban P. Urriolabeitia*,†,§
Departamento de Quı´mica Inorga´nica and Servicio de Resonancia Magne´tica Nuclear,
Instituto de Ciencia de Materiales de Arago´n, Universidad de Zaragoza-CSIC,
E-50009 Zaragoza, Spain
Received J uly 26, 2003
The reaction of [Ph3PCH2-(E)-C(Me)dC(H)PPh3]Cl2 (1b) with PtCl2(NCPh)2 (1:1 molar
ratio) in refluxing 2-methoxyethanol gives the ortho-metalated complex [Pt(C6H3-3-Ph-2-
PPh2-CdC(Me)CH2PPh2-κC,C,P)Cl] (3). The synthesis of complex 3 formally involves three
C-H and one C-P bond activation and one C-C bond coupling. Complex 3 reacts with
excess KBr or NaI to give, after halide metathesis, the complexes [Pt(C6H3-3-Ph-2-PPh2-
CdC(Me)CH2PPh2-κC,C,P)X] (X ) Br (4), I (5)). Complex 5 has been characterized by X-ray
diffraction methods. The influences of several factors, such as the solvent, the platinum
starting complex, and the bis-phosphonium salt, in the synthesis of 3 have been examined,
and a plausible reaction mechanism for the synthesis of 3 is proposed. This mechanism is
supported by the isolation of the Pt(IV) derivative [Pt(C6H4-4-F){C6H3-5-F-2-P(p-FC6H4)2-
CdC(Me)CH2P(p-FC6H4)2-κC,C,P}Cl2] (6), obtained by reaction of [(p-FC6H4)3PCH2-(E)-
C(Me)dC(H)P(p-FC6H4)3]Cl2 (1f) with PtCl2(NCPh)2 in refluxing 2-methoxyethanol. Complex
3 reacts with AgClO4 and neutral monodentate (L) and bidentate (L-L) ligands, giving the
cationic derivatives [Pt(C6H3-3-Ph-2-PPh2-CdC(Me)CH2PPh2-κC,C,P)(L)](ClO4) (L ) NCMe
(8), PPh3 (9), pyridine (10), CtNtBu (11)) and [Pt(C6H3-3-Ph-2-PPh2-CdC(Me)CH2PPh2-
κC,C,P)(L-L-κP)](ClO4) (L-L ) Ph2PCH2PPh2 (12)). Complex 3 reacts with excess X2 (Cl2,
I2) to give the expected Pt(IV) derivatives [Pt(C6H3-3-Ph-2-PPh2-CdC(Me)CH2PPh2-κC,C,P)-
(Cl)(X)2] ((X)2 ) (Cl)2 (13), (I)2 (14)) through a typical oxidative addition process. Complex
14 has also been characterized by X-ray diffraction methods.
In tr od u ction
(R ) Et, Ph; X ) Cl, ClO4) react with PtCl2(NCPh)2,
giving ortho-metalated derivatives containing the C,C-
chelating ligand [C6H4-2-PR2C(H)C(O)CH2PR2Ph]9,10
(see Figure 1A), while the allyl-phosphonium salts
[PhR2PCH2C(R′)dC(H)R′′](X) (R ) Me, Ph; R′ ) H, Me;
R′′ ) H, Me, Ph; X ) Cl, ClO4) gave cycloplatinated
The topic of C-H bond activation reactions promoted
by Pt(II) complexes, as a key step in the functionaliza-
tion of small molecules,1 has undergone a continuous
and impressive growth, due to its important implica-
tions. Representative examples are alkane1,2 and arene3
functionalization, the study of thermodynamic prop-
erties,3i,4 the synthesis of complexes with interesting
optical properties (e.g. luminiscence)5 or structures,6 and
the preparation of chiral auxiliaries,2d,3d,l,7 their involve-
ment in C-C bond coupling reactions,3b,m,n,8 or their
critical role in catalytic cycles.3c,m,4a
(3) (a) Zucca, A.; Doppin, A.; Cinellu, M. A.; Stoccoro, S.; Minghetti,
G.; Manassero, M. Organometallics 2002, 21, 783. (b) Konze, W. V.;
Scott, B. L.; Kubas, G. J . J . Am. Chem. Soc. 2002, 124, 12550. (c)
Fossey, J . S.; Richards, C. J . Organometallics 2002, 21, 5259. (d)
Minghetti, G.; Doppiu, A.; Stoccoro, S.; Zucca, A.; Cinellu, M. A.;
Manassero, M.; Sansoni, M. Eur. J . Inorg. Chem. 2002, 431. (e) Zhong,
H. A.; Labinger, J . A.; Bercaw, J . E. J . Am. Chem. Soc. 2002, 124,
1378. (f) Ryabov, A. D.; Otto, S.; Samuleev, P. V.; Polyakov, V. A.;
Alexandrova, L.; Kazankov, G. M.; Shova, S.; Revenco, M.; Lipkowski,
J .; J ohansson, M. H. Inorg. Chem. 2002, 41, 4286. (g) Harkins, S. B.;
Peters, J . C. Organometallics 2002, 21, 1753. (h) Slater, J . W.; Lydon,
D. P.; Alcock, N. W.; Rourke, J . P. Organometallics 2001, 20, 4418. (i)
Reinartz, S.; White, P. S.; Brookhart, M.; Templeton, J . L. J . Am. Chem.
Soc. 2001, 123, 12724. (j) Thomas, J . C.; Peters, J . C. J . Am. Chem.
Soc. 2001, 123, 5100. (k) Doppin, A.; Minghetti, G.; Cinellu, M. A.;
Stoccoro, S.; Zucca, A.; Manassero, M. Organometallics 2001, 20, 1148.
(l) Riera, X.; Lo´pez, C.; Caubet, A.; Moreno, V.; Solans, X.; Font-Bardia,
M. Eur. J . Inorg. Chem. 2001, 2135. (m) Albrecht, M.; van Koten, G.
Angew. Chem., Int. Ed. 2001, 40, 3750. (n) Albrecht, M.; Spek, A. L.;
van Koten, G. J . Am. Chem. Soc. 2001, 123, 7233. (o) Meijer, M. D.;
Kleij, A. W.; Lutz, M.; Spek, A. L.; van Koten, G. J . Organomet. Chem.
2001, 640, 166.
We recently reported the cycloplatination of several
types of bis-phosphonium salts.9,10 The carbonyl bis-
phosphonium salts [R2PhPCH2C(O)CH2PPhR2](X)2
† Departamento de Qu´ımica Inorga´nica.
‡ Servicio de Resonancia Magne´tica Nuclear.
§ E-mail: esteban@posta.unizar.es.
(1) (a) Crabtree, R. H. J . Chem. Soc., Dalton Trans. 2001, 2437. (b)
J ia, C.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633.
(2) (a) Baratta, W.; Stoccoro, S.; Doppin, A.; Herdtweck, E.; Zucca,
A.; Rigo, P. Angew. Chem., Int. Ed. 2003, 42, 105. (b) Zucca, A.;
Stoccoro, S.; Cinellu, M. A.; Minghetti, G.; Manassero, M.; Sansoni,
M. Eur. J . Inorg. Chem. 2002, 3336. (c) Vedernikov, A. N.; Caulton,
K. G. Angew. Chem., Int. Ed. 2002, 41, 4102. (d) Ryabov, A. D.;
Panyashkina, I. M.; Polyakov, V. A.; Fischer, A. Organometallics 2002,
21, 1633. (e) Wong-Foy, A. G.; Henling, L. M.; Day, M.; Labinger, J .
A.; Bercaw, J . E. J . Mol. Catal. A 2002, 189, 3.
(4) (a) Kua, J .; Xu, X.; Periana, R. A.; Goddard, W. A., III.
Organometallics 2002, 21, 511. (b) Procelewska, J .; Zahl, A.; van Eldik,
R.; Zhong, H. A.; Labinger, J . A.; Bercaw, J . E. Inorg. Chem. 2002, 41,
2808.
10.1021/om0305465 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 10/23/2003

Bond Activation and Coupling Induced by Pt(II) Complexes
Organometallics, Vol. 22, No. 24, 2003 4911
attempted the synthesis of allyl bis-phosphonium salts
through quaternization of a given phosphine by its
reaction with the appropiate amount of 3-chloro-2-
(chloromethyl)propene.
The reaction of H2CdC(CH2Cl)2 with an excess of
PPhMe2 (1:5 molar ratio, refluxing N,N-dimethylaceta-
mide (DMA)) gives the expected salt 1a (see eq 1). The
F igu r e 1.
NMR spectra of 1a show a good agreement with the
symmetrical proposed structure (see the Experimental
Section). However, the reaction of H2CdC(CH2Cl)2 with
an excess of PPh3 (1:3 molar ratio, refluxing DMA) gives
a quite different result, since the allyl-vinyl bis-
phosphonium salt [Ph3PCH2-(E)-C(Me)dC(H)PPh3]Cl2
(1b) (see eq 2) is obtained. The 31P{1H} NMR spectrum
complexes (see Figure 1B) containing the σ,π-vinyl
ligand C6H4-2-PR2C(H)dC(R′)CH2R′′.10
When the reported reactivity is taken into account,
it seems very likely that the presence of functional
groups at the Câ or Cγ atoms of the allyl unit (R′ or R′′)
should give, after cycloplatination, complexes in which
the functional groups still remain incorporated to the
η2-bonded vinylic skeleton. Due to our interest in the
chemistry of ylides as ligands, we have chosen phos-
phonium unitssprecursor of ylidessas functional groups,
since they could be new reactive points in the molecule.
Aiming to obtain new metalated Pt(II) derivatives with
an additional free phosphonium unit (Figure 1C), we
have explored the synthesis of the bis-phosphonium
salts [H2CdC(CH2PPhR2)2](X)2 (R ) Me, Ph; X ) Cl,
Br, ClO4) and their reactivity toward Pt(II) complexes.
In this paper we report the results obtained in this area.
of 1b shows two doublet signals, one at 22.98 ppm
(PCH2) and another at 11.06 ppm (dCP).10 The 1H NMR
spectrum of 1b shows a doublet of doublets at 8.05 ppm
(dCH), a doublet at 5.87 ppm (CH2P), and a triplet at
1.63 ppm (CH3). The E configuration of 1b is inferred
from the 13C{1H} NMR spectrum, since the signal due
to the CH3 carbon appears at 24.67 ppm (dd, 3J PC ) 7.0
Resu lts a n d Discu ssion
3
Hz, J PC ) 0.9 Hz) while the signal due to the CH2
1
3
carbon appears at 35.02 ppm (dd, J PC ) 46.5 Hz, J PC
1. Syn th esis of Bis-P h osp h on iu m Sa lts. Linear
and cyclic phosphonium salts of the type [H2CdC(CH2-
PPh2R)2](X)2 are known,11 and they have been synthe-
sized through quaternization of the two P atoms of
H2CdC(CH2PPh2)2. We have recently reported11e the
synthesis of a related cyclic derivative by reaction of
H2CdC(CH2Cl)2 with Ph2PCH2PPh2 (dppm), a less
complicated (and less expensive) method. We have thus
3
) 19.6 Hz). The value of J PC for the CH2 carbon atom
indicates clearly its trans arrangement with respect to
the vinylic P atom. The comparison of these values with
those reported for [Ph3PC(H)dCMe2]Cl is also in good
agreement with the E configuration.10,12
Several methods have been reported for the synthesis
of vinyl phosphonium salts, including processes cata-
lyzed by Pd, Ti, or Rh complexes12a,b,13 and electrochem-
ical,12c stoichiometric (giving metalated species),14 or
(5) (a) Yam, V. W.-W.; Tang, R. P.-L.; Wong, K. M.-C.; Lu, X.-X.;
Cheung, K.-K.; Zhu, N. Chem. Eur. J . 2002, 8, 4066. (b) Lu, W.; Zhu,
N.; Che, C.-M. Chem. Commun. 2002, 900. (c) Brooks, J .; Babayan,
Y.; Lamansky, S.; Djurovich, P. I.; Tsyba, I.; Bau, R.; Thompson, M.
E. Inorg. Chem. 2002, 41, 3055. (d) Yersin, H.; Donges, D.; Humbs,
W.; Strasser, J .; Sitters, R.; Glasbeek, M. Inorg. Chem. 2002, 41, 4915.
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2001, 20, 4683.
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123, 743.
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P.-H. Organometallics 2001, 20, 2167.
(8) Albe´niz, A. C.; Calle, V.; Espinet, P.; Go´mez, S. Chem. Commun.
2002, 610.
(9) Larraz, C.; Navarro, R.; Urriolabeitia, E. P. New J . Chem. 2000,
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R.; Urriolabeitia, E. P. Organometallics 2001, 20, 1424 and references
therein.
(11) (a) Schmidbaur, H.; Paschalidis, C.; Steigelmann, O.; Mu¨ller,
G. Angew. Chem., Int. Ed. Engl. 1989, 28, 1700. (b) Schmidbaur, H.;
Paschalidis, C.; Steigelmann, O.; Mu¨ller, G. Chem. Ber. 1989, 122,
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S.-L.; Cheng, C.-H. Organometallics 1998, 17, 676. (b) Pd: Duan, J .-
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16, 4572.

4912 Organometallics, Vol. 22, No. 24, 2003
Gracia et al.
base-catalyzed processes.10,15 Despite this, it is worth
noting that the synthesis of 1b can be performed in a
single-step procedure, in the absence of catalysts or
external base, giving a single isomer in quantitative
yield.
ferent positions (Me, H, or PPh3 at Câ; H or PPh3 at Cγ;
F at the para position of the Ph groups). Our purpose
is now the study of the reactivity of these salts toward
Pt(II) complexes, to obtain cycloplatinated derivatives
with an additional phosphonium group.
Due to these facts, we have explored in more detail
this easy synthesis of allyl-vinyl bis-phosphonium salts.
The reaction of 2,3-dibromopropene with PPh3 under the
same experimental conditions as those described for 1b
gives [Ph3PCH2C(PPh3)dCH2]Br2 (1c) (see eq 3 and the
2. Or th o-Meta la tion Rea ction s. The reaction of 1a
with PtCl2(NCPh)2 (1:1 molar ratio) in refluxing 2-meth-
oxyethanol results in the formation of a solid identified
as [H2CdC(CH2PPhMe2)2][PtCl4] (2) (see eq 6). The
PtCl2(NCPh)2
[H CdC(CH PPhMe ) ][PtCl ]
1a MeOCH CH OH, ∆, 24 h8
2
2
2 2
4
2
2
2
(6)
NMR data of 2 (see the Experimental Section) are quite
similar to those described for 1a . For instance, δ(P) in
the 31P{1H} NMR spectrum for 1a is 24.76 ppm and that
of 2 is 26.61 ppm. Moreover, signals corresponding to
the presence of the C6H5 groups in the 1H NMR
spectrum and the persistence of the olefinic and meth-
ylenic protons show that no ortho metalation has taken
place. This reaction was not investigated further.
The reaction of 1b with PtCl2(NCPh)2 in refluxing
2-methoxyethanol gives a quite different result. After
the reaction time (22 h), a pale yellow solid remained
insoluble in the alcoholic media, which was identified
as the cycloplatinated derivative [Pt(C6H3-3-Ph-2-
PPh2CdC(Me)CH2PPh2-κC,C,P)Cl] (3) (see eq 7). The
Experimental Section), in accord with its analytic and
spectroscopic data. The expected allyl-vinyl product is
obtained in very good yield, as a result of the replace-
ment of the two Br atoms by PPh3 groups. We have not
observed isomerization to the bis-vinyl species [Ph3PC-
(H)dC(Me)PPh3]Br2, even at prolonged reaction times
(22 h reflux, DMA). Thus, the bromine atom can be
replaced efficiently at the two positions (aliphatic and
vinylic) without the need of a catalyst.13a When the
starting dihalo derivative is 1,3-dichloropropene, its
reaction with PPh3 (under the same experimental
conditions) gives [Ph3PCH2-(E)-C(H)dC(H)PPh3]Cl2 (1d )
(see eq 4 and the Experimental Section), although in
low yield (34.7%). With the dibromo derivative as the
starting material, the yield for the corresponding salt
[Ph3PCH2-(E)-C(H)dC(H)PPh3]Br2 (1e) (eq 4) improves
notably (91%), due to the fact that the bromide anion is
a better leaving group than the chloride. Compounds
1d and 1e show virtually identical NMR spectra, from
which the E configuration can be inferred.16 The pres-
ence of substituents on the phosphine aryl groups does
not modify the type of bis-phosphonium salt obtained.
The reaction of H2CdC(CH2Cl)2 with P(p-FC6H4)3 gives
the expected [(p-FC6H4)3PCH2-(E)-C(Me)dC(H)P(p-
FC6H4)3]Cl2 (1f) (see eq 5 and the Experimental Section).
synthesis of 3 formally involves three C-H bond activa-
tions (one at the vinylic position and two in two different
phenyl rings), one P-C bond activation, and one C-C
bond coupling. The chloride ligand in complex 3 can be
easily replaced by bromide (4) or iodide anions (5) (see
eq 8) by reaction of 3 with an excess of the corresponding
halide salts. The crystallization of 5 from CH2Cl2/Et2O
affords crystals of adequate quality for X-ray purposes.
A drawing of the organometallic complex 5 is pre-
sented in Figure 2; some relevant parameters concern-
ing the data acquisition and structure solution and
refinement are given in Table 1, and selected bond
distances and angles are collected in Table 2. The
platinum atom is located in a distorted-square-planar
environment, which is defined by the iodine atom I(1)
and by the three donor atoms of the new ligand C6H3-
3-Ph-2-PPh2-CdC(Me)CH2PPh2-κC,C,P: the arylic car-
The salts 1a -f, prepared without the need of a
catalyst or other inductive processes, share a common
characteristic, which is the presence of an allyl phos-
phonium unit possessing different substituents at dif-
(15) (a) Keough, P. T.; Grayson, M. J . Org. Chem. 1964, 29, 631. (b)
Seyferth, D.; Fogel, J . J . Organomet. Chem. 1966, 6, 205. (c) Schweizer,
E. E.; Shaffer, E. T.; Hughes, C. T.; Berninger, C. J . J . Org. Chem.
1966, 31, 2907. For more references, see ref 10 in this work.
(16) Pretsch, E.; Bu¨hlmann, P.; Affolter, C.; Herrera, A.; Mart´ınez,
R. Structure Determination of Organic Compounds; Springer-Verlag
Ibe´rica: Barcelona, Spain, 2001.

Bond Activation and Coupling Induced by Pt(II) Complexes
Organometallics, Vol. 22, No. 24, 2003 4913
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 5
Pt(1)-C(25)
Pt(1)-P(1)
P(1)-C(35)
P(1)-C(28)
P(2)-C(6)
P(2)-C(19)
C(1)-C(6)
C(3)-C(4)
C(5)-C(6)
C(7)-C(8)
C(8)-C(9)
C(10)-C(11)
C(25)-C(26)
C(26)-C(28)
2.010(4)
2.2697(13) Pt(1)-I(1)
Pt(1)-C(1)
2.042(4)
2.6628(9)
1.810(5)
1.759(4)
1.798(4)
1.392(6)
1.378(6)
1.395(6)
1.492(6)
1.392(6)
1.378(6)
1.370(6)
1.497(6)
1.805(4)
1.832(4)
1.793(4)
1.805(4)
1.420(6)
1.375(6)
1.401(6)
1.389(6)
1.355(6)
1.368(6)
1.348(6)
1.509(6)
P(1)-C(29)
P(2)-C(25)
P(2)-C(13)
C(1)-C(2)
C(2)-C(3)
C(4)-C(5)
C(5)-C(7)
C(7)-C(12)
C(9)-C(10)
C(11)-C(12)
C(26)-C(27)
C(25)-Pt(1)-C(1) 86.05(17) C(25)-Pt(1)-P(1) 79.31(13)
C(1)-Pt(1)-P(1)
C(1)-Pt(1)-I(1)
164.99(12) C(25)-Pt(1)-I(1)
96.31(12) P(1)-Pt(1)-I(1)
175.98(12)
98.50(4)
C(35)-P(1)-C(28) 104.2(2)
F igu r e 2.
C(35)-P(1)-C(29) 103.6(2)
C(29)-P(1)-C(28) 110.5(2)
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
C(35)-P(1)-Pt(1) 114.63(15)
Deta ils for 5 a n d 14‚CHCl3
C(29)-P(1)-Pt(1) 123.92(15) C(28)-P(1)-Pt(1) 98.47(14)
5
14‚CHCl3
C(25)-P(2)-C(6)
C(6)-P(2)-C(13)
C(6)-P(2)-C(19)
C(26)-C(25)-P(2) 129.4(3)
P(2)-C(25)-Pt(1) 106.7(2)
C(25)-C(26)-C(28) 116.0(4)
C(26)-C(28)-P(1) 103.7(3)
102.5(2)
110.3(2)
111.8(2)
C(25)-P(2)-C(13) 107.3(2)
C(25)-P(2)-C(19) 114.8(2)
C(13)-P(2)-C(19) 109.8(2)
C(26)-C(25)-Pt(1) 122.9(3)
C(25)-C(26)-C(27) 128.3(4)
C(27)-C(26)-C(28) 115.6(4)
empirical formula
formula wt
T (K)
C
40H33IP2Pt
C41H34Cl4I2P2Pt
1179.31
100(2)
897.59
100(2)
λ, Å
0.71073
triclinic
P1h
0.71073
triclinic
P1h
cryst syst
space group
a, Å
9.8225(16)
13.373(2)
14.254(2)
65.30(3)
76.17(3)
72.61(3)
1609.2(4)
2
9.9831(9)
12.2541(11)
17.9378(16)
72.174(1)
88.082(2)
72.854(1)
1992.3(3)
2
b, Å
c, Å
moreover, it has been transformed into a σ-bonded
biphenyl moiety due to C-C coupling with the phenyl
fragment formed in (i); (iii) the vinylic C-H bond has
also been activated, and a new Pt-C bond is formed.
The description of the bonding of the C6H3-3-Ph-2-PPh2-
CdC(Me)CH2PPh2-κC,C,P ligand merits some com-
ments. The Pt(1)-C(1) bond distance (2.042(4) Å) is
longer than that found in the closely related complex
[Pt(C6H4-2-PPh2-(E)-η2-C(H)dC(H)Me)Cl2]10 (1.997(9) Å,
C-trans-Cl) due to the higher trans influence of the P
atom with respect to the Cl atom. On the other hand,
the Pt(1)-C(1) and the Pt(1)-P(1) bond distances
(2.2697(13) Å) are typical for the Caryl-trans-P arrange-
ment in Pt(II) complexes.17a,e-i The Pt-C(25) bond
distance (2.010(4) Å) is similar, within experimental
error, to that found in the vinyl derivative trans-[Pt-
(CHdCMe2)(I)(PPh3)2] (2.032(7) Å).17d The P(2)-C(25)
bond distance (1.759(4) Å) is shorter than the other P-C
bond distances involving P(2), and this fact has been
observed in other metalated vinyl phosphonium sys-
tems.18 All bond distances within the rings C(1)-C(6)
and C(7)-C(12) are typical for Ph groups, and the C(5)-
C(7) bond distance (1.492(6) Å) shows clearly that it is
a single σ(C-C) bond.19 The bond distances C(26)-C(27)
(1.497(6) Å) and C(26)-C(28) (1.509(6) Å) are also single
C-C bonds, while the C(25)-C(26) bond distance (1.348-
(6) Å) indicates a double bond.19 The dihedral angle
between the best least-squares planes defined by the
Ph rings C(1)-(C6) and C(7)-C(12) is 65.0(4)°.
R, deg
â, deg
γ, deg
V, Å3
Z
F
calcd, Mg/m3
1.852
1.966
µ, mm-1
5.448
5.449
F(000)
868
1124
θ range for data collecn, deg
no. of rflns collected
no. of indep rflns
1.59-25.07
2.14-25.03
15 791
10 852
5681 (Rint
)
6935 (Rint )
0.0347)
0.0232)
no. of data/restraints/params 5681/0/398
6935/0/452
0.995
goodness of fit on F2 a
0.957
R1 ) 0.0263
final R indices (I > 2σ(I))a
R1 ) 0.0430
wR2 ) 0.0519 wR2 ) 0.1268
R indices (all data)a
R1 ) 0.0304
0.0561
wR2 ) 0.0528 wR2 ) 0.1325
largest diff peak, hole, e Å-3
1.161, -0.741 2.414, -1.939
R1 ) ∑||Fo| - |Fc||/∑|Fo|; wR2 ) [∑w(Fo - Fc2)2/∑w(Fo2)2]1/2
;
a
2
GOF ) [∑w(Fo - Fc2)2/(nobservns - nparams)]1/2
.
2
bon C(1), the vinylic carbon C(25), and the phosphorus
P(1) of the terminal PPh2 group. The Pt(1)-I(1) bond
distance (2.6628(9) Å) falls in the range of bond dis-
tances usually reported for this type of bond.17
The most remarkable feature of this structure is the
dramatic transformation undergone by the bis-phos-
phonium salt 1b after reaction with the Pt(II) metallic
center: (i) one of the PPh3 groups has been cleaved into
a PPh2 fragment (Pt bonded) and a phenyl ring; (ii) one
phenyl of the other PPh3 group has been metalated, and
The analytical data of complexes 3-5 are in good
agreement with the proposed stoichiometries, and their
mass spectra show in each case the molecular peak with
(17) (a) Orpen, A. G.; Brammer, L.; Allen, F. H.; Kennard, O.;
Watson, D. G.; Taylor, R. J . Chem. Soc., Dalton Trans. 1989, S1. (b)
Giordano, T. J .; Rasmussen, P. G. Inorg. Chem. 1975, 14, 1628. (c)
Hoover, J . F.; Stryker, J . M. Organometallics 1988, 7, 2082. (d) Stang,
P. J .; Zhong, Z.; Kowalski, M. H. Organometallics 1990, 9, 833. (e)
Romeo, R.; Scolaro, L. M.; Plutino, M. R.; Romeo, A.; Nicolo, F.; Del
Zotto, A. Eur. J . Inorg. Chem. 2002, 629. (f) Gaw, K. G.; Slawin, A. M.
Z.; Smith, M. B. Organometallics 1999, 18, 3255. (g) Blacker, A. J .;
Clarke, M. L.; Loft, M. S.; Mahon, M. F.; Williams, J . M. J . Organo-
metallics 1999, 18, 2867. (h) Crespo, M.; Solans, X.; Font-Bard´ıa, M.
Organometallics 1995, 14, 355. (i) Crespo, M.; Font-Bard´ıa, M.; Solans,
X. Polyhedron 2002, 21, 105.
1
the correct isotopic distribution. The H NMR spectra
(18) (a) Bennett, M. A.; Kwan, L.; Rae, A. D.; Wenger, E.; Willis, A.
C. J . Chem. Soc., Dalton Trans. 2002, 226. (b) Bertani, R.; Casarin,
M.; Ganis, P.; Maccato, C.; Pandolfo, L.; Venzo, A.; Vittadini, A.;
Zanotto, L. Organometallics 2000, 19, 1373.
(19) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J . Chem. Soc., Perkin Trans. 2 1987, 685.

4914 Organometallics, Vol. 22, No. 24, 2003
Gracia et al.
of 3-5 show the same pattern of signals, with logical
of PtCl2(PPh3)2, PtClBr(PPh3)2, and PtBr2(PPh3)2, as a
result of the complete cleavage of the Ph3P-C bonds.
The same result applies for the reaction of 1d or 1e,
despite the similarity of their structures with that of
1b. Given these results, these reactions were not further
investigated. The presence of substituents in the aryl
groups has also been considered. The reaction of 1f with
PtCl2(NCPh)2 affords the Pt(IV) complex [Pt(C6H4-4-F)-
{C6H3-5-F-2-P(p-FC6H4)2-CdC(Me)CH2P(p-FC6H4)2-
κC,C,P}Cl2] (6) (see eq 9 and the Experimental Section).
differences arising from the presence of the ligands Cl-,
1
Br-, and I-. Key features of the H NMR spectra are (i)
the presence of a multiplet signal at the lowest field,
attributed to the H(6) proton (ortho to the metalated
position) showing 195Pt satellites, (ii) the position of this
peak varying as a function of the X ligand (8.77 ppm
(3), 8.83 ppm (4), and 9.09 ppm (5)), suggesting a weak,
but perceptible, contact between X and H(6), (iii) the
3
similarity of the coupling constant J Pt-H(6) (ranging
from 41.4 to 45.9 Hz) with that reported for related
cycloplatinated derivatives (42 Hz),10 and (iv) the ob-
servation of four signals (relative intensity 1:1:2:2) in
the aromatic region, due to the H4 proton and to the
C6H5 group at the 3-position of the metalated ring. The
31P{1H} NMR spectra of 3-5 show also common fea-
tures. They show two doublet signals (3J PP about 25 Hz)
with 195Pt satellites each. The signals at lowest field
appear almost at the same frequency (34.14 ppm (3),
34.16 ppm (4), and 34.29 ppm (5)), show values of the
2
coupling constant J PtP at about 590 Hz, and are
attributed to the P atom in the metalated ring. The
value of 2J PtP is similar to those reported for structurally
related systems.20 The signals at highest field are
assigned to the Pt-bonded PPh2 group and show values
The complete characterization of complex (6) shows
relevant features.
1
of the coupling constant J PtP consistent with their
The presence of two cis chloride ligands in 6 can be
inferred from the observation in the IR spectrum of two
absorptions at 285 and 270 cm-1. The mass spectrum
(positive FAB) shows the presence of two main peaks
at 915 and 878 amu. The peak at 915 amu shows the
correct isotopic distribution for the stoichiometry C40H28-
ClF6P2Pt (loss of a Cl- anion), this fact showing that
only two protons have been lost from the original bis-
phosphonium salt and, hence, that only two C-H bond
activations have been promoted in the synthesis of 6.
The NMR spectra of 6 are particularly informative.
structures, and their positions also change as the halide
changes (25.48 ppm (3), 26.53 (4), and 27.61 ppm (5)).
The 195Pt NMR spectra of 3 and 5 show the expected
doublets of doublets at -5774.3 ppm (3) and -6000.0
ppm (5). Both signals appear in the usual range of
frequencies reported for other Pt(II) complexes,17f-i,21
that of 5 being slightly shifted to high field with respect
to that of 3. The substitution of the Cl- by the I- ligand
accounts for the shielding of the metal center.22 Finally,
the 13C{1H} NMR spectra of 3 and 5 show the expected
peaks of the tridentate-C,C,P ligand. The signals due
to the ortho-metalated carbon atom C(1) appear at very
The 1H NMR spectrum of 6 shows clearly that an
2
low field (about 174 ppm, dd) and show J PC coupling
ortho-metalation reaction has taken place, due to the
constants in keeping with the C-trans-P arrangment
(126.0 Hz (3), 124.8 Hz (5)). Other resonances attributed
to the C6H3 unit (except that of C(3)) are clearly seen.
The peaks due to the vinylic carbon atoms appear at
about 154 ppm (Câ) and 145 ppm (CR), and those
corresponding to the phenyl group at the 3-position of
the metalated ring are observed at about 141 ppm (C(1′))
and in the range 129-126 ppm (C(2′)-C(4′)).
195
observation of a signal at low field (8.53 ppm) with
-
Pt satellites, attributed to the H(6) proton. The value
of the coupling constant (3J PtH(6) ) 38.6 Hz) is slightly
lower than those found for 3-5 and is similar to that
observed for the Pt(IV) derivatives 13 and 14 (see
below). Moreover, resonances due to a Pt-C6H4-4-F
group are clearly seen: the meta protons (H(3′)) appear
at 5.99 ppm and the ortho protons (H(2′)) at 6.67 ppm,
the latter also showing 195Pt satellites (3J PtH(2′) ) 52.8
Hz). The magnitude of 3J PtH(2′) is somewhat smaller than
those found in related Pt(II) complexes with the C6H4-
4-F ligand.23 Moreover, signals due to the H(3) and H(4)
protons are also observed, meaning that on the meta-
lated ring only one C-H bond activation has been
produced, and this fact is in keeping with the mass
spectrum interpretation. The 31P{1H} NMR spectrum
shows two peaks with 195Pt satellites each. The signal
attributed to the P atom on the metalated ring appears
at 30.63 ppm (2J PtP ) 412.1 Hz), while that assigned to
The presence of different substituents in the phos-
phonium salts induces notable changes in the reactivity.
The reaction of 1c with PtCl2(NCPh)2 gives a mixture
(20) (a) J un, H.; Young, V. G., J r.; Angelici, R. J . J . Am. Chem. Soc.
1991, 113, 9379. (b) J un, H.; Angelici, R. J . Organometallics 1993, 12,
4265. (c) J un, H.; Young, V. G., J r.; Angelici, R. J . Organometallics
1994, 13, 2444. (d) J un, H.; Angelici, R. J . Organometallics 1994, 13,
2454.
(21) (a) Fornie´s, J .; Menjo´n, B.; Sanz-Carrillo, R. M.; Toma´s, M.;
Connelly, N. G.; Crossley, J . G.; Orpen, A. G. J . Am. Chem. Soc. 1995,
117, 4295. (b) Crespo, M.; Sales, J .; Solans, X.; Font Altaba, M. J . Chem.
Soc., Dalton Trans. 1988, 1617. (c) Ling, S. S. M.; Payne, N. C.;
Puddephatt, R. J . Organometallics 1985, 4, 1546.
(22) (a) Pregosin, P. S. Coord. Chem. Rev. 1982, 44, 247. (b) Pregosin,
P. S. Transition Metal Nuclear Magnetic Resonance; Elsevier: Am-
sterdam, 1991; pp 217-263. Recent examples: (c) Anderson, C.;
Crespo, M.; Font-Bard´ıa, M.; Klein, A.; Solans, X. J . Organomet. Chem.
2000, 601, 22. (d) Ananikov, V. P.; Mitchenko, S. A.; Beletskaya, I. P.
J . Organomet. Chem. 2000, 604, 290. (e) Ananikov, V. P.; Mitchenko,
S. A.; Beletskaya, I. P. J . Organomet. Chem. 2001, 636, 175. (f) Crespo,
M.; Font-Bard´ıa, M.; Pe´rez, S.; Solans, X. J . Organomet. Chem. 2002,
642, 171.
the P atom bonded to Pt appears at 4.25 ppm (1J PtP
)
1510 Hz). The comparison of these data with those
obtained for 3-5 shows notable differences: while the
(23) Osakada, K.; Sakata, R.; Yamamoto, T. Organometallics 1997,
16, 5354.

Bond Activation and Coupling Induced by Pt(II) Complexes
Sch em e 1
Organometallics, Vol. 22, No. 24, 2003 4915
chemical shift of the P atom on the metalated ring of 6
moves only about 4 ppm to high field with respect to
the signals for 3-5, the P atom bonded directly to the
Pt atom has been shifted, also to high field, at least 21
ppm; in addition, there is a notable decrease in the
nance, with respect to its position in the free bis-
phosphonium salt 1f, is similar to that reported for the
Fpara atom on C6F5 groups after metalation.25 On the
other hand, the 195Pt NMR spectrum of 6 provides
unambiguous proof of the Pt(IV) nature of the metal
center. The chemical shift of the Pt atom was obtained
n
values of both J PtP coupling constants (n ) 1, 2). Once
again, the 31P data of 6 are closer to those obtained from
13 and 14 than to those corresponding to 3-5. Consid-
ering the oxidation reaction Pt(II) f Pt(IV), the decrease
in the values of the coupling constants and the observa-
tion of the “oxidation shift” for the δ values (high-field
shifts) are well-established phenomena in NMR
spectroscopy.17i,21a,c,22a,b,24 These facts and the close
resemblance of the spectroscopic parameters of 6 with
those obtained for the Pt(IV) derivatives 13 and 14
supports strongly the proposal shown in eq 9.
through inverse correlation H-195Pt experiments. The
1
obtained value (δ -3352.0 ppm) is located at the lowest
field among the 195Pt NMR spectra described here (see
the Experimental Section). A sensible explanation can
be given, taking into account two main facts: the Pt-
(IV) nature of the metal center and the presence of a
σ-bonded C6H4-4-F group.22a,b Finally, the 13C{1H} NMR
spectrum of 6 is also in good agreement with the
preceding data. Relevant key features are the observa-
tion of signals corresponding to the C(2′) (137.62 ppm)
and C(3′) (113.04 ppm) carbon atoms, each showing 195
-
Additional evidence for the existence of the Pt-C6H4-
4-F ligand in 6 comes from its 19F NMR spectrum. In
this spectrum, six different complex signals are seen,
corresponding to the six chemically nonequivalent F
atoms of the molecule. The attribution of all resonances
Pt satellites (22.3 and 58.7 Hz, respectively). These
values are similar to those found in related Pt-phenyl
derivatives.26 The ortho-metalated C(1) atom appears
at 169.72 ppm as a doublet of doublets but, as expected,
2
1
has been performed through H{19F} NMR experiments.
with coupling constants J PtransC (87.7 Hz) smaller than
those reported for 3 and 5 (about 125 Hz); the Câ and
CR carbons appear at 157.01 and 122.22 ppm, respec-
tively, the CR signal being shifted to high field more than
20 ppm with respect to its position in 3 or 5.
3. P r op osed Mech a n ism for th e Syn th esis of 3.
The isolation and characterization of 6 allows us to shed
some light on a plausible reaction pathway through
which 3 could be obtained from 1b. This proposal is
depicted in Scheme 1.
One of the signals appears at higher field (-122.38 ppm)
than the others (ranging from -102 to -109 ppm), and
this resonance correlates with both the H(2′) and H(3′)
protons. Hence, this signal is assigned to the Pt-C6H4-
4-F atom. The high-field shift undergone by this reso-
(24) (a) Edelbach, B. L.; Lachicotte, R. J .; J ones, W. D. J . Am. Chem.
Soc. 1998, 120, 2843. (b) Alcock, N. W.; Bryars, K. H.; Pringle, P. G. J .
Chem. Soc., Dalton Trans. 1990, 1433. (c) Hoover, J . F.; Stryker, J . M.
Organometallics 1989, 8, 2973. (d) Hoover, J . F.; Stryker, J . M. J . Am.
Chem. Soc. 1989, 111, 6466. (e) Hassan, F. S. M.; Higgins, S. J .;
J acobsen, G. B.; Shaw, B. L.; Thornton-Pett, M. J . Chem. Soc., Dalton
Trans. 1988, 3011.
(25) Uso´n, R.; Fornie´s, J . Adv. Organomet. Chem. 1988, 28, 219.
(26) Clark, H. C.; Ward, J . E. H. J . Am. Chem. Soc. 1974, 96, 1741.

4916 Organometallics, Vol. 22, No. 24, 2003
Gracia et al.
Sch em e 2
the formation of 3. Once we discard these two possib-
lities, it seems likely that the initial step in the
obtainment of intermediate A should be the η2 coordina-
tion of the olefinic fragment to the Pt(II) metal center
in a way similar to that described and characterized by
us recently for allyl phosphonium systems.10
Once derivative A has been formed, the next logical
step should be the metalation of the olefinic fragment,
with concomitant elimination of HCl, and formation of
the intermediate B in Scheme 1. The metalation of ole-
fin groups to give σ-bonded vinyl derivatives is a process
known for Pt(II) complexes.28 Moreover, this metalation
can also be assisted by the presence of the nonbonded
phosphonium group, since it has been shown that the
presence of a phosphonium group can enhance the
reactivity of adjacent electrophilic centers.29 The next
step, B f C, involves an unprecedented transformation
for Pt(II) complexes. The pendant PPh3 phosphonium
group adds oxidatively to the Pt(II) metal center in B
to give the phenylphosphino Pt(IV) derivative C, which
is basically identical with the isolated complex 6. While
the P-C bond activation process in phosphine groups
promoted by transition metals is a known process,30 the
related P-C bond activation where the PPhnR3-n unity
belongs to a phosphonium or an ylide functionality is
rare.31 In fact, this type of P-C bond activation on ylide
or phosphonium salts have been described to proceed
usually with metals in low oxidation states and results
in interesting reactions: synthesis of catalysts for the
polymerization of ethylene,31a,b studies and applications
of aryl-aryl exchange processes,31d-m and synthesis of
iminophosphoranes.31n,o In our case, a phosphonium
-CH2PPh3 group is transformed into a -CH2PPh2-Pt-
Ph unit; up to now, the activation of a phosphonium
group to give a phenylphosphino derivative has been
Since the bis-phosphonium salt 1b contains an allyl
group, it seems possible that the first step of the reaction
should be an ortho-metalation reaction similar to those
described by us recently.10 This metalation should give
intermediate A in Scheme 1. With respect to this step,
some points need to be considered. There are two
phosphonium units in 1b, one at an allylic position and
the other at a vinylic position. The ortho metalation
should proceed at the PPh3 unit on an allylic positions
followed by a 1,3-prototropic shiftssince we have shown
that the vinyl phosphonium salts do not metalate.10 In
our previous contribution we have proposed that the
initial step of the metalation reaction should begin with
the direct interaction of the allyl moiety with the Pt(II)
center. To achieve this interaction, two possibilities
could be envisaged: η2 coordination of the CdC bond
or a platinum-ylide complex. Aiming to determine
which of the two possibilities are actually operating, we
have synthesized the intermediate ylide phosphonium
salt 7 (see Scheme 2) by deprotonation of 1b with Li-
(NiPr2). Compound 7 has been characterized through
its analytic and spectroscopic data. Similar 1,3-bis-
(phosphonio)propenide cations have been reported
previously,11a,27 and they show spectroscopic behavior
closely related to that observed for 7. Hence, a similar
structure is proposed, in accord with the NMR data.
However, the reaction of 7 with PtCl2(NCPh)2 (1:1 molar
ratio, refluxing 2-methoxyethanol) did not give the
expected results, since extensive decomposition was
observed, showing that 7 does not seem to be a plausible
intermediate in the synthesis of 3.
The observed reactivity of 7 toward PtCl2(NCPh)2
prompted us to determine if other species are generated
from 1b under the experimental conditions, which might
be able to interact with the Pt(II) salt. However, the
treatment of 1b under the metalation conditions affords
a mixture of the phosphonium salts [Ph3PCH2C(Me)d
CH2]Cl and [Ph3PC(H)dCMe2]Cl (Scheme 2), the latter
being produced from the former by a 1,3-prototropic
shift, showing that 1b evolves through P-C bond
cleavage and loss of one PPh3 unit. Moreover, the
reaction of these phosphonium salts with PtCl2(NCPh)2
should result in the formation of the previously reported
ortho-metalated derivative [Pt(C6H4-2-PPh2-η2-C(H)d
CMe2)Cl2] (A′ in Scheme 2), which was not observed
during the synthesis of 3. Thus, the bis-phosphonium
salt 1b does not suffer this type of side reaction during
(28) (a) Bennett, M. A.; Clark, P. W.; Robertson, G. B.; Whimp, P.
O. J . Organomet. Chem. 1973, 63, C15. (b) Robertson, G. B.; Whimp,
P. O. Inorg. Chem. 1974, 13, 2082. (c) Bennett, M. A.; J ohnson, R. N.;
Robertson, G. B.; Tomkins, I. B.; Whimp, P. O. J . Am. Chem. Soc. 1976,
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C. H. Organometallics 2002, 21, 2781. (d) Kwong, F. Y.; Lai, C. W.;
Chan, K. S. J . Am. Chem. Soc. 2001, 123, 8864. (e) Kwong, F. Y.; Chan,
K. S. Organometallics 2001, 20, 2570. (f) de la Torre, G.; Gouloumis,
A.; Va´zquez, P.; Torres, T. Angew. Chem., Int. Ed. 2001, 40, 2895. (g)
Lai, C. W.; Kwong, F. Y.; Wang, Y.; Chan, K. S. Tetrahedron Lett. 2001,
42, 4883. (h) Kwong, F. Y.; Chan, K. S. Chem. Commun. 2000, 1069.
(i) Kwong, F. Y.; Chan, K. S. Organometallics 2000, 19, 2058. (j)
Grushin, V. V. Organometallics 2000, 19, 1888. (k) Reetz, M. T.;
Lohmer, G.; Schwickardi, R. Angew. Chem., Int. Ed. 1998, 37, 481. (l)
Goodson, F. E.; Wallow, T. I.; Novak, B. M. J . Am. Chem. Soc. 1997,
119, 12441. (m) Kong, K. C.; Cheng, C. H. J . Am. Chem. Soc. 1991,
113, 6313. (n) Vicente, J .; Chicote, M. T.; Beswick, M. A.; Ram´ırez de
Arellano, M. C. Inorg. Chem. 1996, 35, 6592. (o) Vicente, J .; Chicote,
M. T.; Ferna´ndez-Baeza, J .; Lahoz, F. J .; Lo´pez, J . A. Inorg. Chem.
1991, 30, 3617.
(27) Bestmann, H. J .; Kisielowski, L. Tetrahedron: Lett. 1990, 31,
3301.

Bond Activation and Coupling Induced by Pt(II) Complexes
Organometallics, Vol. 22, No. 24, 2003 4917
reported to occur, stoichiometrically or catalytically, only
induced by Pd(0) complexes,31e-i but in any case assisted
by Pt(II) complexes. The only reported process in which
Pt(II) salts are involved31n,o occurs with migration of the
entire PPh3 group and P-N coupling to give iminophos-
phoranes or related species.
seen in the 31P{1H} NMR, in which an ABX spin system
(each signal showing 195Pt satellites) is observed. More-
over, the 195Pt NMR spectrum shows the presence of a
signal at -4316 ppm (ddd), shifted to low field with
respect to those obtained in 3 and 5, this unshielding
in keeping with the cationic nature of 9. Complex 10
shows the expected signals for the N-bonded pyridine
ligand, and in addition, the proton H(6) appears strongly
shifted to high field, due to the anisotropic shielding of
the adjacent pyridine ring.33 The 31P{1H}, 195Pt, and 13C-
{1H} NMR spectra are consistent with the structure
depicted in eq 10. The comparison of the 195Pt NMR
spectra of 9 (δ -4316 ppm, PPh3) and 10 (δ -3741 ppm,
py) follows the expected trends.22 Thus, the Pt chemical
shift moves to high field from 10 to 9, indicating a more
shielded Pt atom, as expected when the increase of the
covalency of the donor atom from an N-donor to a
P-donor is taken into account. Complex 11 shows the
Since intermediate C has been isolated and charac-
terized (as the related complex 6), the question remains
as to whether the reaction progresses further (C-C
coupling in the case of 3) or is stopped at this point (in
complex 6). The C-C coupling reaction mediated by Pt-
(IV) complexes is a well-known process and, from
mechanistic and kinetic studies, it seems clearly estab-
lished that, prior to the C-C coupling step, the dis-
sociation of a ligand to give a 16-electron species is a
mandatory prerequisite.24a,32 Considering the interme-
diate C in Scheme 1 and complex 6, the main difference
between them is the presence of a F atom at a para
position. The strong electron-withdrawing nature of the
F atom32d,e results in the electron density around the
metal being less in 6 than in C, which should then force
a lesser degree of dissociation in 6 than in C. This
reasoning could allow us to explain the observed C-C
coupling in C (one of the ligands dissociates easily) and
the isolation of the 18-electron complex 6 (presence of
two ligands with strong electron-withdrawing substit-
uents). Finally, the next step from C is the C-C
coupling to give D, which contains a phosphonium group
with a biphenyl unit as substituent. The rotation of the
biphenyl unit around the P-C bond and subsequent
C-H bond activation at the ortho position with elimina-
tion of HCl gives complex 3 in a typical ortho-metalation
reaction.
t
presence of a BuNtC ligand C-bonded to the Pt atom.
The reaction was performed in the presence of an excess
of ligand (1:2 molar ratio) in order to check if insertion
of the isocyanide into the Pt-C bond occurs,34 but no
inserted products were detected. The simple C-coordina-
tion of the isocyanide ligand is inferred from the
observation of a strong absorption in the IR spectrum
at 2182 cm-1 34
Finally, the coordination of the Ph2-
.
PCH2PPh2 (dppm) ligand in complex 12 is produced
through only one of the P atoms, as is reflected in its
31P{1H} NMR spectrum. There, the appearance of only
one signal at high field (-23.74 ppm) shows that one of
the P atoms of the dppm ligand remains uncoordinated.
In complexes 9 and 12, the differences between the
1J Pt-P coupling constants (e.g. in 9 1923 Hz for the Pt-
PPh2 atom (trans to the aryl group) and 2513 Hz for
the Pt-PPh3 atom (trans to the vinyl ligand)) can be
explained by taking into account the higher trans
influence of the aryl group compared with the vinyl
moiety.
5. Oxid a tive Ad d ition Rea ction s. Complex 3 also
undergoes oxidative additions of halogens X2. The
treatment of a CH2Cl2 solution of 3 with halogens X2
(X ) Cl, I) gives the Pt(IV) derivatives [Pt(C6H3-3-Ph-
2-PPh2-CdC(Me)CH2PPh2-κC,C,P)Cl(X)2] (X ) Cl (13),
I (14)) (see eq 11), in accord with their elemental
analyses and NMR data.
4. Liga n d -Su bstitu tion Rea ction s. Further reac-
tivity of complex 3 has been examined. The treatment
of 3 with AgClO4 and neutral ligands L (1:1:1 molar
ratio) results in the formation of the corresponding
cationic derivatives [Pt(C6H3-3-Ph-2-PPh2-CdC(Me)CH2-
PPh2-κC,C,P)(L)]ClO4 (L ) NCMe (8), PPh3 (9), pyridine
(10), CtNtBu (11), Ph2PCH2PPh2-κP (12)) (see the
Experimental Section and eq 10). The analytical data
are in good agreement with the proposed stoichiom-
etries. The presence of the coordinated L ligands can
be inferred from the IR and NMR data of 8-12. In the
case of 8, the NCMe ligand gives absorptions at 2323
1
1
The H NMR spectra of 13 and 14 are quite similar
cm-1 in the IR spectrum and a signal in the H NMR
to those described for 3-5 and reflect the expected
differences arising from the presence of a Pt(IV) metal
center. The signal assigned to proton H(6) appears in
spectrum at 2.50 ppm assigned to the NCMe group. For
complex 9 the presence of coordinated PPh3 is clearly
(32) (a) Puddephatt, R. J . Angew. Chem., Int. Ed. 2002, 41, 261 and
references therein. (b) Goldberg, K. I.; Yan, J .; Winter, E. L. J . Am.
Chem. Soc. 1994, 116, 1573. (c) Font-Bard´ıa, M.; Gallego, C.; Mart´ınez,
M.; Solans, X. Organometallics 2002, 21, 3305. (d) Bernhardt, P. V.;
Gallego, C.; Mart´ınez, M.; Parella, T. Inorg. Chem. 2002, 41, 1747. (e)
Bernhardt, P. V.; Gallego, C.; Mart´ınez, M. Organometallics 2000, 19,
4862.
(33) Deeming, A. J .; Rothwell, I. P.; Hursthouse, M. B.; New, L. J .
Chem. Soc., Dalton Trans. 1978, 1490.
(34) Cross, R. J . In Comprehensive Organometallic Chemistry II;
Abel, E. W., Stone, F. G. A., Wilkinson, G., Editors-in-Chief; Pud-
dephatt, R. J ., Volume Ed.; Pergamon Press: Oxford, U.K., 1995; Vol.
9, pp 411-430.

4918 Organometallics, Vol. 22, No. 24, 2003
Gracia et al.
both cases (8.84 ppm (13), 8.71 ppm (14)) at a frequency
similar to that observed in 3 (8.77 ppm) and with the
same hyperfine structure, but shows smaller values of
3
the coupling constant J PtH(6) (37.5 Hz (13); 33.3 Hz (14))
than those of 3 (41.4 Hz). The upfield changes in the
chemical shifts of the nuclei directly bonded to the Pt
center and the decrease in the values of the coupling
constants are typical features for the changes from Pt-
(II) to Pt(IV) derivatives and are called “oxidation
shift”.17i,21a,c,22a,b,24 The CH2 protons appear in both
complexes as equivalent, showing that there is a sym-
metry plane containing the C,C,P-metalated ligand. The
31P{1H} NMR spectrum shows the presence of two
doublet signals with 195Pt satellites. While the signals
attributed to the metalated P atom vary only slightly
their position with respect to that in 3, those assigned
to the Pt-PPh2 unit are shifted to high field up to 39
ppm (2.76 ppm (13); -13.46 ppm (14); 25.48 ppm (3)),
in good agreement with the oxidation shift, and a
substantial decrease of the values of the coupling
n
constants J PtP is observed. The 195Pt NMR spectrum
F igu r e 3.
of 14 shows a doublet of doublets at -3978.5 ppm.
Concerning the stereochemistry of 13 and 14, we have
depicted in eq 11 the mer arrangement of the chloride
ligands in 13 and the trans disposition of the iodide
ligands in 14. Assuming that the metalated ligand
preserves the structural arrangment shown in 5 (and
this is logical on the basis of the NMR data), this
structure is the only possibility for 13, while for 14 two
isomers are possible (cis and trans). The NMR data of
14 show the presence of only one isomer, in which the
equivalence of the CH2 protons due to the presence of a
symmetry plane means that the two iodide ligands are
mutually trans. This trans addition of the halogen is in
good agreement with the accepted mechanism for oxida-
tive additions of X2 to Pt(II) derivatives,35,36a,b although
it should be noted that cis additions have also been
reported.36c,d To confirm the trans geometry, the struc-
ture of 14 has been determined through X-ray diffrac-
tion methods.
A drawing of the organometallic complex is shown in
Figure 3, some relevant parameters concerning the data
acquisition and structure solution and refinement are
given in Table 1, and selected bond distances and angles
are collected in Table 3. The platinum atom is located
in a distorted-octahedral environment, which is defined
by the three donor atoms of the ligand [C6H3-3-Ph-2-
PPh2-CdC(Me)-CH2-PPh2-κC,C,P] (C(1), C(13), and P(1)),
the chlorine atom Cl(1), and the two iodine atoms I(1)
and I(2). As expected, the metalated ligand displays the
same structural arrangement as that observed in 5 and
occupies three positions of the equatorial plane. The
chlorine ligand is at the remaining equatorial position,
and the two iodine atoms are in axial trans positions.
A comparison of the structural parameters in 14 with
respect to those in 5 shows similar values, within
experimental error, for the Pt-C bond distances and a
slightly longer Pt-P bond distance in 14 (2.364(2) Å)
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 14‚CHCl3
Pt(1)-C(13)
Pt(1)-P(1)
Pt(1)-I(2)
C(1)-C(6)
C(2)-C(3)
C(3)-C(4)
C(4)-C(5)
C(7)-C(12)
C(8)-C(9)
C(10)-C(11)
C(13)-C(14)
C(14)-C(15)
C(15)-P(1)
P(1)-C(23)
P(2)-C(29)
2.026(9)
2.364(2)
Pt(1)-C(1)
Pt(1)-Cl(1)
Pt(1)-I(1)
C(1)-C(2)
C(2)-P(2)
C(3)-C(7)
C(5)-C(6)
C(7)-C(8)
C(9)-C(10)
C(11)-C(12)
C(13)-P(2)
C(14)-C(16)
P(1)-C(17)
P(2)-C(35)
2.073(10)
2.444(2)
2.6584(9)
1.407(13)
1.802(9)
1.505(13)
1.370(14)
1.388(15)
1.380(18)
1.422(16)
1.801(9)
2.6291(8)
1.388(13)
1.418(13)
1.389(13)
1.399(14)
1.378(15)
1.387(16)
1.370(19)
1.343(13)
1.501(13)
1.835(9)
1.511(12)
1.819(9)
1.809(10)
1.819(10)
1.817(9)
C(13)-Pt(1)-C(1)
C(1)-Pt(1)-P(1)
C(1)-Pt(1)-Cl(1)
C(13)-Pt(1)-I(2)
P(1)-Pt(1)-I(2)
C(13)-Pt(1)-I(1)
P(1)-Pt(1)-I(1)
I(2)-Pt(1)-I(1)
C(14)-C(13)-Pt(1) 122.8(7)
C(13)-C(14)-C(15) 120.7(8)
C(15)-C(14)-C(16) 113.4(8)
C(17)-P(1)-C(23)
C(23)-P(1)-C(15)
C(23)-P(1)-Pt(1)
C(13)-P(2)-C(2)
C(2)-P(2)-C(35)
C(2)-P(2)-C(29)
87.5(4)
171.1(3)
95.0(3)
90.5(3)
91.98(6)
90.1(3)
91.66(6)
C(13)-Pt(1)-P(1)
C(13)-Pt(1)-Cl(1)
P(1)-Pt(1)-Cl(1)
C(1)-Pt(1)-I(2)
Cl(1)-Pt(1)-I(2)
C(1)-Pt(1)-I(1)
Cl(1)-Pt(1)-I(1)
83.6(3)
177.4(3)
93.96(8)
88.7(3)
88.87(6)
87.7(3)
90.70(6)
22.8(7)
114.4(4)
176.36(3) C(14)-C(13)-P(2)
P(2)-C(13)-Pt(1)
C(13)-C(14)-C(16) 125.9(9)
C(14)-C(15)-P(1)
C(17)-P(1)-C(15)
C(17)-P(1)-Pt(1)
C(15)-P(1)-Pt(1)
C(13)-P(2)-C(35)
C(13)-P(2)-C(29)
C(35)-P(2)-C(29)
112.1(6)
106.6(4)
119.2(3)
100.1(3)
111.3(4)
110.3(4)
108.5(4)
102.2(4)
108.9(4)
119.0(3)
102.7(4)
110.8(4)
113.1(4)
than in (5) (2.2697(13) Å). The Pt-I bond distances
(2.6291(8) and 2.6584(9) Å) fall in the usual range found
in the literature for this type of bond.37 The environment
around the Pt(1) atom can be considered as distorted
octahedral, as can be seen from the angles C(1)-Pt(1)-
P(1) (171.1(3)°), C(13)-Pt(1)-P(1) (83.6(3)°), and C(1)-
(37) (a) Lai, S.-W.; Chan, M. C.-W.; Cheung, K.-K.; Che, C.-M.
Organometallics 1999, 18, 3327. (b) van Beek, J . A. M.; van Koten, G.;
Wehman-Ooyevaar, I. C. M.; Smeets, W. J . J .; van der Sluis, P.; Spek,
A. L. J . Chem. Soc., Dalton Trans. 1991, 883. (c) Canty, A. J .;
Honeyman, T.; Skelton, B. W.; White, A. H. J . Organomet. Chem. 1990,
396, 105. (d) Clark, H. C.; Ferguson, G.; J ain, V. K.; Parvez, M.
Organometallics 1983, 2, 806. (e) Cheetham, A. K.; Puddephatt, R. J .;
Zalkin, A.; Templeton, D. H.; Templeton, L. K. Inorg. Chem. 1976, 15,
2997.
(35) Skinner, C. E.; J ones, M. M. J . Am. Chem. Soc. 1969, 91, 4405.
(36) (a) Ruiz, J .; Lo´pez, J . F. J .; Rodr´ıguez, V.; Pe´rez, J .; Ram´ırez
de Arellano, M. C.; Lo´pez, G. J . Chem. Soc., Dalton Trans. 2001, 2683.
(b) Vicente, J .; Chicote, M. T.; Mart´ın, J .; J ones, P. G.; Fittschen, C. J .
Chem. Soc., Dalton Trans. 1987, 881. (c) Fornie´s, J .; Fortun˜o, C.;
Go´mez, M. A.; Menjo´n, B.; Herdtweck, E. Organometallics 1993, 12,
4368. (d) Fornie´s, J .; Mart´ın, A.; Navarro, R.; Sicilia, V.; Villarroya, P.
Organometallics 1996, 15, 1826.

Bond Activation and Coupling Induced by Pt(II) Complexes
Organometallics, Vol. 22, No. 24, 2003 4919
3
3
3
3
6.42 (ttd, 1H, dCH, J HH ≈ J PH ) 16, J HCH2 ) 7.2, J P′H
)
Pt(1)-Cl(1) (95.0(3)°). The bond angle I(1)-Pt(1)-I(2)
is 176.36(3)°, indicating an almost linear arrangement
of the two trans iodine atoms.
2.7), 5.67 (dd, 2H, PCH2, 2J PH ) 16.2, 3J HH ) 7.2). 31P{1H} NMR
(CDCl3, room temperature): 22.43 (d, PCH2, 4J PP ) 6.1), 18.50
(d, dCHP).
[(p-F C6H4)3P CH2-(E)-C(Me)dC(H)P (p-F C6H4)3]Cl2 (1f).
Con clu sion s
Yield: 60.9%. 1H NMR (DMSO-d6, room temperature): 8.17-
8.08 (m, 6H, p-F-C6H4), 7.76-7.60 (m, 19H, p-F-C6H4
+
Several allyl-vinyl bis-phosphonium salts have been
obtained through direct reaction of the corresponding
halo derivatives with PPh3 or P(C6H4-p-F)3 without the
need of added catalyst. The complex PtCl2(NCPh)2 is
an excellent precursor for the synthesis of ortho-plati-
nated derivatives derived from these bis-phosphonium
salts. The metalation of the bis-phosphonium salt 1b
gives the complex [Pt(C6H3-3-Ph-2-PPh2-CdC(Me)-
CH2PPh2-κC,C,P)Cl] (3) through three C-H bond acti-
vations, one P-C bond activation, and one C-C bond
coupling. The isolation of the Pt(IV) complex [Pt(C6H4-
4-F){C6H3-5-F-2-P(p-FC6H4)2CdC(Me)CH2P(p-FC6H4)2-
κC,C,P}Cl2] (6) allows us to propose a plausible reaction
mechanism which involves, for the first time, a P-C
bond activation in a phosphonium salt promoted by a
Pt(II) complex. Further work on the reactivity of phos-
phonium salts toward Pt(II) complexes is now in progress.
dCHP), 5.63 (d, 2H, PCH2, 2J PH ) 17.4), 1.52 (s, 3H, Me). 31P-
{1H} NMR (DMSO-d6, room temperature): 23.29 (d, PCH2, 4J PP
) 5.5), 10.67 (d, dCHP).
[H2CdC(CH2P P h Me2)2][P t Cl4] (2). To a solution of the
bis-phosphonium salt 1a (0.425 g, 1.06 mmol) in 2-methoxy-
ethanol (15 mL) was added PtCl2(NCPh)2 (0.500 g, 1.06 mmol).
This suspension was refluxed for 24 h. During this time, the
initial yellow suspension dissolved and changed its color from
yellow to pale brown and finally a solid precipitated. After the
mixture was cooled, the pale brown solid was filtered, washed
with additional 2-methoxyethanol (5 mL) and Et2O (25 mL),
air-dried, and identified spectroscopically as 2. Yield: 0.544 g
(77%). 1H NMR (DMSO-d6, room temperature): 8.08-8.01 (m,
4H, Hortho, Ph), 7.83-7.78 (m, 2H, Hpara, Ph), 7.73-7.67 (m,
4
4H, Hmeta, Ph), 5.13 (t, 2H, dCH2, J PH ) 6.0), 3.59 (d, 4H,
2
2
CH2P, J PH ) 17.7), 2.34 (d, 12H, PMe, J PH ) 14.1). 31P{1H}
NMR (DMSO-d6, room temperature): 26.61.
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )Cl] (3).
The bis-phosphonium salt 1b (0.585 g, 0.90 mmol) and PtCl2-
(NCPh)2 (0.425 g, 0.90 mmol) were refluxed in 2-methoxyetha-
nol (10 mL) under Ar for 24 h. The resulting cold suspension
was filtered, and the obtained pale yellow solid was washed
with additional 2-methoxyethanol (2 × 2 mL) and Et2O (10
mL), air-dried, and identified as 3. Yield: 0.324 g (44.6%).
Atom numbering for complexes 3-5 is as follows:
Exp er im en ta l Section
Gen er a l Meth od s. Details for general procedures are given
in the Supporting Information. The compound PtCl2(NCPh)2
was prepared according to published methods.38
Syn th esis. The complete synthetic methods and full ana-
lytic and spectroscopic data are collected as Supporting
Information. Only representative synthetic procedures and
selected spectroscopic NMR data (δ, ppm; J , Hz) are described
below.
[Me2P h P CH2C(dCH2)CH2P P h Me2]Cl2 (1a ). To a solution
of 3-chloro-2-(chloromethyl)propene (1.85 mL, 16.0 mmol) in
20 mL of deoxygenated N,N-dimethylacetamide under Ar
atmosphere was added PPhMe2 (11.38 mL, 80 mmol). The
resulting solution was refluxed for 3 h. After the mixture was
cooled, the white solid that precipitated was filtered, washed
with Et2O (75 mL), dried in vacuo, and identified as 1a .
1
Yield: 4.423 g (68.9%). H NMR (CDCl3, room temperature):
8.02-7.96 (m, 4H, Hortho, Ph), 7.53-7.40 (m, 6H, Hmeta + Hpara
,
)
4
2
Ph), 5.13 (t, 2H, dCH2, J PH ) 6.0), 4.07 (d, 4H, PCH2, J PH
2
18.6), 2.38 (d, 12H, PMe, J PH ) 13.5). 31P{1H} NMR (CDCl3,
room temperature): 24.76.
[P h 3P CH2-(E)-C(Me)dC(H)P P h 3]Cl2 (1b ). Quantitative
yield. 1H NMR (CDCl3, room temperature): 8.05 (dd, 1H, d
2
4
1H NMR (CDCl3, room temperature): 8.77 (ddt, 1H, H6, 3J H6H5
CH, J PH ) 19.2, J PH ) 3.6), 7.97-7.89 (m, 6H, PPh3), 7.65-
2
4
) 7.8, 4J H6P(Pt) ) 5.1, 4J H6 H4 ≈ J H6P ) 1.2, 3J H6Pt ) 41.4), 7.77-
7.39 (m, 24H, PPh3), 5.87 (d, 2H, CH2, J PH ) 16.5), 1.63 (t,
4
3H, CH3, J PH ) 2.4). 31P{1H} NMR (CDCl3, room tempera-
7.68 (m, 4H, Ho, PPh2), 7.51-7.38 (m, 9H, PPh2 + H5), 7.33-
4
3
4
ture): 22.98 (d, CH2P, J PP ) 5.5), 11.06 (d, dCHP).
7.22 (m, 8H, PPh2), 7.03 (tt, 1H, H4′, J H4′H3′ ) 7.5, J H4′H2′
)
)
[P h 3P CH2C(dCH2)P P h 3]Br 2 (1c). Yield: 98%. 1H NMR
(CDCl3, room temperature): 7.76-7.61 (m, 30H, PPh3), 6.76
3
1.2), 6.85-6.77 (m, 3H, H4 + H3′), 6.41 (dd, 2H, H2′, J H3′H2′
7.8), 2.99 (dq, 2H, CH2, 2J PH ) 9.3, 4J H-Me ) 0.9, 3J H-Pt ) 17.7),
3
1.31 (dm, 3H, Me, J PH ) 2.4). 31P{1H} NMR (CD2Cl2, room
4
(d, 1H, dCH trans P, J PH ) 45.9), 6.37 (dt, 1H, dCH cis P,
4
2
3
3J PH ) 22.2, J HH ) 2.7), 5.32 (dd, 2H, CH2, J PH ) 14.7, J PH
temperature): 34.14 (d, Ph2P-C-Pt, 3J PP ) 25.0, 2J PtP ) 601),
) 11.1). 31P{1H} NMR (CDCl3, room temperature): 27.48 (d,
1
25.48 (d, Ph2P-Pt, J PtP ) 2064.5).
3
PCH2, J PP ) 18.7), 23.29 (d, dCHP).
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )Br ] (4).
Complex 3 (0.100 g, 0.124 mmol) was suspended in 20 mL of
a mixture of acetone and MeOH (1/1), and KBr (0.118 g, 1.00
mmol) was added. The resulting mixture was stirred at 25 °C
for 3 days and then evaporated to dryness. The gray residue
was extracted with CH2Cl2 (2 × 30 mL), and the extracts were
filtered. The solid was discarded, and the clear yellow solution
was evaporated to dryness. By Et2O addition (20 mL) and
vigorous stirring, a yellow solid (4) was obtained, which was
filtered, washed with Et2O (10 mL), and air-dried. Yield: 0.082
[P h 3P CH2-(E)-C(H)dC(H)P P h 3]Cl2 (1d ). Yield: 34.7%. 1H
NMR (CDCl3, room temperature): 9.11 (pseudo t, 1H, dCHP,
3J HH ≈ J PH ) 16.8), 7.86-7.40 (m, 30H, PPh3), 6.38 (t, broad,
2
not resolved, 1H, dCH), 5.72 (d, broad, 2H, PCH2, 2J PH ) 11.1).
31P{1H} NMR (CDCl3, room temperature): 22.56 (s, PCH2),
18.29 (s, dCHP).
[P h 3P CH2-(E)-C(H)dC(H)P P h 3]Br 2 (1e). Yield: 90.7%. 1H
NMR (CDCl3, room temperature): 8.91 (ddd, 1H, dCHP, 2J PH
3
4
) 20.7, J HH ) 16.0, J PH ) 3.0), 7.83-7.39 (m, 30H, PPh3),
1
g (78%). H NMR (CDCl3, room temperature): 8.83 (ddt, 1H,
3
4
4
4
3
(38) Anderson, G. K.; Lin, M. Inorg. Synth. 1990, 28, 60.
H6, J H6H5 ) 7.8, J H6P(Pt) ) 6.3, J H6H4 ≈ J H6P ) 1.5, J H6Pt
)

4920 Organometallics, Vol. 22, No. 24, 2003
Gracia et al.
43.8), 7.77-7.67 (m, 4H, Ho, PPh2), 7.57-7.29 (m, 17H, PPh2
resulting solution was evaporated to dryness, the residue was
extracted with CH2Cl2 (2 × 20 mL), and the extracts were
filtered over a Celite pad. The obtained solution was washed
with H2O (10 mL), dried with MgSO4, and evaporated to
dryness, giving a yellow residue. This residue was triturated
with Et2O (50 mL), and the resulting yellow solid (7) was
filtered, washed with additional Et2O (50 mL), and dried in
3
4
+ H5), 7.07 (tt, 1H, H4′, J H4′H3′ ) 7.5, J H4′H2′ ) 1.2), 6.89-
3
6.81 (m, 3H, H4 + H3′), 6.46 (dd, 2H, H2′, J H3′H2′ ) 7.8), 3.05
(dq, 2H, CH2, 2J PH ) 8.4, 4J H-Me ) 0.9), 1.31 (dm, 3H, Me, 4J PH
) 2.7). 31P{1H} NMR (CD2Cl2, room temperature): 34.16 (d,
Ph2P-C-Pt, 3J PP ) 24.6, 2J PtP ) 599), 26.53 (d, Ph2P-Pt, 1J PtP
) 2035.6).
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )I] (5).
vacuo. Yield: 0.822 g (87%). 1H NMR (CDCl3, room temper-
1
2
Yield: 81%. H NMR (CD2Cl2, room temperature): 9.09 (ddt,
ature): 7.63-7.16 (m, 30H, PPh3), 3.62 (dd, 1H, CH, J PH
)
4
4
2
1H, H6, 3J H6H5 ) 7.8, 4J H6P(Pt) ) 6.3, 4J H6H4 ≈ J H6P ) 1.5, 3J H6Pt
23.0, J PH ) 7.5), 2.99 (d, 1H, CH, J PH ) 16.4), 1.74 (s, 3H,
CH3). 31P{1H} NMR (CDCl3, room temperature): 11.62 (s),
11.42 (s).
) 45.9), 7.68-7.61 (m, 4H, Ho, PPh2), 7.56-7.28 (m, 17H, PPh2
3
4
+ H5), 7.06 (tt, 1H, H4′, J H4′H3′ ) 7.5, J H4′H2′ ) 1.2), 6.85 (m,
1H, H4), 6.83 (t, 2H, H3′, 3J H4′H3′ ≈ J H3′H2′ ) 7.5), 6.48 (dd, 2H,
3
[P t (C6H 3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )(NC-
Me)]ClO4 (8). To a suspension of 3 (0.100 g, 0.124 mmol) in
15 mL of NCMe was added AgClO4 (0.026 g, 0.124 mmol). The
resulting suspension was stirred at room temperature for 2 h
with exclusion of light and then filtered over a Celite pad. The
clear pale yellow solution was evaporated to small volume (2
mL). By Et2O addition (20 mL) and continuous stirring 8 was
obtained as a light yellow solid, which was filtered and air-
2
4
H2′), 3.12 (dq, 2H, CH2, J PH ) 9.3, J H-Me ) 0.6), 1.27 (dm,
3H, Me, J PH ) 2.4). 31P{1H} NMR (CD2Cl2, room tempera-
4
ture): 34.29 (d, Ph2P-C-Pt, 3J PP ) 23.4, 2J PtP ) 580.5), 27.61
1
(d, Ph2P-Pt, J PtP ) 1981.4).
[P t (C6H 4-4-F ){C6H 3-5-F -2-P (p -F C6H 4)2-CdC(Me)CH 2P -
(p-F C6H4)2-KC,C,P }Cl2] (6). The bis-phosphonium salt 1f
(0.533 g, 0.704 mmol) and PtCl2(NCPh)2 (0.332 g, 0.704 mmol)
were refluxed in 2-methoxyethanol (15 mL) for 24 h. After the
reaction time, some decomposition was evident. The cool
suspension was then evaporated to dryness, leaving a yellow
greenish oil. This oily residue was extracted with CH2Cl2 (3 ×
10 mL), dried with MgSO4, evaporated to drynesss, and treated
with Et2O (15 mL), giving a pale yellow solid, which was
identified spectroscopically as a mixture of 6 and the starting
bis-phosphonium salt 1f. Recrystallization from 2-methoxy-
ethanol affords 6 in analytically pure form as a white solid.
Yield: 0.174 g (26.0%). Atom numbering for compound 6 is as
follows:
1
dried. Yield: 0.075 g (66.3%). H NMR (CDCl3, room temper-
3
4
4
ature): 7.91 (ddt, 1H, H6, J H6H5 ) 7.5, J H6P(Pt) ) 6.3, J H6H4
) 4J H6P ) 1.2, J H6Pt ) 43.5), 7.59-7.34 (m, 21H, PPh2 + H5),
3
3
4
7.06 (tt, 1H, H4′, J H4′H3′ ) 7.2, J H4′H2′ ) 1.2), 6.96 (ddd, 1H,
3
4
4
H4, J H4H5 ) 7.2, J H4P ) 6.3, J H4H6 ) 1.2), 6.82 (t, 2H, H3′,
3J H3′H2′ ) J H3′H4′ ) 7.2), 6.42 (dd, 2H, H2′), 3.23 (d, 2H, CH2,
3
2J PH ) 9.0), 2.50 (d, 3H, NCMe, J PH ) 0.9), 1.46 (d, 3H, CH3,
5
4J PH ) 2.4). 31P{1H} NMR (CDCl3, room temperature): 37.93
3
2
1
(d, PPh2, J PP ) 24.4, J PtP ) 583), 31.80 (d, Pt-PPh2, J PtP
)
2002).
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )(P P h 3)]-
1
ClO4 (9). Yield: 79.5%. H NMR (CDCl3, room temperature):
7.64-7.58 (m, 2H, Ph), 7.43-7.16 (m, 27H, Ph (25H) + C6H3
(2H)), 7.08-6.92 (m, 8H, Ph), 6.87-6.82 (m, 2H, H4′ + C6H3
3
3
(1H)), 6.78 (t, 2H, H3′, J H3′H4′ ) J H3′H2′ ) 7.5), 6.64 (dd, 2H,
4
2
H2′, J H2′H4′ ) 1.2), 3.45 (d, 2H, CH2, J PH ) 9.0), 1.36 (d, 3H,
CH3, J PH ) 2.1). 31P{1H} NMR (CD2Cl2, room temperature):
4
3
35.64 (dd, A part of an ABX spin system, PPh2, J PAPB ) 20.4,
3J PAPPh3 ) 7.4, J PtPA ) 472), 35.04 (dd, B part of an ABX spin
2
system, Pt-PPh2, 3J PAPB ) 20.4, 2J PBPPh3 ) 16.0, 1J PtPB ) 1923),
1
25.67 (dd, X part of an ABX spin system, Pt-PPh3, J PtP
)
2513).
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )(p y)]-
ClO4 (10). Yield: 78.4%. 1H NMR (CDCl3, room tempera-
ture): 8.50 (dd, 2H, Ho, py, 3J HoHm ) 6.6, 4J HoHp ) 1.5, 3J PtHo
25.2), 7.91 (tt, 1H, Hp, py, J HpHm ) 7.8, J HpHo ) 1.5), 7.63-
7.59 (m, 2H, Ph), 7.47-7.35 (m, 12H, Ph + 2Hm (py)), 7.28-
)
3
4
3
4
7.15 (m, 9H, Ph + H5), 7.05 (tt, 1H, H4′, J H4′H3′ ) 7.8, J H4′H2′
3
4
4
) 1.2), 6.91 (td, 1H, H4, J H4H5 ) J H4P ) 6.7, J H4H6 ) 1.2),
3
6.82 (t, 2H, H3′, J H3′H4′
)
3J H3′H2′ ) 7.8), 6.60 (ddt, 1H, H6,
3J H6H5 ) 7.2, 4J H6P(Pt) ) 6.0, 4J H6H4 ) 4J H6P ) 1.2, 3J PtH6 ) 44.1),
2
6.47 (dd, 2H, H2′), 3.33 (d, 2H, CH2, J PH ) 9.0), 1.47 (d, 3H,
CH3, J PH ) 2.4). 31P{1H} NMR (CD2Cl2, room temperature):
4
3
1H NMR (CD2Cl2, room temperature): 8.53 (td, 1H, H6, J H6F
3
2
4
4
3
35.87 (d, PPh2, J PP ) 24.7, J PtP ) 546), 33.28 (d, Pt-PPh2,
≈ J H6P(Pt) ) 10.0, J H6H4 ) 1.0, J PtH6 ) 38.6), 8.13 (ddd, 2H,
Ho, Pt-PC6H4F, J HP ) 10.2, J H6Hm ) 8.7, J HF ) 5.4), 7.97
1J PtP ) 2033).
3
3
4
3
3
4
[P t (C6H 3-3-P h -2-P P h 2-CdC(Me)CH 2P P h 2-KC,C,P )(Ct
(ddd, 2H, Ho, PC6H4F, J HP ) 12.0, J HoHm ) 9.0, J HF ) 5.4),
1
NtBu )]ClO4 (11). Yield: 80.7%. H NMR (CDCl3, room tem-
7.47 (ddd, 2H, Ho, Pt-PC6H4F, 3J HP ) 10.2, 3J HoHm ) 8.7, 4J HF
3
4
) 5.4), 7.31 (td, 2H, Hm, PC6H4F, J HmHo ) 3J HmF ) 9.0, J HmP
3
4
perature): 8.05 (dddd, 1H, H6, J H6H5 ) 8.7, J H6P(Pt) ) 6.3,
4J H6H4 ) 1.8, J H6P ) 1.5, J PtH6 ) 55.2), 7.59-7.28 (m, 21H,
4
3
3
3
) 2.1), 7.10 (td, 2H, Hm, Pt-PC6H4F, J HmHo ) J HmF ) 8.7,
4J HmP ) 2.1), 7.02-6.97 (m, 4H, 2Ho (PC6H4F) + 2Hm (PC6H4F)),
6.89-6.80 (m, 4H, 2Hm (Pt-PC6H4F) + H3 + H4), 6.67 (dd,
3
4
Ph + H5), 7.07 (tt, 1H, H4′, J H4′H3′ ) 7.8, J H4′H2′ ) 1.2), 7.00
3
4
4
(ddd, 1H, H4, J H4H5 ) 7.2, J H4P ) 5.7, J H4H6 ) 1.8), 6.81 (t,
3J H3′H2′ ) 7.8), 6.41 (dd, 2H, H2′), 3.61 (d,
3
3
4
3
2H, H3′, J H3′H4′
)
2H, H2′, J H2′H3′ ) 9.0, J H2′F ) 6.0, J PtH2′ ) 52.8), 5.99 (t, 2H,
2
4
3
2
2H, CH2, J PH ) 9.3), 1.57 (d, 3H, CH3, J PH ) 2.4), 1.46 (s,
H3′, J H2′H3′
)
3J H3′F ) 9.0), 3.95 (dd, 2H, CH2, J PH ) 10.5,
9H, tBu). 31P{1H} NMR (CDCl3, room temperature): 39.22 (d,
4J PH ) 1.5), 2.13 (d, 3H, CH3, 4J PH ) 2.4). 31P{1H} NMR (CD2-
3
2
1
Cl2, room temperature): 30.63 (d, Pring-C-Pt, 3J PP ) 21.4, 2J PtP
PPh2, J PP ) 23.4, J PtP ) 465), 31.83 (d, Pt-PPh2, J PtP
)
5
1
1824).
) 412), 4.25 (dd, Pt-P, J PF ) 8.3, J PtP ) 1510).
[P h 3P C(H)C(Me)C(H)P P h 3]Cl (7). The bis-phosphonium
salt 1b (1.000 g, 1.54 mmol) was suspended in dry THF (30
mL) under Ar, and Li(NiPr2) (0.77 mL of a 2.0 M solution, 1.54
mmol) was added dropwise at room temperature. A deep red
solution was obtained, which was stirred overnight. The
[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )(dppm -
1
KP )]ClO4 (12). Yield: 87%. H NMR (CDCl3, room tempera-
ture): 7.68-7.00 (m, 44H, PPh2 + C6H3 + H4′), 6.77 (t, 2H,
H3′, 3J H3′H4′ ) 3J H3′H2′ ) 7.2), 6.53 (d, 2H, H2′), 3.46 (m, 2H, CH2,
2
4
dppm), 3.11 (dd, 2H, Pt-PCH2, J PH ) 9.9, J PH ) 3.00), 1.38

Bond Activation and Coupling Induced by Pt(II) Complexes
Organometallics, Vol. 22, No. 24, 2003 4921
4
(d, 3H, CH3, J PH ) 2.4). 31P{1H} NMR (CDCl3, room temper-
of four ω-scan runs (starting ω -30°) at values φ ) 0, 90, 180,
and 270° with the detector at 2θ ) 30°. For each of these runs,
606 frames were collected at 0.3° intervals and 5 s per frame.
For the complex 14‚CHCl3 a hemisphere of data was collected
on the basis of three ω-scan runs (starting ω -30°) at values
φ ) 0, 90, and 180° with the detector at 2θ ) 30°. For each of
these runs, frames (606, 435, and 230, respectively) were
collected at 0.3° intervals and 10 s per frame. In both cases,
the diffraction frames were integrated using the program
SAINT39 and the integrated intensities were corrected for
absorption with SADABS.40
Str u ctu r e Solu tion a n d Refin em en t. The two structures
were solved and developed by Patterson and Fourier meth-
ods.41 All non-hydrogen atoms were refined with anisotropic
displacement parameters. The hydrogen atoms were placed
at idealized positions and treated as riding atoms. Each
hydrogen atom was assigend an isotropic displacement pa-
rameter equal to 1.2 times the equivalent isotropic displace-
ment parameter of its parent atom. The structures were
refined to Fo2, and all reflections were used in the least-squares
calculations.42
3
3
2
ature): 36.84 (dd, PPh2, J PP ) 19.0, J PP(dppm) ) 7.2, J PtP
)
)
3
1
467), 35.51 (t, Pt-PPh2, J PP
)
2J P(cis)P(dppm) ) 19.0, J PtP
2 1
1913), 15.84 (ddd, Pt-PPh2, dppm, J PP ) 94, J PtP ) 2526),
2
-23.74 (d, free PPh2, dppm, J PP ) 94).
m er -[P t(C6H3-3-P h -2-P P h 2-CdC(Me)CH2P P h 2-KC,C,P )-
(Cl)3] (13). A suspension of complex 3 (0.100 g, 0.124 mmol)
in 20 mL of CH2Cl2 was treated with a solution of Cl2 in CCl4
(15% excess, 0.143 mmol) at room temperature. The initial pale
yellow suspension gradually dissolved, and a deep yellow
solution was obtained. After 1 h of stirring, a very small
amount of solid remained in suspension. The solid was filtered
and discarded, and the clear solution was evaporated to
dryness. By addition of Et2O (20 mL) and continuous stirring,
13 was obtained as a deep yellow solid, which was filtered and
air-dried. Yield: 0.0745 g (68.5%). 1H NMR (CD2Cl2, room
3
4
temperature): 8.84 (dddd, 1H, H6, J H6H5 ) 10.5, J H6P(Pt)
)
4
4
3
8.1, J H6H4 ) 2.4, J H6P ) 1.2, J PtH6 ) 37.5), 8.14-8.07 (m,
2H, PPh2), 7.97-7.79 (m, 5H, PPh2 + H5), 7.69-7.36 (m, 14H,
PPh2), 7.16 (tt, 1H, H4′, 3J H4′H3′ ) 7.8, 4J H4′H2′ ) 1.2), 6.93 (ddd,
3
4
4
1H, H4, J H4H5 ) 6.0, J H4P ) 5.2, J H4H6 ) 2.4), 6.87 (t, 2H,
3
3
H3′, J H3′H4′ ) J H3′H2′ ) 7.8), 6.42 (dd, 2H, H2′), 3.77 (dd, 2H,
2
4
4
CH2, J PH ) 11.1, J PH ) 2.4), 1.89 (d, 3H, CH3, J PH ) 1.8).
Ack n ow led gm en t. Funding by the Direccio´n Gen-
eral de Investigacio´n Cient´ıfica y Te´cnica (DGICYT)
(Spain, Projects BQU2002-0510 and BQU2002-00554)
is gratefully acknowledged. T.S. thanks the MECD
(Spain) for a postdoctoral fellowship.
31P{1H} NMR (CD2Cl2, room temperature): 32.48 (d, PPh2, 3J PP
2
1
) 25.5, J PtP ) 296), 2.76 (d, Pt-PPh2, J PtP ) 1371).
t r a n s -[P t (C 6 H 3 -3 -P h -2 -P P h 2 -C dC (M e )C H 2 P P h 2 -
1
KC,C,P )(Cl)(I)2] (14). Yield: 77.9%. H NMR (CD2Cl2, room
temperature): 8.71 (dddd, 1H, H6, 3J H6H5 ) 9.3, 4J H6P(Pt) ) 8.1,
4J H6H4 ) 2.4, J H6P ) 1.2, J PtH6 ) 33.3), 7.86-7.79 (m, 4H,
4
3
PPh2), 7.67-7.55 (m, 7H, PPh2 + H5), 7.46-7.33 (m, 10H,
Su p p or tin g In for m a tion Ava ila ble: Text giving general
procedures, full experimental details, synthetic methods, and
analytic and spectroscopic data for all compounds prepared
in this paper and tables giving complete data collection
parameters, atomic coordinates, all bond distances and angles,
and thermal parameters for 5 and 14‚CHCl3. This material is
available free of charge via the Internet at http://pubs.acs.org.
3
4
PPh2), 7.06 (tt, 1H, H4′, J H4′H3′ ) 7.5, J H4′H2′ ) 1.2), 6.79 (t,
3
3
2H, H3′, J H3′H4′ ) J H3′H2′ ) 7.5), 6.76 (m, 1H, H4, overlapped
2
with H3′), 6.51 (dd, 2H, H2′), 3.93 (dd, 2H, CH2, J PH ) 10.8,
4J PH ) 1.8), 2.13 (d, 3H, CH3, 4J PH ) 2.1). 31P{1H} NMR (CD2-
3
2
Cl2, room temperature): 34.41 (d, PPh2, J PP ) 23.3, J PtP
338), -13.46 (d, Pt-PPh2, J PtP ) 1427).
)
1
Cr ysta l Str u ctu r e Deter m in a tion of Com p lexes 5 a n d
14. Crystals of 5 and of 14‚CHCl3 of adequate quality for X-ray
measurements were grown by slow vapor diffusion of Et2O into
a CH2Cl2 (5) or CHCl3 (14) solution of the corresponding crude
complex. A single crystal of dimensions 0.29 × 0.26 × 0.07
mm (5) or 0.12 × 0.11 × 0.087 mm (14) was mounted at the
end of a quartz fiber in a random orientation and covered with
epoxy.
Da ta Collection . Data collection was performed in both
cases at 100 K on a Bruker Smart CCD diffractometer using
graphite-monochromated Mo KR radiation (λ ) 0.710 73 Å).
For complex 5 a full sphere of data was collected on the basis
OM0305465
(39) SAINT Version 5.0; Bruker Analytical X-ray Systems, Madison,
WI.
(40) Sheldrick, G. M. SADABS: Empirical Absorption Correction
Program; Universita¨t Go¨ttingen, Go¨ttingen, Germany, 1996.
(41) Sheldrick, G. M. SHELXS-86. Acta Crystallogr. 1990, A46, 467.
(42) Sheldrick, G. M. SHELXL-97: FORTRAN Program for the
Refinement of Crystal structures from Diffraction Data; Universita¨t
Go¨ttingen, Go¨ttingen, Germany, 1997. Molecular graphics were done
using the commercial package SHELXTL-PLUS: SHELXTL-PLUS,
Release 5.05/V; Siemens Analytical X-ray Instruments, Inc., Madison,
WI, 1996.