Palladium complexes of a novel family of P,N-chelates, the 2-(2-pyridyl)phospholes: Synthesis, structural characterization, and catalytic activity for olefin/CO copolymerization

Article abstract of DOI:10.1021/om011034y

2-(2-Pyridyl)phospholes bearing phenyl or cyclohexyl substituents on the phosphorus atom and 2-pyridyl, phenyl or 2-thienyl groups on the C⁵ atom were prepared using the Fagan-Nugent route. An x ray diffraction study performed on the complex featuring a 1-phenyl-2-(2-pyridyl)phosphole ligand revealed a cis configuration of the phosphorus atom and the methyl group. The geometry of the coordinated P atom was found to be highly distorted due to the rigidity of the 1,4-P,N chelate backbone.

Full text of DOI:10.1021/om011034y

Organometallics 2002, 21, 1591-1602
1591
P a lla d iu m Com p lexes of a Novel F a m ily of P ,N-Ch ela tes,
th e 2-(2-P yr id yl)p h osp h oles: Syn th esis, Str u ctu r a l
Ch a r a cter iza tion , a n d Ca ta lytic Activity for Olefin /CO
Cop olym er iza tion
Mathieu Sauthier,† Franc¸ois Leca,† Lo¨ıc Toupet,‡ and Re´gis Re´au*,†
Organome´talliques et Catalyse: Chimie et Electrochimie Mole´culaires, UMR 6509,
Institut de Chimie de Rennes, and Groupe Matie`re Condense´e et Mate´riaux, UMR 6626,
CNRS-Universite´ de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
Received December 4, 2001
2-(2-Pyridyl)phospholes bearing phenyl or cyclohexyl substituents on the phosphorus atom
and 2-pyridyl, phenyl, or 2-thienyl groups on the C5 atom were prepared according to the
Fagan-Nugent route. They reacted with (cod)PdClCH3, giving rise to stable complexes 3a -c
and 3a ′-c′ as single diastereoisomers in excellent yields. An X-ray diffraction study
performed on complex 3b featuring a 1-phenyl-2-(2-pyridyl)phosphole ligand revealed a cis
configuration of the phosphorus atom and the methyl group. The geometry of the coordinated
P atom is highly distorted due to the rigidity of the 1,4-P,N chelate backbone. Complexes
3a ,a ′, featuring 2,5-bis(2-pyridyl)phosphole ligands, display fluxional behavior. NMR studies
revealed an intramolecular exchange between the pendant and coordinated pyridyl groups,
showing that 2-(2-pyridyl)phospholes can behave as hemilabile ligands. Treatment of
complexes 3a -c and 3a ′-c′ with 1 equiv of AgSbF6 in CH3CN afforded the corresponding
cationic derivatives 4a -c and 4a ′-c′ as single diastereoisomers. Complexes possessing no
pendant pyridyl moiety are air-stable solids that can be isolated in high yield. They are
active for the copolymerization of ethylene and CO in CH2Cl2, whereas complex 4a , bearing
the 2-(2-pyridyl)phosphole ligand 2a , is reduced quantitatively to give the dinuclear
[Pd2(2a )2]2+ complex 6. The catalytic activities obtained with complexes 4b,c a n d 4b′,c′ are
among the highest obtained with P,N chelates. The substitution pattern of the 2-(2-pyridyl)-
phosphole ligands has an impact on the productivity of the Pd catalysts. P-cyclohexylphos-
pholes are more efficient ligands than their P-phenyl analogues. Complex 4c, featuring a
2-(2-pyridyl)-5-(2-thienyl)phosphole ligand, catalyzed the copolymerization of CO and
norbornene at 85 °C, affording oligomers with a narrow molecular weight distribution. In
methanol, the cationic palladium methyl complex 4c afforded the bis-chelate [Pd(2c)2]2+
complex 5, which has been characterized by an X-ray diffraction study. Although the geometry
around the palladium atom is distorted, the metric data of complex 5 are similar to those of
3b.
In tr od u ction
hemilabile ligands and induce selective processes, al-
lowing control over the reactivity of the metal center.
Mixed P,N-chelates are also efficient ligands for impor-
tant catalytic reactions, including reduction,2a,b allylic
alkylation,1g olefin-CO copolymerization,2c-g and the
Heck reaction.2h In several cases, due to their specific
properties, catalytic activities or selectivities higher
than those observed with diphosphines or dinitrogen
donor ligands have been achieved.3
Heteroditopic chelates have attracted considerable
interest in coordination chemistry and homogeneous
catalysis for several decades.1 Among them, bidentate
P,N-ligands combining σ3,λ3-phosphorus and sp2-hybrid-
ized nitrogen donor centers have been particularly
studied.1c-g Owing to the different stereoelectronic
properties of the two coordination sites, they can act as
Many sp2-N donors have been used as synthons for
the design of P,N-ligands. The most frequently en-
* To whom correspondence should be addressed. E-mail:
regis.reau@univ-rennes1.fr.
† Organome´talliques et Catalyse: Chimie et Electrochimie Mole´cu-
laires.
(2) See for recent examples: (a) Yang, H.; Gao, H.; Angelici, R.
Organometallics 2000, 19, 622. (b) Braunstein, P.; Naud, F.; Rettig,
S. New J . Chem. 2001, 25, 32. (c) Braunstein, P.; Fryzuck, M. D.; Le
Dall, M.; Naud, F.; Rettig, S.; Speiser, F. J . Chem. Soc., Dalton Trans.
2000, 1067. (d) Chen, Y.-C.; Chen, C.-L.; Chen, J .-T.; Liu, S.-T.
Organometallics 2000, 20, 1285. (e) Reddy, K. R.; Surekha, K.; Lee,
G.-H.; Peng, S.-M.; Liu, S.-T. Organometallics 2000, 19, 2637. (f) Reddy,
K. R.; Surekha, K.; Lee, G.-H.; Peng, S.-M.; Liu, S.-T. Organometallics
2001, 20, 1292. (g) Aeby, A.; Gsponer, A.; Consiglio, G. J . Am. Chem.
Soc. 1998, 120, 11000. (h) Deng, W.-P.; Hou, X.-L.; Daia, L.-X.; Dong,
X.-W. Chem. Commun. 2000, 1483.
‡ Groupe Matie`re Condense´e et Mate´riaux.
(1) (a) Bader, A.; Lindler, E. Coord. Chem. Rev. 1991, 108, 27. (b)
Younkin, T. R.; Connor, E. F.; Henderson, J . I.; Friederich, S. K.;
Grubbs, R. H.; Bansleben, D. A. Science 2000, 287, 460. (c) Ittel, S. D.;
J ohnson, L. K.; Brookhart, M. Chem. Rev. 2000, 100, 1169. (d)
Newkome, G. R. Chem. Rev. 1993, 93, 2067. (e) Espinet, P.; Soulantica,
K. Coord. Chem. Rev. 1999, 193-195, 499. (f) Braunstein, P.; Naud,
F. Angew. Chem., Int. Ed. 2001, 40, 680. (g) Helchem, G.; Pfaltz, A.
Acc. Chem. Res. 2000, 33, 336.
10.1021/om011034y CCC: $22.00 © 2002 American Chemical Society
Publication on Web 03/20/2002

1592 Organometallics, Vol. 21, No. 8, 2002
Sauthier et al.
Sch em e 1
countered N-donors are pyridines, but oxazolines,1f,g
imines,2d-f or pyrazolines3f,g have also been quite ex-
tensively employed. Less attention has been paid to
variation of the phosphorus moiety, the great majority
of P,N-ligands bearing diphenylphosphino fragments.
This prompted us to prepare new 1,4-P,N chelates
incorporating a pyridyl and a phosphole group as
potential ligands for homogeneous catalysis. Phospholes
act as classical two-electron-donor tertiary phosphines
toward late transition metals4,5 and are versatile syn-
thons for the tailoring of P-ligands in homogeneous
catalysis. For example, mono-, di-, or tetraphospholes
are efficient ligands for the Rh-catalyzed hydroformyl-
ation of olefins5a-d and several C-C bond forming
processes involving palladium catalysts (allylic alkyl-
ation,5e olefin-CO copolymerization,5f Heck reaction5g).
Very few P,N-ligands incorporating phospholes have
been described and used in homogeneous catalysis.6
Furthermore, only the dibenzophosphole system has
been investigated, and it is well-known that this dibenzo-
annelated moiety does not display the classical proper-
ties of a phosphole but behaves like a diphenylphos-
phine.4a,b Herein, we describe the synthesis of 2-(2-
pyridyl)phospholes,7 their coordination behavior toward
neutral and cationic palladium centers, and their use
as ligands for olefin-CO copolymerization, a catalytic
reaction with numerous potential applications.1c,8
Resu lts a n d Discu ssion
Syn th esis of (2-P yr id yl)p h osp h ole Liga n d s. (2-
Pyridyl)phospholes can be obtained via two different
synthetic approaches based on the transformation of the
phosphole ring or on ring closure reactions involving zir-
conacyclopentadienes. Indeed, 2-(2-pyridyl)phospholes
were prepared in 1997 by Mathey and co-workers
according to the first strategy. Thermolysis of 1-(2-
pyridyl)phosphole in the presence of tBuOK afforded a
2-(2-pyridyl)phospholide anion, which acts as a nucleo-
phile toward halogenoalkanes, leading to the corre-
sponding 2-(2-pyridyl)phospholes.9 We have recently
reported that oxidative coupling of bis(2-pyridyl)octa-
1,7-diyne (1a ) with zirconocene followed by treatment
with PhPCl2 gave rise to 1-phenyl-2,5-bis(2-pyridyl)-
phosphole (2a ) (Scheme 1).10a The new 2-(2-pyridyl)-
phospholes 2b,c and 2a ′-c′ described in this study have
been obtained using this synthetic approach (the
Fagan-Nugent route)11 which readily allows variation
in the nature of the P substituent. For example, 1-cyclo-
hexyl-2,5-bis(2-pyridyl)phosphole (2a ′) was obtained in
75% yield from diyne 1a using CyPBr2 (Scheme 1). This
method has been extended to unsymmetrical 1,7-diynes
in order to prepare 2-(2-pyridyl)phospholes possessing
various substituents at the C5 atom of the phosphole
ring. Sonogashira coupling of 1-(2-pyridyl)octa-1,7-diyne
with bromobenzene and 2-bromothiophene allowed an
efficient and large-scale preparation of differently sub-
stituted diynes 1b (77%) and 1c (85%), respectively
(Scheme 1). Compounds 1b and 1c reacted successively
with “zirconocene” and dibromophenylphosphine or di-
bromocyclohexylphosphine to give the corresponding
phospholes 2b,c and 2b′-c′ (Scheme 1). These deriva-
tives are isolated as air-stable solids after purification
(3) See for examples: (a) van Haaren, R.; Duijven, C.; van Stijdonck,
G.; Oevering, H.; Reek, J .; Kamer, P.; van Leeuwen, P. J . Chem. Soc.,
Dalton Trans. 2000, 1549. (b) Shirakawa, E.; Yoshida, H.; Kurahashi,
T.; Nakao, Y.; Hiyama, T. J . Am. Chem. Soc. 1998, 120, 2975. (c)
Loiseleur, O.; Meier, P.; Pfatz, A. Angew. Chem., Int. Ed. 1996, 35,
200. (d) Ripa, L.; Hallberg, A. J . Org. Chem. 1997, 62, 595. (e) Pre´toˆt,
R.; Pfaltz, A. Angew. Chem., Int. Ed. 1998, 37, 323. (f) Schnyder, A.;
Hintermann, L.; Togni, A. Angew. Chem., Int. Ed. Engl. 1995, 34, 931.
(g) Togni, A.; Burckhardt, U.; Gramlich, V.; Pregosin, P. S.; Salzmann,
R. J . Am. Chem. Soc. 1996, 118, 1031. (h) Valk, J . M.; Claridge, T. D.
W.; Brown, J . M.; Hibbs, D.; Hursthouse, M. B. Tetrahedron: Asym-
metry 1995, 6, 2597.
(4) (a) Mathey, F. Chem. Rev. 1988, 88, 429. (b) Quin, L. D. In
Comprehensive Heterocyclic Chemistry; Katritzky, A. R., Ed.; Perga-
mon: Oxford, U.K., 1996; p 757. (c) Redwine, K. D.; Nelson, J . H.
Organometallics 2000, 19, 3054. (d) Redwine, K. D.; Wilson, W. L.;
Moses, D. G.; Catalano, V. J .; Nelson, J . H. Inorg. Chem. 2000, 39,
3392. (e) Ogasawara, M.; Yoshida, K.; Hayashi, T. Organometallics
2001, 20, 1014.
(5) (a) Neibecker, D.; Re´au, R. New J . Chem. 1991, 15, 279. (b) van
der Veen, L.; Kramer, P.; van Leeuwen, P. Angew. Chem., Int. Ed. Engl.
1999, 38, 336. (c) Tissot, O.; Gouyou, M.; Dallemer, F.; Daran, J .-C.;
Balavoine, G. A. Eur. J . Chem. 2001, 2385. (d) Csok, Z.; Klegevich,
G.; Petocz, G.; Kollar, L. J . Organomet. Chem. 1999, 586, 79. (e) Tissot,
O.; Gouyou, M.; Dallemer, F.; Daran, J .-C.; Balavoine, G. A. Angew.
Chem., Int. Ed. 2001, 40, 1076. (f) Doherty, S.; Eastham, G. R.; Tooze,
R. P.; Scanlan, T. H.; Williams, D.; Elsegood, M. R. J .; Clegg, W.
Organometallics 1999, 18, 3558. (g) Mercier, F.; Laporte, F.; Ricard,
L.; Mathey, F.; Schro¨der, M.; Regitz, M. Angew. Chem., Int. Ed. 1997,
39, 22364.
(8) (a) Drent, E.; Budzelarr, P. H. M. Chem. Rev. 1996, 96, 663. (b)
Wul, W. P.; Oosterbeek, H.; Beitel, G. A.; Kramer, G. J .; Drent, E.
Angew. Chem., Int. Ed. 2000, 39, 1848. (c) Sesto, B.; Consiglio, G. Chem.
Commun. 2000, 10011. (d) Baar, C. R.; J ennings, M. C.; Puddephatt,
R. J . Orgnometallics 2001, 20, 3459. (e) Reddy, R.; Chen, C.-L.; Liu,
Y.-H.; Peng, S.-M.; Chen, J .-T.; Liu, S.-T. Organometallics 1999, 18,
2574.
(9) Holand, S.; J eanjean, M.; Mathey, F. Angew. Chem., Int. Ed.
Engl. 1997, 36, 98.
(6) (a) Doucet, H.; Brown, J . M. Tetrahedron: Asymmetry 1997, 8,
3775. Pd-catalyzed copolymerization of olefins and CO: (b) Aeby, A.;
Consiglio, G. J . Chem. Soc., Dalton Trans. 1999, 655. Rh-catalyzed
hydroboration/oxidation of alkenes: (c) Doucet, H.; Fernandez, E.;
Layzell, T. P.; Brown, J . M. Chem. Eur. J . 1999, 5, 1320.
(7) Sauthier, M.; Le Gue´nic, B.; Deborde, V.; Toupet, L.; Halet, J .-
H.; Re´au, R. Angew. Chem., Int. Ed. 2001, 40, 228.
(10) (a) Le Vilain, D.; Hay, C.; Deborde, V.; Toupet, L.; Re´au, R.
Chem. Commun. 1999, 345. (b) Hay, C.; Fischmeister, C.; Hissler, M.;
Toupet, L.; Re´au, R. Angew. Chem., Int. Ed. 2000, 39, 1812. (c) Hay,
C.; Hissler, M.; Fischmeister, C.; Rault-Berthelot, J .; Toupet, L.;
Nyula´szi, L.; Re´au, R. Chem. Eur. J . 2001, 19, 4222.
(11) Fagan, P. J .; Nugent, W. A.; Calabrese, J . C. J . Am. Chem. Soc.
1994, 116, 1880.

Palladium Complexes of 2-(2-Pyridyl)phospholes
Organometallics, Vol. 21, No. 8, 2002 1593
Ta ble 1. Selected NMR Da ta a a n d Yield sb for
Liga n d s 2a -c a n d 2a ′-c′ a n d Com p lexes 3a -c,
3a ′-c′, 4a -c, a n d 4a ′-4c′
Pd-CH3
yield
(%)
compd δ(31P{1H}) δ(1H) (J PC, Hz) δ(13C) (J PC, Hz)
2a 10a
2a ′
2b
2b′
2c
2c′
3a
3a ′
3b
3b′
3c
3c′
4a
4a ′
4b
4b′
4c
+11.7
+27.9
+12.9
+26.9
+12.6
+27.7
+56.9
+70.4
+55.5
+65.2
+55.7
+69.8
+56.8
+62.8
+55.8
+65.2
+57.4
+68.9
73
83
75
65
83
49
88
91
95
87
91
91
90
86
92
95
91
91
0.96 (2.4)
0.68 (2.4)
0.82 (2.8)
0.78 (2.7)
0.92 (2.4)
0.81 (1.3)
1.00 (broad)
-7.5 (2.4)
-11.0 (2.3)
-13.6 (3.3)
-14.3 (3.9)
-10.6 (2.4)
-11.4 (0)
-5.4 (0)
F igu r e 1. ORTEP view of complex 3b with atom labeling.
Thermal ellipsoids show 40% probability levels.
0.72 (1.8)
0.70 (1.7)
0.85 (2.4)
0.70 (2.1)
-12.2 (3.6)
-12.9 (3.9)
-9.2 (2.4)
-9.9 (3.3)
widely used as catalytic precursors for this reaction.
They are usually prepared from the corresponding
neutral chloromethylpalladium derivatives by chlorine
abstraction in a coordinating solvent such as aceto-
nitrile. Reaction of 1 equiv of ligands 2a -c and 2a ′-c′
with Pd(cod)MeCl13 (cod ) 1,5-cycloocta-1,5-diene) af-
forded the corresponding air-stable complexes 3a -c and
3a ′-c′ in excellent yield (Scheme 1, Table 1). The large
coordination 31P{1H} NMR downfield chemical shifts
(ca. 40 ppm) are consistent with the formation of a five-
4c′
a
In CD2Cl2 at room temperature, with the exception of com-
b
pounds 3a (283 K) and 4a /4a ′ (CD2Cl2/CD3CN, 218 K). Isolated
yields, with the exception of complex 4a ′ (spectroscopic yield).
by flash column chromatography in moderate to good
yields (Table 1). It is well-known that the stability of
phospholes depends on the nature of the P substit-
uent.4a,b,10c Phenyl and alkoxy groups12 are stabilizing
substituents, whereas P-alkyl phospholes are generally
highly air sensitive due to their ease of oxidation. Our
results show that P-alkyl phospholes can be easy-to-
handle compounds, provided that the alkyl substituent
is sterically demanding. The new phospholes 2b,c and
2a ′-c′ were characterized by high-resolution mass
spectrometry and gave satisfactory elemental analyses.
Their multinuclear NMR data are typical4a,b and sup-
port the proposed structures. The 31P{1H} NMR spectra
show a single resonance in the range expected for P-aryl
and P-alkyl phospholes (Table 1), and four signals are
observed at low field in the 13C{1H} NMR spectra for
the endocyclic carbon atoms of the phosphole ring. The
Fagan-Nugent reaction is thus a powerful synthetic
route to prepare 2-(2-pyridyl)phospholes with different
substitution patterns. The phosphorus substituent (phen-
yl or cyclohexyl) will directly influence both the steric
and electronic properties of the P-donor atom, while the
second substituent at the C5 atom of the phosphole ring
(2-pyridyl, phenyl, 2-thienyl) is expected to influence the
electronic properties of the N-donor atom via the
extended π-conjugated system.10
Syn th esis a n d Ch a r a cter iza tion of [2-(2-P yr id yl-
p h osp h ole)]p a lla d iu m (II) Com p lexes. We have in-
vestigated the coordination chemistry of 2-(2-pyridyl)-
phospholes toward palladium(II) centers with the aim
to gain more insight into their coordination behavior and
to obtain new catalysts for the copolymerization of
olefins with carbon monoxide. This catalytic reaction has
attracted considerable attention in the past few years,
and much effort has been devoted to the discovery of
new catalytic systems and to an understanding of the
mechanism.1c,2e,f,8 Complexes of the type [Pd(CH3)-
(solvent)(L2)]+, L2 being a chelating ligand, have been
1
membered palladacycle.5f In the H NMR spectra, the
chemical shift of H6 of the pyridyl group is also sensitive
to coordination with a downfield shift superior to 0.6
ppm.
For complexes 3b,c a n d 3b′,c′, bearing no pendant
pyridyl unit, the 31P{1H} NMR spectra of the crude
reaction mixture contain only one sharp resonance,
indicating the formation of a single diastereoisomer. In
the 1H spectra, the methyl group bound to the palladium
appears as a doublet with a weak J PH coupling constant
(Table 1). The magnitude of these coupling constants is
consistent with a cis arrangement of the methyl group
and the phosphorus atom. It is noteworthy that the
13C{1H} NMR chemical shift of the Pd-CH3 moiety is
more sensitive to the nature of the C5 substituent
(phenyl versus 2-thienyl, ∆δ > 3 ppm) than to the P
substituent (phenyl versus cyclohexyl, ∆δ < 0.8 ppm)
(Table 1). The proposed structures were confirmed by
an X-ray diffraction study performed on single crystals
of 3b (Figure 1, Table 2). The coordination sphere
around the Pd atom is close to square planar (maxi-
mum deviation from the best Pd(1)-N(1)-P(1)-C(26)-
Cl(1) plane, 0.03 Å). The five-membered metallacyle
adopts a slightly distorted envelope conformation. The
Pd(1), N(1), C(9), and C(1) atoms lie almost in the same
plane (maximum deviation 0.037 Å) with the P(1) atom
being out of this plane (N(1)-C(9)-C(1)-P(1), 21.3°;
C(9)-N(1)-Pd(1)-P(1), 26.5°). The angles and the
bond lengths of the metallacycle are consistent with
known literature values. For example, the chelate bite
angle P(1)-Pd(1)-N(1) (82.40(12)°) and the Pd(1)-N(1)
(2.197(5) Å) and Pd(1)-P(1) (2.2135(14) Å) distances are
similar to values reported for other 1,4-P,N chelates
such as (phosphinomethyl)oxazoline (83.69(7)°; 2.058(2),
(12) Mattmann, E.; Simonutti, D.; Ricard, L.; Mercier, F.; Mathey,
F. J . Org. Chem. 2001, 66, 755.
(13) Rulke, R. E.; Ernsting, J . M.; Spek, A. L.; Elsevier, C. J .; van
Leeuwen, P. W. N. M.; Vrieze, K. Inorg. Chem. 1993, 32, 5769.

1594 Organometallics, Vol. 21, No. 8, 2002
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles (d eg) for Com p lexes 3b a n d 5
Sauthier et al.
3b
5
5
Pd(1)-P(1)
2.2135(14)
2.197(5)
2.046(5)
2.3356(16)
1.357(7)
1.459(7)
1.352(7)
1.481(7)
1.348(7)
1.808(5)
1.798(5)
82.40(12)
92.99(13)
95.41(18)
89.25(18)
91.9(2)
2.2494(18)
2.154(6)
Pd(1)-P(31)
Pd(1)-N(31)
2.260(2)
2.119(6)
Pd(1)-N(1)
Pd(1)-C(26)
Pd(1)-Cl(1)
N(1)-C(9)
1.344(9)
1.453(10)
1.316(10)
1.487(11)
1.349(10)
1.804(8)
1.811(7)
82.77(16)
N(31)-C(39)
1.320(10)
1.483(11)
1.334(11)
1.481(11)
1.354(11)
1.814(8)
1.794(7)
82.80(17)
94.4(2)
C(9)-C(1)
C(39)-C(31)
C(1)-C(2)
C(31)-C(32)
C(2)-C(7)
C(32)-C(37)
C(7)-C(8)
C(37)-C(38)
C(8)-P(1)
C(38)-P(31)
P(1)-C(1)
P(31)-C(31)
N(1)-Pd(1)-P(1)
N(1)-Pd(1)-Cl(1)
P(1)-Pd(1)-C(26)
C(26)-Pd(1)-Cl(1)
C(1)-P(1)-C(8)
C(1)-P(1)-C(20)
C(1)-P(1)-Pd(1)
C(8)-P(1)-Pd(1)
C(8)-P(1)-C(20)
C(20)-P(1)-Pd(1)
N(31)-Pd(1)-P(31)
N(1)-Pd(1)-N(31)
P(1)-Pd(1)-P(31)
102.64(7)
92.3(3)
109.6(3)
96.2(2)
128.8(2)
109.5(4)
114.6(3)
C(31)-P(31)-C(38)
C(31)-P(31)-C(48)
C(31)-P(31)-Pd(1)
C(38)-P(31)-Pd(1)
C(38)-P(31)-C(48)
C(48)-P(31)-Pd(1)
91.7(4)
110.8(3)
95.2(2)
128.7(3)
107.5(4)
116.9(3)
108.1(2)
96.24(16)
132.97(16)
107.7(2)
113.39(17)
2.2128(8) Å)2c or phosphine-imines (81.37(11)°; 2.224(4),
2.196(2) Å).2d-f The Pd(1)-Cl(1) (2.3356(16) Å) and
Pd(1)-C(26) (2.046(5) Å) bond lengths are essentially
identical with those reported for related Pd complexes.2c-f
The pyridyl and phosphole rings are not coplanar;
however, the twist angle is rather small (21.0°). The
inter-ring C(1)-C(9) bond length (1.459(7) Å) is in the
range expected for a C(sp2)-C(sp2) single bond. The
bond lengths and angles of the two endocyclic P-C-C
fragments are almost similar (Table 2), and it is
noteworthy that the P-C distances (C(1)-P(1), 1.798(5)
Å; C(8)-P(1), 1.808(5) Å) approach that of a P-C single
bond (1.84 Å). These solid-state data suggest a delocal-
ization involving the dienic moiety of the phosphole ring
and the coordinated pyridyl unit. It is well-known that,
as observed for classical phosphines, the phosphorus
atom of phospholes adopts a tetrahedral geometry upon
coordination.4,5,14 The geometry of the P atom in com-
pound 3b is highly distorted with unusually large
exocyclic C(8)-P(1)-Pd(1) (132.97(16°)) and small en-
docyclic C(1)-P(1)-Pd(1) (96.24(16)°) angles. In other
words, the Pd(1)-P(1)-C(20) plane does not have the
traditional perpendicular arrangement with respect to
the phosphole ring. This structural feature is probably
due to the rigidity of the 1,4-P,N chelate backbone,
which contains sp2-carbon atoms, and shows that the
phosphorus atom of phospholes can accommodate severe
deviation from an optimal tetrahedral geometry due to
the high s character of the P lone pair.4,15 It is note-
worthy that no fluxional behavior has been observed for
complexes 3b and 3c between 243 and 313 K in CD2Cl2
solutions.
13C{1H} NMR signals of complex 3a are rather broad,
preventing the observation of the small J PC coupling
constants. The 13C{1H} NMR chemical shifts remained
almost unchanged on cooling the samples down to 283
K, a temperature for which sharp singlets were ob-
served. At this temperature, the 13C NMR spectrum of
complex 3a shows two sets of signals for the pyridyl
moieties and a doublet at -7.8 ppm (J PC ) 2.4 Hz)
attributed to the Pd-CH3 moiety. The low magnitude
of the coupling constant compares with that of related
complexes 3b,c and 3b′,c′ (Table 1), in which the P atom
and the CH3 moiety are in a mutual cis positions. The
ambient-temperature 13C{1H} NMR spectrum of com-
plex 3a ′ displays well-resolved lines with two sets of
signals for the pyridyl groups and a doublet at -11.0
ppm with a small J PC coupling constant (2.3 Hz) for the
Pd-CH3 fragment. These multinuclear NMR data sup-
port the proposed structures (Scheme 1): complexes
3a ,a ′ possess a coordinated and a pendant pyridyl ring,
with the phosphorus atom and the coordinated methyl
1
group being in a cis configuration. The H NMR signals
of both complexes are broad at room temperature (300
K), suggesting fluxional behavior. The spectra of the two
complexes are very similar, and only the results ob-
tained with derivative 3a ′ will be described in detail.
At 300 K, two multiplets centered at 9.08 and 8.58 ppm
are observed for the H6 atom of the coordinated and
noncoordinated pyridyl fragments, respectively. When
the temperature was raised to 348 K, line broadening
leading to the disappearance of these signals occurred,
while at 283 K the 1H NMR spectrum displays well-
resolved signals (Figure 2). These band-shape changes
suggested an intramolecular exchange between the
pendant and coordinated pyridyl groups (Scheme 2), a
phenomenon which has been confirmed by spin transfer
saturation experiments performed at room temperature
on the two H6 atoms. However, this fluxional behavior
is not a simple exchange of the two pyridines since,
according to NMR data (Table 1), the palladium atoms
of the two exchanging complexes possess the same
stereochemistry (cis-disposed P atom and the CH3
fragment). In fact, the two exchanging complexes are
enantiomers (inversion at the P atom, Scheme 2), which
are indistinguishable, since NMR is not sensitive to
In contrast, complexes 3a and 3a ′ possessing a
pendant pyridyl arm exhibited fluxional behavior at
room temperature. The 31P{1H} NMR spectrum of
complexes 3a and 3a ′ showed singlets at +57.0 and
+70.5 ppm, respectively, at 298 K in CD2Cl2 solutions.
Only one diastereisomer has been formed, and these
chemical shifts are similar to those recorded for related
complexes 3b,c and 3b′,c′ (Table 1). At 298 K, the
(14) (a) Gouygou, M.; Tissot, O.; Daran, J . C.; Balavoine, G. A.
Organometallics 1997, 16, 1009. (b) Csok, Z.; Keglevich, G.; Peto¨cz,
G.; Kollar, L. Inorg. Chem. 1999, 38, 831.
(15) Nyulaszi, N. Chem. Rev. 2001, 101, 1209.

Palladium Complexes of 2-(2-Pyridyl)phospholes
Organometallics, Vol. 21, No. 8, 2002 1595
1
F igu r e 2. Variable-temperature H NMR spectra of complex 3a ′ in the pyridine region.
Sch em e 2
and coordination of the second N atom (Scheme 2).
These results on neutral Pd(II) complexes show that
2-(2-pyridyl)phospholes undergo stereoselective coordi-
nation and that they can act as static or dynamic P,N
chelates.
The next step was to prepare the corresponding
cationic palladium complexes. Treatment of complexes
3a -c′ with 1 equiv of AgSbF6 in CH3CN afforded
derivatives 4a -c′ (Scheme 1). In all cases, the 31P{1H}
NMR spectra of the crude reaction mixtures showed one
sharp singlet, indicating the formation of a single
diastereoisomer. The 31P{1H} NMR chemical shifts are
in a similar range for those of their neutral precursors
(δ∆ < 1.6 ppm, Table 1). Complexes 4b,c and 4b′,c′,
with no pendant pyridyl moiety, are air-stable solids
that can be isolated in high yields after workup (Table
1). In marked contrast, derivatives 4a and 4a ′ rapidly
decomposed in CH2Cl2 solutions at room temperature.
Addition of acetonitrile lowers the rate of decomposition,
optical activity. Such hemilabile behavior has recently
been encountered with potentially tridentate N,P,N
donors such as bis(2-pyridyl)phosphine16a or bis(oxazo-
line) phosphite16b ligands. Three possible mechanisms
have been proposed to rationalize this dynamic process
for Pd(II) complexes.16b Two of them imply a tridentate
coordination mode of the N,P,N ligand leading to
pentacoordinate Pd intermediates. This coordination
mode can clearly be discarded for 2,5-bis(2-pyridyl)-
phospholes, due to the rigidity of the carbon backbone
of these ligands. This can easily be visualized in Figure
1: a nitrogen atom which would replace an ortho C atom
of the C(8) phenyl ring cannot bind to the palladium
center without decoordination of N(1). The most plau-
sible mechanism for the interconversion of enantiomers
of complexes 3a and 3a ′ involves a decoordination of the
N donor followed by a rotation around the P-Pd bond
1
and the H and 13C{1H} NMR of complex 4a have been
recorded in CD2Cl2-CD3CN solutions at low tempera-
ture (218 K). This compound has also been characterized
by high-resolution mass spectrometry; however, no
satisfactory elemental analyses could be obtained. It is
noteworthy that, as for its neutral precursor 3a , complex
4a exhibits fluxional behavior involving an exchange of
the two pyridyl rings. Complex 4a ′ is extremely un-
stable, even in CD2Cl2-CD3CN solutions at low tem-
perature, and was only observed by 31P{1H} NMR
spectroscopy. The presence of a pendant pyridyl moiety,
which exchanges with its coordinated counterpart, ap-
pears to be a strong destabilizing factor for cationic
palladium(II) complexes featuring 2-(2-pyridyl)phos-
1
phole ligands. The H and 13C{1H} NMR resonances of
(16) (a) Aranzazu, M.; Casares, J . A.; Espinet, P.; Soulantica, K.;
Charmant, J .; Orpen, A. G. Inorg. Chem. 2000, 39, 705. (b) Braunstein,
P.; Naud, F.; Dedieu, A.; Rohmer, M.-M.; De Cian, A.; Rettig, S. J .
Organometallics 2001, 20, 2966.
the Pd-CH3 moiety of compounds 4a , 4b,c, and 4b′,c′
appeared as doublets at lower field than those of the
corresponding neutral complexes (Table 1). The low

1596 Organometallics, Vol. 21, No. 8, 2002
Sauthier et al.
Ta ble 3. Eth ylen e-CO Cop olym er iza tion
Ca ta lyzed by Com p lexes 4b a n d 4c:a In flu en ce of
th e Tem p er a tu r e, Rea ction Tim e, a n d Solven t
Sch em e 3
reacn
g of PK/
entry catalyst T/°C time/h solvent g of Pd TONb TOFb
1
2
3
4
5
6
7
8
9
4b
4b
4b
4c
4c
4c
4c
4c
4c
35
60
85
35
85
85
85
85
85
15
15
15
15
15
6
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
CH2Cl2
THF
59
145
282
89
551
238
835
160
0
112
276
536
169
1047
452
1586
304
0
7
18
35
11
70
75
42
51
0
38c
6
6
CH3OH
a
Reaction conditions: 0.03 mmol of catalyst, initial p(CO) ) 10
b
bar, initial p(ethylene) ) 10 bar, time 15 h. TON ) moles of
substrate converted per mole of palladium. TOF ) TON per hour.
c After 15 h, the reactor was pressurized with CO (10 bar) and
ethylene (10 bar).
values of the J PH coupling constants (J PH < 2.4 Hz)
support a cis arrangement of the phosphorus atom and
the methyl group. The coordination of acetonitrile is
evidenced by the presence of a single peak in both the
1H (δ, 2.35-2.37) and 13C{1H} (δ, 2.4-2.7) NMR spectra.
As observed for the neutral complexes, the 13C{1H}
NMR chemical shift of the Pd-CH3 moiety is relatively
insensitive to the nature of the P-substituent but is
affected by the nature of the C5 substituent of the
phosphole ring (Table 1).
catalytic activity in MeOH is quite surprising, since this
solvent is commonly used for the Pd-catalyzed ethylene/
CO copolymerization. In fact, complex 4c is not stable
in MeOH solution at room temperature. A rapid pre-
cipitation of “palladium black” occurred, accompanied
by the formation of dicationic complex 5 (Scheme 3),
isolated in 42% yield (based on 4c). Derivative 5 is not
active for the ethylene/CO copolymerization under the
reaction conditions of this study (20 bar, 85 °C). This
behavior is quite usual for bis-chelated dicationic pal-
ladium(II) complexes of the type [Pd(L2)2]2+, which are
active only in the presence of a proton and/or benzo-
quinone.17
Cop olym er iza tion Rea ction s of Dica tion ic P a l-
la d iu m Com p lexes. Ethylene/CO copolymerization
experiments have been performed in CH2Cl2 under an
initial pressure of 20 bar (p(CO) ) p(ethylene)) in a 150
mL autoclave. The catalytic activity is expressed in
grams of polyketone per gram of palladium and turnover
frequency (TOF) as moles of substrates converted per
mole of Pd per hour. At 35 °C, complexes 4b,c yield
insoluble copolymers isolated as gray solids after wash-
ing with methanol. Complex 4c exhibited a higher
catalytic activity than 4b (Table 3, entries 1-4), show-
ing that the nature of the C5 substituent of the phos-
phole ring has a notable influence on the productivity
of the Pd catalysts. The temperature plays an important
role; an increase of the temperature resulted in an
enhancement of the catalytic activity for both complexes.
At 85 °C, the productivity of complexes 4b,c are ca. 5
times higher than those recorded at 35 °C (Table 3,
entries 1-3 and 4 and 5). The influences of the reaction
time and of the solvent were examined at 85 °C with
complex 4c, which is the most active catalyst. The
turnover frequencies, which give an estimate of the
catalytic activity for a given period of time, are very
similar for reaction times varying from 6 h (TOF ) 75
h-1) to 15 h (TOF ) 70 h-1). The small decrease of the
TOF for long reaction time can be attributed to the drop
of the total pressure during the reaction. These data
suggest a negligible decomposition of the active species
under these reaction conditions. Repressurization of the
autoclave with CO (10 bar) and ethylene (10 bar) after
15 h allowed a further production of copolymers; how-
ever, this resulted in an overall lower efficiency (Table
1, entry 7). The nature of the solvent has a marked
influence on the productivity of complex 4c. The amount
of copolymer per gram of Pd is substantially more
important in CH2Cl2 than in THF (Table 3, entries 6-8),
while no polymer is formed in MeOH. The absence of
Complex 5 is an air-stable orange solid easily purified
by crystallization. Its insolubility in common apolar
solvents (pentane, Et2O) supports an ionic structure.
The 31P{1H} NMR spectra of derivative 5 exhibits a
singlet at +69.7 ppm, an unusually low field for a Pd-
coordinated 1-phenylphosphole (for comparison see
derivatives 4a -c, Table 1). The simplicity of the 13C{1H}
NMR spectra is in favor of a highly symmetric struc-
ture: one set of signals is recorded for the two 1-phenyl-
2-(2-pyridyl)-5-(2-thienyl)phosphole ligands. No signal
corresponding to a Pd-CH3 fragment or a coordinated
acetonitrile is observed in the 1H and 13C{1H} NMR
spectra. High-resolution mass spectrometry and ele-
mental analysis support the general formula [Pd-
(2c)2]2+(SbF6-)2. Single crystals of 5 have been grown
at room temperature from a 1,2-dichloroethane/toluene
solution. The X-ray diffraction study performed on these
crystals confirmed the proposed structure; normal van
der Waals distances between the dication [Pd(2c)2]2+
-
(Figure 3a) and the two SbF6 counteranions are
recorded. The P atoms of the two 2-(2-pyridyl)phosphole
ligands 2c are in a mutually cis configuration. It is
noteworthy that this symmetric structure is in ac-
cordance with the NMR data; once again, a stereo-
selective coordination of a 2-(2-pyridyl)phosphole is
observed. Complex 5 shows a distorted-square-planar
(17) (a) Milani, B.; Anzilutti, A.; Vicentini, L.; Sessanto o Santi, A.;
Zangrando, E.; Geremia, S.; Mestroni, G. Organometallics 1997, 16,
5064. (b) Bianchini, C.; Lee, H. M.; Barbaro, P.; Meli, A.; Moneti, S.;
Vizza, F. New J . Chem. 1999, 23, 929.

Palladium Complexes of 2-(2-Pyridyl)phospholes
Organometallics, Vol. 21, No. 8, 2002 1597
Ta ble 4. Eth ylen e-CO Cop olym er iza tion :
Com p a r ison of th e Ca ta lytic Activities of
Com p lexes 4a , 4b,c, a n d 4b′,c′a
entry
catalyst
g of PK/g of Pd
TONb
TOFb
1
2
3
4
5
4a
0
135
357
238
279
4b
4b′
4c
256
678
452
530
43
113
75
4c′
88
a
Reaction conditions: CH2Cl2 (20 mL), 0.03 mmol of catalyst,
initial p(CO) ) 10 bar, initial p(ethylene) ) 10 bar, 85 °C, time 6
b
h. TON ) moles of substrate converted per mole of palladium.
TOF ) TON per hour.
angles (82.77(16), 82.80(17)°) are also almost similar to
those recorded for complex 3b (Table 2). This analogy
shows that the structure of the five-membered pallada-
cycle is imposed by the rigidity of the chelating P,N-
moiety of 2-(2-pyridyl)phospholes.
The cationic palladium complexes, except complex 4a ′,
which is not stable in solution, have been evaluated for
the carbon monoxide-ethylene copolymerization under
the optimal reaction conditions determined with com-
plex 4c (CH2Cl2, 85 °C). All the palladium complexes
afforded copolymers except for complex 4a , which bears
a pendant pyridyl group (Table 4). Under the catalytic
conditions, complex 4a is reduced quantitatively to give
the dinuclear Pd(I) complex 619 (Scheme 3), which is an
inactive species. The catalytic activities observed with
complexes 4b,c and 4b′,c′ are rather low compared to
those attained with diphosphines1c,5f,8a but are among
the highest obtained with P,N-chelates.3c,8e Interest-
ingly, the substitution pattern of the 2-(2-pyridyl)-
phosphole ligands has an impact on the productivity of
the Pd catalysts. P-Cyclohexylphospholes are more
efficient ligands than their P-phenyl-substituted ana-
logues; this trend is more pronounced for 5-phenylphos-
pholes (Table 4, entries 2 and 3) than for 5-(2-thienyl)-
phospholes (Table 4, entries 3 and 4). The P substituent
influences both the σ-donor ability and the steric
demands of the phosphorus center; it is thus rather
difficult to rationalize its influence on the catalytic
activity of the palladium complexes. The nature of the
substituent at the C5 position of the phosphole ring also
has an impact on the catalytic performance (compare
entries 2 and 4 and entries 3 and 5, Table 4). It is quite
clear that these substituents have no influence on the
steric bulk of the metal center; the modulation of the
catalytic activity is thus due to electronic factors. It is
well-known that thienyl and phenyl groups possess very
different electron-donating properties,20 and we have
established that the dienic moiety of the phosphole ring
is highly polarizable.10 Thus, it seems very likely that
the substituent at the C5 position of the phosphole ring
influences the donor ability of the pyridyl group. This
assumption is supported by the fact that the nature of
the C5 substituent has a notable influence on the NMR
data of the Pd-CH3 moiety from complexes 4b,c and
4b′,c′. It is noteworthy that the presence of an electron-
donating thienyl substituent at the C5 position of the P
ring has a positive effect on the catalytic activity in the
F igu r e 3. ORTEP view of the dication of complex 5 with
atom labeling (top) general view; (bottom) view along the
P(1)-Pd(1)-P(31) axis. Thermal ellipsoids show 40% prob-
ability levels.
geometry around the palladium atom; the maximum
deviation from the best PdN2P2 plane reaches 0.206 Å.
The angle between the two planes defined, on one hand,
by the Pd centers and the coordinated N atoms and, on
the other hand, by the Pd centers and the coordinated
P atoms attains 10° (Figure 3). This feature, which has
already been observed in Pd complexes bearing 2-(phos-
phinoamino)pyridine ligands,18 is probably due to the
repulsion of the two H6 hydrogen atoms of the coordi-
nated pyridyl groups (Figure 3). Despite this steric
constraint, derivative 5 shares some important struc-
tural features with complex 3b (Figure 1), which bears
only one 2-(2-pyridyl)phosphole ligand. For example, the
twist angles between the coordinated pyridyl and phos-
phole rings of 5 are only slightly superior to that of
complex 3b (3b, 21.0°; 5, 25.2-25.6°). As observed for
3b, the five-membered metallacycles of complex 5 adopt
a slightly distorted envelope conformation with the P
atoms out of the Pd-N-C-C planes (C-N-Pd-P,
19.1-22.3°; N-C-C-P, 25.2-25.6°), with the geometry
around the P atoms being a highly distorted tetrahedron
(Table 2). The Pd-N (2.119(6), 2.154(6) Å) and Pd-P
distances (2.2494(18), 2.260(2) Å) and the N-Pd-P bite
(19) Complex 6 has been characterized by an X-ray diffraction
study,7 and its full NMR description will be given in a forthcoming
paper on symmetrically bridging phosphines.
(18) Aucott, M.; Slawin, A.; Woollins, D. J . Chem. Soc., Dalton Trans.
2000, 2559.
(20) Albert, I. D. L.; Marks, T. J .; Ratner, M. A. J . Am. Chem. Soc.
1997, 119, 6575.

1598 Organometallics, Vol. 21, No. 8, 2002
Sauthier et al.
) 1.1, 1.8 and 4.9 Hz, 1 H, H6 Py). 13C{1H} NMR (75 MHz,
CDCl3): δ 18.0, 18.9 (s, CtCCH2CH2), 27.3, 27.5 (s, CtCCH2),
68.6 (s, CtCH), 80.7 (s, CtC-Py), 84.0 (s, CtCH), 90.9 (s,
CtC-Py), 122.3 (s, C5 Py), 126.8 (s, C3 Py), 136.0 (s, C4 Py),
143.8 (s, C2 Py), 149.8 (s, C6 Py). HR-MS (EI): m/z 182.0936
P-Ph series (entries 2-4, Table 4) and a negative effect
in the P-Cy series (entries 3-5, Table 4). The ethylene/
CO copolymers exhibit very low solubility in common
organic solvents, preventing gel permeation chroma-
tography (GPC) to determine their exact mass distribu-
tion from being undertaken. However, complex 4c
catalyzes the copolymerization of CO and norbornene
at 85 °C, affording a white solid soluble in most organic
solvents. The molecular weight determined by GPC is
4094, and the low molecular weight distribution (Mw/
Mn ) 1.18) suggests the living polymerization nature
of the catalyst.
In conclusion, 2-(2-pyridyl)phospholes possessing dif-
ferent substitution patterns are readily accessible using
the Fagan-Nugent route. They coordinate to (chloro)-
(methyl)palladium(II) centers in a stereoselective way,
leading to stable complexes. The palladium complexes
of 2-(2-pyridyl)phospholes possessing a pendant pyridyl
moiety are fluxional, revealing the hemilabile nature
of these P,N-chelates. The catalytic activities observed
for the copolymerization of CO and ethylene are rather
high for mixed P,N-ligands. The low Mw/Mn value for
the norbornene-CO co-oligomers are encouraging, and
the use of these catalytic systems to prepare well-
controlled block copolymers is under active investiga-
tion.
(M - H)+; calcd for C13H12N 182.0970. Anal. Calcd for C13H13
N
(183.2): C, 85.21; H, 7.15; N, 7.64. Found: C, 85.00; H, 7.04;
N, 7.78.
1-P h en yl-8-(2-p yr id yl)octa -1,7-d iyn e (1b). Iodobenzene
(0.22 mL, 2.0 mmol) was added, at room temperature, to a
Et3N solution (15 mL) containing 1-(2-pyridyl)octa-1,7-diyne
(0.37 g, 2.0 mmol), a catalytic amount of Pd(PPh3)2Cl2 (0.014
g, 0.02 mmol), and CuI (0.004 g, 0.02 mmol). The heteroge-
neous yellow mixture was stirred for 12 h at room temperature.
A significant amount of precipitate was formed, and the
mixture turned brown. The mixture was filtered, and the
volatile materials were removed under vacuum. After purifica-
tion by column chromatography on silica gel (heptane/Et2O,
50/50, Rf ) 0.30), compound 1b was obtained as a as an yellow
oil after purification on silica gel (heptane/Et2O, 50/50, Rf )
1
0.30) (0.40 g, yield 77%). H NMR (200 MHz, CDCl3): δ 1.74
(m, 4 H, CtCCH2CH2), 2.42 (m, 4 H, CtCCH2), 7.15 (ddd, J
) 1.3, 4.9 and 7.7 Hz, 1 H, H5 Py), 7.20 (m, 3 H, m-/p-H Ph),
7.32 (m, 3 H, H3 Py and o-H), 7.58 (ddd, J ) 1.8, 7.5 and 7.5
Hz, 1 H, H4 Py), 8.51 (ddd, J ) 0.9, 1.8 and 4.9 Hz, 1 H, H6
Py). 13C{1H} NMR (50.323 MHz, C6D6): δ 19.0, 19.1 (s,
tCCH2CH2), 27.5, 27.9 (s, tCCH2), 80.7 (s, CtC-Py), 81.0
(s, CtC-Ph), 89.7 (s, CtC-Ph or CtC-Py), 90.6 (s, CtC-
Ph or CtC-Py), 122.4 (s, C5 Py), 124.0 (s, i-C Ph), 126.9 (s,
C3 Py), 127.6 (s, p-C Ph), 128.2 (s, m-C), 131.6 (s, o-C), 136.1
(s, C4 Py), 143.8 (s, C2 Py), 149.9 (s, C6 Py). HR-MS (EI): m/z
259.1365 (M)+; calcd for C19H17N 259.1361. Anal. Calcd for
Exp er im en ta l Section
C
19H17N (259.1): C, 87.99; H, 6.61; N, 5.40. Found: C, 88.21;
Gen er a l Con sid er a tion s. All experiments were performed
under an atmosphere of dry argon using standard Schlenk
techniques. Solvents were freshly distilled under argon from
sodium/benzophenone (tetrahydrofuran, diethyl ether, toluene)
or from phosphorus pentoxide (pentane, dichloromethane,
acetonitrile). Triethylamine was freshly distilled under argon
from potassium hydroxide. 2-Bromopyridine, octa-1,7-diyne,
Cp2ZrCl2, CuI, and n-BuLi were obtained from Aldrich Chemi-
cal Co. and were used as received. Preparative separations
were performed by gravity column chrommatography on silica
gel (Merck Geduran 60, 0.063-0.200 mm) or basic alumina
(Aldrich, Type 5016A, 150 mesh, 58 Å) in 3.5 × 20 cm columns.
1H, 13C, and 31P NMR spectra were recorded on Bruker AM300,
DPX200, and ARX400 spectrometers. Attribution of carbon
atoms is based on HMBC and HMQC experiments. Melting
point and decomposition point determinations were performed
by using a differential scanning calorimeter (TA-instruments
DSC 2010) and a thermogravimetric analyzer (TA-instruments
TGA 2050), respectively. High-resolution mass spectra were
obtained on a Varian MAT 311 or ZabSpec TOF Micromass
instrument at CRMPO, University of Rennes. Elemental
analyses were performed by the “Centre de Microanalyze du
CNRS” at Vernaison, France.
H, 6.69; N, 5.55.
1-(2-P yr id yl)-8-(2-th ien yl)octa -1,7-d iyn e (1c). Following
the procedure described for the compound 1b, reaction of
2-iodothiophene (0.22 mL, 2.0 mmol), 1-(2-pyridyl)octa-1,7-
diyne (0.37 g, 2.0 mmol), Pd(PPh3)2Cl2 (0.03 g, 0.04 mmol), and
CuI (0.007 g, 0.04 mmol) afforded 1c as an orange oil after
purification by column chromatography on silica gel (heptane/
Et2O, 50/50, Rf ) 0.20) (0.45 g, yield 85%). 1H NMR (200 MHz,
CDCl3): δ 1.75 (m, 4 H, CtCCH2CH2), 2.46 (m, 4 H, CtCCH2),
6.89 (dd, J ) 3.5 and 5.1 Hz, 1 H, H4 thienyl), 7.08 (dd, J )
1.1 and 5.1 Hz, 1 H, H5 thienyl), 7.12 (dd, 3J ) 1.1 and 3.5
Hz, 1 H, H3 thienyl), 7.15 (ddd, 3J ) 1.0, 4.9, and 7.7 Hz, 1 H,
3
H5 Py), 7.33 (ddd, J ) 0.9, 1.0, and 7.7 Hz, 1 H, H3 Py), 7.58
3
3
(ddd, J ) 1.8, 7.7, and 7.7 Hz, 1 H, H4 Py), 8.51 (ddd, J )
0.9, 1.8, and 4.9 Hz, 1 H, H6 Py). 13C{1H} NMR (75 MHz,
CDCl3): δ 19.0, 19.3 (s, CtCCH2CH2), 27.5, 27.7 (s, CtCCH2),
74.1 (s, CtC-thienyl), 80.7 (s, CtC-Py), 90.5 (s, CtC-Py),
93.8 (s, CtC-thienyl), 122.4 (s, C5 Py), 124.0 (s, C2 thienyl),
126.0 (s, C4 thienyl), 126.8 (s, C5 thienyl or C3 Py), 126.9 (s,
C5 thienyl or C3 Py), 131.1 (s, C3 thienyl), 136.1 (s, C4 Py),
143.8 (s, C2 Py), 149.9 (s, C6 Py). HR-MS (EI): m/z 265.0929
(M)+, calcd for C17H15NS 265.0925. Anal. Calcd for C17H15NS
(265.4): C, 76.94; H, 5.70; N, 5.28. Found: C, 76.82; H, 5.62;
N, 5.32.
1-(2-P yr id yl)octa -1,7-d iyn e. 2-Bromopyridine (0.46 mL,
4.8 mmol) and octa-1,7-diyne (0.74 mL, 5.6 mmol) were added,
at room temperature, to a Et3N solution (15 mL) containing a
catalytic amount of Pd(PPh3)2Cl2 (0.080 g, 0.11 mmol) and CuI
(0.020 g, 0.11 mmol). The heterogeneous yellow mixture was
stirred for 12 h at room temperature. A significant amount of
precipitate was formed, and the mixture turned brown. The
mixture was filtered, and the volatile materials were removed
under vacuum. After purification by column chromatography
on silica gel (heptane/Et2O, 40/60, Rf ) 0.40), 1-(2-pyridyl)-
octa-1,7-diyne was obtained as a pale yellow oil (0.46 g, yield
52%). 1H NMR (200 MHz, CDCl3): δ 1.71 (m, 4 H, CtCCH2CH2),
1.93 (t, 3J ) 2.6 Hz, 1 H, CtCH), 2.23 (m, 2 H, CtCCH2),
2.46 (m, 2 H, CtCCH2), 7.15 (ddd, J ) 1.3, 4.9 and 7.5 Hz, 1
H, H5 Py), 7.34 (ddd, J ) 1.1, 1.3 and 7.8 Hz, 1 H, H3 Py),
1-Cycloh exyl-2,5-bis(2-p yr id yl)p h osp h ole (2a′). A solu-
tion of BuLi in hexanes (1.6 M, 2.2 mL, 3.5 mmol) was added
dropwise to a THF solution (40 mL) of Cp2ZrCl2 (0.50 g, 1.72
mmol) and diyne 1a 10c (0.45 g, 1.73 mmol) at -78 °C. The
reaction mixture was warmed to room temperature and stirred
for 12 h, and neat CyPBr2 (0.36 mL, 1.73 mmol) was added.
The solution was stirred for 5 h and filtered, and the volatile
materials were removed under vacuum. Phosphole 2a ′ was
isolated as a yellow solid after purification on basic alumina
1
(THF, Rf ) 0.8) (0.54 g, yield 83%): mp 163 °C. H NMR (300
MHz, C6D6): δ 0.92 (m, 4 H, CH2), 1.10-1.75 (m, 8 H, CH2),
1.95 (m, 2 H, CH2), 2.71 (m, 3 H, CH2 and PCH), 3.43 (m, 2 H,
CdCCH2), 6.60 (ddd, J ) 1.0, 4.9 and 7.5 Hz, 2 H, H5 Py),
7.17 (ddd, J ) 1.0, 7.5 and 7.7 Hz, 2 H, H4 Py), 7.47 (d broad,
3
3
7.58 (ddd, J ) 1.8, 7.5 and 7.8 Hz, 1 H, H4 Py), 8.51 (ddd, J

Palladium Complexes of 2-(2-Pyridyl)phospholes
Organometallics, Vol. 21, No. 8, 2002 1599
J ) 7.7 Hz, 2 H, H3 Py), 8.61 (ddd, J ) 1.0, 2.0, and 4.9 Hz,
2 H, H6 Py). 13C{1H} NMR (50.323 MHz, C6D6): δ 23.5 (s,
dCCH2CH2), 26.4 (s, CH2 Cy), 28.1 (d, J ) 9.7 Hz, CH2 Cy),
29.1 (s, dCCH2), 30.8 (d, J ) 5.9 Hz, CH2 Cy), 38.0 (d, J )
17.2 Hz, CH Cy), 120.5 (s, C5 Py), 124.0 (d, J ) 9.6 Hz, C3
Py), 135.6 (d, J ) 1.6 Hz, C4 Py), 143.4 (s, PCR), 147.9 (d, J )
8.5 Hz, PCâ), 149.6 (s, C6 Py), 157.9 (d, J ) 19.1 Hz, C2 Py).
31P{1H} NMR (81.014 MHz, CD2Cl2): δ 27.9. HR-MS (FAB-
mNBA): m/z 375.1990 (M + H)+, calcd for C25H27N2P 375.1990.
Anal. Calcd for C24H27N2P: C, 76.98; H, 7.27; N, 7.48. Found,
C, 77.13; H, 7.33; N, 7.38.
and 8.0 Hz, 2 H, o-H), 8.47 (ddd, J ) 0.9, 1.8, and 4.8 Hz, 1 H,
H6 Py). 13C{1H} NMR (50.323 MHz, C6D6): δ 23.0 (s,
dCCH2CH2), 29.2, 29.8 (s, dCCH2), 120.4 (s, C5 Py), 123.3 (d,
J ) 9.8 Hz, C3 Py), 125.4 (d, J ) 2.4 Hz, C5 thienyl), 126.4 (d,
J ) 9.8 Hz, C3 thienyl), 127.6 (s, C4 thienyl), 128.9 (d, J )
8.5 Hz, m-C Ph), 129.6 (s, p-C Ph), 133.9 (d, J ) 13.4 Hz, i-C
Ph), 134.4 (d, J ) 18.3 Hz, o-C), 135.7 (s, C4 Py), 139.0 (s,
PCR), 140.3 (d, J ) 20.0 Hz, C2 thienyl), 142.0 (d, J ) 3.8 Hz,
PCR), 144.4 (d, J ) 8.5 Hz, PCâ), 149.6 (s, C6 Py), 149.9 (d, J
) 8.5 Hz, PCâ), 156.2 (d, J ) 19.5 Hz, C2 Py). 31P{1H} NMR
(81.014 MHz, CD2Cl2): δ 12.6. HR-MS (FAB-mNBA): m/z
373.1035 (M)+, calcd for C23H20NSP 373.1054. Anal. Calcd for
1,2-Dip h en yl-5-(2-p yr id yl)p h osp h ole (2b). By the pro-
cedure described for compound 2a ′, the reaction of BuLi (1.6
M, 1.4 mL, 2.20 mmol), Cp2ZrCl2 (0.32 g, 1.10 mmol), diyne
1b (0.28 g, 1.10 mmol), and PhPBr2 (0.25 mL, 1.21 mmol)
afforded 2b as a yellow solid after purification on basic
C
23H20NSP: C, 73.97; H, 5.40; N, 3.75. Found: C, 74.18; H,
5.49; N, 3.62.
1-Cycloh exyl-2-(2-p yr id yl)-5-(2-th ien yl)ph osp h ole (2c′).
By the procedure described for the compound 2a ′, reaction of
BuLi (1.6 M, 1.1 mL, 1.75 mmol), Cp2ZrCl2 (0.25 g, 0.86 mmol),
diyne 1c (0.23 g, 0.87 mmol), and CyPBr2 (0.27 g, 1.00 mmol)
afforded 2c′ as an orange solid after purification on basic
1
alumina (THF, Rf ) 0.90) (0.30 g, yield 75%): mp 177 °C. H
NMR (300 MHz, C6D6): δ 1.21-1.60 (m, 4 H, dCCH2CH2),
2.43-2.89 (m, 3 H, dCCH2), 3.51 (m, 1 H, dCCH2), 6.47 (ddd,
J ) 1.1, 4.9, and 7.5 Hz, 1 H, H5 Py), 6.77-6.86 (m, 3 H, H
Ph), 6.96-7.12 (m, 9 H, H3,4 Py and H Ph), 8.50 (ddd, J )
1.0, 1.8, and 4.9 Hz, 1 H, H6 Py). 13C{1H} NMR (50.323 MHz,
C6D6): δ 23.4, 23.6 (s, dCCH2CH2), 28.2, 29.4 (s, dCCH2),
120.4 (s, C5 Py), 123.5 (d, J ) 9.8 Hz, C3 Py), 126.7 (s, p-C
Ph), 128.6 (s, m-C Ph), 128.7 (d, J ) 11.0 Hz, o-C Ph), 129.2
(d, J ) 1.2 Hz, p-C Ph), 129.7 (d, J ) 9.1 Hz, m-C Ph), 133.3
(d, J ) 12.8 Hz, i-C Ph), 133.9 (d, J ) 18.3 Hz, o-C Ph), 135.7
(d, J ) 1.8 Hz, C4 Py), 137.7 (d, J ) 17.7 Hz, i-C Ph), 142.4 (d,
J ) 4.3 Hz, PCR), 144.4 (d, J ) 11.0 Hz, PCâ), 146.4 (d, J ) 1.0
Hz, PCR), 149.3 (d, J ) 4.3 Hz, PCâ), 149.7 (d, J ) 1.8 Hz, C6
Py), 156.8 (d, J ) 20.1 Hz, C2 Py). 31P{1H} NMR (81.014 MHz,
CD2Cl2): δ 12.9. HR-MS (FAB-mNBA): m/z 367.1490 (M)+,
calcd for C25H22NP 367.1492. Anal. Calcd for C25H22NP: C,
81.72; H, 6.04; N, 3.81. Found: C, 81.44; H, 5.91; N, 3.68.
1-Cycloh exyl-2-p h en yl-5-(2-p yr id yl)p h osp h ole (2b′). By
the procedure described for the compound 2a ′, reaction of BuLi
(1.6 M, 1.4 mL, 2.20 mmol), Cp2ZrCl2 (0.32 g, 1.10 mmol), diyne
1b (0.28 g, 1.10 mmol), and CyPBr2 (0.33 mL, 1.20 mmol)
afforded 2b′ as a yellow solid after purification on basic
alumina (THF, Rf ) 0.90) (0.27 g, yield 65%). 1H NMR (300
MHz, C6D6): δ 0.70-2.05 (m, 14 H, CH2), 2.16 (m, 1 H, CH2),
2.40-2.89 (m, 3 H, CH2 and PCH), 3.51 (m, 1 H, CdCCH2),
6.60 (ddd, J ) 1.1, 4.9, and 7.3 Hz, 1 H, H5 Py), 7.08-7.31
(m, 4 H, H Ph and H4 Py), 7.47 (ddd, J ) 1.0, 1.1, and 7.8 Hz,
1 H, H3 Py), 7.57 (d broad, J ) 8.0 Hz, 2 H, o-H), 8.60 (ddd, J
) 1.0, 1.8, and 4.9 Hz, 1 H, H6 Py). 13C{1H} NMR (50.323 MHz,
C6D6): δ 23.3, 23.4 (s, dCCH2CH2), 26.1, 27.4, 27.5 (s broad,
CH2 Cy), 27.8, 27.9 (s, dCCH2), 30.0 (d broad, J ) 3.1 Hz, CH2
Cy), 30.3 (d broad, J ) 7.0 Hz, CH2 Cy), 37.2 (d, J ) 16.3 Hz,
CH Cy), 119.9 (s, C5 Py), 123.3 (d, J ) 9.4 Hz, C3 Py), 126.3
(s, p-C Ph), 128.4 (s, m-C Ph), 129.4 (d, J ) 9.4 Hz, o-C Ph),
135.4 (d, J ) 1.6 Hz, C4 Py), 139.0 (d, J ) 18.8 Hz, i-C Ph),
141.0 (s, PCR), 143.8 (d, J ) 9.4 Hz, PCâ), 144.4 (d, J ) 1.5 Hz,
PCR), 147.7 (d, J ) 8.6 Hz, PCâ), 149.6 (d, J ) 1.6 Hz, C6 Py),
157.6 (d, J ) 18.9 Hz, C2 Py). 31P{1H} NMR (81.014 MHz,
CD2Cl2): δ 26.9. HR-MS (FAB-mNBA): m/z 374.2055 (M + H)+,
calcd for C25H29NP 374.2055. Anal. Calcd for C25H28NP: C,
80.40; H, 7.56; N, 3.75. Found: C, 80.22; H, 7.41; N, 3.81.
1-P h en yl-2-(2-p yr id yl)-5-(2-th ien yl)p h osp h ole (2c). By
the procedure described for the compound 2a ′, reaction of BuLi
(1.6 M, 1.1 mL, 1.75 mmol), Cp2ZrCl2 (0.25 g, 0.86 mmol), diyne
1c (0.23 g, 0.87 mmol), and PhPBr2 (0.23 mL, 1.12 mmol)
afforded 2c an orange solid after purification on basic alumina
1
alumina (THF, Rf ) 0.90) (0.16 g, yield 49%): mp 100 °C. H
NMR (300 MHz, CDCl3): δ 0.70-2.01 (m, 15 H, CH2), 2.51-
3.32 (m, 4 H, CH2 and PCH), 7.21 (m, 3 H, H5 Py and H3,4
thienyl), 7.22 (d broad, J ) 5.0 Hz, 1 H, H5 thienyl), 7.41 (d
broad, J ) 7.8 Hz, 1 H, H3 Py), 7.80 (ddd, J ) 2.0, 7.8, and
7.8 Hz, 1 H, H4 Py), 8.61 (d broad, J ) 3.9 Hz, 1 H, H6 Py).
13C{1H} NMR (50.323 MHz, C6D6): δ 23.4, 23.5 (s, dCCH2CH2),
26.4 (s, CH2 Cy), 28.0 (d, J ) 8.2 Hz, CH2 Cy), 28.1 (d, J ) 9.5
Hz, CH2 Cy), 28.8, 29.4 (s, dCCH2), 30.2 (d, J ) 5.2 Hz, CH2
Cy), 30.6 (d, J ) 6.8 Hz, CH2 Cy), 38.6 (d, J ) 17.1 Hz, CH
Cy), 120.4 (s, C5 Py), 123.9 (d, J ) 9.8 Hz, C3 Py), 125.5 (d, J
) 2.2 Hz, C5 thienyl), 126.3 (d, J ) 9.7 Hz, C3 thienyl), 127.8
(s, C4 thienyl), 135.8 (s, C4 Py), 136.9 (d, J ) 2.2 Hz, PCR),
140.4 (s, PCR), 140.9 (d, J ) 22.7 Hz, C2 thienyl), 144.2 (d, J
) 7.6 Hz, PCâ), 148.9 (d, J ) 7.1 Hz, PCâ), 149.5 (s, C6 Py),
157.3 (d, J ) 19.4 Hz, C2 Py). 31P{1H} NMR (81.014 MHz,
CD2Cl2): δ 27.7. HR-MS (FAB-mNBA): m/z 380.1601 (M + H)+,
calcd for C23H27NSP 380.1602. Anal. Calcd for C23H26NSP: C,
72.79; H, 6.91; N, 3.69. Found, C, 72.92; H, 6.81; N, 3.89.
[1-p h en yl-2,5-bis(2-p yr id yl)p h osp h ole]P d (CH3)Cl (3a ).
A CH2Cl2 solution (10 mL) of phosphole 2a 10c (0.19 g, 0.52
mmol) was added, at room temperature, to a CH2Cl2 solution
(10 mL) of (COD)Pd(CH3)(Cl) (0.14 g, 0.52 mmol). The reaction
mixture was stirred for 1 h, and the volatile materials were
removed under vacuum. The residue was washed with diethyl
ether (2 × 10 mL) and dried under vacuum. Complex 3a was
1
obtained as an air-stable yellow solid (0.24 g, yield 88%). H
NMR (300 MHz, CD2Cl2, 283 K): δ 0.96 (d, J ) 2.4 Hz, 3 H,
PdCH3), 1.50-2.10 (m, 4 H, dCCH2CH2), 2.70-3.31 (m, 4 H,
dCCH2), 7.21-7.32 (m, 4 H, CH), 7.09 (ddd, J ) 1.0, 4.9, and
7.3 Hz, 1 H, H5 Py), 7.48 (d broad, J ) 8.1 Hz, 1 H, H3 Py),
7.56 (d broad, J ) 8.1 Hz, 1 H, H3 Py), 7.62-7.72 (m, 3 H,
CH), 7.79 (dddd, J ) 1.2, 1.7, 7.3, and 8.1 Hz, 1 H, H4 Py),
8.43 (ddd, J ) 1.0, 1.7, and 4.9 Hz, 1 H, H6 Py), 9.21 (ddd, J
) 1.0, 1.7, and 5.4 Hz, 1 H, H6 Py). 13C{1H} NMR (75.469 MHz,
CD2Cl2, 283 K): δ -7.5 (d, J ) 2.4 Hz, PdCH3), 22.4, 23.0 (s,
dCCH2CH2), 28.5 (d, J ) 7.3 Hz, dCCH2), 31.1 (d, J ) 8.5
Hz, dCCH2), 122.7 (s, C5 Py), 123.1 (d, J ) 7.3 Hz, C3 Py),
123.3 (s, C5 Py), 124.1 (d, J ) 7.3 Hz, C3 Py), 129.0 (d, J )
47.6 Hz, i-C Ph), 129.1 (d, J ) 12.1 Hz, C Ph), 131.5 (d, J )
2.4 Hz, C Ph), 133.7 (d, J ) 13.4 Hz, C Ph), 137.1, 138.6 (s, C4
Py), 139.0 (d, J ) 57.4 Hz, PCR), 142.0 (d, J ) 43.9 Hz, PCR),
147.9 (d, J ) 10.9 Hz, PCâ), 149.8, 151.0 (s, C6 Py), 152.1 (d,
J ) 15.8 Hz, PCâ), 152.7 (d, J ) 13.4 Hz, C2 Py), 152.9 (d, J
) 14.6 Hz, C2 Py). 31P{1H} NMR (81.014 MHz, CD2Cl2): δ 56.9.
HR-MS (FAB-mNBA): m/z 509.0150 (M - CH3)+, calcd for
1
(THF, Rf ) 0.8) (0.27 g, yield 83%): mp 167 °C. H NMR (300
MHz, C6D6): δ 1.21-1.62 (m, 4 H, dCCH2CH2), 2.65 (m, 1 H,
dCCH2), 2.87 (m, 2 H, dCCH2), 3.31 (m, 1 H, dCCH2), 6.43
(ddd, J ) 1.0, 4.8, and 7.6 Hz, 1 H, H5 Py), 6.68 (ddd, J ) 1.2,
3.8, and 4.7 Hz, 1H, H4 thienyl), 6.74-6.90 (m, 4 H, m-/p-H
Ph and H5 thienyl), 6.96 (ddd, J ) 1.8, 7.6, and 7.6 Hz, 1 H,
H4 Py), 7.19 (d broad, J ) 3.8 Hz, 1 H, H3 thienyl), 7.36 (ddd,
J ) 0.9, 1.0, and 7.6 Hz, 1 H, H3 Py), 7.65 (ddd, J ) 1.5, 7.9,
C
24H21N2ClPPd 509.0172. Anal. Calcd for C25H24N2PPdCl: C,
57.16; H, 4.61; N, 5.33. Found: C, 57.36; H, 4.71; N, 5.19.
[1-cycloh exyl-2,5-b is(2-p yr id yl)p h osp h ole]P d (CH 3)Cl
(3a ′). By the procedure described for the compound 3a ,
reaction of phosphole 2a ′ (0.30 g, 0.80 mmol) and (COD)Pd-
(CH3)(Cl) (0.21 g, 0.80 mmol) afforded 3a ′ as an air-stable

1600 Organometallics, Vol. 21, No. 8, 2002
Sauthier et al.
1
orange solid (0.38 g, yield 91%). H NMR (300 MHz, CD2Cl2,
31P{1H} NMR (81.014 MHz, CD2Cl2): δ 65.2. Anal. Calcd for
283 K): δ 0.68 (d, J ) 2.4 Hz, 3 H, PdCH3), 0.80-1.30 (m, 4
H, CH2), 1.45-1.75 (m, 6 H, CH2), 1.95 (m, 2 H, CH2), 2.25
(m, 2 H, CH2), 2.60-2.95 (m, 5 H, CH2 and CH Cy), 7.19 (ddd,
J ) 1.0, 4.9, and 7.9 Hz, 1 H, H5 Py), 7.26 (ddd, J ) 1.0, 5.4,
and 7.9 Hz, 1H, H5 Py), 7.54 (d broad, J ) 7.9 Hz, 1 H, H3
Py), 7.57 (d broad, J ) 7.9 Hz, 1 H, H3 Py), 7.75 (dddd, J )
1.2, 1.7, 7.9, and 7.9 Hz, 1 H, H4 Py), 7.88 (dddd, J ) 1.2, 1.7,
7.9, and 7.9 Hz, 1 H, H4 Py), 8.63 (ddd, J ) 1.0, 1.7, and 4.9
Hz, 1 H, H6 Py), 9.24 (d broad, J ) 5.4 Hz, 1 H, H6 Py).
13C{1H} NMR (50.323 MHz, CD2Cl2): δ -11.0 (d, J ) 2.3 Hz,
PdCH3), 22.0, 22.7 (s, dCCH2CH2), 25.8 (d, J ) 1.1 Hz, CH2
Cy), 26.9 (d, J ) 11.0 Hz, CH2 Cy), 27.4 (d, J ) 14.6 Hz, CH2
Cy), 27.5 (d, J ) 1.6 Hz, CH2 Cy), 27.6 (d, J ) 6.2 Hz, dCCH2),
30.0 (d, J ) 7.8 Hz, dCCH2), 31.2 (d, J ) 3.1 Hz, CH2 Cy),
38.8 (d, J P-C ) 22.5 Hz, CH Cy), 122.0 (s, C5 Py), 123.3 (s, C5
Py), 122.4 (d, J ) 7.0 Hz, C3 Py), 122.7 (d, J ) 7.0 Hz, C3 Py),
136.4 (s, C4 Py), 137.2 (d, J ) 48.5 Hz, PCR), 137.9 (s, C4 Py),
139.1 (d, J ) 40.7 Hz, PCR), 147.4 (d, J ) 10.2 Hz, PCâ), 149.5
(s, C6 Py), 150.6 (s, C6 Py), 151.0 (d, J ) 9.4 Hz, PCâ), 153.1
(d, J ) 16.4 Hz, C2 Py), 153.6 (d, J ) 12.5 Hz, C2 Py). 31P{1H}
NMR (81.014 MHz, CD2Cl2): δ 70.4. HR-MS (FAB-mNBA):
m/z 515.0630 (M - CH3)+, calcd for C24H27N2ClPPd 515.0635.
Anal. Calcd for C25H30N2PPdCl: C, 56.51; H, 5.69; N, 5.27.
Found: C, 56.36; H, 5.35; N, 5.20.
C26H31NPPdCl: C, 58.88; H, 5.89; N, 2.64. Found: C, 58.73;
H, 5.77; N, 2.56.
[1-ph en yl-2-(2-pyr idyl)-5-(2-th ien yl)ph osph ole]P d(CH3)-
Cl (3c). By the procedure described for the compound 3a ,
reaction of phosphole 2c (0.20 g, 0.54 mmol) and (COD)Pd-
(CH3)(Cl) (0.144 g, 0.54 mmol) afforded 3c as an air-stable
1
orange solid (0.26 g, yield 91%). H NMR (300 MHz, CD2Cl2):
δ 0.92 (d, J ) 2.4 Hz, 3 H, PdCH3), 1.50-2.10 (m, 4 H,
dCCH2CH2), 2.70-3.00 (m, 3 H, dCCH2), 3.20 (m, 1 H,
dCCH2), 6.85-7.05 (m, 2 H, H Ph), 7.21-7.62 (m, 6 H, H
arom), 7.69-7.91 (m, 3 H, H arom), 9.25 (d broad, J ) 5.3 Hz,
1 H, H6 Py). 13C{1H} NMR (75.469 MHz, CD2Cl2): δ -10.6 (d,
J ) 2.4 Hz, PdCH3), 21.9, 22.6 (s, dCCH2CH2), 27.9 (d, J )
8.4 Hz, dCCH2), 29.7 (d, J ) 8.6 Hz, dCCH2), 122.4 (s, C5
Py), 123.2 (d, J ) 8.6 Hz, C3 Py), 127.1 (d, J ) 42.4 Hz, i-C
Ph), 127.3 (s, C4 or C5 thienyl), 127.4 (C4 or C5 thienyl), 129.0
(d, J ) 5.5 Hz, C3 thienyl), 129.0 (d, J ) 11.0 Hz, m-C Ph),
131.0 (d, J ) 47.3 Hz, PCR), 131.9 (d, J ) 2.4 Hz, p-C Ph),
134.0 (d, J ) 14.9 Hz, o-C Ph), 137.1 (d, J ) 18.8 Hz, C2
thienyl), 137.9 (d, J ) 1.6 Hz, C4 Py), 138.6 (d, J ) 47.7 Hz,
PCR), 147.8 (d, J ) 13.3 Hz, PCâ), 148.3 (d, J ) 10.9 Hz, PCâ),
150.8 (s, C6 Py), 151.7 (d, J ) 18.0 Hz, C2 Py). 31P{1H} NMR
(81.014 MHz, CD2Cl2): δ +55.7. HR-MS (FAB-mNBA): m/z
494.03384 (M - Cl)+, calcd for C24H23NPSPd 494.0333. Anal.
Calcd for C24H23NPSPdCl: C, 54.35; H, 4.37; N, 2.64. Found,
C, 54.28; H, 4.53; N, 2.61.
[1,2-d ip h en yl-5-(2-p yr id yl)p h osp h ole]P d (CH3)Cl (3b).
By the procedure described for the compound 3a , reaction of
phosphole 2b (0.23 g, 0.61 mmol) and (COD)Pd(CH3)(Cl) (0.16
g, 0.61 mmol) afforded 3b as an air-stable orange solid (0.30
g, yield 95%). Single crystals suitable for an X-ray diffraction
study were grown from a saturated CH2Cl2 solution at room
[1-cycloh exyl-2-(2-p yr id yl)-5-(2-th ien yl)p h osp h ole]P d -
(CH3)Cl (3c′). By the procedure described for the compound
3a , reaction of phosphole 2c′ (0.23 g, 0.61 mmol) and (COD)-
Pd(CH3)(Cl) (0.161 g, 0.61 mmol) afforded 3c′ as an air-stable
1
1
temperature. H NMR (300 MHz, CD2Cl2): δ 0.82 (d, J ) 2.8
orange solid (0.29 g, yield 91%). H NMR (200 MHz, CD2Cl2):
Hz, 3 H, PdCH3), 1.45-2.00 (m, 4 H, dCCH2CH2), 2.71-2.94
(m, 3 H, dCCH2), 3.20 (m, 1 H, dCCH2), 7.10-7.45 (m, 9 H,
CH), 7.61 (d broad, J ) 7.5 Hz, 1 H, H3 Py), 7.75-7.90 (m, 3
H, CH), 9.33 (ddd, J ) 0.7, 1.5, and 5.4 Hz, 1 H, H6 Py).
13C{1H} NMR (75.469 MHz, CD2Cl2): δ -13.6 (d, J ) 3.3 Hz,
PdCH3), 22.2, 22.6 (s, dCCH2CH2), 27.5 (d, J ) 7.8 Hz,
dCCH2), 28.7 (d, J ) 8.6 Hz, dCCH2), 122.4 (s, C5 Py), 123.1
(d, J ) 7.8 Hz, C3 Py), 125.9 (d, J ) 43.0, i-C Ph), 127.9 (d, J
) 1.0 Hz, C Ph), 128.5 (s, C Ph), 128.9 (d, J ) 7.2 Hz, C Ph),
129.0 (d, J ) 8.8 Hz, C Ph), 131.8 (d, J ) 3.1 Hz, C Ph), 133.9
(d, J ) 14.9 Hz, C Ph), 134.3 (d, J ) 14.1 Hz, i-C Ph), 137.6
(d, J ) 46.9 Hz, PCR), 138.0 (d, J ) 1.0 Hz, C4 Py), 140.0 (d,
J ) 46.7 Hz, PCR), 148.4 (d, J ) 11.7 Hz, PCâ), 150.8 (s, C6
Py), 151.0 (d, J ) 14.1 Hz, PCâ), 151.7 (d, J ) 18.0 Hz, C2
Py). 31P{1H} NMR (81.014 MHz, CD2Cl2): δ 55.5. HR-MS
δ 0.81 (d, J ) 1.3 Hz, 3 H, PdCH3), 0.70-2.05 (m, 15 H, CH2),
2.43-2.97 (m, 4 H, CH2 and PCH), 7.13-7.25 (m, 3 H, H3,4
thienyl and H5 Py), 7.44 (d broad, J ) 3.8 Hz, 1 H, H5 thienyl),
7.48 (d broad, J ) 7.3 Hz, 1 H, H3 Py), 7.81 (ddd, J ) 1.8, 7.3
and 7.3 Hz, 1 H, H4 Py), 9.36 (d broad, J ) 4.9 Hz, 1 H, H6
Py). 13C{1H} NMR (75.469 MHz, CDCl3): δ -11.4 (s, PdCH3),
22.0, 22.6 (s, dCCH2CH2), 25.7 (d, J ) 1.6 Hz, CH2 Cy), 26.8
(d, J ) 10.2 Hz, CH2 Cy), 27.2 (d, J ) 5.5 Hz, CH2 Cy), 27.3
(d, J ) 15.6 Hz, CH2 Cy), 27.8 (d, J ) 7.8 Hz, CH2dCCH2),
29.4 (d, J ) 7.8 Hz, CH2dCCH2), 31.2 (d, J ) 3.9 Hz, CH2
Cy), 38.8 (d, J ) 20.3, CH Cy), 122.2 (s, C5 Py), 122.6 (d, J )
7.8 Hz, C3 Py), 125.7, 129.2 (s, C4 and C5 thienyl), 129.1 (d,
J ) 4.7 Hz, C3 thienyl), 129.8 (d, J ) 41.5 Hz, PCR), 135.3 (d,
d, J ) 43.8 Hz, PCR), 137.4 (d, J ) 19.6 Hz, C2 thienyl), 138.08
(s, C4 Py), 147.9 (d, J ) 10.9 Hz, PCâ), 149.1 (d, J ) 8.6 Hz,
PCâ), 150.7 (s, C6 Py), 152.9 (d, J ) 17.2 Hz, C2 Py). 31P{1H}
(FAB-mNBA): m/z 508.0213 (M - CH3)+, calcd for C25H22
-
NClPPd 508.0210. Anal. Calcd for C26H25NPPdCl: C, 59.56;
H, 4.81; N, 2.67. Found: C, 59.44; H, 4.92; N, 2.55.
NMR (81.014 MHz, CD2Cl2): δ 69.8. Anal. Calcd for C24H29
-
NPSPdCl: C, 53.74; H, 5.44; N, 2.61. Found, C, 53.91; H, 5.55;
N, 2.51.
[1-cycloh exyl-2-ph en yl-5-(2-pyr idyl)ph osph ole]P d(CH3)-
Cl (3b′). By the procedure described for the compound 3a ,
reaction of phosphole 2b′ (0.19 g, 0.52 mmol) and (COD)Pd-
(CH3)(Cl) (0.13 g, 0.52 mmol) afforded 3b′ as an air-stable
[1-ph en yl-2,5-bis(2-pyr idyl)ph osph ole]P d(CH3)(CH3CN)-
(SbF 6) (4a ). Solid AgSbF6 (0.20 g, 0.57 mmol) was added to a
CH3CN/CH2Cl2 solution (5 mL/10 mL) of complex 3a (0.30 g,
0.57 mmol) at room temperature. The mixture was stirred for
0.5 h, and the precipitate of AgCl was filtered off using a plug
of Celite. The solvent was removed under vacuum. The residue
was precipitated from a CH2Cl2/Et2O mixture and washed with
Et2O (2 × 10 mL). Complex 4c was isolated as an air- and
1
orange solid (0.24 g, yield 87%). H NMR (300 MHz, CD2Cl2):
δ 0.78 (d, J ) 2.7 Hz, 3 H, PdCH3), 0.82-1.15 (m, 4 H, CH2),
1.40-1.82 (m, 12 H, CH2), 2.40-2.78 (m, 3 H, CH2 and CH
Cy), 7.23 (ddd, J ) 1.3, 5.3, and 7.9 Hz, 1 H, H5 Py), 7.28-
7.48 (m, 5 H, CH), 7.57 (d broad, J ) 8.1 Hz, 1 H, H3 Py), 7.85
(ddd, J ) 1.3, 7.9, and 8.1 Hz, 1 H, H4 Py), 9.28 (d broad, J )
5.3 Hz, 1 H, H6 Py). 13C{1H} NMR (50.323 MHz, CD2Cl2): δ
-14.3 (d, J ) 3.9 Hz, PdCH3), 22.2, 22.5 (s, dCCH2CH2), 25.7
(d, J ) 1.6 Hz, CH2 Cy), 26.7 (d, J ) 10.9 Hz, CH2 Cy), 26.8
(d, J ) 14.1 Hz, CH2 Cy), 27.3 (d, J ) 7.0 Hz, dCCH2), 28.0
(d, J ) 7.0 Hz, dCCH2), 28.5 (d, J ) 2.3 Hz, CH2 Cy), 30.5 (d,
J ) 2.3 Hz, CH2 Cy), 37.8 (d, J P-C ) 22.1 Hz, CH Cy), 122.2
(s, C5 Py), 123.1 (d, J ) 7.8 Hz, C3 Py), 128.0 (s, C Ph), 128.8
(s, C Ph), 129.4 (d, J ) 3.9 Hz, C Ph), 135.1 (d, J ) 13.3, i-C
Ph), 136.8 (d, J ) 42.3 Hz, PCR), 137.0 (d, J ) 41.5 Hz, PCR),
138.0 (s, C4 Py), 148.7 (d, J ) 10.2 Hz, PCâ), 150.4 (d, J )
10.2 Hz, PCâ), 150.8 (s, C6 Py), 152.9 (d, J ) 17.2 Hz, C2 Py).
1
moisture-sensitive orange solid (0.39 g, yield 90%). H NMR
(300 MHz, CD2Cl2 + CD3CN, 218 K): δ 1.00 (s broad, 3 H,
PdCH3), 1.41-2.08 (m, 4 H, dCCH2CH2), 2.67-3.35 (m, 4 H,
dCCH2), 6.94-7.90 (m, 11 H, H arom), 8.33 (s broad, 1 H, H6
Py), 8.57 (s broad). 13C{1H} NMR (75.469 MHz, CD2Cl2
+
CD3CN, 218 K): δ -5.4 (s, PdCH3), 21.6, 22.3 (s, dCCH2CH2),
28.0 (d, J ) 4.7 Hz, dCCH2), 30.3 (d, J ) 9.4 Hz, dCCH2),
122.7 (d, J ) 7.0 Hz, C3 Py), 122.8 (s, C5 Py), 124.0 (s, C5 Py),
124.4 (d, J ) 7.0 Hz, C3 Py), 126.3 (d, J ) 52.8, i-C Ph), 129.1
(d, J ) 11.7 Hz, C Ph), 131.9 (s, C Ph), 133.2 (d, J ) 14.1 Hz,
C Ph), 137.2 (d, J ) 2.3 Hz, C4 Py), 138.6 (d, J ) 59.9 Hz,
PCR), 139.4 (s, C4 Py), 140.3 (d, J ) 46.9 Hz, PCR), 148.8 (d, J

Palladium Complexes of 2-(2-Pyridyl)phospholes
Organometallics, Vol. 21, No. 8, 2002 1601
) 11.7 Hz, PCâ), 149.6, 151.6 (s, C6 Py), 151.1 (d, J ) 16.4 Hz,
PCâ), 151.4 (d, J ) 12.9 Hz, C2 Py), 152.8 (d, J ) 14.6 Hz, C2
Py). 31P{1H} NMR (81.014 MHz, CD2Cl2 + CD3CN, 218 K): δ
56.8. HR-MS (FAB-mNBA): m/z 489.0716 (M - CH3CN -
SbF6)+, calcd for C25H24N2PPd 489.0722.
[1-cycloh exyl-2,5-b is(2-p yr id yl)p h osp h ole]P d (CH 3)-
(CH3CN)(SbF 6) (4a ′). By the procedure described for the
compound 4a , reaction of complex 3a ′ (0.25 g, 0.47 mmol) and
AgSbF6 (0.16 g, 0.47 mmol) afforded 4b as an extremely
sensitive orange solid (0.31 g, yield 86%). 31P{1H} NMR (81.014
MHz, CD2Cl2 + CD3CN, 218 K): δ +62.8.
and 13.5 Hz, 2 H, o-H), 7.91 (ddd, J ) 1.3, 8.0, and 8.0 Hz, 1
H, H4 Py), 8.60 (ddd, J ) 0.9, 1.3, and 5.5 Hz, 1 H, H6 Py).
13C{1H} NMR (50.323 MHz, CD2Cl2): δ -9.2 (d, J ) 2.4 Hz,
PdCH3), 2.4 (s, CH3CN), 21.7, 22.4 (s, dCCH2CH2), 28.0 (d, J
) 9.4 Hz, dCCH2), 29.9 (d, J ) 8.6 Hz, dCCH2), 119.5 (s,
CH3CN), 123.5 (s, C5 Py), 124.1 (d, J ) 8.6 Hz, C3 Py), 124.9
(d, J ) 48.5 Hz, i-C Ph), 127.4 (s, C4 or C5 thienyl), 127.4 (C4
or C5 thienyl), 129.2 (d, J ) 5.5 Hz, C3 thienyl), 129.5 (d, J )
11.7 Hz, m-C Ph), 129.9 (d, J ) 50.3 Hz, PCR), 132.9 (d, J )
3.1 Hz, p-C Ph), 134.1 (d, J ) 14.1 Hz, o-C Ph), 136.4 (d, J )
18.8 Hz, C2 thienyl), 137.0 (d, J ) 45.4 Hz, PCR),139.3 (s, C4
Py), 149.1 (d, J ) 14.1 Hz, PCâ), 150.1 (d, J ) 10.9 Hz, PCâ),
150.5 (s, C6 Py), 151.2 (d, J ) 16.8 Hz, C2 Py). 31P{1H} NMR
(81.014 MHz, CD2Cl2): δ +57.4. HR-MS (FAB-mNBA): m/z
494.0316 (M - CH3CN - SbF6)+, calcd for C24H23NPSPd
494.0333. Anal. Calcd for C26H26N2PSPdSbF6: C, 40.47; H,
3.40; N, 3.63. Found, C, 40.62; H, 3.72; N, 3.51.
[1,2-diph en yl-5-(2-pyr idyl)ph osph ole]P d(CH3)(CH3CN)-
(SbF 6) (4b): By the procedure described for the compound 4a ,
reaction of complex 3b (0.30 g, 0.57 mmol) and AgSbF6 (0.20
g, 0.57 mmol) afforded 4b as an air-stable yellow solid (0.40
1
g, yield 92%). H NMR (300 MHz, CD2Cl2): δ 0.72 (d, J ) 1.8
Hz, 3 H, PdCH3), 1.58-2.09 (m, 4 H, dCCH2CH2), 2.35 (s, 3H,
CH3CN), 2.55-3.10 (m, 4 H, dCCH2), 7.72 (m, 2 H, H Ph),
7.20-7.75 (m, 10 H, H arom), 7.91 (dddd, J ) 1.4, 1.4, 7.8,
and 7.8 Hz, 1 H, H4 Py), 8.57 (d broad, J ) 4.9 Hz, 1 H, H6
Py). 13C{1H} NMR (50.323 MHz, CD2Cl2): δ -12.2 (d, J ) 3.6
Hz, PdCH3), 2.7 (s, CH3CN), 21.9, 22.3 (s, dCCH2CH2), 28.0
(d, J ) 8.5 Hz, dCCH2), 29.0 (d, J ) 9.7 Hz, dCCH2), 123.7
(d, J ) 47.0 Hz, i-C Ph), 124.1 (s, C5 Py), 124.4 (d, J ) 8.5 Hz,
C3 Py), 128.8 (s, C Ph), 129.1 (s, C Ph), 129.2 (d, J ) 3.8 Hz,
C Ph), 129.8 (d, J ) 12.1 Hz, C Ph), 133.1 (d, J ) 3.0 Hz, C
Ph), 133.8 (d, J ) 13.3 Hz, i-C Ph), 134.2 (d, J ) 13.3 Hz, C
Ph), 139.8 (s, C4 Py), 136.1 (d, J ) 52.2 Hz, PCR), 138.7 (d, J
) 49.7 Hz, PCR), 150.6 (d, J ) 12.1 Hz, PCâ), 153.0 (d, J )
14.5 Hz, PCâ), 150.9 (s, C6 Py), 153.5 (d, J ) 17.0 Hz, C2 Py).
31P{1H} NMR (81.014 MHz, CD2Cl2): δ +55.8. HR-MS (FAB-
[1-cycloh exyl-2-(2-p yr id yl)-5-(2-th ien yl)p h osp h ole]P d -
(CH3)(CH3CN)(SbF 6) (4c′). By the procedure described for
the compound 4a , reaction of complex 3c (0.33 g, 0.61 mmol)
and AgSbF6 (0.21 g, 0.61 mmol) afforded 4c′ as an air-stable
1
orange solid (0.43 g, yield 91%). H NMR (200 MHz, CD2Cl2):
δ 0.70 (d, J ) 2.1 Hz, 3 H, PdCH3), 0.78-1.95 (m, 15 H, CH2),
2.37 (s, 3 H, CH3CN), 2.61-3.01 (m, 4 H, CH2 and PCH), 7.16
(m, 2 H, H3,4 thienyl), 7.42 (ddd, J ) 1.1, 4.9, and 7.8 Hz, 1
H, H5 Py), 7.55 (m, 1 H, H5 thienyl), 7.64 (d broad, J ) 7.7
Hz, 1 H, H3 Py), 8.05 (dddd, J ) 1.4, 1.4, 7.8, and 7.8 Hz, 1 H,
H4 Py), 8.60 (d broad, J ) 4.9 Hz, 1 H, H6 Py). 13C{1H} NMR
(50.323 MHz, CDCl3): δ -9.9 (d, J ) 3.3 Hz, PdCH3), 2.7 (s,
CH3CN), 21.7, 22.4 (s, dCCH2CH2), 25.6 (d, J ) 1.1 Hz, CH2
Cy), 26.6 (d, J ) 10.9 Hz, CH2 Cy), 27.0 (d, J ) 5.5 Hz, CH2
Cy), 27.2 (d, J ) 19.7 Hz, CH2 Cy), 27.9 (d, J ) 8.0 Hz, dCCH2),
29.5 (d, J ) 8.5 Hz, dCCH2), 31.3 (d, J ) 2.7 Hz, CH2 Cy),
38.6 (d, J ) 22.2, CH Cy), 120.2 (s, CH3CN), 123.5 (s, C5 Py),
123.5 (d, J ) 8.1 Hz, C3 Py), 127.7, 128.2 (s, C4 and C5
thienyl), 128.5 (d, J ) 47.6 Hz, PCR), 129.2 (d, J ) 4.2 Hz, C3
thienyl), 133.7 (d, d, J ) 46.2 Hz, PCR), 136.6 (d, J ) 18.8 Hz,
C2 thienyl), 139.5 (s, C4 Py), 149.3 (d, J ) 12.4 Hz, PCâ), 150.3
(s, C6 Py), 151.1 (d, J ) 9.7 Hz, PCâ), 152.4 (d, J ) 16.5 Hz,
C2 Py). 31P{1H} NMR (81.014 MHz, CD2Cl2): δ 68.9. HR-MS
(FAB-mNBA): m/z 500.0804 (M - CH3CN - SbF6)+, calcd for
mNBA): m/z 488.0770 (M - CH3CN - SbF6)+, calcd for C26H25
-
NPPd 488.0767. Anal. Calcd for C28H28N2F6PPdSb: C, 43.92;
H, 3.69; N, 3.66. Found, C, 44.18; H, 3.82; N, 3.57.
[1-cycloh exyl-2-ph en yl-5-(2-pyr idyl)ph osph ole]P d(CH3)-
(CH3CN)(SbF 6) (4b′). By the procedure described for the
compound 4a , reaction of complex 3b (0.25 g, 0.47 mmol) and
AgSbF6 (0.16 g, 0.47 mmol) afforded 4b′ as an air-stable yellow
1
solid (0.34 g, 95%). H NMR (300 MHz, CD2Cl2): δ 0.70 (d, J
) 1.7 Hz, 3 H, PdCH3), 0.80-1.20 (m, 4 H, CH2), 1.51-2.02
(m, 11 H, CH2), 2.36 (s, 3 H, CH3CN), 2.42-2.81 (m, 3 H, CH2
and CH Cy), 3.05 (m, 1 H, CH2), 7.26 (m, 2 H, CH), 7.35-7.55
(m, 4 H, CH), 7.67 (d broad, J ) 7.9 Hz, 1 H, H3 Py), 7.85
(dddd, J ) 1.0, 1.9, 7.9, and 7.9 Hz, 1 H, H4 Py), 8.71 (d broad,
J ) 5.2 Hz, 1 H, H6 Py). 13C{1H} NMR (50.323 MHz, CD2Cl2):
δ -12.9 (d, J ) 3.9 Hz, PdCH3), 2.7 (s, CH3CN), 22.0, 22.2 (s,
dCCH2CH2), 25.4 (d, J ) 1.0 Hz, CH2 Cy), 26.5 (d, J ) 10.9
Hz, CH2 Cy), 26.8 (d, J ) 13.3 Hz, CH2 Cy), 27.3 (d, J ) 7.8
Hz, dCCH2), 28.1 (d, J ) 8.6 Hz, dCCH2), 28.5 (d, J ) 3.1 Hz,
CH2 Cy), 30.6 (s broad, CH2 Cy), 37.7 (d, J P-C ) 24.2 Hz, CH
Cy), 120.3 (s, CH3CN), 123.2 (d, J ) 8.6 Hz, C3 Py), 124.2 (s,
C5 Py), 128.7 (s, C Ph), 129.1 (s, C Ph), 129.2 (d, J ) 4.7 Hz,
C Ph), 134.1 (d, J ) 12.5, i-C Ph), 135.5 (d, J ) 46.2 Hz, PCR),
135.7 (d, J ) 44.6 Hz, PCR), 139.5 (s, C4 Py), 150.1 (d, J )
11.0 Hz, PCâ), 151.1 (s, C6 Py), 151.9 (d, J ) 16.4 Hz, C2 Py),
152.2 (d, J ) 12.5 Hz, PCâ). 31P{1H} NMR (81.014 MHz,
CD2Cl2): δ 65.2. HR-MS (FAB-mNBA): m/z 494.1240 (M -
CH3CN - SbF6)+, calcd for C26H31NPPd 494.1229. Anal. Calcd
for C28H34F6N2PPdSb: C, 43.58; H, 4.44; N, 3.63. Found: C,
43.82; H, 4.69; N, 3.42.
[1-ph en yl-2-(2-pyr idyl)-5-(2-th ien yl)ph osph ole]P d(CH3)-
(CH3CN)(SbF 6) (4c). By the procedure described for the
compound 4a , reaction of complex 3c (0.25 g, 0.47 mmol) and
AgSbF6 (0.16 g, 0.47 mmol) afforded complex 4c as an air-
stable orange solid (0.33 g, yield 91%). 1H NMR (200 MHz,
CD2Cl2): δ 0.85 (d, J ) 2.4 Hz, 3 H, PdCH3), 1.51-2.15 (m, 4
H, dCCH2CH2), 2.37 (s, 3 H, CH3CN), 2.70-3.05 (m, 3 H,
dCCH2), 3.18 (m, 1 H, dCCH2), 6.87 (d broad, J ) 3.8 Hz,
1H, H3 thienyl), 6.97 (dd, J ) 3.8 and 5.3 Hz, 1 H, H4 thienyl),
7.30-7.52 (m, 5 H, m,p-H Ph, H5 thienyl, H5 Py), 7.55 (d
broad, J ) 8.0 Hz, 1 H, H3 Py), 7.70 (dddd, J ) 1.5, 1.5, 6.7,
C
24H29NPSPd 500.0812. Anal. Calcd for C26H32N2PSPd-
SbF6: C, 40.15; H, 4.15; N, 3.60. Found: C, 40.51; H, 4.53; N,
3.45.
Bis[1-P h en yl-2-(2-p yr id yl)-5-(2-th ien yl)p h osp h ole]P d -
(SbF 6-)2 (5). A MeOH solution (10 mL) of complex 4c (0.30 g,
0.39 mmol) was stirred at room temperature for 30 min. The
dark precipitate was filtered off using a plug of Celite. The
solvent was removed under vacuum, and the residue was
washed with pentane (3 × 10 mL) and ether (3 × 10 mL).
Complex 5 was obtained by crystallization as a deep red solid
from a CH2Cl2/toluene solution at room temperature (0.21 g,
42% yield). Single crystals suitable for an X-ray diffraction
study were grown from a saturated C2H4Cl2/toluene solution
at -20 °C. 1H NMR (300 MHz, CD2Cl2): δ 2.00 (m, 8H,
dCCH2CH2), 2.65-2.91 (m, 6H, dCCH2), 3.20 (m, 2H, dCCH2),
6.00 (m, 2H), 6.45 (dd, J ) 3.5 and 5.0 Hz, 2H, H4 thienyl),
7.01 (dd, J ) 1.0 and 5.0 Hz, 2H), 7.20-8.20 (m, 16 H), 8.50 (s
broad, 2H, H6 py). 13C{1H} NMR (75.469 MHz, CD2Cl2): δ
21.1, 21.7 (s, dCCH2CH2), 27.6 (m, dCCH2), 30.0 (m, dCCH2),
120.8 (dd, J ) 3.0 and 53.2 Hz, i-C), 124.3 (m, C3 Py), 125.7
(s, C5 Py), 128.0, 128.7 (s, C4 thienyl and C5 thienyl), 129.4
(m, C3 thienyl), 130.0 (m, m-C Ph), 130.1 (s, p-C Ph), 132.1
(d, J ) 54.0 Hz, CR), 132.3 (d, ) 57.9 Hz, CR), 133.9 (m, o-C Ph
), 136.8 (d, J PC ) 4.7 Hz, C2 thienyl), 141.6 (s, C4 Py), 150.3
(d, J ) 18.0 Hz, Câ), 151.3 (m, C6 Py), 152.8 (m, Câ), 159.2 (m,
J ) 18.8 Hz, C2 Py). 31P{1H} NMR (81.014 MHz, CD2Cl2): δ
69.7. HR-MS (FAB-mNBA): m/z 1087.0098 (M - SbF6+), calcd
for C46H40N2P2S2PdSbF6 1087.0100. Anal. Calcd for C46H40N2-
P2S2PdSb2F12: C, 41.70; H, 3.04; N, 2.11. Found, C, 41.21; H,
3.11; N, 2.25.

1602 Organometallics, Vol. 21, No. 8, 2002
Sauthier et al.
Ta ble 5. Cr ysta llogr a p h ic Da ta for Com p ou n d s 3b
a n d 5
X-r a y Str u ctu r a l An a lyses. The unit cell constant, space
group determination, and data collection were carried out on
an automatic CAD4 NONIUS diffractometer with graphite-
monochromatized Mo KR radiation. The cell parameters were
obtained by fitting a set of 25 high-θ reflections. After Lorentz
and polarization corrections and absorption corrections with
ψ scan22a the structures were solved with SIR-97,22b which
reveals non-hydrogen atoms of the structure. During the
refinement, a dichloromethane and two partial molecules of
toluene appear for compound 5. After anisotropic refinement,
many hydrogen atoms may be found with a difference Fourier
map. The entire structures were refined with SHELXL9722c
by full-matrix least-squares techniques (use of F magnitude;
x, y, z, âij for Pd, P, C, S, Cl, and N atoms; x, y, z in riding
mode for H atoms. The structure of 5 shows a statistical
disorder (80/20) between S(31) and C(46). ORTEP views were
prepared with PLATON98.21d All calculations were performed
on a Silicon Graphics Indy computer. Selected crystallographic
data are listed in Table 5.
3b
5‚0.5C2H4Cl2‚C7H8
formula
C26H25ClNPPd
C46H40N2P2S2Sb2F12
0.5C2H4Cl2‚C7H8
1464.92
triclinic
P1h
293
13.655(10)
14.991(2)
16.835(2)
‚
fw
524.29
monoclinic
P21/n
cryst syst
space group
temp (K)
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
293
10.229(2)
14.666(6)
14.930(4)
108.89(2)
97.53(2)
90.10(3)
2221(1)
1064
108.48(3)
3071(2)
1494
F(000)
Z
4
2
λ(Mo KR) (Å)
0.710 69
1.568
10.42
4-54
5097
0.710 69
1.584
15.28
4-54
12 920
7587
D(calcd) (g cm-3
)
µ(Mo KR) (cm-1
2θ range (deg)
no. of data collected
)
Ack n ow led gm en t. This work was financially sup-
ported by the Ministe`re de l’Education Nationale, de la
Recherche et de la Technologie, the Centre National de
la Recherche Scientifique, and the Institut Universitaire
de France.
no. of unique data
4830
no. of params varied
275
645
S
1.033
0.964
0.0735
0.2112
1.570
-0.971
Ra
0.0476
0.1236
0.800
b
Rw
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
and intensity collection data, positional and thermal param-
eters, and interatomic distances and angles for derivatives 3b
and 5. This material is available free of charge via the Internet
at http://pubs.acs.org. Full sets of crystallography data have
been deposited with the Cambridge Crystallographic Data
Center (CCDC 171791 and 149075 for compounds 3b and 5,
respectively).
(∆/F)max (e Å-3
)
)
(∆/F)min (e Å-3
-0.1437
R ) ∑||Fo| - |Fo||/∑||Fo|. Rw ) [∑w(Fo - Fc2)/∑w(Fo2)2]1/2
.
a
b
2
P olym er iza tion P r oced u r e. In a typical procedure, the
cationic Pd complex (0.03 mmol) was dissolved in CH2Cl2 (20
mL) in a Schlenk tube under argon, and the solution was
transferred to a 150 mL autoclave equipped with a magnetic
stirrer. The reaction mixture was pressurized with CO (10 bar)
and ethylene (10 bar) and heated to the desired temperature.
The reaction was quenched by release of CO/ethylene pressure.
The polymer was isolated by filtration, washed with methanol,
dried, and weighed.
Gel permeation chromatographic analysis of CO-nor-
bornene oligomers was performed with THF as the solvent,
and the calibration was made with polystyrene standards. The
13C{1H} NMR data for the oligomers are in agreement with
those of previously described copolymers.21
OM011034Y
(21) Sen, A.; Lai, T.-W. J . Am. Chem. Soc. 1982, 104, 3520.
(22) (a) Spek, A. L. HELENA. Program for the handling of CAD4-
Diffractometer output, SHELX(S/L); Utrecht University, Utrecht, The
Netherlands. 1997. (b) Altomare, A.; Burla, M. C.; Camalli, M.;
Cascarano, G.; Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.;
Polidori, G.; Spagna, R. Sir97: A New Tool for Crystal Structure
Determination and Refinement. J . Appl. Crystallogr. 1998, 31, 74. (c)
Sheldrick, G. M. SHELX97-2: Program for the Refinement of Crystal
Structures; University of Go¨ttingen, Go¨ttingen, Germany, 1998. (d)
Spek, A. L. PLATON: A Multipurpose Crystallographic Tool; Utrecht
University, Utrecht, The Netherlands. 1998.