Synthesis and structure of orthopalladated complexes derived from prochiral iminophosphoranes and phosphorus ylides

Article abstract of DOI:10.1016/j.jorganchem.2007.11.012

The iminophosphorane Ph₂MeP{double bond, long}NPh (1) reacts with Pd(OAc)₂ to give the orthopalladated [Pd(μ-Cl){C₆H₄(PPh(Me){double bond, long}NPh-κ-C,N)-2}]₂ (2) as the racemic mixture, which reacts with Tl(acac) to give [Pd(acac){C₆H₄(PPh(Me){double bond, long}NPh-κ-C,N)-2}] (3). The X-ray structure of (3) has been determined by diffraction methods. The phosphorus ylide Ph₂MeP{double bond, long}CHC(O)Ph (5) reacts with Pd(OAc)₂ to give the dinuclear [Pd(μ-Cl){C₆H₄(PPh(Me)CHC(O)Ph-κ-C,C)-2}]₂ (6) as a mixture of isomers. Complex (6) reacts with Tl(acac), PPh₃ or AgClO₄/dppe giving the mononuclear derivatives [Pd(acac){C₆H₄(PPh(Me)CHC(O)Ph-κ-C,C)-2}] (7), [PdCl{C₆H₄(PPh(Me)CHC(O)Ph-κ-C,C)-2}PPh₃] (8) and [Pd{C₆H₄(PPh(Me)CHC(O)Ph-κ-C,C)-2}(dppe-P,P′)](ClO₄) (9), as mixtures of stereoisomers with high diastereomeric excess.

Full text of DOI:10.1016/j.jorganchem.2007.11.012

Available online at www.sciencedirect.com
Journal of Organometallic Chemistry 693 (2008) 417–424
www.elsevier.com/locate/jorganchem
Synthesis and structure of orthopalladated complexes derived
from prochiral iminophosphoranes and phosphorus ylides
a
a
a
a
b
´
David Aguilar , Miguel Angel Aragues , Raquel Bielsa , Elena Serrano , Tatiana Soler ,
¨
Rafael Navarro a, Esteban P. Urriolabeitia a,*
a Departamento de Compuestos Organometa´licos, Instituto de Ciencia de Materiales de Arago´n, CSIC – Universidad de Zaragoza,
E – 50009, Zaragoza, Spain
b Servicios Te´cnicos de Investigacio´n, Facultad de Ciencias Fase II, 03690 San Vicente de Raspeig, Alicante, Spain
Received 19 October 2007; received in revised form 7 November 2007; accepted 8 November 2007
Available online 13 November 2007
Abstract
The iminophosphorane Ph2MeP@NPh (1) reacts with Pd(OAc)2 to give the orthopalladated [Pd(l-Cl){C6H4(PPh(Me)@NPh-j-C,N)-
2}]2 (2) as the racemic mixture, which reacts with Tl(acac) to give [Pd(acac){C6H4(PPh(Me)@NPh-j-C,N)-2}] (3). The X-ray structure of
(3) has been determined by diffraction methods. The phosphorus ylide Ph2MeP@CHC(O)Ph (5) reacts with Pd(OAc)2 to give the dinu-
clear [Pd(l-Cl){C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}]2 (6) as a mixture of isomers. Complex (6) reacts with Tl(acac), PPh3 or AgClO4/
dppe giving the mononuclear derivatives [Pd(acac){C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}] (7), [PdCl{C6H4(PPh(Me)CHC(O)Ph-j-C,C)-
2}PPh3] (8) and [Pd{C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}(dppe–P,P0)](ClO4) (9), as mixtures of stereoisomers with high diastereomeric
excess.
Ó 2007 Elsevier B.V. All rights reserved.
Keywords: Cyclometallated; CH-bond activation; Iminophosphoranes; Phosphorus ylides; Palladium
1. Introduction
reagents, and behave as good ligands [46–48]. In addition,
they show notable analogies with the phosphorus ylides
R3P@CR0(R00) [46].
The activation of C–H bonds induced by transition met-
als is, at present, one of the most active fields of research in
organometallic chemistry due to its implications, among
others, in fundamental steps in catalytic cycles, in the func-
tionalization of simple substrates through orthometalla-
tion, and in other relevant chemical processes [1–29].
While this type of reaction has been extensively studied
with a large variety of substrates, metallations developed
with iminophosphoranes are still scarcely represented
[30–45]. The iminophosphoranes are compounds of general
structure R3P@NR0 (R = alkyl, aryl; R0 = alkyl, aryl, acyl,
. . .) that have numerous applications in organic chemistry
(e.g., aza-Wittig reaction), either as neutral or as anionic
The orthometallation of these two species, iminophos-
phoranes R3P@NR0 [30–45] and phosphorus ylides
R3P@C(R0)(R00) [49–57], is produced, in the vast majority
of cases, regioselectively at the Ph rings of the phosphine
unit. Some recent contributions have shown, however, that
it is possible to obtain orthopalladated complexes derived
from CH activation at Ph rings belonging to the R0 or R00
substituents of the ylidic carbon and, more precisely,
belonging to benzamide moieties [45].
Aiming to expand the scope of this type of orthometal-
lated derivatives we have studied the C–H bond activation
process, induced by Pd(II) salts, in the iminophosphorane
ligand Ph2MeP@NPh (1) and in the ylide ligand
Ph2MeP@CHC(O)Ph (5), both containing a pro-chiral
phosphorus center. The results obtained show that the pal-
ladation is produced at one phenyl ring of the PPh2Me
*
Corresponding author. Tel.: +34 976762302; fax: +34 976761187.
E-mail address: esteban@unizar.es (E.P. Urriolabeitia).
0022-328X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.11.012

418
D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
group, giving complexes with a stereogenic P center and, in
the case of the ylides, with an additional chiral carbon cen-
ter. In the latter, the final arrangement occurs with high
diastereoselective induction.
organic solvents prevented a more detailed spectroscopic
characterization of 2.
For this reason, complex 2 was reacted with Tl(acac)
(molar ratio 1:2) in CH2Cl2 to obtain the mononuclear ace-
tylacetonate derivate [Pd(acac-O,O0){C6H4(PPh(Me)@
NPh-j-C,N)-2}] (3) (Scheme 1), which is adequately solu-
ble in organic solvents. Its 31P {1H} NMR spectrum shows
a single peak at 48.6 ppm, in the same region than those
2. Results and discussion
The iminophosphorane Ph2MeP@NPh (1) was prepared
following Staudinger method [58], by reaction of N3Ph
with PPh2Me in dry CH2Cl2. Phenylazide was prepared fol-
lowing also reported methods [59], by reaction of aniline
with NaNO2 and NaN3 in H2O at 0 °C for 5 h. The IR
1
observed for 2. The H NMR spectrum of 3 shows the
high-field signals assigned to the acac ligand and to the
methyl group of the phosphine ligand. Full assignment of
the aromatic signals due to the Pd(C6H4) fragment was per-
spectrum of 1 shows a strong absorption at 1314 cmꢀ1
,
formed with the help of a H–1H COSY experiment, and
1
due to the P@N stretch [60–62], and the 31P{1H} NMR
spectrum shows a single peak at 5.89 ppm. These results
are similar to those observed in related species such as
Ph3P@NPh [32].
were found at 7.20–7.27 (2H), 7.45–7.49 (1H) and 7.94
(1H) ppm, while the protons assigned to the P-C6H5 ring
appear at 7.68 (Hm), 7.75 (Hp) and 8.08 (Ho) ppm.
The molecular structure of 3 was determined through X-
ray diffraction methods. A molecular drawing of complex 3
is shown in Fig. 1, crystallographic data and parameters
concerning data collection and structure solution and
refinement are summarized in Table 1 and selected bond
distances and angles are presented in Table 2. Complex 3
crystallizes on the orthorhombic system, on the centrosym-
metric space group Pbca. Although 3 is quiral, the crystal
as a whole is racemic. The absolute configuration of the
phosphorus atom depicted in the structure shown in
Fig. 1 is S. The Pd atom is located on a square-planar envi-
ronment, surrounded by the iminic nitrogen N(1), the met-
allated carbon C(7), and the two oxygen atoms O(1) and
O(2) of the chelating acac ligand. The sum of the bond
angles around the palladium is almost 360.0°. Although
the orthometallated ligand is remarkably warped, the envi-
ronment around the Pd is planar. The Ph ring and the Me
group at the palladacycle occupy the axial and equatorial
positions, respectively. The axial location of the bulkiest
group probably responds to a minimization of intramolec-
The reactivity of 1 with Pd(OAc)2 (OAc = acetate) has
been investigated. The treatment of Pd(OAc)2 with 1 (1:1
molar ratio) in refluxing toluene, and further reaction of
the acetate intermediate with excess LiCl in methanol gives
a very insoluble solid, whose stoichiometry corresponds to
the orthometallated complex [Pd(l-Cl){C6H4(PPh(Me)@
NPh-j-C,N)-2}]2 (2) (Scheme 1). The N-bonding of the
iminophosphorane can be inferred from the IR spectrum,
since a decrease on the P@N stretch is observed. The
31P{1H} NMR spectrum of 2 shows the presence of three
signals, one of them containing two overlapped peaks, in
the range around 45–50 ppm. The range of chemical shifts
denotes the presence of the metallacycle [Pd(C6H4PR2@
NR0)] [32], and means that a palladation has occurred at
the phenyl ring of the phosphonium unit. The proposed
structure is represented in Scheme 1, and shows that the
P atom has been transformed into an stereogenic center.
Taking into account these facts, the presence of four peaks
in the 31P{1H} NMR spectrum of 2 can be easily explained.
Complex 2 is dinuclear and it is obtained as a mixture of
geometric isomers (cis and trans), with two stereogenic P
centers each. A signal is observed for each one of the four
diastereoisomers: cis (RR/SS), cis (RS/SR), trans (RR/SS)
and trans (RS/SR). The high insolubility of 2 in the usual
˚
ular interactions. The Pd(1)–N(1) [2.046(5) A] and the
˚
Pd(1)–C(7) [1.973(6) A] bond distances are statistically
identical than those found in related complexes like
Ph
N
Me
Ph
MePh P
2
N
(1)
P
Ph
(i),(ii)
(1/2)
Pd
Cl
2
(2)
Me
Ph
P
N
Ph
(iii)
Pd
O
O
(3)
Scheme 1. (i) Pd(OAc)2/toluene/D; (ii) LiCl/MeOH; (iii) Tl(acac).
Fig. 1. Molecular structure of complex 3. Ellipsoids are drawn at 50%
probability level.

D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
419
Table 1
respect to that found in 4 (23.13 ppm), as is typical for car-
bonyl-stabilized ylides [49].
Crystal data and structure refinement for compound 3
Empirical formula
Formula weight
Temperature (K)
Radiation (l, A)
Crystal system
Space group
C24H24NO2PPd
495.81
100(1)
Mo Ka (0.71073)
Orthorhombic
Pbca
Treatment of 5 with Pd(OAc)2 (1:1 molar ratio) in
refluxing CH2Cl2, and further reaction of the acetate inter-
mediate with excess LiCl in methanol gives a yellow solid,
whose stoichiometry corresponds to the palladated com-
plex [Pd(l-Cl){C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}]2 (6)
(Scheme 2). Ylide 5 can undergo a C–H activation process
at two different positions, almost equivalents, namely the
phenyl ring of the benzoyl fragment and the phenyl ring
of the phosphine group (Fig. 2). We have recently reported
that the preferred position for palladation on the related
ylides Ph3P@CHC(O)Ph [45] is the phenyl ring bonded to
the P atom, being the activation of the benzoyl ring only
possible in these species in the absence of Ph rings at the
P atom. In addition, we have also reported that the palla-
dation of the benzoyl ring is possible when iminophosphor-
anes Ph3P@NC(O)Ph are considered [45]. Therefore,
although both activations could in principle occur, it seems
that, for ylides, palladation at the PPh3 group is the
expected process. The IR spectrum of 6 shows a sharp
absorption, due to the mCO stretch, shifted to higher fre-
quency with respect to the corresponding absorption in
˚
˚
a (A)
16.0446(14)
14.8842(11)
17.8088(13)
4252.9(6)
˚
b (A)
˚
c (A)
3
˚
V (A )
Z
8
Dcalc (Mg/m3)
1.549
0.968
l (mmꢀ1
)
Crystal size (mm3)
0.14 ꢁ 0.12 ꢁ 0.04
Reflections collected
Independent reflections
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
14188
3742 (Rint = 0.0750)
3742/0/275
1.035
R1 = 0.0548; wR2 = 0.0949
R1 = 0.1039; wR2 = 0.1100
0.433 and ꢀ0.377
ꢀ3
˚
Largest difference in peak, hole (e A
)
Table 2
Selected bond distances (A) and angles (°) for compound 3
˚
Pd1–C7
Pd1–O1
P1–N1
1.973(6)
2.106(5)
1.600(5)
1.802(6)
Pd1–N1
Pd1–O2
P1–C6
2.046(5)
1.987(4)
1.787(6)
1.400(7)
Me
Ph
O
P1–C18
N1–C12
P
C7–Pd1–N1
N1–Pd1–O1
Pd1–C7–C6
C6–P1–N1
85.2(2)
93.2(2)
118.2(5)
102.6(3)
C7–Pd1–O2
O1–Pd1–O2
C7–C6–P1
P1–N1–Pd1
90.4(2)
91.14(18)
114.0(5)
113.8(3)
H
(5)
Ph
Me
O
P
(i),(ii)
Ph
(1/2)
H
Pd
Ph
Me
Cl
2
0
O
˚
˚
[Pd(j -C,N–C6H4(PPh2@NC6H4Me-4 )-2)(l-OAc)]2 [2.050(2)A]
P
2
2
(6)
[42] and [Pd(j -C,N–C6H4PPh2@NPh)(l-Cl)]2 [2.047(2) A]
Ph
[63]. The acac group behaves as an O,O0-chelate ligand and
(iii)
H
Pd
O
(v)
is bonded to the Pd atom giving a six membered ring. The
O
˚
˚
(iv)
Me
distances Pd(1)–O(2) [1.987(4) A] and Pd(1)–O(1) [2.106 A]
are quite different, reflecting the different trans effect of the
nitrogen atom and the arylic carbon. However, the two dis-
tances are in good agreement with other structures where
the acetilacetonate also behaves as a chelate ligand coordi-
nated to a Pd centre [64]. Other internal parameters of the
metallated iminophosphorane ligand do not deviate from
published values [65].
(7)
Ph
Ph
Me
O
O
P
P
Ph
Ph
ClO
4
H
H
Pd
Pd
PPh
2
Cl
Ph P
2
Ph P
3
(8)
(9)
The a-ketostabilized ylide [Ph2MeP@CHC(O)Ph] (5)
was synthesized following reported procedures, with minor
changes (see Section 4) [66,67]. Phenacyl bromide reacts
with PPh2Me to give the corresponding phosphonium salt,
[Ph2MePCH2C(O)Ph]Br (4), which in turn reacts with
Na2CO3 in MeOH/H2O at 25 °C giving 5 as an air-stable
white solid [66,67]. The IR spectrum of 5 shows a strong
absorption at 1504 cmꢀ1 due to the carbonyl stretch. This
band clearly appears at lower energies compared to that
found in the salt 4 (1661 cmꢀ1) due to the charge delocal-
ization present in this kind of compounds. The 31P{1H}
NMR spectrum shows a signal at 10.82 ppm, shielded with
Scheme 2. (i) Pd(OAc)2/CH2Cl2/D; (ii) LiCl/MeOH; (iii) Tl(acac); (iv)
PPh3; (v) AgClO4/THF/dppe.
Me
Ph
O
P
(5)
H
Exo
Endo
Fig. 2. Possible orthometallation sites of the prochiral phosphorus ylide
(5).

420
D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
the free ligand 5, this fact indicating that the ylide is
C-bonded to the Pd center. The 31P{1H} NMR spectrum
of 6 shows eight different signals in the range 15.5–
20 ppm. The presence of such high number of signals can
be easily explained taking into account: (i) that the pallada-
tion has been produced at one of the Ph rings of the phos-
phine moiety; (ii) the C-bonding of the ylide, and (iii) that
6 is dinuclear in nature. Thus, the generated Pd{C6H4-
(PPh(Me)CHC(O)Ph-j-C,C)-2} ligand contains two
stereogenic centers, the P atom and the C atom, and two
diastereoisomers could be expected for each palladated
unit. Moreover, this palladated unit can be arranged, in
a dinuclear complex, in cis and trans orientations, this
giving a total of eight cis diastereosiomers and additional
eight trans diastereoisomers. Although the total number
of 31P NMR peaks arising from these considerations
exceeds the number of signals observed in the spectrum,
we must take into account the possible overlap of peaks
and that not all isomers would be obtained with the same
molar ratio.
In order to simplify the characterization of the palladat-
ed ligand, a decrease in the number of diastereoisomers is
desirable, and further reactivity of 6 has been performed.
Reactions of cleavage of the chloride bridges and substitu-
tions of the halide by other neutral or anionic ligands, which
should give mononuclear derivatives, have been attempted.
The reaction of 6 with Tl(acac) (1:2 molar ratio), PPh3 (1:2
molar ratio) or AgClO4/dppe (1:2:2 molar ratio) gives the
mononuclear derivatives [Pd(acac){C6H4(PPh(Me)CHC(O)-
Ph-j-C,C)-2}] (7), [PdCl{C6H4(PPh(Me)CHC(O)Ph-j-C,
C)-2}PPh3] (8) and [Pd{C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}-
(dppe–P,P0)](ClO4) (9) (see Scheme 2).
different P nuclei (PPh3 and PPh2Me). The coupling con-
3
stants found (2JPH = 8.8 Hz and JPH = 6.8 Hz) suggest
that the PPh3 is located trans to the ylidic carbon[49], in
good agreement with the transphobia between the PPh3
and the arylic carbon [69–71]. Similar conclusions can be
1
derived from the analysis of the H NMR spectrum of 9,
although in this case the extensive overlap of peaks avoids
a careful inspection.
In order to determine the absolute configurations of the
stereogenic centers on the most abundant diastereomer in
7–9, NOE experiments were carried out in 8, as a represen-
tative example. Irradiation of the ylidic proton results in
clear NOEs in signals due to the ortho protons of the ben-
zoyl ring, ortho protons of the P–phenyl ring and in P–Me
protons. On the other hand, saturation at the ortho pro-
tons of the benzoyl group induces clear NOEs in signals
assigned to the neighbor meta protons and in the ylidic
proton, while saturation at the ortho protons of the PPh
group produces strong NOEs at the meta protons of the
same ring, at the ylidic protons and at the methyl group.
With this sequence of NOE effects, the most plausible steric
arrangement at the ylidic P and C atoms is that containing
one Ph ring of the P atom and the bulkiest C(O)Ph group
of the Ca atom in axial positions but in different sides of
the molecular plane, while the methyl group of the P atom
and the ylidic proton Ca–H are located in equatorial posi-
tions. In good agreement with the structures depicted in
Scheme 2, the 31P{1H} NMR spectra of 7–9 also show
two sets of signals, due to the two possible diastereoiso-
mers. That of 7 shows two singlets around 20 ppm, these
signals appearing in the same range that those observed
in 6, and suggesting that the palladacycle has not been
altered. The 31P{1H} NMR spectrum of 8 shows the
expected pairs of doublets, and in that of 9 the P,P’-bond-
ing mode of the dppe is evident, since it shows three low-
field signals [72], one due to the ylide and the other two
to the dppe ligand (range 43–54 ppm).
Complexes 7–9 show correct elemental analyses and
mass spectra. The IR spectra of 7–9 show the presence of
absorptions assigned to the different functional groups:
two strong absorptions due to the tCO stretch of the acac
ligand (1564, 1514 cmꢀ1) in 7 and one intense band in the
range 1615–1625 cmꢀ1 due to the tCO stretch of the ylidic
1
carbonyl, amongst them. The H NMR spectra show in
3. Conclusion
all cases two sets of signals, corresponding to the presence
of two diastereoisomers (RPRC/SPSC) and (RPSC/SPRC).
The relative abundance varies from one to another, but
all syntheses occur with notable diastereomeric excess,
probably related with the fact that the two stereogenic
centers are very near. Observed molar ratios are 5/1
(d.e. = 67%, complex 7), 7/1 (d.e. = 75%, complex 8) and
6.7/1 (d.e. = 74%, complex 9). Similar d.e. have been
reported for Pd(II) complexes with (sulfinylmethyl)phos-
phonium ylide ligands, which also contain two adjacent
stereogenic centers (the Ca atom and the sulfur atom)
New cyclopalladated complexes have been obtained
through CH bond activation processes on the iminophos-
phorane Ph2MeP@NPh (1) and on the ylide ligand
Ph2MeP@CHC(O)Ph (5). Although there are two compet-
ing cyclometallation positions, the palladation is produced
selectively at the phenyl rings of the PPh2Me unit,
giving [Pd(l-Cl){C6H4(PPh(Me)@NPh-j-C,N)-2}]2 (2)
and [Pd(l-Cl){C6H4(PPh(Me)CHC(O)Ph-j-C,C)-2}]2 (6),
which are obtained as mixtures of isomers. The corre-
sponding acac derivatives allow a complete characteriza-
tion of the cyclometallated ligands, including X-ray
determination. The reactivity of (6) with anionic chelating
(7), neutral monodentate (8), or neutral chelating (9)
ligands promotes the cleavage and/or substitution of the
chloride bridging system and the synthesis of new mononu-
clear species, in which the five-membered metallacycle
remains stable.
1
[68]. The H NMR spectrum of 7 shows expected signals
due to the methyl and CH protons of the acac ligand
(around 2 and 5 ppm, respectively), while the ylidic protons
appear around 4.50 ppm as doublets with a small coupling
2
constant JPH, typical for C–bonding of the ylides. For
complex 8, the ylidic protons appear as doublets of
doublets, meaning that each proton is coupled with two

D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
421
4. Experimental
refluxed for 2 h. After the reaction time, some decomposi-
tion (presence of black Pd0) is evident. The cooled suspen-
sion was filtered, the solid was dissolved in MeOH and
treated with an excess of anhydrous LiCl (0.775 g,
17.8 mmol). A grey solid immediately precipitated, which
was filtered, washed with MeOH (20 ml) and Et2O
(50 ml) and dried in vacuo. This grey solid was recrystal-
lized from CH2Cl2 giving 2 as a yellow solid, which was
characterized by NMR as a mixture of the cis and trans iso-
mers in 1/1 molar ratio. Yield: 0.175 g (39.4%). Anal. Calc.
for C38H34Cl2N2P2Pd2 (864.4): C, 52.80; H, 3.96; N, 3.24.
Found: C, 52.66; H, 4.46; N, 3.60%. MS (MALDI+): m/
z (%) = 864 (10) [M]+. IR (m, cmꢀ1): 1254 (mPN). 1H
4.1. General methods
Solvents were dried and distilled under argon using stan-
dard procedures. Elemental analyses were performed on a
Perkin–Elmer 2400-B microanalyser. Infrared spectra
(4000–400 cmꢀ1) were recorded on a Perkin–Elmer Spec-
trum One FT-IR spectrophotometer from nujol mulls
between polyethylene sheets. ESI/APCI mass spectra were
recorded using an Esquire 3000 ion-trap mass spectrometer
(Bruker Daltonic GmbH, Bremen, Germany) equipped
with a standard ESI/APCI source. Samples were intro-
duced by direct infusion with a syringe pump. Nitrogen
served both as the nebulizer gas and the dry gas. Helium
served as a cooling gas for the ion trap and collision gas
for MSn experiments. Other mass spectra (positive ion
FAB) were recorded from CH2Cl2 solutions on a V. G.
2
NMR (dmso-d6): d = 2.30 (d, JPH = 12.5, PMe, both),
6.83–8.18 (m, 28H, PPh2, both). 31P{1H}NMR (dmso-d6):
d = 46.78, 48.49, 48.74 (2P).
4.2.3. Synthesis of [Pd(acac-O,O0){C6H4(PPh(Me)@
NPh-j-C,N)-2}] (3)
Autospec spectrometer. H, 13C{1H} and 31P{1H} NMR
1
spectra (d, ppm; J, Hz) were recorded on CDCl3 or CD2Cl2
solutions at room temperature (other temperatures are
specified) on Bruker ARX-300 or Avance-400 spectrome-
To a solution of 2 (0.372 g, 0.429 mmol) in CH2Cl2
(5 ml) Tl(acac) (0.260 g, 0.858 mmol) was added, resulting
in the immediate precipitation of TlCl. This suspension
was stirred for 1 h at 25 °C and then filtered over Celite.
The clear yellow solution was evaporated to dryness and
the residue treated with cold Et2O (10 ml), to give 3 as a
yellow solid. Yield: 0.341 g (80.33%). Complex 3 was
recrystallized from CHCl3/OEt2, giving crystals of
3.2CHCl3, which were used for analytical purposes. Anal.
Calc. for C24H24NO2PPd ꢃ 2CHCl3 (734.6): C, 42.51; H,
3.57; N, 1.90. Found: C, 42.36; H, 4.26; N, 2.49. MS
(MALDI+): m/z (%): 396 (20) [Mꢀacac]+. IR (m, cmꢀ1):
1582 (mCO), 1515 (mCO), 1261 (mPN). 1H NMR (CDCl3):
d = 1.87 (s, 3H, Me, acac), 2.24 (s, 3H, Me, acac), 2.32
1
ters. The H and 13C{1H} NMR spectra were referenced
to the residual solvent signal while the 31P{1H} NMR spec-
tra was referenced to external H3PO4 (85%).
4.2. Synthesis
4.2.1. Synthesis of Ph2MeP@NPh (1)
The iminophosphorane (1) has been obtained using the
Staudinger method [58]. To a solution of N3Ph [59]
(1.36 g, 11.9 mmol) in dry CH2Cl2 (20 ml) under Ar atmo-
sphere, a solution of PPh2Me (2.21 g, 11.9 mmol) in dry
CH2Cl2 (20 ml) was added dropwise during 20 min. The
evolution of N2 is evident even from the first steps of the
addition. The mixture was stirred at 25 °C until N2 evolu-
tion ceased (ꢂ4 h), and then it was evaporated to dryness. 1
was obtained as a yellow solid. Yield: 3.43 g (100%). Anal.
Calc. for C19H18NP (291.3): C, 78.33; H, 6.23; N, 4.81.
Found: C, 78.15; H, 6.76; N, 4.35%. MS (MALDI+): m/
2
(d, 3H, JPH = 12.3, PMe), 5.47 (s, 1H, CH, acac), 7.01–
7.13 (m, 2H, Hp(NPh) + 1H (C6H4)), 7.20–7.27 (m, 5H,
1H (C6H4) + 2Ho + 2Hm (NPh)), 7.47 (m, 1H, C6H4),
7.68 (m, 2H, Hm, PPh), 7.75 (m, 1H, Hp, PPh), 7.94 (d,
3
3
1H, JHH = 7.6, C6H4), 8.08 (dd, 2H, JHH = 8.0,
3JPH = 11.5, Ho, PPh). 13C{1H} NMR (CDCl3): d =
12.11 (Me, acac), 12.70 (Me, acac), 27.49 (d, JCP = 16.1,
1
1
4
z (%) = 292 (100) [M + H]+. IR (m, cmꢀ1): 1314 (mPN). H
PMe), 100.03 (CH, acac), 122.15 (d, JCP = 2.0, Cm,
2
NMR (CDCl3): d = 2.15 (d, 3H, JPH = 9.6, PMe), 6.68
NPh), 124.32 (d, JCP = 14.3, C6H4), 126.54 (d, JCP =
3
3
2
(t, 1H, JHH = 6.0, Hp, Ph), 6.78 (d, 2H, JHH = 5.7, Ho,
22.6, C6H4), 127.57 (d, JCP = 9.5, C6H4), 127.89 (Cp,
3
3
4
Ph), 7.04 (t, 2H, JHH = 5.7, Hm, Ph), 7.46–7.57 (m, 6H,
NPh), 129.10 (d, JCP = 11.4, Cm, PPh), 130.20 (d, JCP =
Hm + Hp, PPh2), 7.76 (m, 4H, Ho, PPh2). 31P{1H}NMR
(CDCl3): d = 5.89. 13C{1H} NMR (CDCl3): d = 15.22 (d,
1JPC = 74.9, PMe), 117.36 (Cp, Ph), 122.92 (d,
3.2, Cp, PPh), 131.08 (d, JCP = 9.64, Co, PPh), 131.67 (d,
2
1JCP = 82.5, Ci, PPh), 132.34 (C6H4), 132.48 (d, JCP
=
3
1
2.4, Co, NPh), 140.19 (d, JCP = 138.5, C2, C6H4), 146.18
3JPC = 18.8, Co, Ph), 128.79 (d, JPC = 2.6, Cm, Ph),
(d, JCP = 3.3, Ci, NPh), 151.91 (d, JCP = 21.3, C1,
C6H4), 185.28 (CO, acac), 188.04 (CO, acac). 31P{1H}
NMR (CDCl3): d = 48.6.
4
2
2
3
2
128.87 (d, JPC = 11.9, Cm, PPh2), 131.44 (d, JPC = 9.4,
Co, PPh2), 131.54 (d, JPC = 94, Ci, PPh2), 131.79 (Cp,
PPh2), 151.23 (d, JPC = 1.8, Ci, Ph).
1
2
4.2.4. Synthesis of Ph2MeP@CHC(O)Ph (5)
4.2.2. Synthesis of [Pd(l-Cl){C6H4(PPh(Me)@NPh-j-
C,N)-2}]2 (2)
The ylide Ph2MeP@CHC(O)Ph 5 was prepared follow-
´
ing the general method reported by Ramırez et al. [66] in
To a solution of 1 (0.300 g, 1.04 mmol) in dry toluene
(15 ml) under Argon atmosphere, Pd(OAc)2 (0.235 g,
1.04 mmol) was added, and the resulting mixture was
two steps. The reaction of phenacyl bromide (1.500 g,
7.54 mmol) with PPh2Me (1.40 ml, 7.54 mmol) in THF at
r.t. for 24 h gives the salt [Ph2MePCH2C(O)Ph]Br (4)

422
D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
(2.78 g, 92.4%) [67]. In the second step, the phosphonium 4
(1.00 g, 2.51 mmol) reacts with Na2CO3 (0.27 g,
2.51 mmol) in MeOH/H2O (1/7, 80 ml), giving 5 as a white
solid. Yield: 0.45 g (56.7%). Selected spectroscopic data: IR
maj.), 7.83 (m, Ho, PPh, maj.), 7.99 (m, Ho, PPh, min),
3
8.06 (d, JHH = 7.2, Ho, PhC(O), min), 8.10 (d,
3JHH = 7.2, Ho, PhC(O), maj.). 13C{1H} NMR (CDCl3):
1
d = 11.94 (d, PMe, maj., JPC = 52.3), 14.00 (d, PMe,
(m, cmꢀ1): 1504 (mCO). H NMR (CDCl3): d = 2.35 (d, 3H,
min, 1JPC = 62.2), 27.61 (Me, acac, maj.), 27.84 (Me, acac,
1
2JPH = 14.0, PMe), 4.14 (s, br, 1H, PCH), 7.2-7.29 (m, 3H,
min), 27.97 (Me, acac, maj.), 28.02 (Me, acac, min), 30.78
1
Hm, Hp, PhC(O)), 7.42 (m, 4H, Hm, PPh2), 7.48 (td, 2H, Hp,
(d, CHP, maj., JPC = 63.0), 35.14 (d, CHP, min,
3
4
PPh2, JHH = 6.8, JHH = 1.2), 7.63 (dd, 4H, Ho, PPh2,
1JPC = 62.8), 99.45 (CH, acac, maj.), 99.57 (CH, acac,
3JPH = 12.4, JHH = 6.8), 7.87 (dd, 2H, Ho, PhC(O)).
min), 124.40 (d, C5, C6H4, min, JPC = 13.5), 124.75 (d,
3
4
31P{1H} NMR (CDCl3): d = 10.82.
C5, C6H4, maj., JPC = 13.3), 125.31 (d, Ci, PPh, min,
4
3
1JPC = 67.9), 128.29 (d, C6, C6H4, maj., JPC = 16.6),
4.2.5. Synthesis of [Pd(l-Cl){C6H4(PPh(Me)CHC(O)
Ph-j-C,C)-2}]2(6)
128.64 (d, C6, C6H4, min, 4JPC = 16.4), 127.51 (Cm, PhCO,
min), 127.62 (Cm, PhCO, maj.), 127.31 (d, Ci, PPh, maj.,
4
To a solution of 5 (1.000 g, 3.14 mmol) in CH2Cl2 (10 ml),
Pd(OAc)2 (0.710 g, 3.14 mmol) was added, and the resulting
mixture was refluxed with vigorous stirring for 24 h. After the
reaction time, the solvent was evaporated and the yellow
solid residue was dissolved in 15 ml of MeOH and anhydrous
LiCl (0.130 g, 3.140 mmol) was added. Immediately a yellow
solid (6) precipitated. The stirring was maintained during
30 min at room temperature and the resulting suspension
was filtered. The yellow solid was washed with MeOH
(10 ml) and Et2O (50 ml) and air dried. 6 was characterized
(NMR) as a mixture of eight diastereoisomers with a molar
ratio 1.00/0.59/0.67/2.23/3.47/1.34/0.98/0.43. Yield: 1.380 g
(95.7%). Complex 6 was recrystallized from CH2Cl2/OEt2,
giving crystals of 6.CH2Cl2, which were used for analytical
1JPC = 77.1), 128.63 (d, Co, PhCO, maj., JPC = 1.4),
4
128.84 (d, Co, PhCO, min, JPC = 1.4), 128.94 (d, Cm,
3
PPh, min, JPC = 11.2), 129.41 (d, Cm, PPh, maj.,
3
3JPC = 11.2), 130.23 (d, C4, C6H4, min, JPC = 3.4),
3
130.38 (d, C4, C6H4, maj., JPC = 3.4), 131.56 (d, Co,
2
PPh, maj., JPC = 9.3), 131.63 (Cp, PhCO, min), 131.81
4
(Cp, PhCO, maj.), 132.60 (d, Cp, PPh, maj., JPC = 2.8),
4
132.76 (d, Cp, PPh, min, JPC = 2.8), 133.01 (d, Co, PPh,
min, 2JPC = 9.4), 133.72 (d, C3, C6H4, maj.,
2JPC = 15.1 Hz), 138.07 (d, Ci, PhCO, min, 3JPC = 5.2 Hz),
1
138.34 (d, C2,, C6H4, min, JPC = 115.7), 138.48 (d, Ci,
3
PhCO, maj, JPC = 8.1 Hz), 138.69 (d, C2, C6H4, maj.,
2
1JPC = 103.9), 157.99 (d, C1, C6H4, min, JPC = 22.1),
2
158.34 (d, C1, C6H4, maj., JPC = 20.6), 186.04 (CO, acac,
purposes. Anal. Calc. C42H36Cl2O2P2PdÅ CH2Cl2 (1003.3):
maj.), 186.51 (CO, acac, min), 186.79 (CO, acac, min),
186.89 (CO, acac, maj.), 195.00 (d, CO, ylide, min.
2
C, 51.47; H, 3.82. Found: C, 51.52; H, 3.61. MS (MALDI+):
m/z (%) = 881 (50) [MꢀCl]+. IR (m, cmꢀ1): 1614
(mCO).31P{1H} NMR (CDCl3): d = 15.91, 16.12, 17.23,
18.12, 18.95, 19.11, 19.69, 19.90.
2
2JPC = 4.6), 198.59 (d, CO, ylide, maj., JPC = 3.9).
31P{1H} NMR (CDCl3): d = 19.21 (C6H4-2-PPhMe, min),
21.43 (C6H4-2-PPhMe, maj.).
4.2.6. Synthesis of [Pd(acac-O,O0){C6H4(PPh(Me)CHC
(O)Ph-j-C,C)-2}] (7)
4.2.7. Synthesis of [PdCl{C6H4(PPh(Me)CHC(O)Ph-j-
C,C)-2}PPh3] (8)
Complex 7 was prepared following an experimental
method similar to that described for 3, but using 6 as start-
ing compound. Thus, 6 (0.150 g, 0.16 mmol) was reacted
with Tl (acac) (0.100 g, 0.33 mmol), giving 7 as a yellow
solid, which was characterized as a mixture of two diaste-
reoisomers in 5/1 molar ratio (d.e. = 66.7%). Yield:
0.110 g (61.5%). Anal. Calc. for C26H25O3PPd (522.9): C,
59.21; H, 4.82. Found: C, 58.91; H, 4.93%. MS
(MALDI+): m/z (%) = 523 (55) [M]+. IR (m, cmꢀ1): 1625
Solid PPh3 (0.086 g, 0.33 mmol) was added to a suspen-
sion of 6 (0.150 g, 0.16 mmol) in 5 ml of CH2Cl2. The initial
suspension gradually dissolved and, after 30 min stirring at
r.t., a pale yellow solution was obtained. After the reaction
time, any remaining insoluble material was filtered over
Celite and discarded. The resulting solution was evapo-
rated to dryness and the oily residue was treated with
20 ml of Et2O, giving 8 as a white solid. The solid was char-
acterized (NMR) as a mixture of diastereoisomers in 7/1
molar ratio (d.e. = 75%). Yield: 0.092 g (77%). Anal. Calc.
C39H33ClOP2Pd (721.6): C, 64.92; H, 4.61. Found: C,
64.88; H, 4.55%. MS (MALDI+): m/z (%) = 686 (100)
1
(mCO, ylide), 1564 (mCO, acac), 1514 (mCO, acac). H NMR
(CDCl3): d = 1.53 (s, Me, acac, maj.), 1.75 (s, Me, acac,
min), 1.91 (s, Me, acac, maj.), 1.94 (s, Me, acac, min),
2
2
1
2.45 (d, JPH = 12.6, PMe, min), 2.48 (d, JPH = 13.2,
[MꢀCl]+. IR (m, cmꢀ1): 1615 (mCO). H NMR (CDCl3):
2
PMe, maj.), 4.46 (d, JPH = 2.4, CHP, maj.), 4.50 (d,
d = 2.20 (d, 2JPH = 12.4, PMe, maj.), 2.54 (d,
2JPH = 12.6, PMe, min), 5.01 (m, CHP, min), 5.20 (dd,
2JPH = 4.8, CHP, min), 5.11 (s, CH, acac, maj.), 5.17 (s,
CH, acac, min), 6.98–7.09 (m, H6 and H5, C6H4, both),
7.17–7.21 (m, H4, C6H4, both), 7.24 (m, Hm, PhC(O),
3
2JPH = 7.6, JPH = 6.8, CHP, maj.), 6.11–6.25 (m, H6 and
H5, C6H4, min), 6.35 (m, H6, C6H4, maj.), 6.43 (t,
3
min), 7.28 (t, JHH = 7.3, Hm, PhC(O), maj.), 7.34 (t,
3JHH = 7.6, H5, C6H4, maj.), 6.77 (m, H4, C6H4, min),
3JHH = 7.3, Hp, PhC(O), min), 7.38 (t, JHH = 7.2, Hp,
6.85 (td, JPH = 4.8, JHH = 7.0, H4, C6H4, maj.), 7.10
3
4
3
3
4
PhC(O), maj.), 7.45–7.49 (m, Hm, PPh, both), 7.52–7.56
(td, JHH = 3JHH = 7.4, JPH = 1.6, Hm, PPh3, maj.),
7.16–7.18 (m, H3, C6H4, both, Hm, PPh3, min), 7.22 (t,
Hp, PPh3, both), 7.27–7.37 (m, Ho, PPh3, maj., Hm,
3
4
(m, Hp, PPh, both), 7.66 (dd, JHH = 7.8, JHH = 2.6, H3,
C6H4, min), 7.68 (dd,3JHH = 7.4, JHH = 2.1, H3, C6H4,
4

D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
423
PhC(O), maj., Hp, PhC(O), maj.), 7.41 (m, Ho, PPh3, min),
ment, a strong peak Q of residual electron density
remained at 1.08 A of the Pd atom, without chemical sense.
3
˚
7.46 (m, Hm, PPh, maj.), 7.56 (t, JHH = 6.8, Hp, PPh,
3
maj.), 7.69 (m, Ho, PPh, min), 7.99 (dd, JPH = 12.4,
This problem was not solved using three different crystals
of different batches, performing the data collection at dif-
ferent temperatures or using other different strategies. In
the Patterson map the vector Pd. . .Q is clear, meaning that
this electron density is real and not an error of the model.
We assumed the existence of two different crystallographic
domains, in 93% and 7% relative abundance. This Q peak
should then correspond to the Pd atom of the second minor
component. The next heavy atom of the minor component
should be the P atom, with assigned electron density in the
3
3JHH = 7.2, Ho, PPh, maj.), 8.26 (d, JHH = 7.2, Ho,
3
PhC(O), min), 8.41 (d, JHH = 7.2, Ho, PhC(O), maj.)
(some signals of the minor component could not be
assigned due to extensive overlapping). 31P{1H} NMR
3
(CDCl3): d = 11.56 (d, JPP = 20.0, C6H4-2-PPhMe, min),
3
15.22 (d, JPP = 19.3, C6H4-2-PPhMe, maj.), 31.43 (d,
Pd–PPh3, maj.), 32.24 (d, Pd–PPh3, min).
4.2.8. Synthesis of [Pd{C6H4(PPh(Me)CHC(O)Ph-j-
C,C)-2}(Ph2PCH2CH2PPh2)]ClO4 (9)
difference maps of about 1 e Aꢀ3. This atom (and the fol-
˚
To a suspension of 6 (0.150 g, 0.16 mmol) in THF
(20 ml) AgClO4 (0.068 g, 0.33 mmol) was added, and the
resulting mixture was stirred at r.t. for 30 min with exclu-
sion of light. The grey suspension was then filtered through
a Celite pad. To the freshly prepared solution of the sol-
vate, dppe (0.130 g, 0.33 mmol) was added. The resulting
pale-yellow solution was stirred at r.t. for 4 h, then the sol-
vent was evaporated to dryness and the residue treated
with Et2O (10 ml) to give 9 as a white solid. Yield: 0.290
g (95.0%). 9 was characterized (NMR) as a mixture of
two diastereoisomers in 6.7/1 molar ratio (d.e. = 74%).
Anal. Calc. for C47H42ClO5P3Pd (921.6): C, 61.25; H,
4.59. Found: C, 60.98; H, 4.41%. MS (MALDI+): m/z,
lowing lighter atoms) could not be observed in the final dif-
ference maps. Attempts to refine one complete model at
93% occupancy also failed, probably due to the fact that
this model includes the atoms of the 7% occupancy model.
Finally, the proposed model contains two Pd atoms with
93% and 7% occupancies and full occupancy for the rest
of the molecule. 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 assigned an isotropic dis-
placement parameter equal to 1.2 times the equivalent iso-
tropic displacement parameter of its parent atom. The
structures were refined to F 2o, and all reflections were used
in the least-squares calculations [76].
1
(%) = 822 (100) [MꢀClO4]+. IR (m, cmꢀ1): 1617 (mCO). H
NMR (CDCl3): d = 1.73 (m, CH2, dppe, maj.), 2.25 (d,
2JPH = 12.5, PMe, maj.), 2.59–2.76 (m, CH2, dppe, maj.),
4.41 (m, CHP, maj.), 6.76–7.84 (m, aromatic protons,
PPh2, C6H4, Ph-C(O), both.). 31P{1H} NMR (CDCl3):
d = 21.95 (dd, 3JPP = 17.7, 3JPP = 27.8, C6H4PMe, minor.),
26.93 (dd, 3JPP = 17.6, 3JPP = 32.0, C6H4PMe, maj.), 43.78
Acknowledgement
´
Funding by the Ministerio de Educacion y Ciencia
(MEC) (Spain, Project CTQ2005-01037) is gratefully
acknowledged. R.B. thanks MEC (Spain), D.A and E.S.
3
3
´
´
(dd, JPP = 28.2, JPP = 22.8, PPh2 trans CH, min), 44.44
thank Diputacion General de Aragon (Spain) for respec-
3
3
(dd, JPP = 32.2, JPP = 22.4, PPh2 trans CH, maj.), 50.83
tive Ph.D. research grants.
3
3
(dd, JPP = 17.7, JPP = 22.3, PPh2 cis CH, maj.), 53.24
3
3
(dd, JPP = 17.7, JPP = 22.7, PPh2 cis CH, min).
Appendix A. Supplementary material
4.3. X-ray crystallography
CCDC 664274 contains the supplementary crystallo-
graphic data for 3. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif. Supplementary
data associated with this article can be found, in the online
version, at doi:10.1016/j.jorganchem.2007.11.012.
4.3.1. Data collection
Crystals of 3 of adequate quality for X-ray measure-
ments were grown by vapour diffusion of Et2O into a
CH2Cl2 solution of 3 at room temperature. A single crystal
was mounted at the end of a quartz fiber in a random orien-
tation, covered with magic oil and placed under the cold
stream of nitrogen. Data collection was performed at
100 K on an Bruker Smart CCD diffractometer using
References
[1] A.D. Ryabov, Synthesis (1985) 233.
[2] A.D. Ryabov, Chem. Rev. 90 (1990) 403.
[3] S. Murai, F. Kakiuchi, S. Sekine, Y. Tanaka, A. Kamatani, M.
Sonoda, N. Chatani, Nature 366 (1993) 529.
[4] A.E. Shilov, G.B. Shul’pin, Chem. Rev. 97 (1997) 2879.
[5] G. Dyker, Angew. Chem., Int. Ed. 38 (1999) 1698.
[6] J. Dupont, M. Pfeffer, J. Spencer, Eur. J. Inorg. Chem. (2001) 1917.
[7] V. Rietling, C. Sirlin, M. Pfeffer, Chem. Rev. 102 (2002) 1731.
[8] F. Kakiuchi, S. Murai, Acc. Chem. Res. 35 (2002) 826.
[9] F. Kakiuchi, N. Chatani, Adv. Synth. Catal. 345 (2003) 1077.
[10] R.B. Bedford, Chem. Commun. (2003) 1787.
˚
graphite-monocromated Mo Ka radiation (k = 0.71073 A).
An hemisphere of data was collected based on three x
and U-scans runs. The diffraction frames were integrated
using the program SAINT [73] and the integrated intensities
were corrected for absorption with SADABS [74].
4.3.2. Structure solution and refinement
The structure was solved and developed by Patterson
and Fourier methods [75]. In the final steps of the refine-
[11] M.E. van der Boom, D. Milstein, Chem. Rev. 103 (2003) 1759.

424
D. Aguilar et al. / Journal of Organometallic Chemistry 693 (2008) 417–424
[12] K.I. Goldberg, A.S. Goldman (Eds.), Organometallic C–H Bond
Activation; Activation and Functionalization of C–H Bonds, ACS
Symposium Series 885, American Chemical Society, Washington,
DC, 2004.
[47] A. Steiner, S. Zachini, P.I. Richards, Coor. Chem. Rev. 227 (2002)
193.
[48] H.J. Cristau, M. Taillefer, N. Rahier, J. Organomet. Chem. 646
(2002) 94.
´
[49] F. Lopez-Ortiz, Curr. Org. Synth. 3 (2006) 187.
[13] I. Omae, Coord. Chem. Rev. 248 (2004) 995.
[14] V. Farina, Adv. Synth. Catal. 346 (2004) 1553.
[15] B. Schlummer, U. Scholz, Adv. Synth. Catal. 346 (2004) 1599.
[16] I.P. Beletskaya, A.V. Cheprakov, J. Organomet. Chem. 689 (2004)
4055.
[17] W.D. Jones, Inorg. Chem. 44 (2005) 4475.
[18] J. Dupont, C. Consorti, J. Spencer, Chem. Rev. 105 (2005) 2527.
[19] D. Kalyani, N.R. Deprez, L.V. Desai, M.S. Sanford, J. Am. Chem.
Soc. 127 (2005) 7330.
´
[50] L.R. Falvello, S. Fernandez, C. Larraz, R. Llusar, R. Navarro, E.P.
Urriolabeitia, Organometallics 20 (2001) 1424.
[51] E. Ruba, K. Mereiter, R. Schmid, K. Kerchner, E. Bustelo, M.C.
¨
Puerta, P. Valerga, Organometallics 21 (2002) 2912.
[52] J.M. O’Connor, K.D.J. Bunker, J. Organomet. Chem. 671
(2003) 1.
[53] K. Onitsuka, M. Nishii, Y. Matsushima, S. Takahashi, Organome-
tallics 23 (2004) 5630.
[20] A. Zapf, M. Beller, Chem. Commun. (2005) 431.
[21] K. Godula, D. Sames, Science 312 (2006) 67.
[22] A.R. Dick, M.S. Sanford, Tetrahedron 62 (2006) 2439.
[23] K.L. Hull, E.L. Lanni, M.S. Sanford, J. Am. Chem. Soc. 128 (2006)
14047.
[54] W. Petz, C. Kutschera, B. Neumuller, Organometallics 24 (2005)
¨
5038.
´
´
´
[55] E. Serrano, C. Valles, J.J. Carbo, A. Lledos, T. Soler, R. Navarro,
E.P. Urriolabeitia, Organometallics 25 (2006) 4653.
[56] Y. Canac, S. Conejero, M. Soleilhavoup, B. Donnadieu, G. Bertrand,
J. Am. Chem. Soc. 128 (2006) 459.
[24] O. Daugulis, V.G. Zaitsev, D. Shavashov, Q.N. Pham, A. Lazareva,
Synlett (2006) 3382.
[57] A. Kawachi, T. Yoshioka, Y. Yamamoto, Organometallics 25 (2006)
2390.
´
´
[25] J. Vicente, J.A. Abad, M.J. Lopez–Saez, P.G. Jones, Organometallics
25 (2006) 1851.
[58] H. Staudinger, J.J. Meyer, Helv. Chim. Acta 2 (1919) 635.
[59] R.J. Griffin, E. Evers, R. Davison, A.E. Gibson, D. Layton, W.J.
Irvin, J. Chem. Soc., Perkin Trans. 1 (1996) 1205.
[26] N.R. Deprez, M.S. Sanford, Inorg. Chem. 46 (2007) 1924.
[27] J.E. Bercaw, J.A. Labinger, Proc. Nat. Acad. Sci. USA 104 (2007)
6899.
´
´
[60] L.R. Falvello, M.M. Garcıa, I. Lazaro, R. Navarro, E.P. Urriola-
[28] G.S. Chen, J.A. Labinger, J.E. Bercaw, Proc. Nat. Acad. Sci. USA
104 (2007) 6915.
[29] O. Daugulis, H.A. Chiong, Org. Lett. 9 (2007) 1449.
[30] M.W. Avis, M.E. van der Boom, C.J. Elsevier, W.J.J. Smeets, A.L.
Spek, J. Organomet. Chem. 527 (1997) 263.
beitia, New J. Chem. 23 (1999) 227.
[61] P. Imhoff, R. van Asselt, C.J. Elsevier, M.C. Zoutberg, C.H. Stam,
Inorg. Chim. Acta 184 (1991) 73.
´
[62] E. Prestch, P. Buhlman, C. Affolter, A. Herrera, R. Martınez,
¨
´
´
Determinacion estructural de compuestos organicos, Springer-Verlag
´
[31] M.W. Avis, K. Vrieze, J.M. Ernsting, C.J. Elsevier, N. Veldman,
A.L. Spek, K.V. Katti, C.L. Barnes, Organometallics 15 (1996) 2376.
[32] R. Bielsa, A. Larrea, R. Navarro, T. Soler, E.P. Urriolabeitia, Eur. J.
Inorg. Chem. (2005) 1724.
Iberica, Barcelona, 2001, p. 307.
[63] P. Wei, K.T.K. Chan, D.W. Stephan, Dalton Trans. (2003) 3804.
[64] A.G. Orpen, L. Brammer, F.H. Allen, O. Kennard, D.G. Watson,
R. Taylor, J. Chem. Soc., Dalton Trans. (1989) S1.
[33] L. Boubekeur, L. Ricard, N. Mezailles, M. Demange, A. Auffrant,
P. Le Floch, Organometallics 25 (2006) 3091.
[65] F.H. Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen,
R. Taylor, J. Chem. Soc., Perkin Trans. 2 (1987) 685 (S1–S19).
´
´
´
´
[34] V. Cadierno, J. Dıez, J. Garcıa-Alvarez, J. Gimeno, Organometallics
[66] F. Ramırez, S. Dershowitz, J. Org. Chem. 22 (1957) 41.
24 (2005) 2801.
[67] S. Trippett, D.M. Walker, J. Chem. Soc. (1961) 1266.
[68] R. Zurawinski, B. Donnadieu, M. Mikolajczyk, R. Chauvin, J.
Organomet. Chem. 689 (2004) 380.
[35] M. Fang, N.D. Jones, M.J. Ferguson, R. McDonald, R.G. Cavell,
Angew. Chem., Int. Ed. Engl. 44 (2005) 2005.
´
[36] M. Hecht, S. Saucedo, A. Hagenbach, U. Abram, Inorg. Chem. 44
(2005) 3172.
[69] J. Vicente, J.A. Abad, A.D. Frankland, M.C. Ramırez de Arellano,
Chem. Eur. J. 5 (1999) 3066.
´
[37] N.D. Jones, G. Lin, R.A. Gossage, R. McDonald, R.G. Cavel,
Organometallics 22 (2003) 2832.
[70] J. Vicente, J.A. Abad, E. Martınez-Viviente, P.G. Jones, Organome-
tallics 21 (2002) 4454.
[38] M.A. Leeson, B.K. Nicholson, M.R. Olsen, J. Organomet. Chem.
579 (1999) 243.
[71] J. Vicente, A. Arcas, D. Bautista, P.G. Jones, Organometallics 16
(1997) 2127.
´
[39] H. Schmidbaur, W. Wolfsberger, Chem. Ber. 100 (1967) 1016.
[40] A. Steiner, D. Stalke, Angew. Chem., Int. Ed. Engl. 34 (1995) 1752.
[41] C.G. Stuckwisch, J. Org. Chem. 41 (1976) 1173.
[72] C. Cativiela, L.R. Falvello, J.C. Gines, R. Navarro, E.P. Urriolabei-
tia, New J. Chem. 25 (2001) 344.
[73] SAINT Version 5.0, Bruker Analytical X-ray Systems, Madison, WI.
[74] G.M. Sheldrick, SADABS: Empirical Absorption Correction Program,
University of Go¨ttingen, Go¨ttingen, Germany, 1996.
´
[42] J. Vicente, J.A. Abad, R. Clemente, J. Lopez-Serrano, Organometal-
lics 22 (2003) 4248.
[43] Z.X. Wang, C. Qi, Dalton Trans. (2005) 996.
[44] D. Aguilar, M. Contel, R. Navarro, E.P. Urriolabeitia, Organome-
tallics 26 (2007) 4604.
[75] G.M. Sheldrick, Acta Crystallogr., Sect. A. 46 (1990) 467.
[76] G.M. Sheldrick, SHELXL-97, FORTRAN Program for the Refinement of
Crystal Structures from Diffraction Data, University of Go¨ttingen,
Go¨ttingen, Germany; 1997, Molecular graphics were done using the
commercial package SHELXTL-PLUS, Release 5.05/V: Ó Siemens Ana-
lytical X-ray Instruments, Inc., Madison, WI, 1996.
´
[45] D. Aguilar, M.A. Aragues, R. Bielsa, E. Serrano, R. Navarro, E.P.
¨
Urriolabeitia, Organometallics 26 (2007) 3541.
[46] A.W. Johnson, W.C. Kaska, K.A.O. Starzewski, D.A. Dixon, Ylides
and Imines of Phosphorus, Wiley, New York, 1993.