Conversion of a stannyl-phosphenium complex into a stannylene-phosphine complex of Mo and W: Double bond migration from MP to MSn

Article abstract of DOI:10.1016/S0022-328X(00)00642-2

Four-legged piano-stool complexes, Cp(CO)₂(SnR₃)M{PN(Me)CH2CH2NMe(OMe)}, containing a stannyl group (SnPh₃, SnMe₃, SnⁿBu₃) and diamino-substituted phosphite (PN(Me)CH2CH2NMe(OMe) which is abbreviated as PNN(OMe)) were prepared for Mo and W, and the reactions of these complexes with a Lewis acid (BF₃·OEt₂ and TMSOTf) were examined. For the SnPh₃ and SnMe₃ complexes, stannylene complexes [Cp(CO)₂(SnR₂)M{PNN(R)}]X (X=OTf^- or BF₄^-) were formed with migration of an R group from Sn to P. X-ray analyses of [Cp(CO)₂(SnPh₂)W{PNN(Ph)}]OTf and [Cp(CO)₂(SnMe₂)W{PNN(Me)}]OTf reveal that these complexes are regarded as stannylene tungsten complexes stabilized by an oxygen of OTf^-. In the reaction of the SnⁿBu₃ complex with TMSOTf, the corresponding stannylene complex and an unexpected neutral phosphenium complex, Cp(CO)₂M{PNN}, were formed. However, when BF₃·OEt₂ was used in place of TMSOTf, cationic phosphenium complexes in addition to a neutral phosphenium complex were observed. In any case, an OMe anion abstraction by a Lewis acid takes place at the first stage to give a cationic phosphenium complex, and then aryl or alkyl migration takes place to give a stannylene complex. A relatively strong Sn-ⁿBu bond retards the alkyl migration, resulting in the observation of the cationic phosphenium complexes.

Full text of DOI:10.1016/S0022-328X(00)00642-2

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 617–618 (2001) 453–463
Conversion of a stannylꢀphosphenium complex into a
stannyleneꢀphosphine complex of Mo and W: double bond
migration from MꢁP to MꢁSn
Hiroshi Nakazawa *1, Mitsuru Kishishita, Takeshi Ishiyama, Tsutomu Mizuta,
Katsuhiko Miyoshi *2
Department of Chemistry, Graduate School of Science, Hiroshima Uni6ersity, Higashi-Hiroshima 739-8526, Japan
Received 2 August 2000; accepted 11 September 2000
Abstract
¸¹¹¹¹¹¹¹¹¹º
Four-legged piano-stool complexes, Cp(CO)2(SnR3¸)M¹{¹P¹N¹(M¹¹e)¹C¹H¹2ºCH2NMe(OMe)}, containing a stannyl group (SnPh3,
SnMe3, SnnBu3) and diamino-substituted phosphite (PN(Me)CH2CH2NMe(OMe) which is abbreviated as PNN(OMe)) were
prepared for Mo and W, and the reactions of these complexes with a Lewis acid (BF3·OEt2 and TMSOTf) were examined. For
the SnPh3 and SnMe3 complexes, stannylene complexes [Cp(CO)2(SnR2)M{PNN(R)}]X (X=OTf− or BF4−) were formed with
migration of an R group from Sn to P. X-ray analyses of [Cp(CO)2(SnPh2)W{PNN(Ph)}]OTf and [Cp(CO)2(SnMe2)-
W{PNN(Me)}]OTf reveal that these complexes are regarded as stannylene tungsten complexes stabilized by an oxygen of OTf−.
In the reaction of the SnnBu3 complex with TMSOTf, the corresponding stannylene complex and an unexpected neutral
phosphenium complex, Cp(CO)2M{PNN}, were formed. However, when BF3·OEt2 was used in place of TMSOTf, cationic
phosphenium complexes in addition to a neutral phosphenium complex were observed. In any case, an OMe anion abstraction
by a Lewis acid takes place at the first stage to give a cationic phosphenium complex, and then aryl or alkyl migration takes place
to give a stannylene complex. A relatively strong SnꢀnBu bond retards the alkyl migration, resulting in the observation of the
cationic phosphenium complexes. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Phosphenium complex; Stannylene complex; Migration; Double bond
eral methods have been developed to prepare many
phosphenium complexes, and a few review articles ap-
peared recently [3–7].
In contrast to the synthetic approach, information on
the reactivity of the phosphenium complexes is sparse.
During the course of our investigation on cationic
phosphenium complexes of transition metals [8], it was
found that a Group 8 transition metal complex formu-
lated as Cp(CO)(ER3)M{PNN(OMe)} (a) (M=Fe, Ru;
1. Introduction
The wide-ranging applications of metal carbenes
(MꢁC) in organometallic chemistry have aroused inter-
est in transition metal complexes containing metal–het-
eroatom multiple bonds [1]. A cationic phosphenium
(+PR2) has attracted significant attention as a ligand
for transition metals because it is isolobal with a singlet
carbene and its heavier congeners (silylene, germylene,
stannylene, and plumbylene). Since the first report of a
cationic phosphenium complex of iron by Parry in 1978
[2], research efforts have been directed toward the
development of general and effective methods for the
preparation of cationic phosphenium complexes. Sev-
E=C, Si, Ge, Sn. PNN(OMe) stands for
¸¹¹¹¹¹¹¹¹¹º
PN(Me)CH2CH2NMe(OMe) here) reacts with a Lewis
acid to give
a
cationic phosphenium complex
[Cp(CO)(ER3)M{PNN}]+ (b). However, the successive
reaction hinges on the type of E (Scheme 1) [9]. When
E is a tin atom, one of the R groups on the Sn migrates
to the phosphenium P to give a stannylene complex (d).
This reaction is of interest because it corresponds to a
double-bond migration from MꢁP to MꢁSn. Some other
1 *Corresponding author. Tel.: +81-824-247420; fax: +81-824-
240729
2 *Corresponding author
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00642-2

454
H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
reactions related to the migration involving a cationic
phosphenium ligand have been reported [10].
To check the scope and the limitation of this type of
a double-bond migration in a coordination sphere, we
examined the reaction of stannyl complexes of Group 6
transition metals with a Lewis acid. The results of the
reaction of Cp(CO)2(SnR3)M{PNN(OMe)} (M=Mo,
W) are reported in this paper.
2. Results and discussion
2.1. Preparation of Cp(CO)2(SnR3)M{PNN(OMe)}
n
(M=Mo, W; R=Ph, Me, Bu)
To obtain Cp(CO)2(SnR3)M{PNN(OMe)}, Cp(CO)2-
IM{PNN(OMe)} was first prepared in the reaction of
Cp(CO)3IM
with
PNN(OMe).
The
isolated
Scheme 1.
Cp(CO)2IM{PNN(OMe)} is a mixture of the cis and
trans isomers. They could be separated by column
chromatography for the W complex, but they gradually
isomerize in solution and reach equilibrium. It was
found that the cis isomer is a kinetic product. In the
case of the Mo complex, since the isomerization rate is
fast, it is difficult to separate the mixture into the two
geometrical isomers. A mixture of cis and trans isomers
of Cp(CO)2IM{PNN(OMe)} was treated with NaK2.8
and then SnR3Cl to give Cp(CO)2(SnR3)M{PNN-
(OMe)} (Eq. (1)). The stannyl complexes thus obtained
one doublet due to the coupling with 31P. These results
show that all the stannyl complexes have trans geome-
try. It has been reported that the corresponding methyl
complexes, Cp(CO)2(Me)M{PNN(OMe)} (M=Mo,
W), exist in solution as a mixture of the cis and trans
isomers in equilibrium [10b]. The reason for the pre-
ferred trans geometry of these stannyl complexes may
arise from the steric hindrance between the PNN(OMe)
ligand and the relatively bulky stannyl ligand (SnPh3,
SnMe3, and SnnBu3) compared with Me.
1
were characterized by IR, H-, 13C-, 31P-, and 119Sn-
On going from SnPh3 to SnMe3 and to SnnBu3 for
trans-Cp(CO)2(SnR3)M{PNN(OMe)} (that is, Mo-
1a“Mo-2a“Mo-3a and W-1a“W-2a“W-3a), cou-
pling constants show the following trends: JPꢀSn
observed in the 31P-NMR spectra decreases (148.8“
132.1“113.5 Hz for the Mo complexes, and 137.7“
124.7“109.8 Hz for the W complexes), JCꢀSn (carbonyl
C) decreases (150.8“136.6“132.4 Hz for the Mo
complexes, and 138.0“124.4“119.6 Hz for the W
complexes), JSnꢀW greatly decreases (404.6“262.3“
234.4 Hz), JPꢀW slightly increases (422.4“441.0“444.8
Hz), JCꢀP (carbonyl C) shows almost the same value
(30.5“28.8“30.1 Hz for the Mo complexes, and
25.6“23.3“23.2 Hz for the W complexes), and JCꢀW
(carbonyl C) slightly increases (155.0“159.3“159.9
Hz). These trends indicate that the MꢀSn bond be-
comes weaker on going from SnPh3 to SnMe3 and to
SnnBu3, whereas the MꢀP bond is not strongly affected.
NMR spectra and elemental analyses.
(1)
2.2. Reaction of Cp(CO)2(SnPh3)M{PNN(OMe)}
(M=Mo, W) with a Lewis acid
For all stannyl complexes prepared in this paper, a
resonance assigned to CO in the 13C-NMR spectra
showed one doublet, arising from the coupling with 31P,
flanked by satellite lines due to coupling with 119Sn and
117Sn, and with 183W in the case of tungsten complexes.
The results in the reaction of the triphenylstannyl
complexes (Mo-1a, W-1a) with
a
Lewis acid,
trimethylsilyl triflate (TMSOTf) and BF3·OEt2, are
summarized in Scheme 2.
1
In both H- and 13C-NMR spectra, NCH3 gave rise to

H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
455
{PNN(Ph)} (Mo-1c, 73% yield and W-1c, 77% yield)
CH2Cl2 solutions of Mo-1a and W-1a were treated
with TMSOTf at room temperature (r.t.). From the
reaction mixtures, pale yellow powders were isolated.
Although the isolated complexes are so air- and mois-
ture-sensitive that the correct elemental analysis data
could not be obtained, the satisfactory spectroscopic
data were obtained, which established the formation of
a stannylene complex formulated as [Cp(CO)2(SnPh2)-
M{PNN(Ph)}]OTf (Mo-1b and W-1b). The 31P-NMR
spectra show a singlet at 157.05 ppm with Sn satellites
(JPꢀSn=190.2 Hz) for Mo-1b and a singlet at 123.38
1
was isolated and characterized by H-, 13C-, 31P-, 119Sn-
NMR and IR spectroscopies as well as by elemental
analyses.
ppm with Sn and W satellites (JPꢀSn=183.8 Hz, JPꢀW
=
323.6 Hz) for W-1b. The 119Sn-NMR spectra show a
doublet due to a coupling with P at 459.14 for Mo-1b
and 335.32 ppm for W-1b, which are at considerably
lower fields than those of the starting complexes, Mo-1a
(74.97) and W-1a (−1.98 ppm). These very low field
chemical shifts strongly suggest the formation of an
M=Sn fragment [9b–d,11,12]. The coupling constant
between P and Sn is about 50 larger for Mo-1b and 45
Hz larger for W-1b than those of Mo-1a and W-1a,
respectively. For W-1b, the SnꢀW coupling constant is
more than 200 Hz greater than that of W-1a. These
Scheme 2.
1
data together with those of H- and 13C-NMR spectra
support the formation of a stannylene complex.
In the case of W-1b, the X-ray structure analysis
could be performed. The structure is shown in Fig. 1.
The complex can be described as a base-stabilized
stannylene complex. The OMe group on the phospho-
rus in W-1a disappears, and is replaced by a phenyl
group. This means that a phenyl group migration takes
place from an Sn to a P in the W coordination sphere.
The structural details will be discussed later. The spec-
troscopic data of W-1b show that there may be an
equilibrium between base-stabilized and base-free stan-
nylene forms in solution.
Fig. 1. Crystal structure of W-1b with the numbering scheme. Ther-
mal ellipsoids are drawn at 50% probability.
The reaction of M-1a (M=Mo and W) with
BF3·OEt2 in place of TMSOTf was next examined. The
31P- and 119Sn-NMR spectra of the reaction mixture
suggest the formation of the corresponding stannylene
complex (M-1b%) (see Scheme 2). The 31P-NMR chemi-
cal shifts of Mo-1b% (155.63 ppm) and W-1b% (119.27
ppm) are very close, respectively, to those of Mo-1b and
W-1b prepared from M-1a and TMSOTf. The 119Sn-
NMR chemical shifts of Mo-1b% (416.40 ppm) and
W-1b% (293.17 ppm) are at about 42 ppm higher field
than those of Mo-1b and W-1b, respectively. The higher
field shift may arise from the stabilization effect of the
base on the stannylene ligand.
Several efforts to isolate Mo-1b% and W-1b% came into
failure for their instability. Confirming the stannylene
formation, they were converted into an isolable com-
plex. The stannylene complex M-1b% was treated with
MeLi. After work up, Cp(CO)2(SnPh2Me)M-
Scheme 3.

456
H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
2.3. Reaction of Cp(CO)2(SnMe3)M{PNN(OMe)}
(M=Mo, W) with a Lewis acid
to a stannylene complex, Mo-3b. A singlet at 272.46
ppm could be assigned to a neutral phosphenium, Mo-d
[13] (the complex may also be referred to as a 3e-donor
terminal phosphide complex). The detailed discussion
of the formation of Mo-d in this reaction will be
presented elsewhere.
The reaction of Mo-3a with BF3·OEt2 was monitored
by the 31P-NMR spectroscopy. A singlet at 272.46 ppm
due to Mo-d, two broad singlets at 334.71 and 310.08
ppm attributed to phosphenium complexes and some
unidentified resonances were observed. However, a res-
onance due to a corresponding stannylene complex was
not detected. In the reaction of W-3a with BF3·OEt2,
relatively sharp resonances were observed in the 31P-
NMR spectrum at −20°C. In addition to a singlet at
244.61 ppm with W satellites (JPꢀW=218.1 Hz) due to
W-d and several unidentified resonances, a singlet at
298.07 ppm with Sn and W satellites (JPꢀSn=42.5,
Monitoring the reaction of a trimethylstannyl com-
plex (2a) with TMSOTf and that with BF3·OEt2 by
31P-NMR measurements revealed that these reactions
were not clean, that is, several kinds of complexes were
formed. However, the 31P- and 119Sn-NMR spectra
evidenced the formation of the corresponding stan-
nylene complex (Mo-2b, W-2b, Mo-2b%, and W-2b%)
(Scheme 3). In the reaction of W-2a with TMSOTf, a
single crystal of W-2b was obtained. The X-ray struc-
ture analysis was undertaken and revealed that W-2b is
a base-stabilized stannylene complex like W-1b (Fig. 2).
The structural details will be discussed later.
2.4. Reaction of Cp(CO)2(SnnBu3)M{PNN(OMe)}
(M=Mo, W) with a Lewis acid
J
PꢀW=516.4 Hz) and a singlet at 282.76 ppm with Sn
A tri-n-buthylstannyl complex (M-3a) showed some-
what complicated but interesting results in the reaction
with a Lewis acid (see Scheme 4). The 31P-NMR spec-
trum of the reaction mixture of Mo-3a with TMSOTf
exhibited a singlet at 164.11 ppm with Sn satellites
(JPꢀSn=166.5 Hz), a singlet at 272.46 ppm and some
unidentified resonances. The former singlet is attributed
and W satellites (JPꢀSn=291.6 and JPꢀW=543.1 Hz)
were observed. These relatively low field chemical shifts
and the large P-W coupling constants (greater than 500
Hz) compared with that of W-3a (JPꢀW=444.8 Hz) and
that of Cp(CO)2IW{PNN(OMe)} (JPꢀW=387.0 for the
cis isomer and JPꢀW=368.4 Hz for the trans isomer) are
characteristic of a phosphenium complex, W-3e. The
large difference in JPꢀSn (42.5 vs. 291.6 Hz) between the
two singlets strongly suggest that the former is assigned
to a cis isomer (cis-W-3e) and the latter to a trans
isomer (trans-W-3e).
2.5. A 6iew of the reaction of
Cp(CO)2(SnR3)M{PNN(OMe)} with a Lewis acid
The products in the reaction of a stannyl complex
Cp(CO)2(SnR3)M{PNN(OMe)} with a Lewis acid were
found to hinge on the kinds of R in the stannyl group
in any case, and on those of a Lewis acid used in a
particular case (R=nBu), but to be independent of
whether a central transition metal is Mo or W. The
reaction scheme is summarized in Scheme 5. In any
case, an OMe anion abstraction by a Lewis acid uni-
formly takes place at the first stage of the reaction to
give a cationic phosphenium complex e.
Fig. 2. Crystal structure of W-2b with the numbering scheme. Ther-
mal ellipsoids are drawn at 50% probability.
In the case of the triphenylstannyl complex, although
the cationic phosphenium complex is not detected pre-
sumably due to its high reactivity, the reaction proceeds
cleanly to give a stannylene complex 1b with a phenyl
migration from a tin to a phosphenium phosphorus.
When TMSOTf is used as a Lewis acid, stannylene
complexes are isolated in fairly good yields (77% for
Mo-1b, 76% for W-1b). When BF3·OEt2 is used, the
resulting stannylene complexes are not able to be iso-
lated as a solid, but they can be converted into isolable
Scheme 4.

H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
457
complexes in good yield by the reaction with MeLi
(73% for Mo-1c, 77% for W-1c). In contrast, the reac-
tions of the trimethylstannyl complex yield several
kinds of products involving the corresponding stan-
nylene complexes irrespective of the kinds of Lewis
acid. In the case of the tri-n-buthylstannyl complex, the
corresponding stannylene complexes (Mo-3b and W-3b)
and unexpected neutral phosphenium complexes (Mo-d
and W-d) are formed when TMSOTf is used. However,
when BF3·OEt2 is used, cationic phosphenium com-
plexes (Mo-3e and W-3e) in addition to neutral pho-
sphenium complexes are detected, but the stannylene
complexes are not detected.
We have already reported for the corresponding stan-
nyl–phosphenium iron complexes that an OTf− anion
promotes an alkyl migration from Sn to P in a pho-
sphenium complex [9c]. A nucleophilic attack of the
oxygen in OTf− to the Sn would induce the alkyl
migration. It has been reported that the reactivity se-
quence for tinꢀcarbon bonds in electrophilic cleavage
reactions is generally phenyl\methyl\butyl [14].
Therefore, the difference in reactivity of the cationic
phosphenium complexes e may be understood as fol-
lows. Since the SnꢀPh bond in [Cp(CO)2(SnPh3)-
M{PNN}]+ is susceptible to electrophilic cleavage, the
complex readily and so cleanly undergoes phenyl mi-
gration to give the corresponding stannylene complex
M-1b. Since the SnꢀMe bond in [Cp(CO)2-
(SnMe3)M{PNN}]+ is resistant to SnꢀC bond cleavage
compared with the corresponding SnꢀPh bond,
Scheme 5.
Table 1
Summary of crystal data for W-1b and W-2b
[Cp(CO)2(SnMe3)M{PNN}]+ may have a longer life
time, though it is not enough to be detected spectro-
scopically. Therefore, the phosphenium complex may
undergo some intermolecular reactions in addition to
the alkyl migration being presumably an intramolecular
reaction. In the reaction of Cp(CO)2(SnnBu3)-
M{PNN(OMe)} with BF3·OEt2, the resulting cationic
phosphenium complex [Cp(CO)2(SnnBu3)M{PNN}]+
has a relatively strong SnꢀC bond and there is no OTf−
which tends to promote the alkyl migration. Therefore,
the cationic phosphenium complexes (M-3e and W-3e)
are observed and the alkylmigration products are not.
W-1b
W-2b
Formula
C30H30F3N2O5PS- C15H24F3N2O5PS-
SnW
SnW
Formula weight
Crystal system
Space group
921.15
Monoclinic
P21/a
734.93
Monoclinic
P21/c
Cell constants
,
a (A)
17.513(2)
10.7492(6)
18.740(4)
110.39(l)
3306.6(7)
4
7.346(2)
13.319(2)
23.603(5)
93.15(2)
2305.9(8)
4
,
b (A)
,
c (A)
i (°)
V (A )
3
,
Z
Dcalc (g cm−3
)
1.85
44.04
2.12
62.85
2.6. X-ray structures of W-1b and W-2b
v (cm−1
)
Crystal size (mm)
0.50×0.50×0.25
Mo–Ka
(u=0.71069)
ꢀ–2q
3B2qB55
8705
0.25×0.38×0.25
Mo–Ka
(u=0.71069)
ꢀ–2q
3B2qB55
5663
X-ray structure analyses of W-1b and W-2b were
undertaken. The ORTEP drawings of W-1b and W-2b
are displayed in Figs. 1 and 2, respectively. The cell
constants and the data collection parameters are sum-
marized in Table 1. The selected bond distances and
angles are listed in Tables 2 and 3.
Both complexes have typical four-legged piano-stool
structures, and two carbonyl ligands are situated in
mutually trans positions. The WꢀP bond distances
,
Radiation (A)
Scan technique
Scan range (°)
Number of unique data
Number of unique data
Fo\3|(Fo)
5263
3513
R
Rw
0.032
0.032
0.039
0.038

458
H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
Table 2
,
With W-2b, the WꢀSn bond distance is 2.745 A,
which is longer than that for W-1b. However, the
WSnC1C2 unit forms a fairly good trigonal plane (the
sum of angles around Sn amounts 358.5°). The SnꢀO3
,
Selected bond distances (A) and angles (°) for W-1b
Bond distances
WꢀSn
WꢀP
WꢀC23
WꢀC24
SnꢀO3
SnꢀCl
SnꢀC7
SꢀO3
SꢀO4
SꢀO5
SꢀC25
PꢀN1
2.709(l)
2.428(l)
1.964(6)
1.967(7)
2.160(4)
2.147(6)
2.149(7)
1.467(5)
1.399(7)
1.444(7)
1.79(l)
PꢀN2
PꢀC13
1.662(6)
1.828(7)
1.35(l)
1.28(l)
1.28(l)
1.162(7)
1.156(9)
1.402(9)
1.445(9)
1.419(10)
1.439(9)
1.44(l)
,
bond distance (2.346 A) falls in the range of an SnꢀO
F1ꢀC25
F2ꢀC25
F3ꢀC25
O1ꢀC23
O2ꢀC24
N1ꢀC19
N1ꢀC20
N2ꢀC21
N2ꢀC22
C20ꢀC21
dative bond listed above. Therefore, W-2b can be re-
garded as a cationic stannylene complex weakly stabi-
lized by TfO−. Electron donating ability of a methyl
group may make a stannylene fragment stable, which
leads to a weak SnꢀOTf bond.
3. Experimental
1.669(5)
Bond angles
SnꢀWꢀP
3.1. General remarks
135.76(4)
74.9(2)
71.8(2)
81.1(2)
80.0(2)
105.7(3)
113.6(l)
118.6(2)
122.5(l)
98.6(2)
N1ꢀPꢀN2
92.2(3)
105.9(3)
105.5(3)
136.9(3)
128.6(5)
112.8(4)
118.5(6)
111.8(5)
126.0(5)
120.9(6)
108.4(6)
110.7(7)
174.2(6)
176.1(5)
107.7(7)
111.9(9)
111.2(7)
107.2(8)
108(l)
SnꢀWꢀC23
SnꢀWꢀC24
PꢀWꢀC23
PꢀWꢀC24
C23ꢀWꢀC24
WꢀSnꢀO3
WꢀSnꢀC1
WꢀSnꢀC7
O3ꢀSnꢀCl
O3ꢀSnꢀC7
C1ꢀSnꢀC7
O3ꢀSꢀO4
O3ꢀSꢀO5
O3ꢀSꢀC25
O4ꢀSꢀO5
O4ꢀSꢀC25
O5ꢀSꢀC25
WꢀPꢀN1
N1ꢀPꢀC13
N2ꢀPꢀC13
SnꢀO3ꢀS
All reactions were carried out under an atmosphere
of dry nitrogen using standard Schlenk techniques. All
solvents were purified by distillation: THF was distilled
from sodium–benzophenone, hexane and pentane were
distilled from sodium metal, and CH2Cl2 was distilled
from P2O5. All solvents were stored under a nitrogen
PꢀN1ꢀC19
PꢀN1ꢀC20
C19ꢀN1ꢀC20
PꢀN2ꢀC21
PꢀN2ꢀC22
C21ꢀN2ꢀC22
N1ꢀC20ꢀC21
N2ꢀC21ꢀC20
WꢀC23ꢀO1
WꢀC24ꢀO2
SꢀC25ꢀF1
SꢀC25ꢀF2
SꢀC25ꢀF3
F1ꢀC25ꢀF2
F1ꢀC25ꢀF3
F2ꢀC25ꢀF3
92.5(2)
Table 3
105.6(2)
113.2(3)
112.4(4)
100.9(4)
120.2(4)
105.6(5)
101.4(5)
117.3(2)
118.1(2)
114.9(2)
,
Selected bond distances (A) and angles (°) for W-2b
Bond distances
WꢀSn
WꢀP
2.745(l)
2.425(2)
1.93(l)
PꢀN2
PꢀC5
1.665(8)
1.80(l)
1.31(l)
1.30(l)
1.30(l)
1.17(l)
1.16(l)
1.43(l)
1.45(l)
1.48(l)
1.40(2)
1.51(2)
WꢀC3
WꢀC4
SnꢀO3
SnꢀCl
SnꢀC2
SꢀO3
SꢀO4
SꢀO5
SꢀC15
PꢀN1
FlꢀC15
F2ꢀC15
F3ꢀC15
O1ꢀC3
O2ꢀC4
N1ꢀC6
N1ꢀC7
N2ꢀC8
N2ꢀC9
C7ꢀC8
1.94(l)
2.346(6)
2.131(9)
2.14(l)
1.434(6)
1.436(7)
1.410(8)
1.78(l)
WꢀPꢀN2
WꢀPꢀC13
110.5(9)
,
(2.428 for W-1b and 2.425 A for W-2b) are slightly
shorter than those reported as a normal WꢀP dative
bond (2.47–2.69 A) [15].
With W-1b, the WꢀSn bond distance is 2.709 A. This
bond is significantly shorter than a normal WꢀSn single
bond; 2.837 for Cp(CO)2W(ꢁC(H)C6H4Me-4)(SnPh3)
[16], 2.813 for (CO)3(MeCN)2W(SnPh3) [17], and 2.768
1.679(8)
,
Bond angles
SnꢀWꢀP
SnꢀWꢀC3
SnꢀWꢀC4
PꢀWꢀC3
,
140.03(6)
77.5(3)
72.6(3)
79.6(3)
79.9(3)
N1ꢀPꢀN2
N1ꢀPꢀC5
N2ꢀPꢀC5
SnꢀO3ꢀS
92.8(4)
104.7(5)
104.7(5)
145.2(4)
120.2(8)
110.7(7)
115.1(8)
113.2(8)
127.3(8)
116(l)
PꢀWꢀC4
PꢀN1ꢀC6
PꢀN1ꢀC7
C6ꢀN1ꢀC7
PꢀN2ꢀC8
PꢀN2ꢀC9
C8ꢀN2ꢀC9
WꢀC3ꢀO1
WꢀC4ꢀO2
N1ꢀC7ꢀC8
N2ꢀC8ꢀC7
SꢀC15ꢀF1
SꢀC15ꢀF2
SꢀC15ꢀF3
F1ꢀC15ꢀF2
F1ꢀC15ꢀF3
F2ꢀC15ꢀF3
,
A for Cp2W(HgI)(SnPh3) [18]. This is also slightly
C3ꢀWꢀC4
WꢀSꢀO3
100.2(5)
105.6(2)
121.1(3)
126.5(3)
91.3(3)
shorter than the WꢀSn distances for stannylene tung-
sten complexes reported; 2.722 for (CO)5W-
WꢀSnꢀCl
WꢀSnꢀC2
O3ꢀSnꢀCl
O3ꢀSnꢀC2
C1ꢀSnꢀC2
O3ꢀSꢀO4
O3ꢀSꢀO5
O3ꢀSꢀCl5
O4ꢀSꢀO5
O4ꢀSꢀCl5
O5ꢀSꢀC15
WꢀPꢀN1
WꢀPꢀN2
WꢀPꢀC5
(ꢁSnCl2·THF), 2.737 for (CO)5W(ꢁSnCl2·2THF), and
t
,
2.751 A for (CO)5W(ꢁSn(C3H2Bu-2,4,6)(CH2CMe2C6-
Ht3Bu-3,5) [19]. The WSnC1C7 unit is distorted from a
trigonal plane (the sum of angles around Sn amounts
84.0(3)
175(l)
110.9(4)
113.3(4)
113.7(5)
102.8(5)
117.0(5)
102.6(5)
105.2(6)
117.7(3)
119.7(3)
114.2(3)
178.1(9)
105.5(8)
106.0(8)
112(l)
112.8(9)
111.9(9)
107(l)
,
346.7°). The SnꢀO3 bond distance (2.160 A) is signifi-
cantly shorter than that for oxygen-stabilized stan-
nylene complexes; 2.276 and 2.344 [20], 2.29 [21], 2.223,
,
2.356 and 2.350 [19], 2.343 [9c], 2.346 A (vide infra).
Therefore, W-1b may be classified into base stabilized
stannylene complexes, but bear character, to some ex-
tent, of a stannyl complex with two phenyl and OTf
substituents on the tin.
107(l)
105(l)

H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
459
atmosphere. TMSOTf and BF3·OEt2 were distilled
prior to use. Other reagents employed in this study
were used as received. Column chromatography was
carried out quickly in air on Merck aluminium oxide
90.
C12H18IN2O3PW: C, 24.85; H, 3.13; N, 4.83. Found: C,
24.78; H, 3.11; N, 4.69%. The isolated complex is a
mixture of the cis and trans isomers. They could be
separated by means of column chromatography on
alumina with hexane–CH2Cl2 (1/2). The cis isomer is
IR spectra were recorded on a Shimadzu FTIR-
8100A spectrometer. A JEOL LA-300 multinuclear
eluted first. For the cis isomer: IR (wCO, in CH2Cl2):
1
1953, 1868. H-NMR (l, in CDCl3): 2.63 (d, JHꢀP
=
1
spectrometer was used to obtain H-, 13C-, 31P-, 119Sn-
11.2 Hz, 3H, NCH3), 2.71 (d, JHꢀP=10.9 Hz, 3H,
NCH3), 3.12–3.18 (m, 2H, NCH2), 3.36 (d, JHꢀP=11.2
Hz, 3H, OCH3), 3.38–3.44 (m, 2H, NCH2), 5.54 (s, 5H,
C5H5). 13C-NMR (l, in CDCl3): 33.57 (d, JCꢀP=9.1
Hz, NCH3), 34.60 (d, JCꢀP=12.8 Hz, NCH3), 53.18 (s,
NCH2), 53.23 (s, NCH2), 53.35 (s, OCH3), 90.82 (s,
1
NMR spectra. The reference was as follows: for H-
and 13C-NMR data, Si(CH3)4 as an internal standard;
for 31P-NMR data, 85% H3PO4 as an external stan-
dard; for 119Sn-NMR data, Sn(CH3)4 as an external
standard. Elemental analyses were performed on a
Perkin–Elmer 2400CHN elemental analyzer.
C5H5), 228.06 (d, JCꢀP=7.5 Hz, CO), 241.30 (d, JCꢀP
=
32.4 Hz, CO). 31P-NMR (l, in CH2Cl2): 115.85 (s with
3.2. Preparation of [Cp(CO)2IM{PNN(OMe)}]
(M=Mo, W)
W satellites, JPꢀ W=387.0 Hz). For the trans isomer:
183
IR (wCO, in CH2Cl2): 1959, 1871. 1H-NMR (l, in
CDCl3): 2.81 (d, JHꢀP=10.6 Hz, 6H, NCH3), 3.13–3.17
(m, 2H, NCH2), 3.43 (d, JHꢀP=12.2 Hz, 3H, OCH3),
3.43–3.48 (m, 2H, NCH2), 5.24 (d, JHꢀP=2.0 Hz, 5H,
C5H5). 13C-NMR (l, in CDCl3): 33.31 (d, JCꢀP=13.6
Hz, NCH3), 51.66 (s, OCH3), 52.65 (s, NCH2), 90.43 (s,
A solution of Cp(CO)3IMo (1728 mg, 4.65 mmol) in
CH2Cl2 (40 ml) was treated with PNN(OMe) (0.80 ml,
5.40 mmol) at room temperature (r.t.) with stirring for
10 h. The solvent was removed under reduced pressure
and the residue was dissolved in a small amount of
THF. The solution was loaded on an alumina column,
and eluted with THF. The red band eluted was col-
lected, and the solvent was removed in vacuo to give
Cp(CO)2IMo{PNN(OMe)} as a red powder (2016 mg,
4.10 mmol, 88%). Anal. Calc. for C12H18IMoN2O3P: C,
29.29; H, 3.69; N, 5.69. Found: C, 29.18; H, 3.63; N,
5.57%. For the cis isomer: IR (wCO, in CH2Cl2): 1964,
C5H5), 221.76 (d with
183
W satellites, JCꢀP=27.2,
JCꢀ W=162.2 Hz CO). 31P-NMR (l, in CH2Cl2):
123.36 (s with W satellites, JPꢀ W=368.4 Hz).
183
3.3. Preparation of [Cp(CO)2(SnPh3)Mo{PNN(OMe)}]
(Mo-1a)
A solution of [Cp(CO)2IMo{PNN(OMe)}] (1069 mg,
2.17 mmol) in THF (20 ml) was treated with NaK2.8
(1.0 ml, 6.49 mmol) at r.t. with stirring for 1 h. The
color of the solution changed from red to pale yellow.
After an excess of NaK2.8 was filtered off, the filtrate
was added to the THF solution of SnPh3Cl (1000 mg,
2.59 mmol) at r.t. The reaction mixture was stirred for
2 h. The solvent was removed under reduced pressure
and the residue was extracted with CH2Cl2. The extract
was loaded on an alumina column, and eluted with a
mixture of 1:1 hexane–CH2Cl2. The pale yellow band
eluted first was collected, and the solvents were re-
moved in vacuo to give Mo-1a as a white powder (1286
1
1888. H-NMR (l, in CDCl3): 2.65 (d, JHꢀP=11.5 Hz,
3H, NCH3), 2.72 (d, JHꢀP=11.0 Hz, 3H, NCH3), 3.06–
3.10 (m, 2H, NCH2), 3.26–3.31 (m, 2H, NCH2), 3.35
(d, JHꢀP=11.2 Hz, 3H, OCH3), 5.42 (s, 5H, C5H5).
13C-NMR (l, in CDCl3): 33.39 (d, JCꢀP=6.1 Hz,
NCH3), 33.93 (d, JCꢀP=13.4 Hz, NCH3), 52.58 (d,
JCꢀP=2.4 Hz, NCH2), 52.86 (d, JCꢀP=12.2 Hz,
OCH3), 53.01 (d, JCꢀP=2.4 Hz, NCH2), 92.59 (s,
C5H5), 237.89 (d, JCꢀP=3.3 Hz, CO), 250.41 (d, JCꢀP
=
40.3 Hz, CO). 31P-NMR (l, in CH2Cl2): 150.55 (s). For
the trans isomer: IR (wCO, in CH2Cl2): 1964, 1888.
1H-NMR (l, in CDCl3): 2.84 (d, JHꢀP=10.7 Hz, 6H,
NCH3), 3.14–3.19 (m, 2H, NCH2), 3.41 (d, JHꢀP=12.2
Hz, 3H, OCH3), 3.44–3.48 (m, 2H, NCH2), 5.16 (d,
mg,
1.80
mmol,
83%).
Anal.
Calc.
for
C30H33MoN2O3PSn: C, 50.38; H, 4.65; N, 3.92. Found:
J
HꢀP=2.2 Hz, 5H, C5H5). 13C-NMR (l, in CDCl3):
C, 50.07; H, 4.53; N, 3.94%. IR (wCO, in CH2Cl2):
1
33.30 (d, JCꢀP=11.0 Hz, NCH3), 51.33 (d, JCꢀP=11.0
Hz, OCH3), 51.82 (d, JCꢀP=2.4 Hz, NCH2), 92.10 (s,
C5H5), 230.46 (d, JCꢀP=36.6 Hz, CO). 31P-NMR (l, in
CH2Cl2): 162.51 (s).
[Cp(CO)2IW{PNN(OMe)}] was prepared by reflux-
ing a benzene solution (110 ml) for 4.5 h containing
Cp(CO)3IW (2479 mg, 5.61 mmol) and PNN(OMe)
(0.80 ml, 5.40 mmol). The purification was carried out
in a manner similar to that for the corresponding Mo
complex to give a red powder of [Cp(CO)2IW{PNN-
(OMe)}] (2916 mg, 5.03 mmol, 93%). Anal. Calc. for
1909, 1837. H-NMR (l, in CDCl3): 2.84 (d, JHꢀP
=
10.9 Hz, 6H, NCH3), 3.15–3.26 (m, 2H, NCH2), 3.37
(d, JHꢀP=12.2 Hz, 3H, OCH3), 3.40–3.50 (m, 2H,
NCH2), 4.97 (d, JHꢀP=1.0 Hz, 5H, C5H5), 7.25–7.33
(m, 9H, Ph), 7.61–7.65 (m, 6H, Ph). 13C-NMR (l, in
CDCl3): 33.54 (d, JCꢀP=11.0 Hz, NCH3), 51.91 (d,
J
CꢀP=2.4 Hz, NCH2), 52.35 (d, JCꢀP=11.0 Hz,
OCH3), 88.44 (s, C5H5), 127.62 (s, Ph), 127.78 (s with
Sn satellites, JCꢀ Sn=42.7 Hz, Ph), 137.07 (s with Sn
119
satellites, JCꢀ Sn=35.4 Hz, Ph), 145.12 (s with Sn
119
satellites, JCꢀ Sn=358.8 Hz, Ph), 231.88 (d with Sn
119

460
H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
satellites, JCꢀP=30.5 Hz, JCꢀ Sn=150.8 Hz, CO). 31P-
3.6. Preparation of [Cp(CO)2(SnPh3)W{PNN(OMe)}]
(W-1a)
119
NMR (l, in CH2Cl2): 171.00 (s with Sn satellites,
119
JPꢀ Sn=148.8 Hz). 119Sn-NMR (l, in CDCl3): 74.97
A treatment of [Cp(CO)2IW{PNN(OMe)}] (2533 mg,
4.37 mmol) with NaK2.8 (1.0 ml, 6.49 mmol) followed
by SnPh3Cl (1710 mg, 4.44 mmol) in a manner similar
to that for Mo-1a gave a white powder of W-1a (2952
(d, J119SnꢀP=146.1 Hz).
3.4. Preparation of
[Cp(CO)2(SnMe3)Mo{PNN(OMe)}](Mo-2a)
mg,
3.68
mmol,
84%).
Anal.
Calc.
for
C30H33N2O3PSnW: C, 44.87; H, 4.14; N, 3.49. Found:
C, 44.77; H, 4.06; N, 3.51%. IR (wCO, in CH2Cl2):
A treatment of [Cp(CO)2IMo{PNN(OMe)}] (2920
mg, 5.93 mmol) with NaK2.8 (1.5 ml, 9.09 mmol) fol-
lowed by SnMe3Cl (1340 mg, 6.73 mmol) in a manner
similar to that for Mo-1a gave a white powder of
Mo-2a (2534 mg, 4.79 mmol, 81%). Anal. Calc. for
C15H27MoN2O3PSn: C, 34.06; H, 5.14; N, 5.30. Found:
C, 34.11; H, 4.85; N, 5.28%. IR (wCO, in CH2Cl2):
1
1903, 1828. H-NMR (l, in CDCl3): 2.78 (d, JHꢀP
=
11.2 Hz, 6H, NCH3), 3.11–3.18 (m, 2H, NCH2), 3.34
(d, JHꢀP=12.2 Hz, 3H, OCH3), 3.37–3.40 (m, 2H,
NCH2), 5.02 (d, JHꢀP=0.7 Hz, 5H, C5H5), 7.25–7.32
(m, 9H, Ph), 7.59–7.69 (m, 6H, Ph). 13C-NMR (l, in
CDCl3): 33.78 (d, JCꢀP=9.8 Hz, NCH3), 51.73 (s,
NCH2), 52.87 (d, JCꢀP=11.0 Hz, OCH3), 86.99 (s,
C5H5), 127.64 (s, Ph), 127.76 (s with Sn satellites,
1
1897, 1823. H-NMR (l, in CDCl3): 0.33 (s with Sn
satellites, JHꢀ
J
=45.5 Hz, 9H, SnCH3), 2.80 (d,
119
HꢀP=11.6 Hz, S6nH, NCH3), 3.11–3.22 (m, 2H, NCH2),
JCꢀ Sn=42.8 Hz, Ph), 137.19 (s with Sn satellites,
119
JCꢀ Sn=35.4 Hz, Ph), 144.54 (s with Sn satellites,
119
3.31 (d, JHꢀP=12.1 Hz, 3H, OCH3), 3.36–3.44 (m, 2H,
J
Cꢀ Sn=368.7 Hz, Ph), 222.43 (d with Sn and W
NCH2), 4.94 (s, 5H, C5H5). 13C-NMR (l, in CDCl3):
119
satellites, JCꢀP=25.6 Hz, JCꢀ Sn=138.0 Hz, JCꢀ
=
119
183
155.0 Hz, CO). 31P-NMR (l, in CH2Cl2): 134.50 (s Wwith
Sn and W satellites, JPꢀ Sn=137.7 Hz, JPꢀ W=422.4
−5.55 (s with Sn satellites, JCꢀ Sn=252.9 Hz,
119
SnCH3), 33.65 (d, JCꢀP=10.7 Hz, NCH3), 51.70 (d,
119
183
JCꢀP=3.2 Hz, NCH2), 52.16 (d, JCꢀP=9.6 Hz, OCH3),
Hz). 119Sn-NMR (l, in CH2Cl2): −1.98 (d with W
87.92 (s, C5H5), 231.82 (d with Sn satellites, JCꢀP=28.8
119
satellites, J119SnꢀP=140.6 Hz, J119
W=404.6 Hz).
183
Snꢀ
Hz, JCꢀ Sn=136.6 Hz, CO). 31P-NMR (l, in CH2Cl2):
119
177.70 (s with Sn satellites, JPꢀ Sn=132.1 Hz). 119Sn-
3.7. Preparation of [Cp(CO)2(SnMe3)W{PNN(OMe)}]
(W-2a)
NMR (l, in CH2Cl2): 128.87 (d, J119SnꢀP=133.3 Hz).
A treatment of [Cp(CO)2IW{PNN(OMe)}] (2356 mg,
4.06 mmol) with NaK2.8 (1.5 ml, 9.09 mmol) followed
by SnMe3Cl (880 mg, 4.42 mmol) in a manner similar
to that for Mo-1a gave a white powder of W-2a (1885
3.5. Preparation of
[Cp(CO)2(SnnBu3)Mo{PNN(OMe)}] (Mo-3a)
A treatment of [Cp(CO)2IMo{PNN(OMe)}] (3060
mg, 6.22 mmol) with NaK2.8 (1.5 ml, 9.09 mmol) fol-
lowed by SnnBu3Cl (1.70 ml, 6.27 mmol) in a manner
similar to that for Mo-1a gave a white powder of
Mo-3a (3237 mg, 4.94 mmol, 79%). Anal. Calc. for
C24H45MoN2O3PSn: C, 43.99; H, 6.92; N, 4.28. Found:
C, 44.14; H, 6.68; N, 4.30%. IR (wCO, in CH2Cl2):
mg,
3.06
mmol,
75%).
Anal.
Calc.
for
C15H27N2O3PSnW: C, 29.20; H, 4.41; N, 4.54. Found:
C, 29.25; H, 4.20; N, 4.50%. IR (wCO, in CH2Cl2):
1
1890, 1815. H-NMR (l, in CDCl3): 0.34 (s with Sn
satellites, JHꢀ
J
=45.4 Hz, 9H, SnCH3), 2.76 (d,
119
HꢀP=11.5 Hz, S6nH, NCH3), 3.12–3.17 (m, 2H, NCH2),
3.32 (d, JHꢀP=12.2 Hz, 3H, OCH3), 3.38–3.41 (m, 2H,
1
NCH2), 5.01 (s, 5H, C5H5). 13C-NMR (l, in CDCl3):
1894, 1821. H-NMR (l, in CDCl3): 0.90 (t, JHꢀH=7.3
Hz, 9H, Bu), 1.05–1.13 (m, 6H, Bu), 1.35 (d, JHꢀH=7.6
Hz, 6H, Bu), 1.49–1.61 (m, 6H, Bu), 2.81 (d, JHꢀP
11.2 Hz, 6H, NCH3), 3.14–3.21 (m, 2H, NCH2), 3.32
(d, JHꢀP=11.9 Hz, 3H, OCH3), 3.37–3.42 (m, 2H,
NCH2), 4.97 (d, JHꢀP=1.0 Hz, 5H, C5H5). 13C-NMR
−6.69 (s with Sn satellites, JCꢀ Sn=258.8 Hz,
119
=
SnCH3), 33.91 (d, JCꢀP=9.7 Hz, NCH3), 51.50 (d,
J
CꢀP=2.5 Hz, NCH2), 52.86 (d, JCꢀP=8.6 Hz, OCH3),
86.50 (s, C5H5), 222.66 (d with Sn and W satellites,
J
CꢀP=23.3 Hz, JCꢀ Sn=124.4 Hz, JCꢀ W=159.3 Hz,
119
183
CO). 31P-NMR (l, in CH2Cl2): 141.70 (s with Sn and
W satellites, JPꢀ Sn=124.7 Hz, JPꢀ W=441.0 Hz).
(l, in CDCl3): 13.70 (s with Sn satellites, JCꢀ
119
248.5 Hz, Bu), 13.80 (s, Bu), 27.66 (s with Sn satelSlintes,
=
119
183
119Sn-NMR (l, in CH2Cl2): 45.04 (d with W satellites,
JCꢀ Sn=59.0 Hz, Bu), 30.21 (s with Sn satellites,
119
JCꢀ
=19.7 Hz, Bu), 33.72 (d, JCꢀP=11.6 Hz,
J119SnꢀP=128.9 Hz, J119
W=262.3 Hz).
183
Snꢀ
119
NCHS3n), 51.84 (d, JCꢀP=3.5 Hz, NCH2), 52.16 (d,
3.8. Preparation of [Cp(CO)2(SnnBu3)W{PNN(OMe)}]
(W-3a)
J
CꢀP=10.4 Hz, OCH3), 87.53 (s, C5H5), 232.20 (d with
Sn satellites, JCꢀP=30.1 Hz, JCꢀ Sn=132.4 Hz, CO).
119
31P-NMR (l, in CH2Cl2): 177.38 (s with Sn satellites,
119
JCꢀ Sn=113.5 Hz). 119Sn-NMR (l, in CH2Cl2): 117.00
A treatment of [Cp(CO)2IW{PNN(OMe)}] (2600 mg,
4.48 mmol) with NaK2.8 (1.5 ml, 9.09 mmol) followed
(d, J119SnꢀP=116.1 Hz).

H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
461
by SnnBu3Cl (1.20 ml, 4.42 mmol) in a manner similar
to that for Mo-1a gave a white powder of W-3a (2718
7.39–7.73 (m, 15H, Ph). 13C-NMR (l, in CDCl3): 34.39
(d, JCꢀP=7.3 Hz, NCH3), 51.49 (s, NCH2), 89.13 (s,
C5H5), 119.22 (q, JCꢀF=318.6 Hz, CF3), 128.10 (d,
mg,
3.66
mmol,
82%).
Anal.
Calc.
for
C24H45N2O3PSnW: C, 38.79; H, 6.10; N, 3.77. Found:
J
CꢀP=8.5 Hz, PPh), 128.60 (s with Sn satellites,
JCꢀ Sn=48.8 Hz, SnPh), 129.56 (s, SnPh), 130.27 (d,
C, 38.70; H, 5.92; N, 3.82%. IR (wCO, in CH2Cl2):
119
1
1888, 1812. H-NMR (l, in CDCl3): 0.90 (t, JHꢀH=7.3
JCꢀP=11.0 Hz, PPh), 130.67 (s, PPh), 135.10 (s with Sn
Hz, 9H, Bu), 1.05–1.11 (m, 6H, Bu), 1.34 (d, JHꢀH=7.3
satellites, JCꢀ
=46.4 Hz, SnPh), 140.02 (d, JCꢀP
=
=
119
Hz, 6H, Bu), 1.48–1.59 (m, 6H, Bu), 2.77 (d, JHꢀP
=
41.5 Hz, PPh),Sn147.42 (s with Sn satellites, JCꢀ
119
11.6 Hz, 6H, NCH3), 3.12–3.19 (m, 2H, NCH2), 3.33
(d, JHꢀP=12.2 Hz, 3H, OCH3), 3.38–3.41 (m, 2H,
NCH2), 5.03 (d, JHꢀP=1.0 Hz, 5H, C5H5). 13C-NMR
343.0 Hz, SnPh), 222.01 (d with
W
satelSlintes,
J
CꢀP=20.8 Hz, JCꢀ W=151.4 Hz, CO). 31P-NMR (l,
183
in CH2Cl2): 123.38 (s with Sn and W satellites,
(l, in CDCl3): 12.60 (s with Sn satellites, JCꢀ
=
JPꢀ Sn=183.8 Hz, JPꢀ W=323.6 Hz). 119Sn-NMR (l,
119
119
183
253.9 Hz, Bu), 13.82 (s, Bu), 27.64 (s with Sn satelSlintes,
in CH2Cl2): 335.32 (d with W satellites, J119SnꢀP=188.1
Hz, J119 W=610.1 Hz).
JCꢀ Sn=57.3 Hz, Bu), 30.33 (s with Sn satellites,
119
183
Snꢀ
JCꢀ
=18.3 Hz, Bu), 33.96 (d, JCꢀP=9.8 Hz, NCH3),
119
51.63S(nd, JCꢀP=2.4 Hz, NCH2), 52.81 (d, JCꢀP=9.7 Hz,
3.10. Reaction of M-1a (M=Mo, W) with BF3·OEt2
OCH3), 86.07 (s, C5H5), 222.95 (d with Sn and W
satellites, JCꢀP=23.2 Hz, JCꢀ Sn=119.6 Hz, JCꢀ
=
A solution of Mo-1a (400 mg, 0.56 mmol) in CH2Cl2
(7 ml) was treated with BF3·OEt2 (0.14 ml, 1.12 mmol)
at r.t. with stirring for 5 h. The color of the solution
changed from pale yellow to yellow. An effort to isolate
Mo-1b% came into failure for instability of the product.
Confirming the formation of Mo-1b%, the reaction mix-
ture was cooled to −78°C and treated with a di-
ethylether solution of MeLi (0.7 ml, 0.7 mmol). The
solution was warmed to r.t. with stirring for 22 h. The
solvents were removed under reduced pressure and the
residue was loaded on an alumina column, and eluted
with a CH2Cl2–hexane (1/1). The pale yellow band
eluted first was collected, and the solvents were re-
moved in vacuo to give Mo-1c as a white powder (283
119
183
159.9 Hz, CO). 31P-NMR (l, in CH2Cl2): 141.07 (s Wwith
Sn and W satellites, JPꢀ Sn=109.8 Hz, JPꢀ W=444.8
119
183
Hz). 119Sn-NMR (l, in CH2Cl2): 37.72 (d with W
satellites, J119SnꢀP=113.2 Hz, J119
W=234.4 Hz).
183
Snꢀ
3.9. Reaction of M-1a (M=Mo, W) with TMSOTf
A solution of Mo-1a (403 mg, 0.56 mmol) in CH2Cl2
(7 ml) was treated with TMSOTf (0.10 ml, 0.55 mmol)
at r.t. with stirring for 5 h. The color of the solution
changed from pale yellow to yellow. The solvent was
removed under reduced pressure and the residue was
washed with hexane. Hexane was diffused slowly to a
CH2Cl2 solution of the residue to result in a pale yellow
supernatant and a black oil. The supernatant was trans-
ferred to another Schlenk tube by cannula under nitro-
gen atmosphere, and the solvents were removed in
vacuo to give a pale yellow powder of Mo-1b (354 mg,
0.43 mmol, 77%). IR (wCO, in CH2Cl2): 1920, 1847.
1H-NMR (l, in CDCl3): 2.82 (d, JHꢀP=11.9 Hz, 6H,
NCH3), 3.27 (m, 4H, NCH2), 5.37 (s, 5H, C5H5),
7.31–7.67 (m, 15H, Ph). 13C-NMR (l, in CDCl3): 34.40
(d, JCꢀP=8.6 Hz, NCH3), 51.81 (s, NCH2), 90.53 (s,
C5H5), 119.29 (q, JCꢀF=318.6 Hz, CF3) 128.21 (d,
mg,
0.41
mmol,
73%).
Anal.
Calc.
for
C30H33MoN2O2PSn: C, 51.53; H, 4.76; N, 4.01. Found:
C, 51.78; H, 4.77; N, 4.04%. IR (wCO, in CH2Cl2):
1
1900, 1828. H-NMR (l, in CDCl3): 0.73 (s with Sn
satellites, JHꢀSn=44.9 Hz, 3H, SnCH3), 2.69 (d, JHꢀP
=
11.6 Hz, 6H, NCH3), 3.12 (d, JHꢀP=2.0 Hz, 2H,
NCH2), 3.14 (s, 2H, NCH2), 4.95 (d, JHꢀP=1.0 Hz, 5H,
C5H5), 7.17–7.66 (m, 15H, Ph). 13C-NMR (l, in
CDCl3): −6.11 (s with Sn satellites, J
Sn=266.1
119
Hz, SnCH3), 34.23 (d, JCꢀP=9.7 Hz, NCCHꢀ3), 51.63 (d,
J
CꢀP=2.5 Hz, NCH2), 89.15 (s, C5H5), 127.51 (s,
JCꢀP=9.8 Hz, PPh), 128.68 (s, SnPh), 129.56 (s, SnPh),
SnPh), 127.64 (s with Sn satellites, JCꢀ Sn=42.7 Hz,
119
129.87 (d, JCꢀP=11.0 Hz, PPh), 130.64 (s, PPh), 134.95
SnPh), 127.64 (d, JCꢀP=9.8 Hz, PPh), 129.65 (s, PPh),
130.17 (d, JCꢀP=12.2 Hz, PPh), 136.41 (s with Sn
(s with Sn satellites, JCꢀ Sn=47.7 Hz, SnPh), 139.85
119
(d, JCꢀP=33.0 Hz, PPh), 148.18 (s with Sn satellites,
satellites, JCꢀ Sn=34.2 Hz, SnPh), 140.88 (d with Sn
119
JCꢀ
=317.1 Hz, SnPh), 230.81 (d, JCꢀP=28.1 Hz,
satellites,
J
CꢀP=29.3 Hz, JCꢀ Sn=9.5 Hz, PPh),
119
CO). S3n1P-NMR (l, in CH2Cl2): 157.05 (s with Sn satel-
119
119
145.70 (s with Sn satellites, JCꢀ Sn=352.8 Hz, SnPh),
119
lites, JPꢀ Sn=190.2 Hz). 119Sn-NMR (l, in situ):
459.14 (d, J119SnꢀP=192.1 Hz).
A treatment of W-1a (463 mg, 0.58 mmol) with
TMSOTf (0.10 ml, 0.55 mmol) in a manner similar to
that for Mo-1b gave a pale yellow powder of W-1b (404
mg, 0.44 mmol, 76%). IR (wCO, in CH2Cl2): 1926,
233.23 (d with Sn satellites, JCꢀP=25.6 Hz, JCꢀ Sn=
119
146.4 Hz, CO). 31P-NMR (l, in CH2Cl2): 166.24 (s with
119
Sn satellites, JPꢀ Sn=143.7 Hz). 119Sn-NMR (l, in
CH2Cl2): 81.46 (d, J119SnꢀP=146.1 Hz).
When W-1a (398 mg, 0.50 mmol) was treated with
BF3·OEt2 (0.12 ml, 0.96 mmol), the spectroscopic mea-
surements of the reaction mixture suggested a forma-
tion of W-1b%: 31P-NMR (l, in situ): 119.27 (br.).
1
1847. H-NMR (l, in CDCl3): 2.79 (d, JHꢀP=11.2 Hz,
6H, NCH3), 3.25 (m, 4H, NCH2), 5.47 (s, 5H, C5H5),

462
H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
119Sn-NMR (l, in situ): 293.17 (d, J119SnꢀP=152.6 Hz).
Subsequently, a diethylether solution of MeLi (0.6 ml, 0.6
mmol) was added to the reaction mixture in a manner
similar to that for Mo-1c to give a pale yellow powder
of W-1c (300 mg, 0.38 mmol, 77%). Anal. Calc. for
C30H33N2O2PSnW: C, 45.78; H, 4.23; N, 3.56. Found: C,
45.63; H, 4.17; N, 3.57%. IR (wCO, in CH2Cl2): 1893,
reaction. The spectroscopic measurements in situ, how-
ever, suggested a formation of M-2b%. Mo-2b%: 31P-NMR
(l, in situ): 163.14 (br.). 119Sn-NMR (l, in situ): 575.80
(br.). W-2b%: 31P-NMR (l, in situ): 124.40 (br.). 119Sn-
NMR (l, in situ): 445.93 (br.).
3.13. Reaction of M-3a (M=Mo, W) with TMSOTf
1
1818. H-NMR (l, in CDCl3): 0.72 (s with Sn satellites,
A treatment of Mo-3a (380 mg, 0.58 mmol) with
TMSOTf (0.10 ml, 0.55 mmol) in a manner similar to that
for Mo-1b resulted in a complicated reaction. The
spectroscopic measurements in situ, however, suggested
a formation of Mo-3b and Mo-d. The reaction mixture
was condensed and was kept standing at −10°C to give
yellow crystals of Mo-d (42 mg, 0.13 mmol, 22%). Mo-3b:
31P-NMR (l, in situ): 164.11 (s with Sn satellites,
JHꢀ Sn=44.9 Hz, 3H, SnCH3), 2.71 (d, JHꢀP=11.6 Hz,
119
6H, NCH3), 3.18 (d, JHꢀP=3.6 Hz, 2H, NCH2), 3.21 (s,
2H, NCH2), 5.06 (d, JHꢀP=1.0 Hz, 5H, C5H5), 7.24–7.58
(m, 15H, Ph). 13C-NMR (l, in CDCl3): −7.10 (s with
Sn satellites, JCꢀ Sn=275.9 Hz, SnCH3), 34.41 (d,
119
JCꢀP=9.7 Hz, NCH3), 51.50 (s, NCH2), 87.82 (s, C5H5),
127.59 (d, JCꢀP=3.6 Hz, PPh), 127.65 (s with Sn satel-
lites, JCꢀ Sn=41.5 Hz, SnPh), 127.76 (s, SnPh), 129.81
119
JPꢀ Sn=166.5 Hz). 119Sn-NMR (l, in situ): 667.08 (d,
119
J119SnꢀP=167.9 Hz). Mo-d: 31P-NMR (l, in THF):
272.46 (s).
(d, JCꢀP=2.5 Hz, PPh), 130.72 (d, JCꢀP=11.0 Hz, PPh),
136.60 (s with Sn satellites, JCꢀ Sn=34.2 Hz, SnPh),
119
141.23 (d with Sn satellites, JCꢀP=37.8 Hz, JCꢀ Sn
=
=
119
A treatment of W-3a (474 mg, 0.64 mmol) with
TMSOTf (0.11 ml, 0.61 mmol) in a manner similar to that
for Mo-1b resulted in a complicated reaction. The
spectroscopic measurements in situ, however, suggested
a formation of W-3b and W-d. The reaction mixture was
condensed and was kept standing at −10°C to give
yellow crystals of W-d (70 mg, 0.17 mmol, 26%). W-3b:
31P-NMR (l, in situ): 126.91 (s with Sn and W satellites,
JPꢀ Sn=155.5 Hz, JPꢀ W=396.1 Hz). 119Sn-NMR (l,
12.2 Hz, PPh), 145.05 (s with Sn satellites, JCꢀ
119
360.1 Hz, SnPh), 224.42 (d with Sn and W satelSlintes,
J
CꢀP=19.5 Hz, JCꢀ Sn=133.0 Hz, JCꢀ W=158.1 Hz,
119
183
CO). 31P-NMR (l, in CH2Cl2): 130.52 (s with Sn and W
satellites, JPꢀ Sn=145.2 Hz, JPꢀ W=362.9 Hz). 119Sn-
119
183
NMR (l, in CH2Cl2): −1.02 (d with W satellites,
J119SnꢀP=146.1 Hz, J119 W=313.8 Hz).
183
Snꢀ
119
183
3.11. Reaction of M-2a (M=Mo, W) with TMSOTf
in situ): 539.44 (d, J119SnꢀP=158.4 Hz). W-d: Anal. Calc.
for C11H15N2O2PW: C, 31.30; H, 3.58; N, 6.64. Found:
C, 31.32; H, 3.48; N, 6.60%. IR (wCO, in benzene): 1910,
1838. 1H-NMR (l, in C6D6): 2.42 (d, JHꢀP=5.7 Hz, 6H,
NCH3), 2.58–2.66 (m, 4H, NCH2), 5.15 (s, 5H, C5H5).
13C-NMR (l, in C6D6): 34.23 (d, JCꢀP=15.1 Hz, NCH3),
51.28 (d, JCꢀP=2.3 Hz, NCH2), 86.53 (s, C5H5), 222.83
(d, JCꢀP=9.1 Hz, CO). 31P-NMR (l, in benzene): 244.61
A treatment of Mo-2a with TMSOTf in a manner
similar to that for Mo-1b resulted in a complicated
reaction. The spectroscopic measurements in situ, how-
ever, suggested a formation of Mo-2b: 31P-NMR (l, in
situ): 162.56 (s with Sn satellites, JPꢀ Sn=201.7 Hz).
119
119Sn-NMR (l, in situ): 655.79 (d, J119SnꢀP=194.8 Hz).
A treatment of W-2a with TMSOTf in a manner
similar to that for Mo-1b resulted in a complicated
reaction. The spectroscopic measurements in situ, how-
ever, suggested a formation of W-2b. The solvent of the
reaction mixture was removed under reduced pressure
and the residue was recrystallized from CH2Cl2–hexane
system at −10°C to give several yellow crystals of W-2b:
13C-NMR (l, in CH2Cl2): 5.61 (s with Sn satellites,
(s with W satellites, JPꢀ W=718.1 Hz).
183
3.14. Reaction of M-3a (M=Mo, W) with BF3·OEt2
A treatment of M-3a with BF3·OEt2 in a manner
similar to that for Mo-1b% resulted in a complicated
reaction. The spectroscopic measurements in situ, how-
ever, suggested a formation of M-d, and cis and trans-M-
3e. cis-Mo-3e: 31P-NMR (l, in situ): 334.71 (br.).
trans-Mo-3e: 31P-NMR (l, in situ): 310.08 (br.). cis-W-
3e: 31P-NMR (l, in situ/−20°C): 298.07 (s with Sn and
W satellites, JPꢀ Sn=42.5 Hz, JPꢀ W=516.4 Hz).
JCꢀ
=201.4 Hz, SnCH3), 21.82 (d, JCꢀP=29.3 Hz,
119
PCH3S)n, 33.88 (d, JCꢀP=7.3 Hz, NCH3), 51.41 (s, NCH2),
88.83 (s, C5H5), 119.33 (q, JCꢀF=317.4 Hz, CF3), 220.83
(d with Sn and W satellites, JCꢀP=19.5 Hz, JCꢀ Sn
=
119
152.0 Hz, JCꢀ W=152.0 Hz, CO). 31P-NMR (l, in
119
183
183
trans-W-3e: 31P-NMR (l, in situ/−20°C): 282.76 (s with
Sn and W satellites, JPꢀ Sn=291.6 Hz, JPꢀ W=543.1
CH2Cl2): 125.14 (s with Sn and W satellites, JPꢀ Sn
=
119
194.3 Hz, JPꢀ W=315.7 Hz). 119Sn-NMR (l, in
119
183
Hz).
183
CH2Cl2): 526.53 (d, J119SnꢀP=203.2 Hz).
3.15. X-ray structure determination for W-1b and
W-2b
3.12. Reaction of M-2a (M=Mo, W) with BF3·OEt2
A treatment of M-2a with BF3·OEt2 in a manner
similar to that for Mo-1b% resulted in a complicated
Crystallographic and experimental details of X-ray
crystal structure analyses are given in Table 1. Suitable

H. Nakazawa et al. / Journal of Organometallic Chemistry 617–618 (2001) 453–463
463
Nakazawa, Y. Yamaguchi, T. Mizuta, K. Miyoshi,
Organometallics 14 (1995) 4173. (e) Y. Yamaguchi, H.
Nakazawa, T. Itoh, K. Miyoshi, Bull. Chem. Soc. Jpn. 69 (1996)
983. (f) Y. Yamaguchi, H. Nakazawa, M. Kishishita, K.
Miyoshi, Organometallics 15 (1996) 4383. (g) H. Nakazawa, Y.
Yamaguchi, K. Miyoshi, A. Nagasawa, Organometallics 15
(1996) 2517.
crystals of W-1b and W-2b were mounted indepen-
dently on an Enraf–Nonius CAD-4 automatic diffrac-
tometer. Data were collected at room temperature.
Intensities were collected for Lorents and polarization
effects in the usual manner. The structures were solved
by a combination of direct methods [22] and Fourier
synthesis [23] and refined by full matrix least-squares
calculations. During the course of the refinement, it was
found that the Cp ring carbon atoms of W-2b were
disordered. Therefore, they were refined by using two
rigid models with an occupancy factor=0.5 and
isotropic thermal parameters for each carbon atom. All
non-hydrogen atoms were refined anisotropically, and
hydrogen atoms were treated isotropically. An empiri-
cal absorption correction using the program DIFABS
[24] was applied. Final values of R=0.032 and Rw=
0.039 for compound W-1b and R=0.032 and Rw=
[9] (a) H. Nakazawa, Y. Yamaguchi, T. Mizuta, S. Ichimura, K.
Miyoshi, Organometallics 14 (1995) 4635. (b) H. Nakazawa, Y.
Yamaguchi, K. Miyoshi, Organometallics 15 (1996) 1337. (c) H.
Nakazawa, Y. Yamaguchi, K. Kawamura, K. Miyoshi,
Organometallics 16 (1997) 4626. (d) K. Kawamura, H.
Nakazawa, K. Miyoshi, Organometallics 18 (1999) 4785.
[10] (a) H. Nakazawa, Y. Yamaguchi, K. Miyoshi, Organometallics
22 (1996) 4661. (b) H. Nakazawa, M. Kishishita, S. Yoshinaga,
Y. Yamaguchi, T. Mizuta, K. Miyoshi, J. Organomet. Chem.
529 (1997) 423. (c) K. Kawamura, H. Nakazawa, K. Miyoshi,
Organometallics 18 (1999) 1517. (d) H. Nakazawa, M.
Kishishita, T. Nakamoto, N. Nakamura, T. Ishiyama, K.
Miyoshi, Chem. Lett. (2000) 230.
[11] A. Tzschach, K. Jurkschat, M. Scheer, J. Meunier-Piret, M. van
Meerssche, J. Organomet. Chem. 259 (1983) 165.
[12] (a) W. Petz, Chem. Rev. 86 (1986) 1019. (b) M.F. Lappert, R.S.
Rowe, Coord. Chem. Rev. 100 (1990) 267.
[13] L.D. Hutchins, R.T. Paine, C.F. Campana, J. Am. Chem. Soc.
102 (1980) 4521.
0.038
for
compound
W-2b,
were
obtained
2
2 1/2
(Rw=[SwꢀꢀFoꢀ−ꢀFcꢀꢀ /SwꢀFoꢀ ]
and w=4F2o/s2(Fo)).
All calculations were performed using TEXSAN [25] with
neutral atom scattering factors from Cromer and
Waber [26], Df% and Df%% values [27], and mass attenua-
tion coefficients [28].
[14] J.L. Wardell, in: P.G. Harrison (Ed.), Chemistry of Tin, Chap-
man and Hall, New York, 1989, p. 170 (Chapter 5).
[15] D.E.C. Corbridge, Phosphorus, An Outline of its Chemistry,
Biochemistry and Technology, Elsevier, New York, 1980, p. 467
(Chapter 10).
Acknowledgements
[16] D. Hodgson, J.A.K. Howard, F.G.A. Stone, M.J. Went, J.
Chem. Soc. Chem. Commun. (1985) 1331.
This work was supported by Grant-in-Aid for Scien-
tific Research (No. 12640539) from the Ministry of
Education, Science, Sports and Culture of Japan.
[17] L.-K. Liu, J.-T Lin, D. Fang, Inorg. Chim. Acta 161 (1989) 239.
[18] S. Seebald, B. Mayer, U. Schubert, Inorg. Chem. 34 (1995) 5285.
[19] A.L. Balch, D.E. Oram, Organometallics 7 (1988) 155.
[20] J.F. Almeida, K.R. Dixon, C. Eaborn, P.B. Hitchcock, A.
Pidock, J. Vinaixa, J. Chem. Soc. Chem. Commun. (1982) 1315.
[21] O. Scheidsteger, G. Huttner, K. Dehnicke, J. Pebler, Angew.
Chem. Int. Ed. Engl. 24 (1985) 428.
References
[22] H.-F. Fan, SAPI-91: Structure Analysis Programs with Intelligent
Control, Rigaku Corporation, Tokyo, Japan, 1991.
[1] W.A. Nugent, J.M. Mayer, in: W.A. Nugent, J.M. Mayer (Eds.),
Metal–Ligand Multiple Bonds, Wiley, New York, 1988.
[2] R.G. Montemayor, D.T. Sauer, S. Fleming, D.W. Bennett, M.G.
Thomas, R.W. Parry, J. Am. Chem. Soc. 100 (1978) 2231.
[3] A.H. Cowley, R.A. Kemp, Chem. Rev. 85 (1985) 367.
[4] M. Sanchez, M.R. Mazieres, L. Lamande, R. Wolf, in: M.
Regitz, O.J. Scherer (Eds.), Multiple Bonds and Low Coordina-
tion in Phosphorus Chemistry, Thieme, New York, 1990 (Chap-
ter D1).
[23] P.T. Beurskens, G. Admiraal, G. Beurskens, W.P. Bosman, S.
Garcia-Granda, R.O. Gould, J.M.M. Smits, C. Smykalla,
DIRDIF-92: The DIRDIF Program System, Technical Report of
the Crystallography Laboratory, University of Nijmegen,
Netherlands, 1992.
[24] N.S. Walker, DIFABS: Acta Crystallogr. Sect. A 39 (1983) 158.
[25] TEXSAN: Crystal Structure Analysis Package, Molecular Struc-
ture Corporation, 1985 and 1992.
[5] A. Schmidpeter, in: M. Regitz, O.J. Scherer (Eds.), Multiple
Bonds and Low Coordination in Phosphorus Chemistry,
Thieme, New York, 1990 (Chapter D2).
[26] D.T. Cromer, J.T. Waber, International Tables for X-ray Crys-
tallography, vol. IV, Kynoch Press, Birmingham, 1974 Table
2.2.A.
[6] D. Gudat, Coord. Chem. Rev. 163 (1997) 71.
[27] D.C. Creagh, W.J. McAuley, in: A.J.C. Wilson (Ed.), Interna-
tional Tables for Crystallography, vol. C, Kluwer, Boston, 1992,
pp. 219–222 Table 4.2.6.8.
[28] D.C. Creagh, J.H. Hubbell, in: A.J.C Wilson (Ed.), International
Tables for Crystallography, vol. C, Kluwer, Boston, 1992, pp.
200–206 Table 4.2.4.3.
[7] H. Nakazawa, J. Organomet. Chem. (2000) in press.
[8] (a) H. Nakazawa, M. Ohta, H. Yoneda, Inorg. Chem. 27 (1988)
973. (b) H. Nakazawa, M. Ohta, K. Miyoshi, H. Yoneda,
Organometallics 8 (1989) 638. (c) H. Nakazawa, Y. Yamaguchi,
K. Miyoshi, J. Organomet. Chem. 465 (1994) 193. (d) H.
.