Stereochemically defined metal carbene complexes as chemical probes for studies of the ring formation of 2H-azaphosphirene complexes

Article abstract of DOI:10.1016/S0022-328X(00)00603-3

Strong evidence for a strictly intramolecular rearrangement process leading to 2H-azaphosphirene complex 4 was obtained by reactions of {[amino(phenyl)carbene]pentacarbonyltungsten(0)} (1) with [bis(trimethylsilyl)methylene]chlorophosphane (2) and triethylamine under CO atmosphere; the byproducts, dinuclear carbene complexes 3a,b, were obtained and characterized as E,E- and E,Z-isomers. Reaction of a 5:2 mixture of complexes 3a,b with triethylamine in dichloromethane afforded 2H-azaphosphirene complex 4 and another product 5, which could not be isolated, but showed ³¹P-NMR characteristics of a σ⁴λ⁵-phosphorus center possessing a P-H function. {cis-[ethoxy/amino(aryl)carbene](triorganylphosphane)chromium(0)} and -tungsten(0) complexes 6a,b, 7a,b and 11, 12 were synthesized, 6a and 7b additionally characterized by X-ray crystallography, and reacted also with methylene(chloro)phosphane 2 in the presence of triethylamine, thus yielding cis-2H-azaphosphirene triorganylphosphane complexes 8a,b and 13a,b, which were unambiguously confirmed by NMR spectroscopy. The latter reactions proceeded with cis-stereospecificity. Significant chiral induction was not observed in the reaction leading to 13a,b, and racemization occured, most probably, at the phosphorus of the 2H-azaphosphirene complex. These results provide strong evidence for non-participation of the metal atom center in the ring-closure process giving the three-membered 2H-azaphosphirene ring system.

Full text of DOI:10.1016/S0022-328X(00)00603-3

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 617–618 (2001) 423–434
Stereochemically defined metal carbene complexes as chemical
probes for studies of the ring formation of 2H-azaphosphirene
complexes
Rainer Streubel *, Siegfried Priemer, Jo¨rg Jeske, Peter G. Jones
Institut fu¨r Anorganische und Analytische Chemie der Technischen Uni6ersita¨t Braunschweig, PO Box 3329, D-38023 Braunschweig, Germany
Received 27 July 2000; accepted 24 August 2000
Dedicated to Professor Ernst Otto Fischer on the occasion of his 80th birthday
Abstract
Strong evidence for a strictly intramolecular rearrangement process leading to 2H-azaphosphirene complex 4 was obtained by
reactions of {[amino(phenyl)carbene]pentacarbonyltungsten(0)} (1) with [bis(trimethylsilyl)methylene]chlorophosphane (2) and
triethylamine under CO atmosphere; the byproducts, dinuclear carbene complexes 3a,b, were obtained and characterized as E,E-
and E,Z-isomers. Reaction of a 5:2 mixture of complexes 3a,b with triethylamine in dichloromethane afforded 2H-azaphosphirene
complex 4 and another product 5, which could not be isolated, but showed 31P-NMR characteristics of a s4l5-phosphorus center
possessing a P–H function. {cis-[ethoxy/amino(aryl)carbene](triorganylphosphane)chromium(0)} and -tungsten(0) complexes 6a,b,
7a,b and 11, 12 were synthesized, 6a and 7b additionally characterized by X-ray crystallography, and reacted also with
methylene(chloro)phosphane 2 in the presence of triethylamine, thus yielding cis-2H-azaphosphirene triorganylphosphane
complexes 8a,b and 13a,b, which were unambiguously confirmed by NMR spectroscopy. The latter reactions proceeded with
cis-stereospecificity. Significant chiral induction was not observed in the reaction leading to 13a,b, and racemization occured, most
probably, at the phosphorus of the 2H-azaphosphirene complex. These results provide strong evidence for non-participation of
the metal atom center in the ring-closure process giving the three-membered 2H-azaphosphirene ring system. © 2001 Elsevier
Science B.V. All rights reserved.
Keywords: Aminocarbene complexes; 2H-Azaphosphirene complexes; Phosphorus; Ring-closure; Tungsten
rearranged to 2H-azaphosphirene metal complexes IV
(Scheme 1) [5]. Quite recently, we observed that this
rearrangement was hindered in the case of a chromium
[6] complex or when bulky substituted aryl groups were
bonded to the carbene center [7] and, therefore, we
suggested that steric protection should enhance the
lifetime of such metallaheterobutadiene intermediates
of type III.
These observations increased our interest in two im-
portant questions: (1) is the rearrangement truly in-
tramolecular, meaning the ligand does not dissociate
prior to the formation of the three-membered ring, and
(2) is the P–C-bond formation directed by the transi-
tion metal center as in reductive elimination reactions?
Here, we report on the influence of CO and 13CO
atmosphere on the product formation and also on
preliminary investigations of stereochemical aspects of
1. Introduction
Since the discovery of stable carbene complexes by
Fischer [1], alkoxycarbene metal complexes have re-
ceived widespread interest as powerful synthons in or-
ganic and organometallic synthesis [2]. In recent years
we have studied the reaction of metal carbene com-
plexes with various organophosphorus halides, which,
depending on the organic substituents, led to stable or
unstable O- [3] I or N-organophosphorus-substituted
[4] II metal carbene complexes, bearing s3l3- and/or
s2l3-phosphorus centers. Unexpectedly, complex
derivatives of type III, formed as reactive intermediates,
* Corresponding author. Tel.: +49-531-3915311; fax: +49-531-
3915387.
E-mail address: r.streubel@tu-bs.de (R. Streubel).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00603-3

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R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
Scheme 1. Fischer-type carbene complexes with various C, O, P and C, N, P linkages I–III and 2H-azaphosphirene complexes IV ([M]=metal
complex fragment, R denotes ubiquitous organic substituents).
Scheme 2. Reaction of complex 1 with 2 under CO atmosphere.
the formation of 2H-azaphosphirene metal complexes;
the latter was studied by employing various cis-
[amino(aryl)carbene] triorganylphosphane metal(0)
complexes.
function of the carbene complex 1 to the P–N double
bond. A remarkable finding is also that at −50°C (19
h) the isomers 3a,b were formed in ca. 25:1-ratio,
whereas at higher temperature (−15°C, 1 h) the 3a,b-
ratio was ca. 3:1 (31P-NMR monitoring). Furthermore,
the product at l=26.2 is of interest because of its
phosphorus-proton couplings of 535.6 and 19.5 Hz,
thus pointing to the dinuclear carbene complex 5 with a
s4l5-phosphorus center, possessing a P–H function, as
a bridging unit. The reaction of tungsten carbene com-
plex 1 and methylene(chloro)phosphane 2 under a N2
atmosphere (−50°C, 19 h, otherwise the same reaction
conditions) needed longer reaction times – probably
because of solvent-like effects of dissolved CO in the
other case – (ca. 15% of 2 was unreacted at that time)
and yielded complexes 3a,b as main products (60%,
3a,b-ratio 14:1; 4 (16%)). Finally, 13C-NMR studies on
the ratio of the CH–, the cis-CO and the trans-CO
resonances of 2H-azaphosphirene complex 4 formed
under CO or N2 atmosphere revealed that, in the
former case, no significant amounts of 13CO (uncer-
tainty: B5%) had been incorporated into the W(CO)5
group [11].
2. Results and discussion
Amino(phenyl)carbene tungsten complex 1 [8] was
reacted with the methylene(chloro)phosphane 2 [9] at
−15°C, −30°C and −50°C (slow warm-up) in the
presence of triethylamine under CO atmosphere under
otherwise standard conditions [10] giving, in all cases,
the two dinuclear tungsten carbene complexes 3a,b as
E,E- and E,Z-isomers and the 2H-azaphosphirene
complex 4 [10] as main products (Scheme 2). Together
with 3a,b (ca. 35%) and 4 (ca. 40%), other products
were formed at −50°C in very low quantities at l=
357.5, 353.3 349.8, 330.9, 328.2 and 26.2 (ca. 1–3%;
complete reaction after 19 h); the formation of W(CO)6
could not be detected. This result has several interesting
aspects. First, the 2H-azaphosphirene complex forma-
tion seems to proceed entirely intramolecularly without
dissociation of phosphorus-containing ligands at any
step of the rearrangement. Secondly, the formation of
the complexes 3a,b points, once more, to the intermedi-
acy of a complex of type III with a P–N double bond,
having an increased lifetime at lower temperature, thus
forming the complexes 3a,b by addition of the N–H
By changing the solvent to dichloromethane, com-
plexes 3a,b were obtained, after rapid work-up and
low-temperature column chromatography, by reacting
complex 1 with methylene(chloro)phosphane 2 at 0°C
in the presence of triethylamine. Examination of the
reactivity of a pure 5:2 mixture of complexes 3a,b

R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
425
Scheme 4. Synthesis and reactions of tungsten carbene complexes 7a,b
with 2 and triethylamine.
whereas that of complex 5 decreased, thus reaching a
4:5-ratio of 1:1 after 48 h (Fig. 1); the 4:5-ratio re-
mained unchanged for a longer period of time. There-
fore, we conclude that complex 5 plays a role as
reactive intermediate for formation of the 2H-azaphos-
phirene complex, under these conditions [10]. There
seems however to be also a reaction pathway from
complex 4 to 5, which is not understood at present.
Scheme 3. Reaction of a 3:2 mixture of complexes 3a,b with triethyl-
amine.
towards triethylamine in dichloromethane showed the
formation of complexes 4 and 5 (Scheme 3); unfortu-
nately complex 5 decomposed during column chro-
matography. The 31P-NMR monitoring showed a fast
decrease of complex 3a during the first 90 min. (as
compared to 3b) and a predominant formation of com-
plex 5 (4:5-ratio: 1:6). The situation changed signifi-
cantly after 90 min, because the amounts of
2H-azaphosphirene complex 4 started to increase,
The
cis-amino(aryl)carbene
triphenylphosphane
tungsten complexes 7a,b, synthesized by heating the
ethoxy(aryl)carbene tungsten complexes [10] and
triphenylphosphane in toluene [12] and subsequent am-
monolysis of complexes 6a,b, were reacted with
methylene(chloro)phosphane 2 in dichloromethane at
room temperature, thus giving selectively the cis-2H-
azaphosphirene triphenylphosphane tungsten com-
Fig. 1. 31P-NMR monitoring of the reaction of complexes 3a,b with triethylamine.

426
R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
perature, thus giving the diastereomeric cis-2H-aza-
phosphirene methyl(phenyl)-n-propylphosphane chro-
mium complexes 13a,b and an unknown product at
l=351.9 (ca. 10%) (Scheme 5). After purification, the
former were characterized by NMR spectroscopy as a
1:1 mixture. As in the previous case for 8, the forma-
tion of 13a,b proceeded with cis-stereospecifity (trans-
isomers were not detected), but only a very small
diastereomeric excess was observed by 31P-NMR spec-
troscopy after 1.5 h (ca. 10%). Therefore, we conclude
that the metal atom fragment is not directly involved
in the P–C bond formation. Interestingly, the
diastereomeric excess changed within the next few
hours, reaching an equilibrium after ca. 20 h. This
racemization of the 2H-azaphosphirene phosphorus
centers in 13a,b occurs probably via an intermediate
ring-opening/ring-closure process.
Scheme 5. Synthesis and reactions of chiral chromium carbene com-
plex 12 with 2 and triethylamine.
2.1. Discussion of NMR and X-ray data
plexes 8a,b in good yields (Scheme 4). The formation of
trans-isomers, which should exhibit greater values of
the J(P,P) coupling constants [13], or triphenylphos-
The composition of all complexes was confirmed by
elemental analyses and mass spectrometry and the
structural formulation of the complexes is based on
their characteristic NMR spectral data in solution.
Proof for the structures of the carbene complexes 3a,b
and the triorganophosphane-substituted carbene com-
plexes 6a,b, 7a,b, 11 and 12 is given through the car-
bene and carbonyl carbon atom resonances (Table 1);
the latter were tentatively assigned. The numerical val-
ues are in the typical range of related Fischer-type
carbene complexes [17]. It is very interesting that the
complexes 3a,b display an E,E- (3a) and E,Z-isomerism
(3b) at the C–N bond, thus representing the first exam-
ples of such an isomerism of dinuclear N-phosphanyl
aminocarbene complexes [7]. The phosphorus nuclei of
2
phane-substituted analogs of 3a,b was not observed.
Apart from the cis-stereospecifity of the reaction 7“8,
the latter aspects provide further evidence for a truly
intramolecular rearrangement cascade without dissocia-
tion of ligands.
To examine the possibility of chiral induction, we
reacted the (−)(R)-cis-[amino(phenyl)carbene]methyl-
(phenyl)-n-propylphosphane chromium complex 12,
synthesized by heating the ethoxy(phenyl)carbene
chromium complex 9 [14] and (−)(R)-methyl(phenyl)-
n-propylphosphane [15] (10) in toluene [16] and subse-
quent ammonolysis of complex 11, with methylene-
(chloro)phosphane 2 in dichloromethane at room tem-
Table 1
Selected 13C- and 31P-NMR data of the carbene complexes 6a,b, 7a,b, 11 and 12 a
l
13C
CAO
2JCP
CBO
2JCP
CCO
2JCP
CDO
2JCP
MꢀCR2
2JCP
l
31P
1JPW
6a
6b
7a
7b
11
12
202.8
203.0
204.1
203.7
220.9
221.1
7.0
7.1
7.4
7.2
14.9
14.7
202.8
203.0
204.1
203.7
221.0
221.3
7.0
7.1
7.4
7.2
14.8
14.5
211.8
211.7
211.3
210.8
226.1
228.0
7.4
6.3
6.9
6.2
8.3
6.6
205.6
205.8
208.5
208.2
231.5
229.3
21.8
22.0
25.1
22.8
12.9
12.6
318.3
317.7
269.6
269.0
347.7
293.4
7.5
7.3
6.9
7.1
13.8
12.6
26.4
26.5
27.1
27.3
28.0
30.8
238.0
237.1
235.1
233.2
–
–
a l (ppm), J (Hz), CDCl3; assignment and notation of the carbonyl groups according to the formulae.

R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
427
to those of 6a,b and 7a,b, whereas the 2H-azaphos-
phirene phosphorus nuclei of 8a,b remain unchanged as
compared to their pentacarbonyltungsten complexes
[5,10]. The latter finding is in contrast to the situation
of complexes 13a,b, because the 2H-azaphosphirene
phosphorus nuclei appear at l= −46.1 and −45.1,
respectively, whereas the resonance of the related
pentacarbonylchromium complex was observed at l=
−54.3 [6].
The molecular structures of complexes 6a (Figs. 2
and 3) and 7b (Fig. 4, Table 3) were established by
X-ray diffraction analyses.1 In both cases, two indepen-
dent molecules were found in the unit cell (together
with one molecule of diethyl ether in the case of 6a); in
neither case were significant differences in bond dis-
tances or angles observed. Like {cis-(N-methyl-1,2-
dihydro - benzoxazole - 2 - ylidene)(triphenylphosphane)-
tetracarbonyltungsten(0)} [19] (14), complexes 6a and
7b show distorted octahedral coordination of the tung-
sten atoms and approximately ecliptic conformation of
the carbene group and the neighboring CO groups, as
shown in Fig. 3 for 6a (the shown independent
molecule of 6a is denoted as 6a% in Table 4). A compari-
Fig. 2. Structure of one independent molecule of complex 6a (denoted
as 6a% in Table 4) (hydrogen atoms are omitted for clarity). Selected
bond lengths (pm) and angles (°) of the two independent molecules of
complex 6a: W(1)–C(2) 203.1(8), W(1%)–C(2%) 202.6(9), W(1)–C(5)
204.9(9), W(1%)–C(5%) 206.2(9), C(1)–C(8) 152.2(10), C(1%)–C(8%)
148.3(11); C(1)–W(1)–C(2) 97.7(3), C(1%)–W(1%)–C(2%) 96.4(3), C(1)–
W(1)–C(5) 87.2(3), C(1%)–W(1%)–C(5%) 86.9(3).
Fig. 3. View of complex 6a along the axis C1%–W1% (hydrogen atoms
are omitted for clarity).
Fig. 4. Structure of one independent molecule of complex 7b (ellip-
soids represent 50% probability level). Selected bond lengths (pm)
and angles (°) of the two independent molecules of complex 7b:
W(1)–C(2) 201.0(4), W(1%)–C(2%) 199.4(5), W(1)–C(5) 203.1(4),
W(1%)–C(5%) 204.8(5), C(1)–C(6) 149.4(6), C(1%)–C(6%) 149.8(6); C(1)–
W(1)–C(2) 90.48(17), C(1%)–W(1%)–C(2%) 87.80(17), C(1)–W(1)–C(5)
91.49(17), C(1%)–W(1%)–C(5%) 88.47(18).
3a,b display resonances at l=93.5 (3a) and 109.0 (3b);
the deshielding of the latter resonance probably stems
from an increased steric repulsion in the E,Z-isomer 3b.
It is also remarkable that, in the case of the
triphenylphosphane-substituted complexes, the car-
bonyl atom resonances differentiate completely only if
bulky 2H-azaphosphirenes are ligated (8a,b) (Table 2),
thus pointing to an increased hindrance of the rotation
about the P–W axes. The carbonyl carbon atoms of
complexes 8a,b, which are in trans-position to 2H-aza-
phosphirenes, showed significantly larger phosphorus–
carbon couplings. The triphenylphosphane phosphorus
nuclei of 8a,b display slightly upfield-shifted resonances
1 Structure analysis of 6a and 7b: crystals were mounted in a
perfluoropolyether oil at −100°C on a Siemens P4 diffractometer.
Intensities were registered to 2q 50°. Absorption corrections were
based on psi-scans. The structures were solved by the heavy-atom
method and refined against F2 [18]. Methyl H atoms were included
using rigid groups, all other H atoms with a riding model (exceptions:
solvent methyl for 6a riding, N–H for 7b free with N–H distance
restraints). For further details see Table 3.

Table 2
Selected 13C- and 31P-NMR data of the 2H-azaphosphirene complexes 8a,b and 13a,b a
/
l
13C
CAO
2JCP
CBO
2JCP
CCO
2JCP
CDO
2JCP
l
31PPR3 (2JPP
)
1JPW
l
31PPCN
1JPW
617
8a
8b
200.8
200.8
10.8, 7.6
10.6, 7.6
201.8,
201.8,
10.0, 6.9
10.2, 7.2
203.5
203.6
40.5, 5.3
40.8, 5.7
205.6
205.6
23.6, 4.6
23.7, 4.4
22.9 (33.4)
22.9 (33.5)
237.2
235.9
−108.8
−111.9
284.3
283.0
618
13a,b b
220.6
mc
224.3
mc
226.1
mc
231.0
mc
26.6/27.2
−46.1/−45.1
(47.4)/(46.3)
(
(47.4)/(46.3)
a l (ppm), J (Hz), CDCl3; assignment and notation of the carbonyl groups according to the formulae.
423
b No assignment possible.
4

R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
429
Table 3
Table 5
a
,
Crystal structure analyses of complexes 6a and 7b
Hydrogen bonds (A and °) for compound 6a
Complex
6a·1/2C4H10
O
7b
D–H···A d(D–H) d(H···A) d(D···A) B(DHA)
Formula
Mr
C33H30O5.5PW
729.39
Red prism
0.40×0.30×0.30
Monoclinic
P21/c
C30H24NO4PW
677.32
Yellow prism
0.50×0.25×0.10
Triclinic
C(17%)–H(17%)···O(99)c1 0.95
C(18)–H(18)···O(1)c2 0.95
C(97)–H(97B)···O(3%)c2 0.99
a Symmetry transformations used to generate equivalent atoms:
c1, x−1, y, z; c2, −x+1, y+1/2, −z+3/2.
2.49
2.57
2.60
3.409(11) 161.8
3.499(10) 167.5
3.437(13) 141.9
Crystal habit
Crystal size (mm)
Crystal system
Space group
Unit cell dimensions
a (pm)
b (pm)
c (pm)
h (°)
i (°)
(
P1
2503.6(2)
1246.09(14)
2069.7(2)
90
110.893(6)
90
6.0321(10)
8
1.595
915.2(2)
1668.5(2)
2023.8(3)
112.843(8)
92.344(12)
105.543(12)
2.7071(7)
4
Table 6
a
,
Hydrogen bonds (A and °) for compound 7b
DꢁH···A
d(DꢁH) d(H···A) d(D···A) B(DHA)
k (°)
N(1)ꢁH(01)···O(2%)c1
N(1)ꢁH(02)···O(4)c2
N(1%)ꢁH(01%)···O(2)c1
N(1%)ꢁH(02%)···O(4%)c2
0.84(2) 2.41(4)
0.85(2) 2.14(3)
0.84(2) 2.35(4)
0.84(2) 2.21(3)
3.004(5) 128(4)
2.980(5) 169(5)
3.027(5) 138(4)
3.002(5) 158(4)
V (nm3)
Z
DX (Mg m−3
)
1.662
4.362
v (mm−1
)
3.924
a Symmetry transformations used to generate equivalent atoms:
c1 −x+1, −y+1, −z; c2 x−1, y, z.
Transmissions
F(000)
T (K)
0.67–0.97
2848
173
0.56–1.0
1328
173
2qmax
50
50
tungsten bond length, which decreases upon lengthen-
ing of the W1–C1 bond, or of the C4–W1–C1 angles.
In the packing of compound 6a, the (ordered) ether
molecule accepts a C–H···O hydrogen bond from
C17%–H17%, with CꢁH···O 162° (Table 5). The NH2
group of complex 7b form hydrogen bonds to carbonyl
groups (Table 6).
No. of reflections
Measured
Unique
14 757
10 588
0.0502
712
13 947
9179
0.0222
681
Rint
Parameters
Restraints
wR (F2, all reflections)
R (F, \4|(F))
S
584
498
0.0783
0.0425
0.851
1267
0.0535
0.0247
0.906
904
Max Dz (e nm−3
)
3. Experimental
3.1. General
son of selected bond lengths and angles of complexes
6a, 7b and 14 (Table 4) highlights the most important
stereoelectronic effects on the bonding situations, thus
showing for example the variability of the phosphorus–
All operations were carried out under an inert atmo-
sphere of deoxygenated dry nitrogen. Solvents were
dried according to standard procedures. NMR spectra
Table 4
Selected bond lengths (pm) and angles (°) of the two independent molecules of complexes 6a, 7b and 14 a [19]
Compound
W1–C1
W1–P1
O1–C1
N1–C1
W1–C4
W1–C3
6a
6a%
7b
7b%
14
214.6(8)
217.0(9)
221.7(5)
221.8(4)
219.6(6)
255.02(19)
255.7(2)
251.99(12)
252.39(12)
254.2(2)
133.0(9)
133.8(9)
–
–
–
205.3(10)
204.7(9)
198.1(5)
198.4(5)
198.6(7)
198.8(8)
199.8(9)
202.5(5)
199.9(5)
199.8(8)
130.9(6)
131.1(5)
133.4(9)
–
137.3(8)
C4–W1–C1
C3–W1–P1
C1–W1–P1
O1–C1–W1
N1–C1–W1
X–C1–Y
6a
6a%
7b
7b%
14
170.4(3)
169.9(3)
179.1(2)
176.61(17)
176.12(3)
173.1(2)
172.9(2)
176.59(13)
176.37(13)
179.0(2)
99.1(2)
131.4(6)
131.4(6)
–
–
–
103.2(6)
104.5(7)
109.6(4)
110.9(4)
105.1(5)
100.1(2)
92.86(12)
93.00(11)
88.8(2)
119.8(4)
122.2(3)
135.2(5)
–
119.8(4)
a For the notation see Figs. 2 and 4.

430
R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
were recorded on a Bruker AC-200 spectrometer (200
phases combined and the solvent removed under re-
duced pressure. 13C-NMR spectra were measured of
one sample of the residue dissolved in 0.5 ml of
[d6]benzene and another sample dissolved in 0.5 ml
[d]chloroform.
1
MHz for H; 50.3 MHz for 13C; 81 MHz for 31P) using
[d6]chloroform and [d6]benzene as solvents, the latter as
internal standard; shifts are given relative to tetra-
methylsilane (1H, 13C) and 85% H3PO4 (31P); only
coupling constant magnitudes are given. MS: Finnigan
Mat 8430 (70 eV); selected data given. Elemental analy-
ses: Carlo Erba analytical gas chromatograph. IR: Bio-
rad FT-IR-165; selected data given.
The following compounds were synthesized by the
literature methods: {[amino(phenyl)-carbene]pentacar-
bonyltungsten(0)} [8] (1), [bis(trimethylsilyl)methyl-
ene]chlorophosphane [9] (2), {[ethoxy(phenyl)carbene]-
pentacarbonylchromium(0)} [14] (9) and (−)(R)-
methyl(phenyl)n-propyl-phosphane [15] (10).
3.4. Synthesis of N,N%-bis{amino[(phenyl)carbene]-
pentacarbonyltungsten(0)}bis(trimethylsilyl)-
methyl-phosphane (3a,b)
To a solution of 2.15 g (5 mmol) {[amino(phenyl)-
carbene]pentacarbonyltungsten(0)} (1) in
5 ml of
dichloromethane, 0.63 g (2.8 mmol) of [bis(trimethyl-
silyl)methylene]chlorophosphane (2) and 1.66 ml
(22 mmol) of triethylamine was added at 0°C and
stirred at 0°C for 10 min (31P-NMR). The solvent was
removed under reduced pressure (0.01 mbar), and the
residue extracted with 10 ml of n-pentane (three times)
and subjected to low-temperature column chromatogra-
phy (SiO2, −10°C, n-hexane–diethyl ether, 1:1). Re-
moving the solvents under reduced pressure of the first
yellow–orange fraction yielded complexes 3a,b as an
orange solid. Yield: 1.83 g (1.75 mmol, 70%). M.p.
140°C (decomp.). IR (KBr) w¯ =3300 (w), 3252 (w)
(NH); 2066 (s), 1987(m), 1917(vs) (CO) cm−1. MS (CI,
(NH3, pos), (184W): m/z (%): 1047 (7) [(M+H)+], 991
(3) [(M+H–2CO)+], 914 (42) [(M+H–2CO–Ph)+],
723 (81) [(M+H–W(CO))+], 620 (100) [M+–
(CO)5WꢀC(C6H5)(NH))+], 428 (96) [(M–(CO)5Wꢀ
C(C6H5)(NH)–PCH(SiMe3)2)+]. Calc. for C31H31N2-
O10PSi2W2 (1046.4): C, 35.58; H, 2.99; N, 2.68. Anal.
Found: C, 35.58; H, 2.98; N, 2.56%.
3.2. Procedure for the reaction of complexes 1 and 2
in diethyl ether under CO atmosphere
In an apparatus, consisting of two flasks connected
via a bridge, a solution of 0.43 g (1.0 mmol) of complex
1 and 0.22 g (1.0 mmol) of 2 in 10 ml of diethyl ether
transferred to one and 3.3 ml of triethylamine to the
second flask. The solutions were cooled to −196°C
and the N2 atmosphere was removed at 0.01 mbar and
replaced by CO atmosphere (1 atm). Thereafter the
triethylamine was added to the solution of complexes 1
and 2 at −15°C, −30°C or −50°C and the reaction
mixtures were stirred. After (a) 50 min, (b) 240 min, (c)
940 min, 4 ml of the reaction mixtures were taken,
immediately evaporated to dryness, the residues redis-
solved in 1 ml of diethyl ether and the 31P-NMR
spectra of the samples immediately recorded. As a
control, the same experiments were carried out simulta-
neously under N2 atmosphere.
1
4
3a: H-NMR (CDCl3): l=0.21 (d, 18H, JHP=0.4
2
Hz, Si(CH3)3), 0.48 (d, 1H, JPH=4.1 Hz, PCH), 6.55
(mc, 4H, Ph–H), 7.35 (mc, 6H, Ph–H), 9.66 (s, br, 2H,
NH). 13C{1H}-NMR (CDCl3): l=2.4 (s br, Si(CH3)3),
21.2 (d, 1JCP=48.3 Hz, PCH), 120.1 (s, Ph–C3/3%),
3
128.0 (s, Ph–C4), 128.2 (s, Ph–C2/2%), 152.7 (d, JCP
=
3.3. Procedure for the reaction of complexes 1 and 2
1
11.2 Hz, Ph–C1), 197.8 (s, JCW=128.0 Hz, cis-CO),
203.8 (s, trans-CO), 285.8 (d, JCP=5.8 Hz, WꢀCR2).
in diethyl ether under 13CO atmosphere
2
31P{1H}-NMR (CDCl3): l=93.5 (s).
In an apparatus consisting of two flasks connected
via a bridge, a solution of 0.86 g (2.0 mmol) of complex
1 and 0.45 g (2.0 mmol) of 2 in 20 ml of diethyl ether
transferred to one and 6.6 ml of triethylamine to the
second flask. The solutions were cooled to −196°C
and the N2 atmosphere was removed at 0.01 mbar and
replaced by a 13CO atmosphere (1 atm). Afterwards the
triethylamine was added to the solution of complexes 1
and 2 at ambient temperature and the reaction mixture
was stirred for 20 h. The resulting yellow–orange mix-
ture was evaporated to dryness under reduced pressure
(0.01 mbar) and the residue extracted twice with 40 ml
of n-pentane and filtered. The filtration residue was
washed twice with 5 ml of n-pentane, the organic
1
4
3b: H-NMR (CDCl3): l=0.31 (pt, 18H, JHP=0.9
4
2
Hz, JHP=1.1 Hz, Si(CH3)3), 0.83 (d, 1H, JPH=2.9
Hz, PCH), 7.03 (mc, 4H, Ph–H), 7.35 (mc, 6H, Ph–H),
9.12 (s, br, 1H, NH), 9.69 (s, br, 1H, NH). 13C{1H}-
NMR (CDCl3): l=2.2 (s, Si(CH3)3), 2.3 (s, Si(CH3)3),
20.5 (d, 1JCP=47.9 Hz, PCH), 120.1 (s, Ph–C3/3%),
120.7 (s, Ph–C3/3%), 128.6 (s, Ph–C4), 128.8 (s, Ph–
C2/2%), 128.9 (s, Ph–C2/2%), 129.2 (s, Ph–C4), 152.9 (d,
3
3JCP=9.7 Hz, Ph–C1), 158.3 (d, JCP=8.6 Hz, Ph–
C1), 197.9 (s, 1JCW=127.9 Hz, cis-CO), 197.9 (s,
1JCW=127.9 Hz, cis-CO), 203.7 (s, trans-CO), 281.1 (s,
WꢀCR2), 282.3 (s, WꢀCR2). 31P{1H}-NMR (CDCl3):
l=109.0 (s).

R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
431
3.4.1. Reaction of a 5:2 mixture of E,E- and
E,Z-N,N%-bis{amino[(phenyl)carbene]-
pentacarbonyl-tungsten(0)}bis(trimethylsilyl)-
l=14.8 (s, CH2–CH3), 21.4 (s, p-Ar–CH3), 77.6 (s,
O–CH2), 126.3 (s, p-Tol–C2/2%),128.0 (s, p-Tol–C3/
3%), 128.4 (d, 3JCP=9.4 Hz, PhA–C3/3%), 130.1 (d,
4JCP=1.7 Hz, PhA–C4), 133.3 (d, 2JCP=12.1 Hz,
methylphosphane (3a,b) with triethylamine
1
To 26 mg (0.025 mmol) of 3a,b, dissolved in 0.5 ml of
dichloromethane, 0.2 ml of triethylamine was added at
ambient temperature with stirring. 31P-NMR monitor-
ing showed the formation of complexes 4 and 5 (Fig. 1).
PhA–C2/2%), 135.8 (d, JCP=37.2 Hz, PhA–C1), 140.3
(s, p-Tol–C4), 154.5 (s, p-Tol–C1), 203.0 (d, 2JCP=7.1
Hz, cis-(PPh3, CR2)–CO), 205.8 (d, 2JCP=22.0 Hz,
(cis-CR2, trans-PPh3)–CO), 211.7 (d, 2JCP=6.3 Hz,
(trans-CR2, cis-PPh3)–CO), 317.7 (d, 2JCP=7.3 Hz,
1
3.5. General procedure for the preparation of
{cis-[ethoxy(aryl)carbene]tetracarbonyl-
(triphenylphosphane)tungsten(0)} complexes 6a,b
WꢀCR2). 31P{1H}-NMR (CDCl3): l=26.5 (s, JPW
=
237.1 Hz). MS (70 eV), (184W); m/z (%): 706 (2) [M+],
678 (2) [(M–CO)+], 622 (1) [(M–3CO)+], 594 (1) [(M–
4CO)+], 444 (3) [(M–PPh3)+], 387 (2) [(M–PPh3–CO–
C2H5)+], 275 (3) [(M–PPh3–5CO–C2H5)+], 262 (100)
[PPh+3 ]. Calc. for C32H27O5PW (706.4): C, 54.41; H,
3.85. Anal. Found: C, 54.32; H, 3.78%.
Solutions of 5 mmol of the ethoxy(aryl)carbene tung-
sten complexes and 2.19 g (5.5 mmol) of triphenylphos-
phane in 20 ml of toluene were stirred at 80°C for 6 h
until triphenylphosphane was consumed (31P-NMR).
The solvent was removed under reduced pressure (0.01
mbar), and the residues purified by low-temperature
column chromatography. Phenyl groups at phosphorus
are denoted hereafter as PhA and those at the carbene
atom as PhB.
3.6. General procedure for the preparation of
{cis-[amino(aryl)carbene]tetracarbonyl-
(triphenylphosphane)tungsten(0)} complexes 7a,b
A gentle flow of ammonia was bubbled through a
solution of 5 mmol of the complexes 6a,b in 60 ml of
THF (100 ml three-necked flask) until a yellow colour
persisted and thin liquid chromatography (SiO2, n-hex-
ane/Et2O, 2:1) indicated that all the starting material
had reacted. All volatile compounds were removed
under reduced pressure (0.01 mbar) and the yellow
residues were purified by low-temperature column
chromatography.
3.5.1. {cis-[Ethoxy(phenyl)carbene]-
tetracarbonyl(triphenylphosphane)tungsten(0)} (6a)
A total of 1.66 g of 6a (48%) was obtained as a
dark-red powder after chromatography (SiO2, −10°C;
n-hexane/diethyl ether, 10:1). M.p. 108°C (decomp.).
1H-NMR (CDCl3): l=1.36 (t, 3JHH=7.2 Hz, 3H,
3
CH3), 4.47 (q, JHH=7.2 Hz, 2H, CH2), 7.08 (mc, 2H,
Ph–H), 7.36 (mc, 18H, Ph-H). 13C{1H}-NMR (CDCl3):
l=14.8 (s, CH3), 77.5 (s, CH2), 125.2 (s, PhB–C),
3.6.1. {cis-[Amino(phenyl)carbene]-
2
127.3 (s, PhB–C), 128.4 (d, JCP=9.8 Hz, PhA-C2/2%),
tetracarbonyl(triphenylphosphane)tungsten(0)} (7a)
A total of 2.6 g of 7a (79%) was obtained as a yellow
powder. M.p. 180°C (decomp.). 1H-NMR (CDCl3):
l=7.06 (mc, 2H, Ph–H), 7.36 (mc, 18H, Ph–H), 7.76
(s, br, 1H, NH), 7.92 (s, br, 1H, NH). 13C{1H}-NMR
(CDCl3): l=124.7 (s, PhB–C), 128.6 (s, PhB–C), 128.7
(d, 2JCP=7.2 Hz, PhA–C2/2%), 129.9 (s, PhB–C4),
4
129.4 (s, PhB–C4), 130.1 (d, JCP=1.8 Hz, PhA–C4),
3
1
133.3 (d, JCP=12.0 Hz, PhA–C3/3%), 135.7 (d, JCP
=
=
2
38.7 Hz, PhA–C1), 157.1 (s, PhB–C1), 202.8 (d, JCP
7.0 Hz, cis-CO), 205.6 (d, 2JCP=21.8 Hz,
(trans-PPh3)–CO), 211.8 (d, 2JCP=7.4 Hz, (trans-
2
CR2)–CO), 318.3 (d, JCP=7.5 Hz, WꢀCR2). 31P{1H}-
1
3
NMR (CDCl3): l=26.4 (s, JPW=238.0 Hz). MS (70
130.2 (s, PhA–C4), 133.7 (d, JCP=12.0 Hz, PhA–C3/
eV), (184W); m/z (%): 692 (1) [M+], 664 (4) [(M–CO)+],
608 (3) [(M–3CO)+], 262 (100) [Ph3P+]. Calc. for
C31H25O5PW (692.4): C, 53.77; H, 3.65. Anal. Found:
C, 53.75; H, 3.85%.
5), 136.1 (d, JCP=37.7 Hz, PhA–C1), 153.5 (s, PhB–
1
C1), 204.1 (d, 2JCP=7.4 Hz, cis-CO), 208.5 (d,
2
2JCP=25.1 Hz, (trans-PPh3)–CO), 211.3 (d, JCP=6.9
Hz, (trans-CR2)–CO), 269.6 (d, 2JCP=6.9 Hz,
1
WꢀCR2). 31P{1H}-NMR (CDCl3): l=27.1 (s, JPW
=
3.5.2. {cis-[Ethoxy(p-methylphenyl)carbene]-
235.1 Hz, PPh3). MS (70 eV), (184W); m/z (%): 663 (2)
[M+], 635 (10) [(M–CO)+], 607 (8) [(M–2CO)+], 551
(17) [(M–4CO)+], 262 (100) [Ph3P+]. Calc. for
C29H22NO4PW (663.3): C, 52.51; H, 3.35; N, 2.11.
Anal. Found: C, 52.11; H, 3.32; N, 2.03%.
tetracarbonyl(triphenylphosphane)tungsten(0) (6b)
A total of 6.19 g of 6b (62%) was obtained as a red
powder after chromatography (SiO2, −10°C; n-hex-
ane/diethyl ether, 10:1). M.p. 111°C (decomp.). IR
(KBr) w¯ =2020 (m) cm−1, 1917 (m), 1903 (s), 1885 (s)
(CO). 1H-NMR (CDCl3): l=1.38 (t, 3H, 3JHH=7.1
Hz, CH2–CH3), 2.31 (s, 3H, p-Ar–CH3), 4.52 (q, 2H,
3.6.2. {cis-[Amino(p-methylphenyl)carbene]-
tetracarbonyl(triphenylphosphane)tungsten(0)} (7b)
A total of 2.95 g of 7b (87%) was obtained as a
yellow powder. M.p. 169°C (decomp.). IR (KBr) w¯ =
3437 (m) cm−1, 3331 (m), 3270 (m) (NH), 2004 (m),
3
3JHH=7.1 Hz, O–CH2), 6.94 (d, 2H, JHH=7.3 Hz,
3
p-Tol–H3/3%), 7.01 (d, 2H, JHH=7.5 Hz, p-Tol–H2/
2%), 7.37 (mc, 15H, Ph–H). 13C{1H}-NMR (CDCl3):

432
R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
3
1931 (m), 1911 (s), 1876 (s), 1852 (s), 1839 (s) (CO).
1JCP=38.1, JCP=2.2 Hz, PhA–C1), 190.8 (d, S JCP
=
2
2
1H-NMR (CDCl3): l=2.35 (s, 3H, p-Ar–CH3), 7.03 (d,
1.5 Hz, PCN), 200.8 (dd, JCP=10.8, JCP=7.6 Hz,
cis-(PPh3, PCN)–CO), 201.8 (dd, JCP=10.0, JCP
2
2
3
3
=
2H, JHH=7.3 Hz, p-Tol–H3/3%), 7.12 (d, 2H, JHH
=
2
6.9 Hz, cis-(PPh3, PCN)–CO), 203.5 (dd, JCP=40.5,
2JCP=5.3 Hz, (cis-PPh3, trans-PCN)–CO), 203.5 (dd,
2JCP=23.8, 2JCP=19.2 Hz, (trans-PPh3, cis-PCN)–
7.5 Hz, p-Tol–H2/2%), 7.33 (mc, 15H, Ph–H), 7.65 (s,
br, 1H, NH2), 7.89 (s, br, 1H, NH2). 13C{1H}-NMR
(CDCl3): l=21.3 (s, p-Aryl–CH3), 124.9 (s, Tolyl–C2/
CO). 31P{1H}-NMR (CDCl3): l=22.9 (d, JPP=33.4
2
3
2%), 128.3 (d, JCP=9.5 Hz, PhA–C3/3%), 129.0 (s, Tol–
Hz, 1JPW=237.2 Hz, PPh3), −108.8 (d, 2JPP=33.4 Hz,
1JPW=284.3 Hz, PCN). MS (70 eV), (184W); m/z (%):
M+ was not detected, 262 (100) [PPh+3 ], 103 (52)
[PhCN+], 73 (18) [Me3Si+]; (pos-FAB, m-NBA),
C3/3%), 129.8 (s, PhA–C4), 133.4 (d, 2JCP=12.0 Hz,
1
PhA–C2/2%), 135.7 (d, JCP=37.2 Hz, PhA–C1), 140.2
(s, Tol–C4), 150.3 (s, Tol–C1), 203.7 (d, 2JCP=7.2 Hz,
cis-(PPh3, CR2)–CO), 208.2 (d, 2JCP=2.8 Hz, (cis-CR2,
2
(
184W); m/z (%): M+ was not detected, 748 (6) [(M–
trans-PPh3)–CO), 210.8 (d, JCP=6.2 Hz, (trans-CR2,
PhCN)+], 720 (56) [(M–PhCN–CO)+], 692 (68) [(M–
PhCN–2CO)+], 262 (14) [PPh+3 ], 103 (18) [PhCN+], 73
(100) [Me3Si+]. C36H39NO4P2Si2W (851.7): Calc. Anal.:
C, 50.76; H, 4.63; N, 1.65; Anal. Found: C, 50.52; H,
4.80; N, 1.56%.
cis-PPh3)–CO), 269.0 (d, 2JCP=7.1 Hz, WꢀCR2).-
1
31P{1H}-NMR (CDCl3): l=27.3 (s, JPW=233.2 Hz,
PPh3). MS (70 eV), (184W); m/z (%): 677 (1) [M+], 649
(1) [(M–CO)+], 621 (1) [(M–2CO)+], 586 (1) [(M–
C7H7)+], 565 (3) [(M–4CO)+], 415 (2) [(M–PPh3)+],
262 (100) [PPh3+]. Calc. for C30H24NO4PW (677.4): C,
53.19; H, 3.57; N, 2.07. Anal. Found: C, 53.38; H, 3.57;
N, 2.03%.
3.7.2. {cis-[2-Bis(trimethylsilyl)methyl-3-
(4-methylphenyl)-2H-azaphosphirene-sP]tetracarbonyl
(triphenylphosphane)tungsten(0)} (8b)
A total of 0.83 g of 8b (64%) was obtained as a yellow
powder after chromatography (SiO2, −20°C; n-hexane/
diethyl ether, 15:1). M.p. 118°C (decomp.). IR (KBr)
w¯ =2020 (s) cm−1, 1928 (s), 1899 (vs), 1886 (vs) (CO),
1618 (w) (CN). 1H-NMR (CDCl3): l=0.10 (s, 9H,
3.7. General procedure for the preparation of
cis-(2H-azaphosphirene)(triphenylphosphane) complexes
8a,b
To a solution of 1.5 mmol of complexes 7a,b and
0.34 g (1.5 mmol) of [bis(trimethylsilyl)methylene]-
chlorophosphane (2) in 15 ml of dichloromethane, 5 ml
of NEt3 was added at 0°C. The reaction mixture was
stirred at ambient temperature until 2 was consumed
(31P-NMR). The yellow–orange reaction mixture was
evaporated to dryness under reduced pressure (0.1
mbar). The residue was extracted with 5×50 ml of
n-pentane and filtered. The filtration residue was
washed twice with 5 ml of pentane, the organic phases
combined and the solvent removed under reduced pres-
sure. The residue was purified, if necessary, by low-tem-
perature column chromatography (SiO2, −20°C;
n-hexane/diethyl ether, 15:1).
2
Si(CH3)3), 0.23 (s, 9H, Si(CH3)3), 0.98 (d, 1H, JHP 2.3
Hz, PCH), 2.46 (s, 3H, p-Ar–CH3), 7.36 (mc, 19H,
3
Ar–H). 13C{1H}-NMR (CDCl3): l=1.3 (d, JCP=2.9
3
Hz, Si(CH3)3), 2.3 (d, JCP=2.4 Hz, Si(CH3)3), 21.9 (s,
p-Ar–CH3), 28.3 (d, 1JCP=22.7 Hz, 3JCP=1.5 Hz,
2
PCH), 124.2 (d, JCP=15.3 Hz, p-Tol–C1), 128.0 (d,
3JCP=9.7 Hz, PhA–C3/3%), 129.5 (d, 4JCP=1.3 Hz,
PhA–C4), 129.58, 129.62 (s, p-Tol–C2/2%; s, p-Tol–C3/
2
3%), 133.2 (d, JCP=12.0 Hz, PhA–C2/2%), 135.5 (dd,
3
1JCP=38.6 Hz, JCP=2.0 Hz, PhA–C1), 144.1 (s, p-
Tol–C4), 189.9 (d, 1JCP=1.0 Hz, PCN), 200.8 (dd,
2
2JCP=10.6 Hz, JCP=7.6 Hz, cis-(PPh3, PCN)–CO),
201.8 (dd, 2JCP=10.2 Hz, 2JCP=7.2 Hz, cis-(PPh3,
2
2
PCN)–CO), 203.6 (dd, JCP=40.8 Hz, JCP=5.7 Hz,
2
(cis-PPh3, trans-PCN)–CO), 205.6 (dd, JCP=23.7 Hz,
2JCP=4.5 Hz, (trans-PPh3, cis-PCN)–CO). 31P{1H}-
3.7.1. {cis-[2-Bis(trimethylsilyl)-
methyl-3-phenyl-2H-azaphosphirene-sP]-
1
2
NMR (CDCl3): l=22.9 (d, J(PW)=235.9 Hz, JPP
=
33.5 Hz, PPh3), −111.9 (d, 1J(PW)=283.0 Hz,
2JPP=33.5 Hz, PCN). MS (pos.-CI, (NH3), 184W); m/z
(%): M+ was not detected, 837 (1) [M+–CO], 751 (2)
[(M–3CO–3CH3)+], 587 (3) [(M–C7H7CN–C6H5–
3CO)+], 263 (100) [(PPh3+H)+]. Calc. for
C37H41NO4P2Si2W (865.7): C, 51.33; H; 4.77; N, 1.62.
Anal. Found: C, 51.56; H, 4.86; N, 1.78%.
tetracarbonyl(triphenyl-phosphane)tungsten(0)} (8a)
A total of 0.87 g of 8a (68%) was obtained as a yellow
powder after chromatography (SiO2, −20°C; n-hexane/
diethyl ether, 15:1). M.p. 122°C (decomp.). IR (KBr)
w¯ =2021 (s) cm−1, 1936 (m), 1926 (s), 1909 (vs), 1889
(vs) (CO). 1H-NMR (CDCl3): l= −0.05 (s, 9H,
Si(CH3)3), 0.09 (s, 9H, Si(CH3)3), 0.85 (d, 2JHP=2.7 Hz,
1H, PCH), 7.15–7.69 (mc, 20H, Ph–H). 13C{1H}-NMR
3
(CDCl3): l=1.3 (d, JCP=3.0 Hz, Si(CH3)3), 2.4 (d,
3.8. {(−)(R)-cis-[Ethoxy(phenyl)carbene]-
tetracarbonyl(methyl-phenyl-n-propylphosphane)-
chromium(0)} (11)
1
3
3JCP=3.0 Hz, Si(CH3)3), 28.5 (dd, JCP=22.1, JCP
=
2.0 Hz, PCH), 127.4 (d, 1JCP=15.3 Hz, PhB–C1), 128.2
(s, PhA–C4), 129.3 (d, 3JCP=12.2 Hz, PhA–C2/2%),
129.5, 129.7 (s, PhB–C2/2%, PhB–C3/3%), 133.2 (s, PhB–
A solution of 10.1 g (31.0 mmol) of chromium car-
bene complex 9 and 2.0 g (12.0 mmol) (−)(R)-
3
C4), 133.3 (d, JCP=32.1 Hz, PhA–C3/3%), 135.5 (dd,

R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
433
3
methyl(phenyl)-n-propylphosphane (10) in 60 ml of tol-
uene was heated for 2 h at 45°C, until the phosphane
was consumed (31P-NMR). The toluene was evaporated
under reduced pressure (ca. 0.01 mbar) and the residue
was subjected to twofold low-temperature column chro-
matography (1: SiO2, −10°C, n-hexane–diethyl ether
(10:1); 2: SiO2, −10°C, n-hexane/diethyl ether (10:1)).
The first fraction contained mainly {[ethoxy(phenyl)-
carbene]pentacarbonylchromium(0)} (9) and the second
fraction (red–black) complex 11 (ca. 0.01 mbar); evap-
oration of the solvents yielded slightly impure complex
11 as a red–black oil. Yield approximately 60–65%
(s, C–Ph–C2/2%), 128.4 (d, JCP=8.0 Hz, P–Ph–C3/
2
3%), 128.7 (s, C–Ph–C4, P–Ph–C4), 129.3 (d, JCP
=
8.6 Hz, P–Ph–C2/2%), 137.9 (d, 1JCP=28.8 Hz,
2
P–Ph–C1), 153.1 (s, C–Ph–C1), 221.1 (d, JCP=14.7
Hz, cis-(P(CH3, C3H7, C6H5), CR2)–CO), 221.3 (d,
2JCP=14.5 Hz, cis-(P(CH3, C3H7, C6H5), CR2)–CO),
2
228.0 (d, JCP=6.6 Hz, (cis-CR2, trans-(P(CH3, C3H7,
C6H5)–CO), 229.3 (d, JCP=12.6 Hz, (trans-CR2, cis-
2
2
(P(CH3, C3H7, C6H5)–CO), 293.4 (d, JCP=12.6 Hz,
CrꢀCR2). 31P{1H}-NMR (CDCl3): l=30.8 (s). Optical
rotation (25°C, toluene): [h]578= −87°. MS (EI, 52Cr):
m/z (%): 435 (8) [M+], 407 (4) [(M–CO)+], 379 (4)
[(M–2CO)+], 351 (2) [(M–3CO)+], 323 (100) [(M–
4CO)+], 218 (8) [(Cr(P(CH3,C3H7,C6H5))+], 166 (17)
1
(31P-NMR). H-NMR (CDCl3): l=1.45 (mc, 13H, P–
CH2–CH2–CH3, P–CH3, O–CH2–CH3), 4.09 (q, 2H,
3JHH=6.9 Hz, O–CH2), 6.69 (mc, 2H, C6H5), 7.24 (mc,
8H, C6H5). 13C{1H}-NMR (CDCl3): l=13.6 (d,
1JCP=22.7 Hz, P–CH2–CH2–CH3), 15.0 (s, O–CH2–
CH3), 15.7 (d, 2JCP=12.1 Hz, P–CH2–CH2–CH3),
17.3 (d, 3JCP=4.9 Hz, P–CH2–CH2–CH3), 34.7 (d,
1JCP=21.1 Hz, P–CH3), 73.8 (s, O–CH2–CH3), 121.7
(s, C–Ph–C3/3%), 127.4 (s, C–Ph–C2/2%), 127.9 (s,
C–Ph–C4), 128.4 (d, 3JCP=8.6 Hz, P–Ph–C3/3%),
128.8 (d, 4JCP=1.7 Hz, P–Ph–C4), 129.3 (d, 2JCP=8.8
Hz, P–Ph–C2/2%), 138.7 (d, 1JCP=31.4 Hz, P–Ph–
[P(CH3,C3H7,C6H5)+],
157
(47)
[(M–4CO–
(P(CH3,C3H7,C6H5))+], 124 (11) [(P(CH3,C6H5)H)+],
77 (5) [C6H+5 ], 52 (16) [Cr+]. C21H22CrNO4P (435.4),
HR EI MS (res.: 10 000, 10% Tal-def.): 435.0691
(theor.), 435.069093 (exp.).
3.10. Reaction of {(−)(R)-cis-[amino(phenyl)carbene]-
tetracarbonyl(methyl(phenyl)-n-propylphosphane)-
chromium(0)} (12) with [bis(trimethylsilyl)methylene]-
chlorophosphane (2) in the presence of triethylamine
C1), 153.7 (s, C–Ph–C1), 220.9 (d, 2JCP=14.9 Hz,
To a stirred solution of 600 mg (1.38 mmol) of
{(−)(R) - cis - [amino(phenyl)carbene]tetracarbonyl-
(methyl(phenyl)-n-propylphosphane)chromium(0)} (12)
in 14 ml of dichloromethane 300 mg (1.38 mmol) of
[bis(trimethylsilyl)methylene]chlorphosphane (2) and
6.6 ml (90 mmol) of triethylamine was added at −60°C
and warmed up to room temperature within 17 h. All
volatile compounds were removed under reduced pres-
sure (ca. 0.01 mbar). The residue was extracted with
3×100 ml of n-pentane, filtered and all volatile com-
pounds removed from the filtrate under reduced pres-
sure. The residue was purified by column
chromatography (SiO2, −20°C, n-hexane/diethyl ether,
5:1). Complexes 13a,b were thus obtained as a 1:1
mixture, which was slightly impurified by unknown
compounds (B5%). 13C{1H}-NMR (CDCl3): l=1.3
(d, 3JCP=2.7 Hz, Si(CH3)3), 1.5 (d, 3JCP=2.7 Hz,
Si(CH3)3), 2.37 (s, Si(CH3)3), 2.42 (s, Si(CH3)3), 12.4
(dd, 1JCP=21.4 Hz, 3JCP=2.1 Hz, P–CH2–CH2–
CH3), 13.8 (dd, 1JCP=22.2 Hz, 3JCP=3.6 Hz, P–CH2–
CH2–CH3), 15.6 (d, 2JCP=12.5 Hz, P–CH2–
CH2–CH3), 17.2 (d, 3JCP=4.4 Hz, P–CH2–CH2–
2
cis-(P(CH3, C3H7, C6H5), CR2)–CO), 221.0 (d, JCP
=
14.8 Hz, cis-(P(CH3, C3H7, C6H5), CR2)–CO), 226.1
(d, 2JCP=8.3 Hz, (cis-CR2, trans-(P(CH3, C3H7,
2
C6H5)–CO), 231.5 (d, JCP=12.9 Hz, (trans-CR2, cis-
2
(P(CH3, C3H7, C6H5)–CO), 347.7 (d, JCP=13.8 Hz,
CrꢀCR2). 31P{1H}-NMR (CDCl3): l=28.0 (s).
C23H25CrO5P (464.4).
3.9. {(−)(R)-cis-[Amino(phenyl)carbene]-
tetracarbonyl(methyl(phenyl)-n-propylphosphane)-
chromium(0)} (12)
A gentle flow of ammonia was bubbled through a
solution of 5.0 g (10.8 mmol) of complex 11 in 60 ml of
THF (100 ml three-necked flask) until a bright red
colour persisted and thin layer chromatography (SiO2;
n-hexane/Et2O, 2:1) indicated that all starting material
had reacted. All volatile compounds were removed
under reduced pressure (ca. 0.01 mbar) and the red
residue was purified by column chromatography (SiO2,
n-hexane/Et2O, 2:1). Complex 12 was thus obtained as
a red powder. Yield: 0.85 g (1.95 mmol) 18%. M.p.
118°C (decomp.). IR (KBr): w¯ =3431 (w), 3323 (w),
3249 (w) (NH), 1996 (s), 1896 (s, sh), 1871 (s) (CO)
1
3
CH3), 29.2 (dd, JCP=27.8 Hz, JCP=1.7 Hz, PCH),
34.0 (dd, JCP=20.9 Hz, JCP=2.8 Hz, P–CH3), 35.6
1
3
1
3
(dd, JCP=21.9 Hz, JCP=5.5 Hz, P–CH3), 127.5 (d,
1
cm−1. H-NMR (CDCl3): l=1.43 (mc, 13H, P–CH2–
2JCP=14.9 Hz, Ph), 127.9 (d, 3JCP=8.4 Hz, P–Ph),
2
CH2–CH3, P–CH3), 7.19 (mc, 10H, C6H5), 7.66 (s, br,
1H, NH), 8.10 (s, br, 1H, NH). 13C{1H}-NMR
(CDCl3): l=13.4 (d, 1JCP=22.2 Hz, P–CH2–CH2–
CH3), 15.7 (d, 2JCP=12.0 Hz, P–CH2–CH2–CH3),
17.3 (d, 3JCP=4.5 Hz, P–CH2–CH2–CH3), 34.6 (d,
1JCP=21.3 Hz, P–CH3), 122.7 (s, C–Ph–C3/3%), 128.1
129.4 (d, JCP=9.4 Hz, P–Ph), 129.1 (s, Ph), 129.3 (s,
Ph), 129.4 (s, Ph), 130.9 (s, Ph), 133.2 (s, Ph), 137.5 (d,
1JCP=31.7 Hz, P–Ph), 138.3 (d, JCP=34.0 Hz, P–
1
1
1
Ph), 193.5 (d, JCP=6.0 Hz, PCN), 194.0 (d, JCP=6.0
Hz, PCN), 220.6 (mc, cis-(P(CH3, C3H7, C6H5), PCN)–
CO), 224.3 (mc, cis-(P(CH3, C3H7, C6H5), PCN)

434
R. Streubel et al. / Journal of Organometallic Chemistry 617–618 (2001) 423–434
Pergamon, Oxford, UK, 1995, p. 469. (b) L.S. Hegedus, in E.W.
Abel, F.G.A. Stone, G. Wilkinson (Eds.), Comprehensive
Organometallic Chemistry II, Vol. 12, Pergamon, Oxford, UK,
1995, p. 549. (c) K.H. Do¨tz, P. Tomuschat, Chem. Soc. Rev. 28
(1999) 187.
–CO), 226.1 (mc, (trans-(P(CH3, C3H7, C6H5), cis-
PCN)–CO). 31P{1H}-NMR (CDCl3): l=26.6 (d,
2JPP=47.4 Hz, P(CH3, C3H7, C6H5)), −46.1 (d,
2JPP=47.4 Hz, PCN) and 27.2 (d, 2JPP=46.4 Hz,
P(CH3, C3H7, C6H5)), −45.1 (d, 2JPP=46.4 Hz,
PCN).
[3] (a) H. Fischer, E.O. Fischer, J. Organomet. Chem. 69 (1974) C1.
(b) S. Anderson, D.J. Cook, A.F. Hill, J. Organomet. Chem. 463
(1993) C3. (c) J. Barluenga, G.A. Revelli, F.J. Fan˜ana´s, B.
Sanni, S. Garc´ıa-Granda, Organometallics 16 (1997) 3732. (d) R.
Streubel, M. Hobbold, S. Priemer, J. Organomet. Chem. (in
press).
[4] (a) R. Streubel, M. Hobbold, J. Jeske, F. Ruthe, P.G. Jones, J.
Organomet. Chem. 529 (1997) 351. (b) R. Streubel, M. Hobbold,
J. Jeske, F. Ruthe, P.G. Jones, J. Organomet. Chem. 595 (2000)
12.
[5] R. Streubel, J. Jeske, P.G. Jones, R. Herbst-Irmer, Angew.
Chem. 106 (1994) 115; Angew. Chem. Int. Ed. Engl. 33 (1994)
80.
[6] R. Streubel, F. Ruthe, P.G. Jones, Eur. J. Inorg. Chem. (1998)
571.
4. Supplemenary material
Crystallographic data (excluding structure factors)
for the structures reported in this paper have been
deposited with the Cambridge Crystallographic Data
Centre, CCDC no. 147354 for compound 6a and
CCDC no. 147355 for compound 7b. Copies of this
information may be obtained free of charge from the
Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK (fax: +44-1223-336-033; e-mail: deposit@
ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk).
[7] R. Streubel, S. Priemer, F. Ruthe, P.G. Jones, Eur. J. Inorg.
Chem. (2000) 1253.
[8] G.M. Bodner, S.B. Kahl, K. Bork, B. N: Storhoff, J.E. Wuller,
L.J. Todd, Inorg. Chem. 12 (1973) 1071.
[9] R. Appel, A. Westerhaus, Tetrahedron Lett. 22 (1981) 2159.
[10] R. Streubel, A. Ostrowski, S. Priemer, U. Rohde, J. Jeske, P.G.
Jones, Eur. J. Inorg. Chem. (1998) 257.
Acknowledgements
[11] C.P. Casey, M.C. Cesa, Organometallics 1 (1982) 87.
[12] H. Werner, H. Rascher, Inorg. Chim. Acta 22 (1968) 181.
[13] (a) J.G. Verkade, Coord. Chem. Rev. 9 (1972) 1. (b) P.S.
Pregosin, R.W. Kunz, NMR, Basic Principles and Progress 16
(1979) 1. (c) X.L.R. Fontaine, J.D. Kennedy, B.L. Shaw, J.M.
Vila, J. Chem. Soc. Dalton Trans. (1987) 2401.
[14] E.O. Fischer, H.J. Kollmeier, Chem. Ber. 104 (1971) 1339.
[15] O. Korpiun, R.A. Lewis, J. Chickos, K. Mislow, J. Am. Chem.
Soc. 90 (1968) 4842.
Financial support by the Deutsche Forschungsge-
meinschaft and the Fonds der Chemischen Industrie
and MS measurements by Dr. Hans-Martin Schiebel
(Universita¨t Braunschweig) are gratefully acknowl-
edged.
[16] M.D. Cooke, E.O. Fischer, J. Organomet. Chem. 56 (1973) 279.
[17] K.H. Do¨tz, H. Fischer, P. Hofmann, F.R. Kreissl, U. Schubert,
K. Weiss, in: D. Seyferth (Ed.), Transition Metal Carbene Com-
plexes, Verlag Chemie, Weinheim, 1983.
[18] G.M. Sheldrick, SHELXL-93, Universita¨t Go¨ttingen, Go¨ttingen,
Germany, 1993.
References
[1] E.O. Fischer, A. Maasbo¨l, Angew. Chem. Int. Ed. Engl. 3 (1964)
580.
[2] (a) W.D. Wulff, in E.W. Abel, F.G.A. Stone, G. Wilkinson
(Eds.), Comprehensive Organometallic Chemistry II, Vol. 12,
[19] E. Hahn, M. Tamm, Organometallics 14 (1995) 2597.
.