Mesoionic pyrrolium complexes and dihydropyrroles by cycloaddition of (Non-enolizable) imines to an [(1-alkynyl)carbene]tungsten complex

Article abstract of DOI:10.1002/(SICI)1099-0682(199811)1998:11<1623::AID-EJIC1623>3.0.CO;2-P

Reaction of the [(1-alkynyl)carbene]tungsten complex (CO)₅W=C(OEt)C≡CPh (1a) with non-enolizable imines, e.g. 9-fluorenone imines 2 [NR = N(iPr), N(c-C₆H₁₁)], affords novel mesoionic pyrrolium carbonyltungstates 3 (by [3+2] cycloaddition) together with dihydropyrroles 4 (by dichotomy of the C=N bond and subsequent insertion of the carbene carbon atom into an NC-H bond). Cross-conjugated azametallatrienes 6 and pentacarbonyltungsten complexes 7 of the dihydropyrroles 4 have been identified to be precursors to compound 4. Compounds 3b, 4a, and 6a have been characterized by X-ray crystal structure analyses.

Full text of DOI:10.1002/(SICI)1099-0682(199811)1998:11<1623::AID-EJIC1623>3.0.CO;2-P

FULL PAPER
Organic Syntheses via Transition Metal Complexes, XCVII[᭛]
Mesoionic Pyrrolium Complexes and Dihydropyrroles by Cycloaddition of
(Non-enolizable) Imines to an [(1-Alkynyl)carbene]tungsten ComplexȠ
Rudolf Aumann*, Zhengkun Yu[°], Roland Fröhlich[°°], and Frank Zippel[°°]
Organisch-Chemisches Institut der Universität Münster,
´
Orleans-Ring 23, D-48149 Münster, Germany
Received June 2, 1998
Keywords: (1-Alkynyl)carbene complexes / Pyrroles / Imines / Mesoionic compounds / Tungsten complexes
Reaction of the [(1-alkynyl)carbene]tungsten complex
(CO)5W=C(OEt)CϵCPh (1a) with non-enolizable imines, e.g.
9-fluorenone imines 2 [NR = N(iPr), N(c-C6H11)], affords
carbon atom into an NC–H bond). Cross-conjugated
azametallatrienes 6 and pentacarbonyltungsten complexes 7
of the dihydropyrroles
4 have been identified to be
novel mesoionic pyrrolium carbonyltungstates 3 (by [3+2] precursors to compound 4. Compounds 3b, 4a, and 6a have
cycloaddition) together with dihydropyrroles 4 (by dichotomy
been characterized by X-ray crystal structure analyses.
of the C=N bond and subsequent insertion of the carbene
Reactions of imines with group-VI heteroatom-stabilized hydropyridinyl)carbene complexes (in an overall [4ϩ2]
carbene complexes of the Fischer-type are varied and have cycloaddition initiated by 4-addition) and mesoionic 1-
provided some useful synthetic applications. Depending on azonia-5H-cycloheptatrien-3-yl carbonylmetalates (in an
the type of carbene complex and the imine, nucleophilic overall [4ϩ3] cycloaddition initiated by 2-addition),[6][7] al-
substitution at the carbene carbon atom,[2] condensation at kenyl N( alkyl) -imidates, e.g. RCHϭCHϪC(OEt)NR1 (R,
the α-carbon atom (under thermal conditions) or formation R1 ϭ aryl, alkyl) were found to afford binuclear compounds
of β-lactams[3] (under the influence of sun light) is achieved. as the only products, resulting from a domino [4ϩ2] and
The latter type of reaction has been extensively studied by [2ϩ2] cycloaddition of two equivalents of compound 1.[8]
Hegedus et al., and many N-substituted imines have been Thus, with respect to the addition of α,β-unsaturated imines
converted into β-lactams. Reactions of imines with α,β-un- to (1-alkynyl)carbene complexes 1, it should be noted that
saturated carbene complexes are channeled by competing 4- open-chain adducts as well as four- and five-membered N-
addition of the nitrogen atom to a CϭC (or CϵC) bond, heterocyclic rings are obtained from N-unsubstituted alk-
and by 2-addition to the MϭC, respectively. For example, enyl imidates, whilst bicyclic systems are generated from N-
reactions of NH-ketimines R2CϭNH (R ϭ alkyl, aryl) with substituted alkenyl imidates, and six- and seven-membered
the [(1-alkynyl)carbene]chromium complex (CO)5CrϭC(O- rings are generated from N-substituted alkenylimines (but
Et)CϵCPh (1b) were shown to afford mainly 5-aza-1- supposedly not from N-unsubstituted alkenylimines).
chroma-1,3,5-hexatrienes (CO)5CrϭC(OEt)CHϭC(Ph)Nϭ
CR2 by 4-addition.[4] Alkenyl NH-imidates R2CHϭ
CR1ϪC(OEt)ϭNH (R1, R2 ϭ Ph, Me, H) and (1-alkynyl)-
Reaction of (1-Alkynyl)carbene Complex 1a with Non-
enolizable Imines 2
carbene complexes 1a, b (M ϭ W, Cr) were found to pro-
duce 5-aza-1-metalla-1,3,5,7-octatetraenes (CO)5MϭC(O-
Et)ϪCRϭCRϪNϭC(OEt)ϪCR1ϭCHR2 (R ϭ alkyl, aryl)
by 4-addition, but also 2,5-diethoxy-2H-pyrrole and 2,4-di-
The investigation of fundamental reaction paths of im-
ethoxy-2H-dihydroazete complexes, both of which by 2-ad- ines and imidates with (1-alkynyl)carbene complexes 1 was
dition (in an overall [3ϩ2] and [2ϩ2] cycloaddition, respec- extended to aliphatic compounds. It was found that enoliz-
tively).[5] Furthermore, reactions of both alkenyl N( alkyl) - able imidates, e.g., O-alkyl lactims ϳ(CH2)nϪNϭC(OR)ϳ
imines, and -imidates, respectively, involve participation of (n ϭ 3Ϫ6) and (1-alkynyl)carbene complexes 1a, b gave 1-
the alkenyl unit, but lead to different types of products with azacycloalkene derivatives as the main products, involving
(1-alkynyl)carbene complexes 1a, b. Whilst the alkenyl the transfer of an α-hydrogen atom.[1] Focusing more
N( alkyl) -imines, e.g. PhCHϭCHϪCHϭN(iPr) yield (di- strongly on the reactivity of the CϭN bonds in aliphatic
systems, it was envisaged that non-enolizable imines might
[᭛] Part XCVI: Ref.[1]
.
yield pyrrolium (ϭ azoniacyclopentadiene) complexes by
[3ϩ2] cycloaddition of a C3 unit of compounds 1 to the Cϭ
N bond (Scheme 1). This reaction mode was anticipated as
an extension of the recently described access to cyclopen-
[°] On leave of absence from Dalian Institute of Chemical Physics,
Chinese Academy of Sciences, P. O. Box 110, 116023 Dalian,
China.
[°°] X-ray structure analyses.
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
1434Ϫ1948/98/1111Ϫ1623 $ 17.50ϩ.50/0
1623

R. Aumann, Z. Yu, R. Fröhlich, F. Zippel
FULL PAPER
tadienes by [3ϩ2] cycloaddition of (1-alkynyl)carbene com- similar to that found for iminium carbonylmetalates[10] de-
plexes to HCϭC(N) bonds.[9]
rived from vinylogous seven-membered N-heterocyclic li-
gands[7] (WϪC: δ ϭ 181.9).[6c] Furthermore, the signal of
CϭNϩ is appreciably shifted downfield (3a: δ ϭ 198.2; 3b:
δ ϭ 197.3) if compared to a normal CϭN bond. Com-
pounds 3 are first representatives of a (supposedly) large
group of mesoionic pyrrolium complexes, which, like syd-
nones and related species,[11] can not be satisfactorily de-
scribed by Lewis formulas excluding charge separation. In
line with expectation, compounds 3 were found to undergo
hydrolysis of the enol ether unit with formation of a spiro
compound 5 as the only detectable product, in addition to
W(CO)6 (Scheme 3).
Scheme 1. [3ϩ2] Cycloaddition of [(1-alkynyl)carbene]tungsten
complex 1a to olefines and imines, respectively
Scheme 3. Hydrolysis of zwitterionic pyrrolium complexes 3
Reaction of the (1-alkynyl)carbene complex 1a with non-
enolizable imines, like fluorenone imines 2a, b at 90°C, 2 h,
molar ratio 1:1, affords two types of compounds in a clean
reaction: (a) novel pyrrolium complexes 3a, b as minor and
(b) dihydropyrroles 4a, b as major products (Scheme 2).
Compounds 3 and 4 were isolated by chromatography on
silica gel and characterized spectroscopically as well as by
X-ray crystal structure analyses. Whilst it is quite obvious
that compounds 3 are generated in an overall [3ϩ2] cyclo-
addition as outlined above (Scheme 1), formation of com-
pounds 4 seems to involve a more complicated reaction se-
quence (v.s.).
Structural details of spiro compounds 3 are based on a
crystal structure analysis of compound 3b (Figure 1, Table
1). The distance WϪC4 [2.276(4)] A is longer than in
˚
non-heteroatom (carbene)tungsten complexes, such as
(CO)5WϭCPh2 [2.15(1)][12] and even longer than in pyryl-
ium pentacarbonyltungstates, e.g. 2.193(5).[13] In line with
the mesoionic character of compound 3b is the pattern of
alternating bond lengths found in the N-heterocyclic ring
[NϪC2 1.474(5), C2ϪC3 1.517(5), C3ϪC4 1.357(5),
Scheme 2. Two different routes to pyrrole derivatives from non-
enolizable imines 2 and (1-alkynyl)carbene complex 1a
˚
C4ϪC5 1.434(6), C5ϪN 1.324(5) A] and an essentially
planar arrangement of the bonds to the nitrogen atom (sum
of valence angles is 360.0°). The plane defined by the five-
membered heterocycle bisects the angle between two
neighboring carbonyltungsten groups, C3ϪC4ϪWϪC41
Ϫ37.5 (4)°, and is arranged almost perpendicular to the
phenyl group, C4ϪC5ϪC50ϪC51 97.6 (5)°.
Figure 1. Molecular structure of the mesoionic pyrrolium complex 3b
2؊4
R,R
[3] ϩ [4] [3]/[4]
a
b
Me,Me
93%
1:8
2:7
Ϫ[CH2]4Ϫ 89%
Spectroscopy and Structure Determinations
The mesoionic character of the novel pyrrolium com-
pounds 3 is indicated in its 13C-NMR spectrum by a
characteristic upfield shift of the signal WϪC(ring) (3a: δ ϭ
The structure of the dihydropyrroles 4a, b is based on
3
187.9; 3b: δ ϭ 187.3), which now is observed in a range the 1J-, 2J-, and J(13C,1H) coupling constants in the NMR
1624
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629

Organic Syntheses via Transition Metal Complexes, XCVII
FULL PAPER
˚
Reaction Course
Table 1. Selected bond lengths [A] and angles [°] for pyrrolium
compound 3b
Since there is ample precedence for reactions of (1-alkyn-
yl)carbene complex (CO)5WϭC(OEt)CϵCPh (1a) with ni-
trogen bases N (and also phosphanes) to form zwitterionic
adducts Ϫ(OC)5WϪC(OEt)ϭCϭC(Ph)Nϩ as initial prod-
ucts,[14] it is suggested for the present case that an inter-
mediate A might be generated from addition of an imine 2
to the (1-alkynyl)carbene complex 1a. A zwitterionic species
A might act as precursor to both a five-membered cycload-
duct 3 and a four-membered dihydroazete derivative B
(Scheme 4).
N(1)ϪC(5)
N(1)ϪC(2)
N(1)ϪC(10)
C(2)ϪC(3)
C(2)ϪC(20)
C(2)ϪC(30)
C(3)ϪO(3)
C(3)ϪC(4)
C(4)ϪC(5)
C(4)ϪW
1.324(5)
1.474(5)
1.485(5)
1.517(5)
1.521(6)
1.535(6)
1.331(5)
1.357(5)
1.434(6)
2.276(4)
1.488(5)
1.434(5)
1.496(7)
N(1)ϪC(2)ϪC(3)
N(1)ϪC(2)ϪC(20)
C(3)ϪC(2)ϪC(20)
N(1)ϪC(2)ϪC(30)
C(3)ϪC(2)ϪC(30)
C(20)ϪC(2)ϪC(30)
O(3)ϪC(3)ϪC(4)
O(3)ϪC(3)ϪC(2)
C(4)ϪC(3)ϪC(2)
C(3)ϪC(4)ϪC(5)
C(3)ϪC(4)ϪW
100.5(3)
112.8(3)
117.0(3)
112.7(3)
112.4(3)
102.0(3)
121.9(4)
125.1(3)
112.8(3)
103.3(3)
123.7(3)
132.1(3)
114.6(3)
122.6(4)
122.7(4)
123.7(4)
C(5)ϪC(50)
O(3)ϪC(310)
C(310)ϪC(311)
C(5)ϪC(4)ϪW
N(1)ϪC(5)ϪC(4)
N(1)ϪC(5)ϪC(50)
C(4)ϪC(5)ϪC(50)
C(3)ϪO(3)ϪC(310)
Scheme 4. Competing [3ϩ2] and [2ϩ2] cycloadditions of (1-alky-
nyl)carbene complex 1a to the CϭN bond of non-enoli-
zable imines 2
C(5)ϪN(1)ϪC(2)
108.7(3)
C(5)ϪN(1)ϪC(10) 132.5(3)
C(2)ϪN(1)ϪC(10) 118.8(3)
O(3)ϪC(310)ϪC(311) 107.0(4)
N(1)ϪC(2)ϪC(3)
100.5(3)
spectra, as well as on a crystal structure analysis of com-
pound 4a (Figure 2, Table 2). The N-heterocyclic ring exhi-
bits the expected pattern of bond lengths [C1ϪC2 1.514(3),
C2ϪC3 1.554(4), C3ϪN4 1.489(3), N4ϪC5 1.291(3),
˚
C1ϪC5 1.481(3) A] and is slightly twisted against the fluor-
enylidene unit, C5ϪC1ϪC6ϪC7 18.0 (4)°.
Figure 2. Molecular structure of the dihydropyrrol 4a
It is suggested that dihydroazetes B would be key inter-
mediates en route to dihydropyrroles 4. This assumption is
supported by the fact that organometallic intermediates 6
and 7 could be isolated and characterized.
Organometallic Reaction Intermediates
Reaction of (1-alkynyl)carbene complex 1a with fluor-
enone imines 2 at 20°C (instead of 90°C, as it has been
applied for the reaction given in Scheme 2), affords two
colored compounds 6 and 7, which were isolated by column
chromatography on silica gel (Scheme 5). It could be easily
demonstrated that the azametallatriene unit of compounds
6 in solution undergoes a thermally induced ring closure to
give dihydropyrroles 7, from which finally pyrroles 4 and
W(CO)6 are obtained as the only products.
˚
4a
Table 2. Selected bond lengths [A] and angles [°] for dihydropyrrole
Scheme 5. Organometallic intermediates en route to dihydropyrro-
les 4
C(1)ϪC(6)
C(1)ϪC(5)
C(1)ϪC(2)
C(2)ϪO(2)
C(2)ϪC(3)
O(2)ϪC(21)
C(21)ϪC(22)
C(3)ϪN(4)
C(3)ϪC(31)
C(3)ϪC(32)
N(4)ϪC(5)
C(5)ϪC(51)
1.352(3)
1.481(3)
1.514(3)
1.428(3)
1.554(4)
1.428(3)
1.503(4)
1.489(3)
1.522(4)
1.528(4)
1.291(3)
1.477(3)
O(2)ϪC(2)ϪC(1)
O(2)ϪC(2)ϪC(3)
C(1)ϪC(2)ϪC(3)
C(21)ϪO(2)ϪC(2)
115.5(2)
114.6(2)
100.4(2)
115.5(2)
O(2)ϪC(21)ϪC(22) 109.4(2)
N(4)ϪC(3)ϪC(31)
N(4)ϪC(3)ϪC(32)
C(31)ϪC(3)ϪC(32) 110.0(2)
N(4)ϪC(3)ϪC(2)
C(31)ϪC(3)ϪC(2)
C(32)ϪC(3)ϪC(2)
C(5)ϪN(4)ϪC(3)
N(4)ϪC(5)ϪC(51)
N(4)ϪC(5)ϪC(1)
C(51)ϪC(5)ϪC(1)
110.7(2)
108.3(2)
104.0(2)
113.9(2)
109.8(2)
108.9(2)
119.9(2)
113.2(2)
126.0(2)
yield [%]
yield [%]
C(6)ϪC(1)ϪC(5)
C(6)ϪC(1)ϪC(2)
C(5)ϪC(1)ϪC(2)
131.0(2)
124.8(2)
103.5(2)
3a
4a
6a
7a
11
48
30
Ϫ
3b
4b
6b
7b
20
35
13
4
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629
1625

R. Aumann, Z. Yu, R. Fröhlich, F. Zippel
FULL PAPER
Cross-Conjugated Azametallatrienes 6
Structural characterization of compound 7b is based on
NMR spectra. The sets of 13C- and 1H-NMR signals of
dihydropyrrole 4b and its pentacarbonyltungsten derivative
7b are quite similar. Characteristic downfield shifts are ob-
served for the signals CϭN (4b: δ ϭ 170.2; 7b: δ ϭ 179.2)
and CϪN (4b: δ ϭ 77.1; 7b: δ ϭ 83.3).
Since the signal of the WϭC group in the 13C-NMR
spectra of compounds 6 (6a: δ ϭ 321.8; 6b: δ ϭ 321.2) is
observed in a range typical of non-conjugated (carbene)-
tungsten complexes, e.g. (CO)5WϭC(OEt)Me (δ ϭ 319.6),
little or no π-conjugation is expected within the WϭCϪCϭ
C moiety. Furthermore, π-conjugation is not expected to be
effective within the CϭCϪCϭN group, since the CϭN sig-
nal (6a: δ ϭ 157.9; 6b: δ ϭ 157.8) appears in the normal
range. Strong distortion from planarity of the WϭCϪCϭ
C as well as of the CϭCϪCϭN unit [WϪC1ϪC2ϪC3
Ϫ109.0(3), N28ϪC21ϪC2ϪC3 Ϫ94.0(4)°] is confirmed by
an X-ray structure analysis of compound 6a (Figure 3,
Table 3). It should be noted that the structural features of
the MϭCϪC(ϭC)ϪCϭN backbone in compound 6a are
unique and different from that of other cross-conjugated
This work was supported by the Volkswagen-Stiftung and the
Fonds der Chemischen Industrie. Experimental assistance by Bar-
bara Hildmann is gratefully acknowledged.
Experimental Section
All operations were performed under argon. Dried solvents were
used in all experiments. Ϫ Melting points are not corrected. Ϫ In-
strumentation: 1H- and 13C-NMR spectra were obtained with
Bruker WM 300, WP 360 and Varian U 600 spectrometers (multi-
plicities were determined by DEPT. Chemical shifts refer to δTMS ϭ
1
0.00. 13C shifts were assigned on the basis of J(CH) and 2,3J(CH)
azametallatrienes,
e.g.
(CO)5WϭC(OEt)ϪC(ϭ
CHNC4H8)ϪC(Ph)ϭNPh,[15] in which partial planaris-
ation of the (CO)5WϭCϪCϭC(N) portion of the ligand is
achieved by π-electron delocalization. Rapid equilibration
of diastereomers by rotation about the C1ϪC2 bond of 6a
correlation experiments). Low-temperature NMR measurements
were carried out with Bruker AM 360 instrument. Ϫ Other analy-
ses: IR Diglab FTS 45; MS Finnigan MAT 312; elemental analysis,
Perkin-Elmer 240 elemental analyzer; TLC, Merck DC-Alufolien
Kieselgel 60 F254. Rf values refer to TLC tests. Ϫ Column-chroma-
tographic purifications were made on Merck Kieselgel 100.
1
is indicated by dynamic line-broadening of the H-NMR
signals of the diastereotopic OCH2 group at 20°C.
( Fluoren-9-ylidene) alkylamine (2) was obtained in high yields by
condensation of 9-fluorenone (1.80 g, 10 mmol) with the corre-
sponding amine (10 mmol) in 30 ml of pentane and 15 g of molecu-
Figure 3. Molecular structure of the cross-conjugated azametalla-
˚
triene 6a
lar sieves (Acros, 4 A) at 20°C, 24 h, and were purified by distil-
lation prior to use.
Pentacarbonyl[ 5-( 2,2Ј-biphenylene) -4-ethoxy-1-isopropyl-2-
phenyl-1-azoniacyclopenta-1,3-dien-3-yl] tungstate (3a), 3-Ethoxy-4-
( fluoren-9-ylidene) -2,2-dimethyl-5-phenyl-3,4-dihydro-2H-pyrrole
(4a),
Pentacarbonyl[ 1-ethoxy-2-( fluoren-9-ylidene) -3-( isopropyl-
imino) -3-phenylprop-1-ylidene] tungsten (6a): To pentacarbonyl(1-
ethoxy-3-phenyl-2-propyn-1-ylidene)tungsten (1a) (482 mg 1.00
mmol) in a 3-ml screw-top vessel is added (fluoren-9-ylidene)isop-
ropylamine (2a) (221 mg, 1.00 mmol) in 3 ml of toluene. The mix-
ture is shaken until homogeneity (ca. 3 min). After ca. 5 min at
20°C, a dark oil begins to precipitate which consists of compound
3a and W(CO)6. After compound 1a is consumed completely (ca.
2 d at 20°C according to TLC), the supernatant is decanted and
the solid washed with n-pentane (3 ϫ 1 ml). The solution is sepa-
rated by chromatography on silica gel. Elution with pentane/di-
chloromethane (2:1) affords a brown fraction with compound 6a
(Rf ϭ 0.4 in pentane/dichloromethane, 2:1, 215 mg, 30%, brown
crystals from pentane at Ϫ40°C, mp 102°C). Elution with diethyl
ether affords a yellow fraction of compound 4a (180 mg, 48%, Rf ϭ
0.8 in diethyl ether, yellow crystals from cyclohexane/dichlorometh-
ane (4:1) at Ϫ78°C, mp 106°C). The solid residue of the reaction
mixture (ca. 240 mg) is dissolved in dichloromethane (ca. 3 ml).
W(CO)6 is removed by crystalization at Ϫ15°C and compound 3a
is obtained from the mother liquor at 20°C after addition of pen-
tane (2 ml) (ca. 78 mg, 11%, amber-colored crystals). If 1a (52 mg,
0.11 mmol) and 2a (22 mg, 0.10 mmol) in 1 ml of C6D6 are heated
˚
Table 3. Selected bond lengths [A] and angles [°] for cross-conju-
gated azametallatriene 6a
WϪC(1)
2.180(3)
1.309(4)
1.504(4)
1.351(4)
1.520(4)
1.270(4)
1.493(4)
1.474(4)
1.519(6)
1.521(5)
1.459(4)
1.43(2)
O(16)ϪC(1)ϪW
130.0(2)
125.3(2)
123.2(2)
123.0(2)
113.7(2)
117.7(2)
124.0(2)
118.3(2)
122.5(3)
108.3(3)
107.1(3)
112.6(4)
123.3(3)
111.4(12)
106.5(11)
C(1)ϪO(16)
C(1)ϪC(2)
C(2)ϪC(3)
C(2)ϪC(1)ϪW
C(3)ϪC(2)ϪC(1)
C(3)ϪC(2)ϪC(21)
C(1)ϪC(2)ϪC(21)
N(28)ϪC(21)ϪC(22)
N(28)ϪC(21)ϪC(2)
C(22)ϪC(21)ϪC(2)
C(21)ϪN(28)ϪC(29)
N(28)ϪC(29)ϪC(31)
N(28)ϪC(29)ϪC(30)
C(31)ϪC(29)ϪC(30)
C(1)ϪO(16)ϪC(17)
C(18B)ϪC(17)ϪO(16)
C(18A)ϪC(17)ϪO(16)
C(2)ϪC(21)
C(21)ϪN(28)
C(21)ϪC(22)
N(28)ϪC(29)
C(29)ϪC(31)
C(29)ϪC(30)
O(16)ϪC(17)
C(17)ϪC(18B)
C(17)ϪC(18A)
1
to 90°C for 2 h the H-NMR spectrum of the solution shows sig-
nals of compounds 4a and 3a in a molar ratio of 8:1 as the only
products. Removal of the solvent gives a residue of 39 mg, which
corresponds to 82% of compound 4a and 11% of compound 3a.
1.45(2)
1
3a: H NMR (C6D6, 600 MHz): δ ϭ 7.33, 7.26 and 7.18 (2:2:1
H; “d”, “t”, “t”; Ph), 7.30 (2 H, d, 4Ј-H and 5Ј-H), 7.10 (2 H, t,
3Ј-H and 6Ј-H), 7.05 (2 H, d, 1Ј-H and 8Ј-H), 6.95 (2 H, t, 2Ј-H
O(16)ϪC(1)ϪC(2) 104.7(2)
1626
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629

Organic Syntheses via Transition Metal Complexes, XCVII
FULL PAPER
and 7Ј-H), 3.29 and 0.70 (2:3 H; q and t, OCH2CH3), 2.73 (1 H,
6a: 1H NMR (C6D6): δ ϭ 8.40 (2 H, s broad, o-H Ph); 7.71,
quint, NCH), 0.18 [6 H, d, CH(CH3)2]. Ϫ 13C NMR (C6D6): δ ϭ 7.56, 7.39 and 7.29 (1 H each, “d” each; 1Ј-H, 4Ј-H, 5Ј-H and 8Ј-
204.8 and 201.8 [1:4, Cq each, cis- and trans-CO W(CO)5], 198.2
(Cq, C2), 187.9 (Cq, C3), 142.8 (2 Cq, C8aЈ and C9aЈ), 137.3 (2 Cq,
C4aЈ and C4aaЈ), 136.0 (Cq, i-C Ph), 135.8 (Cq, C4), 130.9 (2 CH,
C2Ј and C7Ј), 130.3 (p-CH Ph), 129.8 (2 CH, C3Ј and C6Ј), 128.1
H); 7.16, 7.10, 6.89 and 6.59 (1 H each, “t” each; 2Ј-H, 3Ј-H, 6Ј-H
and 7Ј-H), 7.00 (3 H, m broad, m- and p-H Ph), 4.81 (1 H, sept,
NCH), 4.78 and 4.26 (1 H each, m broad each, OCH2), 1.19 and
1.17 [6 H, d, C(CH3)2], 1.03 (3 H, t, OCH2CH3). Ϫ 13C NMR
(2 m-CH Ph), 127.8 (2 o-CH Ph), 124.5 (2 CH, C1Ј and C8Ј), 121.6 (C6D6): δ ϭ 321.8 (Cq, WϭC), 203.4 and 196.8 [1:4, Cq each, trans-
(2 CH, C4Ј and C5Ј), 84.2 (Cq, C5 ϵ C9Ј), 65.9 (OCH2), 50.8 and cis-CO, W(CO)5], 157.9 (Cq, CϭN, C3), 152.2 (Cq, C9Ј); 144.6,
(NCH), 22.4 [C(CH3)2], 14.8 (OCH2CH3). Ϫ IR (diffuse reflec-
142.3, 141.8, 137.7, 137.0, and 134.7 (Cq each, C2, C4aЈ, C4aaЈ,
tion): ν˜ [cmϪ1 (%)] ϭ 2048.5 (30), 1975.0 (10), 1950.4 (20), 1895.2 C8aЈ, C9aЈ, and i-C Ph); 130.8, 129.9 (2 C), 129.7, 129.5, 128.7 (2
(100), 1858.5 (80) [ν(CϵO)]. Ϫ C32H25NO6W (703.4): calcd. C
54.64, H 3.58, N 1.99; found C 54.61, H 3.69, N 2.05.
C), 127.8, 127.3, 127.0, 126.9, 120.5, and 120.1 (CH each, fluorene
and Ph), 81.2 (OCH2), 53.8 (NCH), 25.5 and 24.1 [C(CH3)2], 13.6
(OCH2CH3). Ϫ IR (hexane): ν˜ [cmϪ1 (%)] ϭ 2072.0 (35), 1994.7
(10), 1964.8 (60), 1945.0 (100) [ν(CϵO)]. Ϫ MS (70 eV); m/z 184W
(%): 703 (1) [Mϩ], 647 (1) [Mϩ Ϫ 2 CO], 619 (3) [Mϩ Ϫ 3 CO],
563 (2) [Mϩ Ϫ 5 CO], 504 (2), 463 (2), 379 (100) [Mϩ Ϫ W(CO)5],
350 (35), 322 (6), 265 (65), 180 (10), 165 (25), 111 (15), 104 (75),
83 (35), 71 (55), 57 (80). Ϫ C32H25NO6W (703.4): calcd. C 54.64,
H 3.58, N 1.99; found C 54.63, H 3.70, N 2.00.
1
3
4a: H NMR (C6D6, 600 MHz): δ ϭ 8.49 (1 H, d, J ϭ 7.7 Hz,
8Ј-H), 7.85 and 7.04 (2:3 H, broad each, Ph), 7.45 (1 H, d, 3J ϭ
3
3
7.4 Hz, 1Ј-H), 7.35 (1 H, d, J ϭ 7.5 Hz, 5Ј-H), 6.87 (1 H, d, J ϭ
7.9 Hz, 4Ј-H); 7.24, 7.18, 7.08, and 6.90 (1 H each, t each, 2Ј-H,
3Ј-H, 6Ј-H and 7Ј-H), 5.07 (1 H, s, 3-H), 3.52 and 3.34 (1:1 H, m
each, OCH2), 1.68 and 1.12 [3:3 H, s each, C(CH3)2], 1.02 (3 H, t,
OCH2CH3). Ϫ 13C NMR (C6D6): δ ϭ 170.2 (Cq, CϭN, C5), 141.9
and 141.8 (Cq each, C4 and C9Ј), 140.4 (Cq, C8aЈ), 140.1 (Cq,
C9aЈ), 138.4 (Cq, C4aaЈ), 136.6 (Cq, C4aЈ), 136.3 (Cq, i-C Ph); 130.1
(2 C), 129.7, 129.2, 128.9, 128.8 (2 C, broad), 128.1 (2 C), 126.64,
126.63, 119.9 and 119.6 (CH each, fluorene and Ph), 90.6 (CH,
C3), 74.4 (Cq, C2), 62.3 (OCH2), 27.8 and 22.9 [C(CH3)2], 15.8
(OCH2CH3). Ϫ MS (70 eV); m/z (%): 379 (100) [Mϩ], 350 (30) [Mϩ
Ϫ Et], 332 (5), 322 (5), 265 (70) [Mϩ Ϫ NCMe2 Ϫ HCOEt], 215
(5), 165 (10) [fluorenyl], 146 (10), 104 (50), 58 (15). Ϫ C27H25NO
(379.5): calcd. C 85.45, H 6.64, N 3.69; found C 85.53, H 6.55,
N 3.85.
X-ray Crystal Structure Analysis of 6a:[16] Formula
C32H25NO6W, M ϭ 703.38, 0.30 ϫ 0.30 ϫ 0.10 mm, a ϭ 9.962(2),
˚
b ϭ 12.281(2), c ϭ 12.929(2) A, α ϭ 88.20(1), β ϭ 85.64(2), γ ϭ
3
66.31(1)°, V ϭ 1444.3(4) A , ρcalcd. ϭ 1.617 g cmϪ3, µ ϭ 40.43
˚
cmϪ1, empirical absorption correction with φ-scan data (0.788 Յ
¯
C Յ 0.999), Z ϭ 2, triclinic, space group P1 (No. 2), λ ϭ 0.71073
˚
A, T ϭ 293 K, ω/2θ scans, 6134 reflections collected (±h, ±k, ϩl),
[(sinθ)/λ] ϭ 0.62 AϪ1, 5861 independent and 5338 observed reflec-
˚
tions [I Ն 2 σ(I)], 375 refined parameters, R ϭ 0.020, wR2 ϭ 0.052,
max. residual electron density 1.02 (Ϫ0.90) e AϪ3, C18 refined as
˚
splitted atom, hydrogen atoms calculated and refined as riding
atoms.[17]
Pentacarbonyl[ 5-( 2,2Ј-biphenylene) -1-cyclohexyl-4-ethoxy-2-
phenyl-1-azoniacyclopenta-1,3-dien-3-yl] tungstate (3b), 3-Ethoxy-4-
( fluoren-9-ylidene) -2-pentamethylene-5-phenyl-3,4-dihydro-2H-
pyrrole (4b), Pentacarbonyl[ 1-ethoxy-3-cyclohexylimino-2-( fluoren-
9-ylidene) -3-phenylprop-1-ylidene] tungsten (6b), Pentacarbonyl[ 3-
ethoxy-4-( fluoren-9-ylidene) -2-pentamethylene-5-phenyl-3,4-di-
hydro-2H-pyrrole] tungsten (7b): To pentacarbonyl(1-ethoxy-3-phe-
nyl-2-propyn-1-ylidene)tungsten (1a) (482 mg, 1.00 mmol) in a 3-
ml screw-top vessel is added fluoren-9-ylidenecyclohexylamine (2b)
(260 mg, 1.00 mmol) in 2.5 ml of pentane. The mixture is shaken
until it becomes homogeneous. After ca. 1Ϫ2 h at 20°C, a dark
precipitate begins to form consisting of compound 3b and W(CO)6.
After ca. 2Ϫ3 d at 20°C (TLC), the reaction is almost complete.
X-ray Crystal Structure Analysis of 4a:[16] Formula C27H25NO,
M ϭ 379.48, 0.30 ϫ 0.20 ϫ 0.20 mm, a ϭ 14.371(4), b ϭ 8.989(1),
c ϭ 16.259(4) A, β ϭ 92.12(2)°, V ϭ 2098.9(8) A3, ρcalcd. ϭ 1.201 The supernatant is decanted and the solid residue washed with
˚
˚
g cmϪ3, µ ϭ 0.72 cmϪ1, empirical absorption correction with φ-
scan data (0.975 Յ C Յ 0.999), Z ϭ 4, monoclinic, space group
toluene (3 ϫ 1 ml). Pentane and toluene extracts are combined,
brought to dryness (20°C, 10 Torr) and separated by chromatogra-
phy on silica gel with pentane/dichloromethane (2:1) to give suc-
˚
P21/c (No. 14), λ ϭ 0.71073 A, T ϭ 293 K, ω/2θ scans, 4422 reflec-
tions collected (ϩh, Ϫk, ±l), [(sinθ)/λ] ϭ 0.62 AϪ1, 4248 indepen- cessively a small amount of red compound 7b (Rf ϭ 0.6 in pentane/
˚
dent and 1858 observed reflections [I Ն 2 σ(I)], 265 refined param-
eters, R ϭ 0.048, wR2 ϭ 0.093, max. residual electron density 0.19
dichloromethane, 2:1, 30 mg, 4%), the brown compound 6b (Rf ϭ
0.4 in pentane/dichloromethane 2:1, 100 mg, 13%, brown crystals
(Ϫ0.23) e AϪ3, hydrogen atoms calculated and refined as riding from pentane at Ϫ40°C). Elution with diethyl ether affords yellow
˚
atoms.[17]
product 4b (131 mg, 35%, Rf ϭ 0.3 in pentane/diethyl ether (10:1),
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629
1627

R. Aumann, Z. Yu, R. Fröhlich, F. Zippel
FULL PAPER
1
3
yellow crystals from toluene/pentane 1:1 at Ϫ15°C, mp 172°C).
The solid residue of the reaction mixture (ca. 260 mg) is dissolved
in dichloromethane (ca. 3 ml). W(CO)6 is removed by crystalization
at Ϫ15°C and compound 3b is obtained from the mother liquor at
20°C after addition of pentane (2 ml) (ca. 150 mg, 20%, amber-
colored crystals). If 1a (52 mg, 0.11 mmol) and 2b (26 mg, 0.10
7b: H NMR (C6D6, 600 MHz): δ ϭ 8.70 (1 H, d, J ϭ 7.4 Hz,
8Ј-H), 7.98 and 7.15 (2:3 H, broad each, Ph), 7.22 (1 H, d, 5Ј-H),
7.12 (1 H, d, 1Ј-H), 7.08 (1 H, dd, 6Ј-H), 7.05 (1 H, dd, 7Ј-H), 6.84
(1 H, dd, 2Ј-H), 6.46 (1 H, dd, 3Ј-H), 6.16 (1 H, d, 4Ј-H), 5.46 (1
H, s, 3-H), 3.46 and 3.37 (1:1 H, m each, OCH2); 2.78, 2.47, 1.84,
1.80, 1.56, 1.44, 1.42, 1.24, 1.15, 1.10, and 1.02 (1 H each, m each,
cyclohexyl), 1.03 (3 H, t, OCH2CH3). Ϫ 13C NMR (C6D6): δ ϭ
201.8 and 198.8 [Cq each, cis- and trans-CO W(CO)5], 179.2 (Cq,
1
mmol) in 1 ml of C6D6 are heated to 90°C for 2 h the H-NMR
spectrum of the solution shows signals of compounds 4b and 3b in
a molar ratio of ca. 3.5:1 as the only detectable products. Removal CϭN, C5), 147.3 and 142.3 (Cq each, C4 and C9Ј), 142,2 (Cq,
of the solvent and of W(CO)6 leaves a residue of 44 mg, which
corresponds to 69% of the pyrrol derivative 4b and 20% of com-
pound 3b.
C9aЈ), 140.0 (Cq, C8aЈ), 108.7 (Cq, C4aaЈ), 137.6 (Cq, C4aЈ), 136.0
(Cq, i-C Ph); 131.5, 131.0, 130.1, 128.2, 128.5, 128.3, 127.7, 126.8,
120.0 (CH each, fluorene); 129.8, 129.0 and 128.3 (CH each broad,
Ph), 83.2 (Cq, C2), 82.7 (CH, C3), 61.1 (OCH2); 36.6, 35.4, 25.3,
24.4, 24.2 (CH2 each, cyclohexyl), 15.5 (OCH2CH3). Ϫ IR (hex-
ane): ν˜ [cmϪ1 (%)] ϭ 2063.7 (30), 1982.6 (10), 1928.2 (100), 1914.2
(60) [ν(CϵO)]. Ϫ MS (70 eV); m/z 184W (%): 743 (10) [Mϩ], 715
(40) [Mϩ Ϫ CO], 659 (50) [Mϩ Ϫ 3 CO], 603 (40) [Mϩ Ϫ 5 CO],
543 (100), 419 (80) [Mϩ Ϫ W(CO)5], 390 (60), 265 (60).
1
3b: H NMR (C6D6, 600 MHz): δ ϭ 7.38, 7.30, and 7.22 (2:2:1
H; d, t, t; Ph), 7.36 (2 H, d, 4Ј-H and 5Ј-H), 6.99 (2 H, t, 3Ј-H and
6Ј-H), 7.15 (2 H, t, 2Ј-H and 7Ј-H), 7.10 (2 H, d, 1Ј-H and 8Ј-H),
3.30 and 0.70 (2:3 H; q and t, OCH2CH3), 2.50 (1 H, m, NCH);
0.98, 0.90, 0.80, 0.75, and 0.11 (2 H each, CH2 cyclohexyl). Ϫ 13C
NMR (C6D6): δ ϭ 204.8 and 201.0 [1:4, Cq each, cis- and trans-
CO W(CO)5], 197.3 (Cq, C2), 187.1 (Cq, C3), 142.1 (2 Cq, C8aЈ and
C9aЈ), 136.5 (2 Cq, C4aЈ and C4aaЈ), 135.6 (Cq, i-C Ph), 134.3 (Cq,
C4), 130.5 (2 CH, C2Ј and C7Ј), 129.7 (p-CH Ph), 129.0 (2 CH,
C3Ј and C6Ј), 127.9 (2 m-CH Ph), 127.2 (2 o-CH Ph), 124.0 (2 CH,
C1Ј and C8Ј), 121.1 (2 CH, C4Ј and C5Ј), 83.6 (Cq, C5 ϵ C9Ј),
65.2 (OCH2), 59.6 (NCH); 32.9, 25.7, 24.2 (2:2:1, CH2 each, cyclo-
X-ray Crystal Structure Analysis of 3b:[16] Formula
C35H29NO6W, M ϭ 743.47, 0.50 ϫ 0.30 ϫ 0.10 mm, a ϭ 9.626(2),
˚
b ϭ 16.259(3), c ϭ 19.291(3) A, β ϭ 91.51(1)°, V ϭ 3018.2(10)
3
A , ρcalcd. ϭ 1.636 g cmϪ3, µ ϭ 38.75 cmϪ1, empirical absorption
˚
correction via φ-scan data (0.684 Յ C Յ 0.999), Z ϭ 4, monoclinic,
˚
space group P21/c (No. 14), λ ϭ 0.71073 A, T ϭ 223 K, ω/2θ scans,
hexyl), 14.3 (OCH CH ). Ϫ IR (diffuse reflection): ν [cmϪ1 (%)] ϭ
˜
2
3
6296 reflections collected (±h, Ϫk, Ϫl), [(sinθ)/λ] ϭ 0.62 AϪ1, 6110
˚
2048.3 (30), 1975.1 (10), 1950.7 (20), 1895.3 (100), 1858.9 (80)
[ν(CϵO)]. Ϫ MS (70 eV); m/z 184W (%): 743 (1) [Mϩ], 687 (1) [Mϩ
Ϫ 2 CO], 659 (3) [Mϩ Ϫ 3 CO], 603 (2) [Mϩ Ϫ 5 CO], 391 (60),
308 (100). Ϫ C35H29NO6W (743.5): calcd. C 56.54, H 3.93, N 1.88;
found C 56.33, H 3.71, N 1.97.
independent and 5305 observed reflections [I Ն 2 σ(I)], 389 refined
parameters, R ϭ 0.031, wR2 ϭ 0.083, max. residual electron density
Ϫ3
˚
1.54 (Ϫ2.24) e A close to tungsten, hydrogen atoms calculated
and refined as riding atoms.[17]
1
3
4b: H NMR (C6D6, 600 MHz): δ ϭ 8.56 (1 H, d, J ϭ 7.4 Hz,
8Ј-H), 7.90 and 7.10 (2:3 H, broad each, Ph), 7.45 (1 H, d, 1Ј-H),
7.35 (1 H, d, 5Ј-H); 7.25, 7.16, 7.04, and 6.90 (1 H each, t each, 2Ј-
3-( 2,2Ј-Biphenylene) -1-isopropyl-5-phenyl-1,2-dihydropyrrol-3-
one (5a): Pentacarbonyl[1-isopropyl-4-ethoxy-2-phenyl-1-azoniacy-
clopenta-1,3-dien-3-yl]tungstate (3a) (70 mg, 0.10 mmol) in CHCl3
(1 ml) is treated with water (1.8 mg, 0.01 mmol) for 6 h at 20°C.
Evaporation of the solvent leaves compound 5a together with
3
H, 3Ј-H, 6Ј-H, and 7Ј-H), 6.63 (1 H, d, J ϭ 7.9 Hz, 4Ј-H), 5.29 (1
H, s, 3-H), 3.52 and 3.38 (1:1 H, m each, OCH2); 2.15, 1.72, 1.50,
1.31 (2:2:2:2, CH2 each, cyclohexyl), 1.03 (3 H, t, OCH2CH3). Ϫ
13C NMR (C6D6): δ ϭ 170.2 (Cq, CϭN, C5), 141.9 and 141.8 (Cq
each, C4 and C9Ј), 140.7 (Cq, C8aЈ), 140.3 (Cq, C9aЈ), 138.3 (Cq,
C4aaЈ), 136.8 (Cq, C4aЈ), 136.2 (Cq, i-C Ph); 130.0, 129.7, 129.2,
128.9 (2 C), 128.8 (2 C, broad), 128.1 (2 C), 126.6, 126.5, 119.9,
and 119.6 (CH each, fluorene and Ph), 88.9 (CH, C3), 77.1 (Cq,
C2), 62.1 (OCH2); 37.4, 32.2, 26.3, 24.4, 23.4 (CH2 each, cyclo-
hexyl), 15.9 (OCH2CH3). Ϫ MS (70 eV); m/z (%): 419 (100) [Mϩ],
390 (30) [Mϩ Ϫ Et], 265 (70), 165 (10) [fluorenyl], 146 (10), 104
(30). Ϫ C30H29NO (419.6): calcd. C 85.88, H 6.97, N 3.34; found
C 85.59, H 6.85, N 3.45.
1
W(CO)6. Ϫ H NMR (C6D6): δ ϭ 7.46 (2 H, d, 4Ј-H and 5Ј-H),
7.35 (2 H, d, 1Ј-H and 8Ј-H), 7.26 (2 H, “t”, m-H Ph), 7.17 and
7.08 (2 H each, dd each; 2Ј-H, 3Ј-H, 6Ј-H, and 7Ј-H), 7.09 (3 H,
o- and p-H Ph), 5.40 (1 H, s, 4-H), 3.41 (1 H, m, NCH), 0.50 [6 H,
d, CH(CH3)2]. Ϫ 13C NMR (C6D6): δ ϭ 195.5 (Cq, CϭO), 179.3
(Cq, C5), 143.9 (2 Cq, C8aЈ and C9aЈ), 142.5 (2 Cq, C4aЈ and
C4aaЈ), 133.6 (Cq, i-C Ph); 129.6, 128.9, and 128.6 (CH each, 1:2:2,
Ph), 124.2 (2 CH, C2Ј and C7Ј), 120.8 (2 CH, C3Ј and C6Ј), 101.1
(CH, C4), 82.3 (Cq, C2 ϵ C9Ј), 49.7 (NCH), 23.1 [C(CH3)2]. Ϫ IR
(diffuse reflection): ν [cmϪ1 (%)] ϭ 1675.5 (100) [ν(CϭO)].
˜
6b: 1H NMR (C6D6): δ ϭ 8.40 (2 H, s broad, o-H Ph); 7.70,
3-( 2,2Ј-Biphenylene) -1-cyclohexyl-5-phenyl-1,2-dihydropyrrol-3-
7.52, 7.40, and 7.26 (1 H each, “d” each; 1Ј-H, 4Ј-H, 5Ј-H, and 8Ј- one (5b): Pentacarbonyl[1-cyclohexyl-4-ethoxy-2-phenyl-1-azonia-
H); 7.13, 7.10, 6.80, and 6.54 (1 H each, “t” each; 2Ј-H, 3Ј-H, 6Ј-
H, and 7Ј-H), 7.05 (3 H, m broad, m- and p-H Ph), 4.82 (1 H, “t”,
NCH), 4.78 and 3.95 (1 H each, m broad each, OCH2), 1.80 and
cyclopenta-1,3-dien-3-yl]tungstate (3b) (74 mg, 0.10 mmol) in
CHCl3 (1 ml) is treated with water (1.8 mg, 0.10 mmol) for 6 h at
20°C. Evaporation of the solvent leaves compound 5b together with
W(CO)6. Ϫ H NMR (C6D6): δ ϭ 7.52 (2 H, d, 4Ј-H and 5Ј-H),
7.40 (2 H, d, 1Ј-H and 8Ј-H), 7.31 (2 H, “d”, o-H Ph), 7.19 and
7.09 (2 H each, dd each; 2Ј-H, 3Ј-H, 6Ј-H and 7Ј-H), 7.15 and 7.12
1
1.20 (5 H each,
m
each broad, cyclohexyl), 0.87 (3 H, t,
OCH2CH3). Ϫ 13C NMR (C6D6): δ ϭ 321.2 (Cq, WϭC), 202.2 and
196.9 [1:4, Cq each, trans- and cis-CO, W(CO)5], 157.8 (Cq, CϭN,
C3), 152.5 (Cq, C9Ј); 141.9, 141.5, 137.7, 137.1, 136.3, and 132.4 (2:1 H, m- and p-H Ph), 5.41 (1 H, s, 4-H), 3.29 (1 H, m, NCH);
(Cq each, C2, C4aЈ, C4aaЈ, C8aЈ, C9aЈ, and i-C Ph); 130.8, 129.9 1.40, 1.00, 0.85, 0.42, and 0.21 (3:3:2:1:1, CH2 cyclohexyl). Ϫ 13C
(2 C), 129.7, 129.5, 128.7 (2 C), 127.8, 127.3, 127.0, 126.9, 120.5,
and 120.1 (CH each, fluorene and Ph), 80.6 (OCH2), 61.9 (NCH); C8aЈ and C9aЈ), 142.4 (2 Cq, C4aЈ and C4aaЈ), 133.6 (Cq, i-C Ph);
33.9, 26.1, 24.5, 24.3, and 22.7 (CH2 each, cyclohexyl), 13.9 129.6, 128.9, and 128.6 (CH each, 1:2:2, Ph), 124.4 (2 CH, C2Ј and
(OCH2CH3). Ϫ IR (hexane): ν˜ [cmϪ1 (%)] ϭ 2071.9 (30), 1994.4 C7Ј), 120.9 (2 CH, C3Ј and C6Ј), 100.6 (CH, C4), 82.2 (Cq, C2 ϵ
(10), 1964.7 (60), 1945.3 (100) [ν(CϵO)]. Ϫ MS (70 eV); m/z 184W
C9Ј), 58.9 (NCH); 34.2, 26.2, and 25.0 (CH2 each, 2:2:1, cyclo-
NMR (C6D6): δ ϭ 195.5 (Cq, CϭO), 179.4 (Cq, C5), 144.1 (2 Cq,
(%): 743 (1) [Mϩ], 715 (1) [Mϩ Ϫ CO], 659 (1) [Mϩ Ϫ 3 CO], 603 hexyl). Ϫ IR (diffuse reflection): ν˜ [cmϪ1 (%)] ϭ 1676.1 (100)
(1) [Mϩ Ϫ 5 CO], 419 (100) [Mϩ Ϫ W(CO)5], 390 (60), 265 (60).
[ν(CϭO)].
1628
Eur. J. Inorg. Chem. 1998, 1623Ϫ1629

Organic Syntheses via Transition Metal Complexes, XCVII
FULL PAPER
Ƞ
[10]
[11]
[12]
[13]
[14]
[15]
[16]
Dedicated to Professor E. O. Fischer on the occasion of his
R. Aumann, K. Roths, R. Fröhlich, Organometallics 1997, 16,
5893.
80th birthday
For a review see, e.g.: [11a] Y. Noe¨l, Bull. Soc. Chim. Fr. 1964, 5,
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Data sets were collected with an Enraf Nonius CAD4 dif-
fractometer using an FR591 rotating anode generator. Pro-
grams used: data reduction MolEN, structure solution
SHELXS-86, structure refinement SHELXL-93, graphics DIA-
MOND.
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J. Barluenga, M. Toma´s, J. A. Lo´pez-Pelegr´ın, E. Rubio,
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Crystallographic data (excluding structure factors) for the struc-
tures reported have been deposited with the Cambridge Crystal-
lographic Data Centre. Copies of the data can be obtained free
of charge by quoting the depository numbers CCDC-102622,
-102623 and -102624, the names of the authors, and the journal
citation on application to CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK [fax: int code ϩ 44-12238 336-033, e-mail:
deposit@ccdc.cam.ac.uk].
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1629