Reactions of Complex Ligands Part 84. Chiral Diene-dienophile-functionalzed Aminocarbene Complexes of Molybdenum: Synthesis and Intramolecular Diels-Alder Reaction

Article abstract of DOI:10.1016/S0022-328X(99)00098-4

Chiral at metal carbene complexes (η⁵-C5H5)(CO)(NO)Mo=C[C(CH3)=CH2(NRCH2)(2-CH3O)] 2-4 have been synthesized from (η⁵-C5H5)Mo(CO)2NO via a nucleophilic addition/alkylation/aminolysis sequence. In contrast to 2 (R=H), the N-alkylated analogs 3 and 4 undergo intramolecular Diels-Alder reaction upon warming to give the isoindole derivatives 6 and 7 with moderate diastereoselection. These molybdenum carbenes cyclise more readily than their isolobal analogous methacrylic amides, but they are less reactive than their analogs containing a [η⁵-C5(CH3)H4](CO)2Mn or a (CO)5W fragment. This sequence reflects the increasing electron-withdrawing ability of the metal coligand moiety in the order of the molybdenum < manganese < tungsten coligand fragments.

Full text of DOI:10.1016/S0022-328X(99)00098-4

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 583 (1999) 34–41
Reactions of complex ligands
Part 84. Chiral diene–dienophile-functionalized aminocarbene
complexes of molybdenum: synthesis and intramolecular
Diels–Alder reactionꢀ,ꢀꢀ
K.H. Do¨tz *, D. Bo¨ttcher, M. Jendro
Kekule´-Institut fu¨r Organische Chemie und Biochemie der Uni6ersita¨t Bonn, Gerhard-Domagk-Str. 1, D-53121 Bonn, Germany
Received 17 June 1998
Abstract
Chiral at metal carbene complexes (h5-C5H5)(CO)(NO)MoꢀC[C(CH3)ꢀCH2(NRCH2(2-C4H3O)] 2–4 have been synthesized
from (h5-C5H5)Mo(CO)2NO via a nucleophilic addition/alkylation/aminolysis sequence. In contrast to 2 (R=H), the N-alkylated
analogs 3 and 4 undergo intramolecular Diels–Alder reaction upon warming to give the isoindole derivatives 6 and 7 with
moderate diastereoselection. These molybdenum carbenes cyclize more readily than their isolobal analogous methacrylic amides,
but they are less reactive than their analogs containing a [h5-C5(CH3)H4](CO)2Mn or a (CO)5W fragment. This sequence reflects
the increasing electron-withdrawing ability of the metal coligand moiety in the order of the molybdenumBmanganeseBtungsten
coligand fragments. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Carbene complexes; Cycloaddition reactions; Diels–Alder reactions; Intramolecular cycloaddition; Molybdenum complexes
1. Introduction
[5] and Diels–Alder reaction [6] have been shown to
proceed with excellent regio- and stereoselectivity.
Recently, we reported on the intramolecular Diels–
Alder reaction of diene–dienophile-functionalized
aminocarbene complexes [7] which, according to the
isolobal analogy of a M(CO)5 fragment (M=Cr, Mo,
W) and an oxygen atom [8], represent the organometal-
lic counterparts of carboxylic amides. The pentacar-
bonyl metal fragment is a potent electron-withdrawing
functionality, even superior to a Lewis acid coordinated
oxygen atom that allows mild conditions for metal
carbene based Diels–Alder reactions. After we found
that intramolecular Diels–Alder reactions of 2-furfuryl-
amino carbene ligands are promoted by half-sandwich
carbene complexes of manganese [9], we focused our
attention on a similar type of complexes CpML1L2L3 in
order to examine whether a chiral metal center [10] can
be exploited in an asymmetric induction along the
cycloaddition reaction. Based on the straightforward
synthetic access to Cp(CO)(NO)MoꢀC(OCH3)Ph [11],
which can be easily prepared from dicarbonylcyclopen-
Over the past two decades, Fischer-type carbene
complexes have been established as useful tools in
organic chemistry [2]. Based on the strongly elec-
trophilic carbene carbon atom attached to a low-valent
metal center, manifold applications have been devel-
oped for selective carbon–carbon bond formation [3].
Both metal-centered and ligand-centered cycloaddition
reactions, such as the chromium-mediated carbene ben-
zannulation by alkynes [4], the Pauson–Khand reaction
ꢀ Dedicated to Professor A. Ceccon on the occasion of his 65th
birthday.
* Corresponding author. Tel.: +49-228-735-608; fax: +49-228-73-
5813.
E-mail address: doetz@uni-bonn.de (K.H. Do¨tz)
ꢀꢀ For part 83, see Ref. [1].
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00098-4

K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
35
tadienyl(nitrosyl)molybdenum(0) [12], we chose the
Cp(CO)(NO)Mo moiety to control the diastereoselec-
tivity of the intramolecular Diels–Alder reaction.
2. ‘Chiral at metal’ molybdenum carbene complexes
The diene–dienophile-functionalized carbene com-
plex 2 was synthesized from (h5-C5H5)Mo(CO)2NO by
addition of 2-lithiopropene, alkylation of the resulting
acylmolybdate with [(CH3)3O][BF4] to give methoxycar-
bene complex 1 followed by aminolysis with 2-furfuryl
amine (Scheme 1). High yield-aminolysis of 1 requires
four equivalents of furfuryl amine which have to be
added to a concentrated solution (3.5 M) of 1 in
dichloromethane at −30°C; following this protocol the
furfurylaminocarbene complex 2 is obtained as a 1/4
mixture of E/Z isomers in 94% yield. Since the propen-
sity of carbene complexes for intramolecular Diels–
Alder reactions is enhanced by N-substitution [9,13]
carbene complex 2 was alkylated with lithium diiso-
propylamide/methyl iodide or benzyl bromide to give
aminocarbene complexes 3 and 4 as a mixture of
Fig. 1. Conformations of the Mo–carbene bond.
and 4a, 4b/4c, 4d are reversed in comparison with the
precursor 2 indicating that the aminocarbene complex
anion formed upon deprotonation is configurationally
labile under the reaction conditions shifting the equi-
librium towards the less congested E-configuration. The
isomers having the same configuration at the CcarbeneꢁN
bond differ partly in the 13C-NMR spectra reflecting
the complementary configuration at the metal. This is
most evident for the chemical shifts of the terminal
alkene carbon atoms in 3a/b or 3c/d which, assigned by
DEPT 135 experiments, differ by ca. 7 ppm. This fact is
underlined by the splitting of the IR absorption of the
NO ligand as a strong p-acceptor ligand. For both
compounds 3 and 4 a strong absorption at 1620 cm−1
with a shoulder at about 1609 cm−1 is observed in the
spectra recorded in petroleum ether (Fig. 1). Increasing
N-substitution hinders the rotation of the metal frag-
ment around the molybdenum–carbene bond. As a
consequence the NO ligand adopts two different orien-
tations relative to the conjugated double bond of the
carbene ligand as indicated in Fig. 1, which explains
both the splitting of the NO absorption and the 13C-
NMR shifts of the sp2-methylene carbon atoms. Similar
results were obtained for methyloxycarbene complexes
of molybdenum bearing hydridotris(3,5-dimethylpyra-
zolyl)borate as h5-ligand attached to the metal center
[15]. This bulky s-donor ligand hampers the rotation
around the molybdenum–carbene bond and two iso-
mers that are conformationally stable on the NMR
time scale were observed representing the two different
orientations of the NO ligand with respect to the car-
diastereomers
3a:3b:3c:3d=1.9:1.4:1.4:1
and
4a:4b:4c:4d=2.0:1.3:1.3:1 in 80 and 68% overall yield,
respectively (Scheme 1).
To elucidate the stereochemistry within the amino
substituent NMR spectra of 3 and 4 were recorded
both in an isotropic (CDCl3) and in an anisotropic
solvent (C6D6). Based on the well-documented fact that
the upfield shift of E-CH2 protons is more pronounced
than that of Z-CH2 protons if CDCl3 is replaced as a
solvent by C6D6 [14] an E-configuration is assigned to
3a and 3b, whereas 3c and 3d are identified as Z-
aminocarbene complexes. The E/Z ratios 3a, 3b/3c, 3d
Scheme 1. Synthesis of chiral carbene complexes 2–4.
Scheme 2. Intramolecular Diels–Alder reactions.

36
K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
Table 1
Intramolecular Diels–Alder reaction of methacrylic acid derivatives 2–4 and 8–18
a
Entry
Educt
X
R
Conditions
Product
Yield (%)
d.e. (%)
1
2
2
2
Cp(CO)(NO)Mo
H
H
3 h; 90°C
120 h; 90°C
5
5
0
0
–
–
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
3
3
3
4
8
9
10
11
12
13
14
15
15
16
17
18
CH3
CH3
CH3
CH2Ph
H
CH3
CH2Ph
(S)-CH(CH3)Ph
H
CH3
CH2Ph
(S)-CH(CH3)Ph
(S)-CH(CH3)Ph
H
CH3
CH2Ph
3 h; 90°C
4 h; 70°C
24 h; 50°C
3 h; 90°C
ª
ª
ª
ª
ª
ª
ª
ª
6
6
6
7
22
19
7.5
50
0
27
36
97
79
100
100
100
73
48
72
75
62
59
67
71
–
O
19
20
21
22
23
24
25
26
26
27
28
29
–
–
(CO)5W
–
–
–
0
15
–
6 h; rt
24 h; 80°C
6 h; 80°C
4 h; 80°C
MeCp(CO)2Mn
–
–
a Isolated yields of 6, 7 and 27–29; yields of 19–26 were determined by NMR spectroscopy [9].
a similar trans-fusion of the newly formed five-mem-
bered rings as has been established for 23 by X-ray
analysis [7].
bene ligand. Both electronic and steric effects may be
responsible to explain the existence of rotamers at room
temperature.
In order to compare the diastereoselection arising
from the chiral metal center with that due to a chiral
N-substituent we incorporated the (S)-1-phenylethyl
group into the heteroatom carbene side chain of the
pentacarbonyl tungsten complex [16]. When a solution
of chiral 15 was warmed in toluene at 90°C for 3 h
quantitative conversion to the cycloaddition product
occurred but no diastereomeric excess could be detected
(entry 14). Under milder conditions, in diethyl ether at
room temperature for 6 h, tungsten carbene 15 under-
went cyclization to give 26 in low diastereomeric excess
(15% d.e., entry 15). These results demonstrate that the
stereodifferentiating potential of the chiral metal frag-
ment is superior to chiral N-substitution.
On the other hand, in comparison with the (CO)5W
fragment, the more electron-rich Cp(CO)(NO)Mo moi-
ety is a less efficient acceptor group, which results in a
reduced reactivity towards intramolecular Diels–Alder
reaction. Within the N-protonated (entries 1, 11 and
16), the N-methyl (entries 3, 12 and 17) and the N-ben-
zyl (entries 6, 13 and 18) series the pentacarbonyl
tungsten complexes gave the highest (entries 11–13)
and the carbonyl(cyclopentadienyl)(nitrosyl)molybde-
num (entries 1, 3 and 6) the lowest yields, while the
3. Intramolecular Diels–Alder reactions
While the N-protonated amino carbene complex 2
gave no epoxy-3aH-isoindolylidene complex 5 upon
warming in di-n-butyl ether to 120°C, its N-alkylated
analogs 3 and 4 underwent cyclization within 3 h at
90°C to give 6 and 7 in 22 and 50% yield with moderate
diastereomeric excess of 62 and 71%, respectively
(Scheme 2, Table 1, entries 1–6). As demonstrated for
the N-methyl complex 3 lowering the reaction tempera-
ture does not result in a significant increase of the d.e.
but, instead, in a dramatical decrease of the yield; for
instance, only a 7.5% yield of 6 is obtained at 50°C. As
previously observed both in the pentacarbonyl tungsten
series and in the dicarbonyl(methylcyclopentadi-
enyl)manganese series the propensity for ring closure
increases with increasing bulk of the N-substitution
pattern [9]. A similar tendency was also found for their
isolobal-analogous acrylic furfuryl amides [13]. These
results can be rationalized in terms that bulky N-substi-
tution favors the conformation within the furfuryl
group required for cyclization. Unreacted 3 recovered
from the reaction mixture revealed an unchanged ratio
of isomers indicating that N-alkylation was performed
under thermodynamic control (in spite of low tempera-
ture). Single diastereomers were obtained from the cy-
dicarbonyl(methylcyclopentadienyl)manganese
com-
plexes range in between (entries 16–18). Although the
molybdenum compounds bear the strongly electron-
withdrawing the NO ligand, its striking p-acceptor ca-
pability is overruled by the efficient p-donating
cyclopentadienyl ligand. The different overall acceptor
properties of the metal coligand fragments are reflected
1
clization of 3 and 4. H- and 13C-NMR spectra of the
cycloaddition products 6 and 7 resemble those recorded
for the pentacarbonyl tungsten analog 23 [9] suggesting

K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
37
in the N-H acidities as evident from the 1H-NMR
spectra: An increased deshielding for the N-H proton is
observed in the order of molybdenum complex E/Z-12
(l=7.51 and 8.25 ppm), the manganese complex E/Z-
16 (l=9.35 and 9.54 ppm) and the tungsten complex
12 (l=10.77 ppm).
Anal. Found: C, 43.94; H, 4.40; N, 4.62;
C11H13MoNO3 (303.2). Calc.: C, 43.58; H, 4.32; N,
4.62%.
4.2. rac-(E/Z)-Carbonyl(cyclopentadienyl)[N-2-furfuryl-
amino(2-propenyl)carbene](nitrosyl)molybdenum 2
2-Furfurylamine (2.44 ml, 27.6 mmol) was added at
−30°C to a solution of 2.10 g (6.9 mmol) of 1 in 2 ml
of dichloromethane. After stirring overnight the reac-
tion mixture was allowed to reach room temperature.
The solvent and excess of amine were removed at
reduced pressure, and the residue was purified by
column chromatography on silica gel at −10°C (eluent
petroleum ether:diethyl ether 8:1) to give 2.38 g (94%)
of 2 as a red solid (E/Z=1:4). Rf=0.45 (petroleum
ether:diethyl ether 8:1). IR (petroleum ether): w=1942 s
(CO), 1620 s (NO) cm−1. 1H-NMR (400 MHz, CDCl3):
E-isomer: l=8.25 (sbr, 1H, NH), 7.40 (dd, 1H, J=
0.78, 1.78 Hz, 5-Hfuryl), 6.35 (dd, 1H, J=1.76, 3.13 Hz,
4-Hfuryl), 6.27 (dd, 1H, J=0.78, 3.13 Hz, 3-Hfuryl), 5.46
(s, 5H, C5H5), 4.80 (m, 1H, H3CꢁCꢀCHH), 4.52 (dd,
1H, J=6.06, 15.26 Hz, NCHH), 4.49 (m, 1H,
H3CꢁCꢀCHH), 4.46 (dd, 1H, J=6.06, 15.26 Hz,
NCHH), 1.89 (m, 3H, J=1.37 Hz, H3CꢁCꢀCH2). Z-
isomer: l=7.51 (sbr, 1H, NH), 7.41 (dd, 1H, J=0.78,
1.76 Hz, 5-Hfuryl), 6.43 (dd, 1H, J=0.78, 3.32 Hz,
3-Hfuryl), 6.37 (dd, 1H, J=1.76, 3.32 Hz, 4-Hfuryl), 5.48
(s, 5H, C5H5), 4.94 (dd, 1H, J=6.06, 15.65 Hz,
NCHH), 4.86 (dd, 1H, J=6.06, 15.65 Hz, NCHH),
4.61 (dq, 1H, J=1.37, 1.56 Hz, H3CꢁCꢀCHH), 4.48
(dq, 1H, J=0.78, 1.37 Hz, H3CꢁCꢀCHH), 1.84 (m,
4. Experimental
All operations were carried out under inert gas.
Solvents were dried using standard methods, distilled,
saturated and stored under argon. Merck silica gel 60
(0.063–0.200 mm) was used for column chromatogra-
phy. 1H- and 13C-NMR: Bruker AC-200, AC-300,
WM-250 and AM-400. MS: Kratos MS 50, Varian
MAT CH 7A and MAT 711. FT-IR: Nicolet 510 and
Magna 550. Elemental analyses: Heraeus-CH-O-Rapid.
The synthesis and analytical characterization of com-
pounds 19–21, 23–25 and 27–29 were previously de-
scribed in Ref. [9].
4.1. rac-Carbonyl(cyclopentadienyl)[methoxy(2-propen-
yl)carbene](nitrosyl)molybdenum 1
Dicarbonyl(cyclopentadienyl)(nitrosyl)molybdenum
(2.47 g, 10 mmol) was added at −78°C to a solution of
2-lithiopropene prepared from 0.89 ml (10 mmol) 2-
bromopropene and 11.8 ml (20 mmol) of a 1.7 M
solution of tert-butyllithium in 50 ml of diethyl ether.
After 45 min the solvent was removed at reduced
pressure. The residue was dissolved in 50 ml of
dichloromethane and 2.96 g (20 mmol) of trimethyloxo-
nium tetrafluoroborate were added at −30°C. The
reaction mixture was allowed to reach room tempera-
ture overnight, filtered over silica gel, and the residue
was washed with dichloromethane until the filtrate re-
mained colourless. The solvent was removed at reduced
pressure, and the crude product was purified by column
chromatography on silica gel (5×4 cm, eluent:
petroleum ether). After elution of the starting material
the eluent was changed to petroleum ether:diethyl ether
(8:1) and 2.69 g (89%) of 1 were obtained as a yellow
solid. Rf=0.06 (petroleum ether); Rf=0.67 (petroleum
ether:diethyl ether 8:1). IR (petroleum ether): w=1975 s
(CO), 1638 s (NO) cm−1. 1H-NMR (400 MHz, CDCl3):
l=5.60 (s, 5H, C5H5), 4.99 (dq, 1H, J=1.54, 1.37 Hz,
CH3ꢁCꢀCHH), 4.62 (dq, 1H, J=0.78, 1.56 Hz,
CH3ꢁCꢀCHH), 4.38 (s, 3H, OCH3), 1.77 (dd, 3H,
J=0.78, 1.37 Hz, CH3ꢁCꢀCHH). 13C-NMR (100
MHz, CDCl3): l=328.8 (MoꢀC), 225.4 (CO), 156.4
(H3CꢁCꢀCH2), 116.7 (H3CꢁCꢀCH2), 96.9 (C5H5), 66.2
(OCH3), 19.7 (H3CꢁCꢀCH2). MS (EI): m/z (%): 305 (7)
[M+], 277 (100) [M+ −CO], 231 (71), 202 (68), 177
(44), 163 (24), 137 (15), 41 (17).
1
3H, J=1.37 Hz, H3CꢁCꢀCH2). H-NMR (400 MHz,
C6D6): E-isomer; l=8.19 (sbr, 1H, NH), 7.04 (m, 1 H,
5-Hfuryl), 6.05 (m, 1H, 4-Hfuryl), 5.91 (m, 1H, 3-Hfuryl),
5.15 (s, 5H, C5H5), 4.43 (m, 1H, H3CꢁCꢀCHH), 4.33
(m, 1H, H3CꢁCꢀCHH), 3.86 (dd, 1H, J=6.06, 15.3
Hz, NCHH), 3.81 (dd, 1H, J=6.06, 15.3 Hz, NCHH),
1.59 (m, 3H, H3CꢁCꢀCH2). Z-isomer: l=7.06 (dd, 1H,
J=0.8, 1.8 Hz, 5-Hfuryl), 7.04 (sbr, 1H, NH), 6.23 (dd,
1H, J=0.8, 3.3 Hz, 3-Hfuryl), 6.05 (m, 1H, 4-Hfuryl),
5.19 (s, 5H, C5H5), 4.93 (m, 1H, H3CꢁCꢀCHH) 4.93
(dd, 1H, J=5.36, 15.65 Hz, NCHH), 4.89 (dd, 1H,
J=5.36, 15.65 Hz, NCHH), 4.20 (m, 1H,
H3CꢁCꢀCHH), 1.50 (m, 3H, H3CꢁCꢀCH2). 13C-NMR
(100 MHz, CDCl3): E-isomer: l=284.7 (MoꢀC), 237.5
(CO), 150.3 (2-Cfuryl), 149.4 (H3CꢁCꢀCH2), 142.9 (5-
Cfuryl), 110.6 (3-Cfuryl), 108.8 (4-Cfuryl), 108.3
(CH3ꢁCꢀCH2), 95.9 (C5H5), 44.8 (NHCH2), 26.8
(CH3ꢁCꢀCH2). Z-isomer: lr=280.1 (MoꢀC), 235.9
(CO), 156.5 (2-Cfuryl), 149.9 (H3CꢁCꢀCH2), 142.7 (5-
Cfuryl), 110.6 (3-Cfuryl), 108.8 (4-Cfuryl), 107.7
(CH3ꢁCꢀCH2), 96.0 (C5H5), 48.9 (NHCH2), 23.4
(CH3ꢁCꢀCH2). 13C-NMR (100 MHz, C6D6): E-isomer:
l=285.8 (MoꢀC), 239.3 (CO), 157.4 (2-Cfuryl), 150.9
(H3CꢁCꢀCH2), 143.3 (5-Cfuryl), 111.4 (3-Cfuryl), 109.6

38
K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
(4-Cfuryl), 108.6 (CH3ꢁCꢀCH2), 96.7 (C5H5), 45.3
(NHCH2), 24.0 (CH3ꢁCꢀCH2). Z-isomer: l=281.3
(MoꢀC), 237.4 (CO), 157.4 (2-Cfuryl), 151.2
(H3CꢁCꢀCH2), 143.4 (5-Cfuryl), 111.5 (3-Cfuryl), 109.6
(4-Cfuryl), 107.9 (CH3ꢁCꢀCH2), 96.7 (C5H5), 49.6
(NHCH2), 24.0 (CH3ꢁCꢀCH2). MS (EI): m/z (%): 370
(6) [M+], 342 (100) [M+ −CO], 312 (4) [M+ −CO−
NO], 280 (10), 259 (14), 232 (21), 231 (20), 202 (31), 194
(40), 163 (15), 148 (6), 132 (17), 81 (56), 53 (16).
HR-MS: Found 338.0267. C14H16MoN2O2 [M+ −CO].
Calc.: 338.0280.
1H, J=1.57 Hz, H3CꢁCꢀCHH), 4.20 (m, 1H,
H3CꢁCꢀCHH), 3.23 (s, 3H, NCH3), 1.79 (m, 3H,
1
H3CꢁCꢀCH2). H-NMR (400 MHz, C6D6). 3a: l=7.08
(dd, 1H, J=0.78, 1.76 Hz, 5-Hfuryl), 6.53 (m, 1H,
3-Hfuryl), 6.08 (dd, 1H, J=1.76, 3.2 Hz, 4-Hfuryl), 5.22
(s, 5H, C5H5), 4.44 (2 dd, 2H, J=0.78, 1.37, 1.57 Hz,
H3CꢁCꢀCH2), 4.05 (d, 1H, J=15.26 Hz, NCHH), 3.99
(d, 1H, J=15.26 Hz, NCHH), 3.31 (s, 3H, NCH3),
1.56 (m, 3H, H3CꢁCꢀCH2). 3b: l=6.98 (dd, 1 H,
J=0.78, 1.76 Hz, 5-Hfuryl), 5.98 (dd, 1H, J=1.76, 3.2
Hz, 4-Hfuryl), 5.87 (dd, 1H, J=0.78, 3.13 Hz, 3-Hfuryl),
5.21 (s, 5H, C5H5), 4.39 (m, 1H, J=1.57 Hz,
Anal. Found: C, 46.66; H, 4.51; N, 7.22;
C15H16MoN2O3 (368.2). Calc.: C, 48.93; H, 4.38; N,
7.61%.
H3CꢁCꢀCHH),
4.31
(m,
1H,
J=1.56
Hz,
H3CꢁCꢀCHH), 4.15 (d, 1H, J=15.06 Hz, NCHH),
4.11 (d, 1H, J=15.06 Hz, NCHH), 3.31 (s, 3H,
NCH3), 1.69 (m, 3H, H3CꢁCꢀCH2). 3c: l=6.96 (dd,
1H, J=0.78, 1.76 Hz, 5-Hfuryl), 5.98 (dd, 1H, J=1.76,
3.2 Hz, 4-Hfuryl), 5.83 (dd, 1H, J=0.78, 3.13 Hz, 3-
Hfuryl), 5.14 (s, 5H, C5H5), 5.11 (d, 1H, J=14.48 Hz,
NCHH), 4.81 (d, 1H, J=14.48 Hz, NCHH), 4.37 (m,
1H, J=1.57 Hz, H3CꢁCꢀCHH), 4.13 (m, 1H,
H3CꢁCꢀCHH), 2.65 (s, 3H, NCH3), 1.35 (m, 3H,
H3CꢁCꢀCH2). 3d: l=7.04 (dd, 1H, J=0.78, 1.76 Hz,
5-Hfuryl), 6.19 (dd, 1H, J=0.78, 3.13 Hz, 3-Hfuryl), 6.03
(dd, 1H, J=1.76, 3.2 Hz, 4-Hfuryl), 5.14 (s, 5H, C5H5),
5.12 (d, 1H, J=14.86 Hz, NCHH), 4.85 (d, 1H, J=
14.86 Hz, NCHH), 4.26 (dd, 1H, J=1.37, 1.57 Hz,
H3CꢁCꢀCHH), 3.87 (m, 1H, H3CꢁCꢀCHH), 2.70 (s,
3H, NCH3), 1.53 (m, 3H, H3CꢁCꢀCH2). 13C-NMR (100
MHz, CDCl3): 3a: l=280.0 (MoꢀC), 238.1 (CO), 150.9
(2-Cfuryl), 149.0 (H3CꢁCꢀCH2), 142.7 (5-Cfuryl), 110.5
(3-Cfuryl), 109.0 (4-Cfuryl), 105.6 (H3CꢁCꢀCH2), 96.0
4.3. Carbonyl(cyclopentadienyl)[N-2-furfuryl-N-methyl-
amino(2-propenyl)carbene](nitrosyl)molybdenum 3
A solution of 1.30 g (3.5 mmol) of 2 in 2 ml of THF
was added dropwise at −78°C to a solution of lithium
diisopropyl amide prepared from 0.59 ml (4.2 mmol)
diisopropylamine and 2.75 ml (4.2 mmol) of a 1.53 M
n-butyllithium solution in 20 ml of THF. After 1.5 h
0.26 ml (4.2 mmol) of methyl iodide were added and
the reaction mixture was allowed to warm to room
temperature overnight. After removal of the solvent
and purification of the residue by chromatography on
silica gel at −10°C (eluent petroleum ether:diethyl
ether 8:1) 1.06 g (80%) of 3 were obtained as a red oil
(ratio of isomers: 3a:3b:3c:3d=1.9:1.4:1.4:1). Rf=0.18
(petroleum ether:diethyl ether 8:1). IR (petroleum
ether): w=1933 s (CO), 1620 s (NO), 1609 sh (NO)
cm−1. IR (di-n-butyl ether): w=1927 s (CO), 1612 s
(C5H5),
52.1
(NCH2),
46.7
(NCH3),
21.7
1
(NO) cm−1. 3a: H-NMR (400 MHz, CDCl3): l=7.40
(H3CꢁCꢀCH2). 3b: l=279.0 (MoꢀC), 238.4 (CO),
151.1 (2-Cfuryl), 149.1 (H3CꢁCꢀCH2), 142.7 (5-Cfuryl),
111.5 (H3CꢁCꢀCH2), 110.5 (3-Cfuryl), 109.0 (4-Cfuryl),
95.8 (C5H5), 52.2 (NCH2), 46.9 (NCH3), 20.5
(H3CꢁCꢀCH2). 3c: l=279.2 (MoꢀC), 238.9 (CO),
151.6 (2-Cfuryl), 149.9 (H3CꢁCꢀCH2), 142.4 (5-Cfuryl),
110.6 (3-Cfuryl), 109.1 (4-Cfuryl), 105.0 (H3CꢁCꢀCH2),
96.5 (C5H5), 57.7 (NCH2), 40.4 (NCH3), 24.2
(H3CꢁCꢀCH2). 3d: l=278.4 (MoꢀC), 239.3 (CO),
151.8 (2-Cfuryl), 149.7 (H3CꢁCꢀCH2), 142.4 (5-Cfuryl),
111.8 (H3CꢁCꢀCH2), 110.5 (3-Cfuryl), 109.1 (4-Cfuryl),
96.4 (C5H5), 57.8 (NCH2), 40.6 (NCH3), 23.3
(H3CꢁCꢀCH2). 13C-NMR (100 MHz, C6D6): 3a: l=
281.3 (MoꢀC), 239.7 (CO), 152.8 (2-Cfuryl), 150.3
(H3CꢁCꢀCH2), 143.5 (5-Cfuryl), 111.4 (3-Cfuryl), 109.8
(4-Cfuryl), 106.0 (H3CꢁCꢀCH2), 97.3 (C5H5), 52.7
(NCH2), 47.3 (NCH3), 22.3 (H3CꢁCꢀCH2). 3b: l=
280.4 (MoꢀC), 240.0 (CO), 152.9 (2-Cfuryl), 150.4
(H3CꢁCꢀCH2), 143.3 (5-Cfuryl), 111.9 (H3CꢁCꢀCH2),
111.7 (3-Cfuryl), 109.8 (4-Cfuryl), 96.6 (C5H5), 52.5
(NCH2), 47.6 (NCH3), 21.0 (H3CꢁCꢀCH2). 3c: l=
280.7 (MoꢀC), 240.4 (CO), 152.2 (2-Cfuryl), 151.3
(dd, 1H, J=0.79, 1.76 Hz, 5-Hfuryl), 6.5–6.2 (m, 2H,
3-Hfuryl, 4-Hfuryl), 5.48 (s, 5H, C5H5), 4.77 (dd, 1H,
J=1.37, 1.57 Hz, H3CꢁCꢀCHH), 4.67 (d, 1H, J=
15.26 Hz, NCHH), 4.59 (d, 1H, J=15.26 Hz, NCHH),
4.46 (dd, 1H, J=0.98, 1.57 Hz, H3CꢁCꢀCHH), 3.46 (s,
3H, NCH3), 1.90 (dd, 3H, J=0.78, 1.37 Hz,
H3CꢁCꢀCH2). 3b: l=7.39–7.38 (m, 1H, 5-Hfuryl), 6.5–
6.2 (m, 2H, 3-Hfuryl, 4-Hfuryl), 5.48 (s, 5H, C5H5), 4.81
(d, 1H, J=15.06 Hz, NCHH), 4.73 (dq, 1H, J=1.37,
1.57 Hz, H3CꢁCꢀCHH), 4.66 (d, 1H, J=15.06 Hz,
NCHH), 4.34 (dq, J=0.8, 1.59 Hz, H3CꢁCꢀCHH),
3.50 (s, 3H, NCH3), 1.79 (dd, 3H, J=0.98, 1.57 Hz,
H3CꢁCꢀCH2). 3c: l=7.39–7.38 (m, 1H, 5-Hfuryl), 6.5–
6.2 (m, 2H, 3-Hfuryl, 4-Hfuryl), 5.40 (s, 5H, C5H5), 5.20
(d, 1H, J=15.06 Hz, NCHH), 5.00 (d, 1H, J=15.06
Hz, NCHH), 4.74 (dq, 1H, J=1.37, 1.57 Hz,
H3CꢁCꢀCHH), 4.38 (dq, 1H, J=0.98, 1.56 Hz,
H3CꢁCꢀCHH), 3.19 (s, 3H, NCH3), 1.89 (m, 3H,
H3CꢁCꢀCH2). 3d: l=7.36 (dd, 1H, J=0.7, 1.7 Hz,
5-Hfuryl), 6.44–6.39 (m, 1H, 3-Hfuryl), 6.34–6.31 (m, 1H,
4-Hfuryl) 5.40 (s, 5H, C5H5), 5.26 (d, 1H, J=15.06 Hz,
NCHH), 4.99 (d, 1H, J=15.06 Hz, NCHH), 4.66 (m,

K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
39
(H3CꢁCꢀCH2), 143.3 (5-Cfuryl), 111.6 (3-Cfuryl), 110.2
4.5. Pentacarbonyl [E/Z-2-(S)-phenylethylamino(2-
propenyl)carbene]tungsten
(4-Cfuryl), 105.3 (H3CꢁCꢀCH2), 96.8 (C5H5), 58.5
(NCH2), 40.8 (NCH3), 24.9 (H3CꢁCꢀCH2). 3d: l=
279.9 (MoꢀC), 240.8 (CO), 152.3 (2-Cfuryl), 151.1
(H3CꢁCꢀCH2), 143.4 (5-Cfuryl), 111.9 (H3CꢁCꢀCH2),
111.7 (3-Cfuryl), 110.2 (4-Cfuryl), 97.3 (C5H5), 58.6
(NCH2), 41.0 (NCH3), 24.0 (H3CꢁCꢀCH2). MS (EI):
m/z (%): 356 (7) [M+ −CO], 234 (4), 179 (100), 164
(9), 81.0 (88), 41 (25). HR-MS: Found 350.0441.
C15H18MoN2O2 [M+ −CO]. Calc.: 350.0436.
2-(S)-Phenylethylamine (0.46 ml, 4.00 mmol) was
added slowly at −30°C to a solution of 0.82 g (2.00
mmol)
pentacarbonyl[methoxy-(2-propenyl)carbene]-
tungsten in 15 ml dichloromethane. After 30 min the
solution was allowed to reach ambient temperature and
was stirred for another hour. The solvent was removed
and the residue was purified by chromatography on
silica gel using petroleum ether:dichloromethane 3:1 as
eluent. The first yellow band gave yellow needles of the
E-isomer, while the second band afforded the Z-isomer
as a bright-yellow oil. Aminolysis at −78°C afforded
exclusively the E-isomer.
4.4. [N-Benzyl-N-2-furfurylamino(2-propenyl)carbene]-
(carbonyl)(cyclopentadienyl)(nitrosyl)molybdenum 4
As described for the preparation of 3, the reaction of
4.87 ml (7.4 mmol) of 1.6 M n-butyllithium, 1.04 ml
(7.4 mmol) of diisopropylamine, 2.28 g (6.2 mmol) of 2
and 0.88 ml (7.4 mmol) of benzyl bromide gave 1.94 g
(68%) of 4 as a red oil (ratio of isomers 4a:4b:4c:4d=
2:1.3:1.3:1). Rf=0.23 (petroleum ether:diethyl ether
8:1). IR (petroleum ether): w=1933 s (CO), 1620 s
(NO), 1609 sh (NO) cm−1. IR (di-n-butyl ether): w=
1
E-isomer: Yield 0,66 g (66%). H-NMR (300 MHz,
CD3COCD3): l=10.89 (s, 1H, NH), 7.42 (m, 5H,
Haryl), 5.26 (dq, 1H, J=2.27 Hz, 6.85 Hz, CH), 4.76 (s,
1H, ꢀCHH), 4.45 (s, 1H, ꢀCHH), 1.95 (s, 3H, ꢀC(CH3),
1
1.76 (d, 3H, J=6.90 Hz, CH3); H-NMR (300 MHz,
C6D6): l=8.68 (s, 1H, NH), 7.00 (m, 5H, Haryl), 4.48
(dq, 1H, J=2.34 Hz, 6.77 Hz, CH), 4.28 (s, 1H,
ꢀCHH), 4.18 (s, 1H, ꢀCHH), 1.51 (s, 3H, ꢀC(CH3),
0.86 (d, 3H, J=6.86 Hz, CH3). 13C-NMR (75 MHz,
CD3COCD3): l=255.1 (WꢀC), 204.2 (COtrans), 199.6
(COcis), 154.0 (H3CꢁCꢀCH2), 142.0, 129.7, 128.6, 127.0
(Caryl), 104.6 (H3CꢁCꢀCH2), 60.2 (CH), 21.9
(H3CꢁCꢀCH2), 20.1 (H3CꢁCH).
1
1927 s (CO), 1612 s (NO) cm−1. H-NMR (400 MHz,
CDCl3): l=7.43–7.26 (m, 5H, C6H5), 7.20–7.13 (m,
1H, 5-Hfuryl), 6.45–6.15 (m, 2H, 3-Hfuryl, 4-Hfuryl), 5.51,
5.49, 5.44, 5.40 (s, 5H, C5H5), 5.25–4.30 (m, 6H,
H3CꢁCꢀCH2, NCH2,benzyl, NCH2,furfuryl), 1.99, 1.94,
1.83, 1.79 (dd, 3H, J=0.78, 1.37 Hz, H3CꢁCꢀCH2).
13C-NMR (100 MHz, CDCl3): 4a: l=281.4 (MoꢀC),
237.7 (CO), 150.8 (2-Cfuryl), 150.0 (CH3ꢁCꢀCH2), 142.3
(5-Cfuryl), 135.8 (1-Cphenyl), 128.9 (3, 5-Cphenyl), 127.5 (2,
6-Cphenyl), 127.0 (4-Cphenyl), 110.5 (3-Cfuryl), 109.1 (4-
Cfuryl), 105.3 (CH3ꢁCꢀCH2), 96.3 (C5H5), 56.4
(NCH2,furfuryl), 53.7 (NCH2,benzyl), 21.5 (CH3ꢁCꢀCH2).
4b: l=280.6 (MoꢀC), 238.1 (CO), 150.9 (2-Cfuryl),
150.0 (CH3ꢁCꢀCH2), 142.4 (5-Cfuryl), 135.7 (1-Cphenyl),
128.9 (3, 5-Cphenyl), 127.7 (2, 6-Cphenyl), 127.0 (4-Cphenyl),
112.4 (CH3ꢁCꢀCH2), 110.4 (3-Cfuryl), 109.1 (4-Cfuryl),
96.7 (C5H5), 56.2 (NCH2,furfuryl), 53.7 (NCH2,benzyl),
21.8 (CH3ꢁCꢀCH2). 4c: l=282.2 (MoꢀC), 239.0 (CO),
151.4 (2-Cfuryl), 148.9 (CH3ꢁCꢀCH2), 142.8 (5-Cfuryl),
136.0 (1-Cphenyl), 128.7 (3, 5-Cphenyl), 127.7 (2, 6-Cphenyl),
127.0 (4-Cphenyl), 110.5 (3-Cfuryl), 109.4 (4-Cfuryl), 105.4
(CH3ꢁCꢀCH2), 96.1 (C5H5), 60.7 (NCH2,furfuryl), 48.0
(NCH2,benzyl), 24.2 (CH3ꢁCꢀCH2). 4d: l=281.3
(MoꢀC), 238.1 (CO), 151.3 (2-Cfuryl), 149.0
(CH3ꢁCꢀCH2), 142.8 (5-Cfuryl), 135.8 (1-Cphenyl), 128.7
(3, 5-Cphenyl), 127.5 (2, 6-Cphenyl), 127.0 (4-Cphenyl), 111.9
(CH3ꢁCꢀCH2), 110.6 (3-Cfuryl), 109.5 (4-Cfuryl), 95.8
(C5H5), 60.8 (NCH2,furfuryl), 48.1 (NCH2,benzyl), 24.4
(CH3ꢁCꢀCH2). MS (EI): m/z (%): 432 (7) [M+ −CO],
255 (50), 164 (31), 149 (29), 91 (100), 81 (38). HR-MS:
Found: 426.0746. C21H22MoN2O2 [M+ −CO]. Calc.:
426.0749.
1
Z-isomer: Yield 0.18 g (18%). H-NMR (300 MHz,
CD3COCD3): l=10.55 (s, 1H, NH), 7.55 (m, 5H,
Haryl), 5.57 (q, 1H, J=6.77 Hz, CH), 4.66 (s, 1H,
ꢀCHH), 4.57 (s, 1H, ꢀCHH), 2.04 (s, 3H, ꢀC(CH3)),
1
1.84 (d, 3H, J=6.75 Hz, CH3); H-NMR (300 MHz,
C6D6): l=8.11 (s, 1H, NH), 7.04 (m, 5H, Haryl), 5.36
(q, 1H, J=6.78 Hz, CH), 4.19 (s, 1H, ꢀCHH), 4.16 (s,
1H, ꢀCHH), 1.72 (d, 3H, J=6.90 H, CH3), 1.20 (d,
3H, J=6.87 Hz, CH3). 13C-NMR (75 MHz,
CD3COCD3): l=253.8 (WꢀC), 203.8 (COtrans), 199.1
(COcis), 159.4 (H3CꢁCꢀCH2), 141.1, 129.7, 128.8, 127.3
(Caryl), 105.8 (H3CꢁCꢀCH2), 65.5 (CH), 21.4
(H3CꢁCꢀCH2), 16.3 (H3CꢁCH).
Anal. Found: C, 41.00; H, 3.02; N, 2.61;
C17H15NO5W (497.2). Calc.: C, 41.07; H, 3.04; N,
2.82%.
4.6. Pentacarbonyl [E/Z-N-furfuryl-2-(S)-phenylethyl-
amino-(2-propenyl)carbene]tungsten 15
NaH (0.10 g, 4.00 mmol) was added to a solution of
2.6 ml (3.00 mmol) furfuryl alcohol in 10 ml THF at
0°C. After 30 min the solution was cooled to –45°C,
combined with a solution of 0.46 g (2.4 mmol) tosyl
chloride in 5 ml THF and kept below −35°C for 8 h.
A solution of 1.00 g (2.00 mmol) pentacarbonyl [E/Z-
2-(S)-phenylethylamino(2-propenyl)carbene]tungsten,

40
K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
deprotonated with 0.05 g (2.20 mmol) NaH, in 10 ml
THF was added, and the solution was allowed to reach
room temperature over 4 h. Removal of the solvent and
chromatographic work-up on silicia gel using petroleum
ether:dichloromethane 3:1 afforded a mixture (40:60) of
E/Z-15 as a yellow oil.
(MoꢀC), 241.1 (CO), 138.1 (4-C), 131.8 (5-C), 94.0
(3a-C), 93.9 (C5H5), 79.1 (6-C), 74.2 (7a-C), 60.5 (3-C),
42.9 (NCH3), 39.3 (7-C), 25.5 (CH3).-MS (EI): m/z (%):
384 (13) [M+], 356 (28) [M+ −CO], 275 (4), 234 (8),
179 (100), 81 (60), 57 (37). HR-MS: Found: 378.0388.
C16H18MoN2O3. Calcd.: 378.0386.
Yield: 0.61
g
(53%). 1H-NMR (300 MHz,
CD3COCD3): l=7.43 (m, 12H, Haryl, 5-Hfuryl), 6.38
(m, 2H, 4-Hfuryl), 6.21 (dd, 1H, J=0.95 Hz, 2.16 Hz,
3-Hfuryl), 6.09 (d, 1H, J=3.29 Hz, 3-Hfuryl), 6.09 (q, 1H,
J=7.11 Hz, CH), 5.83 (q, 1H, J=6.89 Hz, CH), 5.44,
5.01 (d, 2H, J=16.2 Hz, CH2), 5.43, 4.93 (d, 2H,
J=15.9 Hz, CH2), 4.84 (s, 1H, ꢀCHH), 4.78 (s, 1H,
ꢀCHH), 4.72 (s, 1H, ꢀCHH), 4.65 (s, 1H, ꢀCHH), 2.23
(s, 3H, ꢀC(CH3), 2.14 (s, 3H, ꢀC(CH3), 1.69 (d, 3H,
J=7.09 Hz, CH3), 1.58 (d, 3H, J=6.98 Hz, CH3).
13C-NMR (75 MHz, CD3COCD3): l=199.8, 199.6
(COcis), 157.5 (2-Cfuryl), 149.0 (H3CꢁCꢀCH2) 143.3,
143.7 (5-Cfuryl), 139.0, 127.9–130.9 (Caryl), 111.7 (5-
4.8. Carbonylcyclopentadienyl[(2-benzyl-7a-methyl-1,2,-
3,6,7,7a-hexahydro-3a,6-epoxy-3aH-isoindol)-1-yli-
dene]nitrosylmolybdenum 7
As described for 6 the reaction of 0.46 g (1.0 mmol)
of 4 gave 0.23 g (50%) of 7 as a red solid (ratio of
diastereomers 7a:7b=6:1, d.e.=71%). Rf=0.15
(petroleum ether:diethyl ether 1:1). IR (petroleum
ether): w=1923 s (CO), 1620 s (NO) cm.−1 IR (di-n-
butyl ether): w=1919 s (CO), 1612 s (NO) cm−1
.
1H-NMR (500 MHz, CDCl3): 7a: l=7.40–7.21 (m, 5
H, C6H5), 6.48 (dd, 1H, J=1.69, 5.76 Hz, 5-H), 6.33
(d, 1H, J=5.76 Hz, 4-H), 5.41 (s, 5H, C5H5), 4.97 (dd,
1H, J=1.76, 4.89 Hz, 6-H), 4.85 (d, 1H, J=14.67 Hz,
NCHHC6H5), 4.46 (d, 1H, J=14.67 Hz, NCHHC6H5),
3.89 (d, 1H, J=13.2 Hz, NCHH), 3.67 (d, 1H, J=13.2
Hz, NCHH), 2.90 (dd, 1H, J=5.08, 12.13 Hz, 7-Hanti-6-
H), 1.79 (d, 1H, J=12.13 Hz, 7-Hsyn-6-H), 1.20 (s, 3 H,
CH3). 7b: l=7.40–7.21 (m, 5H, C6H5), 6.47 (dd, 1H,
J=1.78, 5.86 Hz, 5-H), 6.32 (d, 1H, J=5.87 Hz, 4-H),
5.43 (s, 5H, C5H5), 4.82 (dd, 1H, J=1.76 4.89 Hz,
6-H), 4.77 (d, 1H, J=14.87 Hz, NCHHC6H5), 4.45 (d,
1H, J=14.87 Hz, NCHHC6H5), 3.82 (d, 1H, J=11.54
Hz, NCHH), 3.72 (d, 1H, J=11.54 Hz, NCHH), 2.94
(dd, 1H, J=4.89, 12.13 Hz, 7-Hanti-6-H), 1.70 (d, 1H,
J=12.13 Hz, 7-Hsyn-6-H), 1.18 (s, 3H, CH3). 13C-NMR
(125 MHz, CDCl3): 7a: l=281.6 (MoꢀC), 240.8 (CO),
138.3 (4-C), 134.4 (1-Cphenyl), 132.0 (5-C), 129.2 (3,
5-Cphenyl), 128.2 (4-Cphenyl), 127.4 (2, 6-Cphenyl), 93.7
(C5H5), 93.6 (3a-C), 79.5 (6-C), 72.9 (7a-C), 58.9 (3-C),
56.7 (NCH2C6H5), 40.3 (7-C), 22.9 (CH3). 7b: l=280.8
(MoꢀC), 239.9 (CO), 138.1 (4-C), 134.4 (1-Cphenyl),
131.8 (5-C), 129.1 (3, 5-Cphenyl), 128.1 (4-Cphenyl), 127.2
(2, 6-Cphenyl), 93.9 (C5H5), 93.1 (3a-C), 79.1 (6-C), 74.0
(7a-C), 58.8 (3-C), 56.4 (NCH2C6H5), 39.5 (7-C), 20.7
(CH3). MS (EI): m/z (%): 460 (14) [M+], 432 (64)
[M+ −CO], 402 (6) [M+ −CO−NO], 91 (100), 81
(32). HR-MS: Found: 454.0700. C22H22MoN2O3.
Calcd.: 454.0699.
Cfuryl
)
109.5,
109.4
(4-Cfuryl),
105.4,
104.5
(H3CꢁCꢀCH2), 69.3 (CH), 56.3, 54.8 (CH2), 21.4
(H3CꢁCꢀCH2), 19.0, 18.4 (H3CꢁCH). MS (EI): m/z:
577. C22H19NO6W. Calc.: 577.25.
4.7. Carbonyl(cyclopentadienyl)[(2,7a-dimethyl-1,2,3,6,-
7,7a-hexahydro-3a,6-epoxy-3aH-isoindol)-1-ylidene]-
(nitrosyl)molybdenum 6
Compound 3 (0.23 g, 0.7 mmol) was dissolved in 10
ml of di-n-butylether and stirred for 3 h at 90°C. After
removal of the solvent the residue was purified by
chromatography on silica gel at −10°C (eluent
petroleum ether:diethyl ether 1:1). After elution of un-
reacted
3 the eluent was changed to petroleum
ether:diethyl ether (1:4) and 0.05 g (22%) of 6 were
obtained as a red oil (ratio of diastereomers 6a:6b=
4.3:1, d.e.=62%). Rf=0.15 (petroleum ether:diethyl
ether 1:1). IR (petroleum ether): w=1925 s (CO), 1620
s (NO) cm−1. IR (di-n-butyl ether): w=1923 s (CO),
1
1611 s (NO) cm−1. H-NMR (400 MHz, CDCl3): 6a:
l=6.49 (dd, 1H, J=1.58, 5.50 Hz, 5-H), 6.40 (d, 1H,
J=5.48 Hz, 4-H), 5.45 (s, 5H, C5H5), 4.92 (dd, 1H,
J=1.56, 4.69 Hz, 6-H), 4.10 (d, 1H, J=13.30 Hz,
NCHH), 3.89 (d, 1H, J=13.30 Hz, NCHH), 3.17 (s,
3H, NCH3), 2.78 (dd, 1H, J=4.70, 12.52 Hz, 7-Hanti-6-
H), 1.72 (d, 1H, J=12.52 Hz, 7-Hsyn-H-6), 1.14 (s, 3H,
CH3). 6b: l=6.47 (dd, 1H, J=1.58, 5.48 Hz, 5-H),
6.36 (d, 1H, J=5.48 Hz, 4-H), 5.46 (s, 5H, C5H5), 4.94
(dd, 1H, J=1.62 5.48 Hz, 6-H), 4.11 (d, 1H, J=12.52
Hz, NCHH), 3.79 (d, 1H, J=12.52 Hz, NCHH), 3.16
(s, 3H, NCH3), 2.82 (dd, 1H, J=5.48, 12.52 Hz, 7-
Hanti-6-H), 1.66 (d, 1H, J=11.73 Hz, 7-Hsyn-H-6), 1.06 (s,
3H, CH3). 13C-NMR (100 MHz, CDCl3): 6a: l=279.7
(MoꢀC), 241.1 (CO), 138.2 (4-C), 132.0 (5-C), 93.9
(3a-C), 93.8 (C5H5), 79.4 (6-C), 73.2 (7a-C), 60.0 (3-C),
42.3 (NCH3), 40.1 (7-C), 23.0 (CH3). 6b: l=278.8
4.9. Pentacarbonyl[3a-(S*),6-(R*),7a-(R*)-2-(S)-phen-
ylethyl-7a-methyl-1,2,3,6,7,7a-hexahydro-3a,6-epoxy-
3aH-isoindol)-1-ylidene]tungsten 26
A solution of 1.36 g (2.35 mmol) 15 in 20 ml toluene
was warmed to 90°C for 3 h. Removal of the solvent
and chromatographic work-up gave a nearly quantita-
tive yield of two diastereomeric yellow crystalline or

K.H. Do¨tz et al. / Journal of Organometallic Chemistry 583 (1999) 34–41
41
oily products 26, respectively. When the reaction was
carried out in diethyl ether at room temperature for 6 h
a 73% overall yield of 26 was obtained.
Anal. Found: C, 47.20; H, 3.80; N, 2.31;
C22H19NO6W (578.1). Calcd.: C, 45.78; H, 3.32; N,
2.43%. MS (EI): m/z: 577.
3H, CH3). 13C-NMR (75 MHz, CDCl3): l=178.0 (1-
C), 137.5 (4-C), 131.6 (5-C), 139.9, 126.8–128.6 (Caryl),
91.0 (3a-C), 78.8 (6-C), 52.5, 52.4 (7a-C), 48.7, 48.5
(3-C), 43.3 (CH), 35.9 (7-C), 20.5, 20.2 (CH3), 15.5, 15.2
(H3CꢁCH).
Major diastereomer: Yield 0.57
g
(42%). IR
(petroleum ether): w=2065, 1965, 1930, 1915 (CO)
Acknowledgements
1
cm−1. H-NMR (300 MHz, CD3COCD3): l=7.46 (m,
5H, Haryl), 6.62 (dd, 1H, J=1.77 Hz, 5.82 Hz, 5-H),
6.54 (d, 1H, J=5.72 Hz, 4-H), 6.23 (q, 1H, J=6.92
Hz, CH), 5.08 (dd, 1H, J=1.64 Hz, 4.89 Hz, 6-H),
4.47, 3.74 (d, 2H, J=14.15 Hz, 3-CH2), 2.88 (dd, 1H,
J=4.87 Hz, 11.17 Hz, 7-Htrans), 1.96 (d, 3H, J=7.01
Hz, CH3), 1.64 (d, 1H, J=11.79 Hz, 7-Hcis), 1.20 (s,
3H, CH3). 13C-NMR (75 MHz, CD3COCD3): l=260.5
(WꢀC), 203.3 (COtrans), 199.8 (COcis), 139.6 (4-C), 132.8
(5-C), 138.6, 129.7, 128.9, 127.3 (Caryl), 93.6 (3a-C), 80.0
(6-C), 75.6 (7a-C), 65.7 (CH), 54.2 (3-C), 40.8 (7-C),
23.0 (CH3), 17.7. (H3CꢁCH).
Support from the Deutsche Forschungsgemeinschaft
(SFB 334), the Fonds der Chemischen Industrie and the
Ministery of Science and Research (NRW) is gratefully
acknowledged.
References
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Minor diastereomer: Yield 0.42
g (31%). IR
(petroleum ether): w=2065, 1965, 1930, 1915 (CO)
1
cm−1. H-NMR (200 MHz, CD3COCD3): l=7.41 (m,
5H, Haryl), 6.53 (dd, 1H, J=1.78 Hz, 5.81 Hz, 5-H),
6.43 (d, 1H, J=5.78 Hz, 4-H), 6.10 (q, 1H, J=6.09
Hz, CH), 4.79 (dd, 1H, J=1.72 Hz, 4.95 Hz, 6-H),
3.94, 3.58 (d, 2H, J=14.31 Hz, 3-CH2), 2.83 (dd, 1H,
J=4.98 Hz, 11.79 Hz, 7-Htrans), 1.81 (d, 3H, J=7.06
Hz, CH3), 1.55 (d, 1H, J=11.77 Hz, 7-Hcis), 1.06 (s,
3H, CH3). 13C-NMR (75 MHz, CD3COCD3): l=258.0
(WꢀC), 203.3 (COtrans), 199.8 (COcis), 139.5 (4-C), 132.8
(5-C), 137.8, 130.1, 129.6, 128.3 (Caryl), 93.3 (3a-C), 79.8
(6-C), 75.4 (7a-C), 66.1 (CH), 54.5 (3-H), 40.9 (7-C),
22.7 (CH3), 16.3 (H3C-CH).
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4.10. 3a-(S*),6-(R*),7a-(R*)-2-(S)-Phenylethyl-7a-
methyl-1,2,3,6,7,7a-hexahydro-3a,6-epoxy-3aH-
isoindol-1-one 22
A solution of 1.00 g (3.71 mmol) N-furfuryl-N-2-(S)-
phenylethylmethacrylic amide in 50 ml toluene was
warmed to 90°C for 3 h. After removal of the solvent
and chromatographic work-up on silica gel using ether
as eluent the product was obtained as a colourless
liquid.
Yield 0.97 g (97%). 1H-NMR (300 MHz, CDCl3):
l=7.21 (m, 10H, Haryl), 6.38 (m, 2H, 5-H), 6.28 (d,
1H, J=5.83 Hz, 4-H), 6.01 (d, 1H, J=5.81 Hz, 4-H),
5.46 (q, 2H, J=7.06 Hz, CH), 4.89 (m, 2H, 6-H), 3.68,
3.30 (d, 2H, J=11.60 Hz, 3-CH2), 3.46, 3.25 (d, 2H,
J=11.79 Hz, 3-CH2), 2.43 (dd, 1H, J=11.74 Hz,
7-Htrans), 2.42 (dd, 1H, J=4.83 Hz, 11.74 Hz, 7-Htrans),
1.50 (d, 3H, J=7.14 Hz, CH3), 1.46 (d, 3H, J=7.12
Hz, CH3), 1.06 (d, 1H, J=11.80 Hz, 7-Hcis), 1.04 (d,
3H, J=11.91 Hz, 7-Hcis), 1.01 (s, 3H, CH3), 0.93 (s,
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