Influence of the presence of heteroatoms in the olefin chain on the Pauson-Khand reaction with metal (Cr, W) carbene enyne complexes

Article abstract of DOI:10.1016/S0022-328X(99)00287-9

The study of the influence caused by the presence of an heteroatom, either at an internal or terminal site of the olefin, on the outcome of the Pauson-Khand cycloaddition in metal carbene enyne complexes is reported. In this study the steric and electronic effects have been evaluated. A diversion from the normal course of the reaction mechanism is observed.

Full text of DOI:10.1016/S0022-328X(99)00287-9

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 586 (1999) 247–253
Influence of the presence of heteroatoms in the olefin chain on the
Pauson–Khand reaction with metal (Cr, W) carbene enyne
complexes
a
Joan Pares a, Josep M. Moreto´ , Susagna Ricart a,*, Jose´ Barluenga b,1,
Francisco J. Fan˜ana´s b
a Departament de Qu´ımica Orga`nica i Biolo´gica, Institut d’In6estigacions Qu´ımiques i Ambientals de Barcelona Josep Pascual Vila,
(CSIC) C/J.Girona 18-26, E-08034 Barcelona, Spain
b Instituto Uni6ersitario de Qu´ımica Organometalica Enrique Moles, Unidad Asociada al CSIC, Uni6ersidad de O6iedo, Julia´n Cla6eria 8,
E-33011 O6iedo, Spain
Received 7 April 1999
Abstract
The study of the influence caused by the presence of an heteroatom, either at an internal or terminal site of the olefin, on the
outcome of the Pauson–Khand cycloaddition in metal carbene enyne complexes is reported. In this study the steric and electronic
effects have been evaluated. A diversion from the normal course of the reaction mechanism is observed. © 1999 Elsevier Science
S.A. All rights reserved.
Keywords: Carbene complexes; Pauson–Khand cycloadditions; Steric effects; Electronic effects
hances the resulting stereoselectivity. The presence of
the amino group, in the case of metal carbene com-
plexes, is essential for the cycloaddition to be accom-
plished, but we wondered about the possible effects of
the presence of other (coordinating or not) heteroatoms
on the allylic chain either in the product distribution or
in the trapping of intermediates.
A previous study related to the synthesis of different
heteroatom substituted allyl amino derivatives [4] al-
lowed us to obtain heteroatom substituted metal car-
bene enynes by means of their reaction with the carbene
functionality by low temperature aminolysis of the cor-
responding alkoxycarbenes.
1. Introduction
The presence of a transition metal amino carbene
moiety adjacent to a triple bond has been found to
facilitate the intramolecular cobalt mediated Pauson–
Khand (P–K) cycloaddition [1]. Moreover, it allows, in
some cases, the isolation of an intermediate correspond-
ing to the stage immediately preceding the final reduc-
tive elimination (when all the CꢀC bonds but one have
already been accomplished) [2]. Modifications on the
enyne chain seem to be a good way to gain insight into
the reaction mechanism and, in addition, by altering
the electronic and/or steric features to achieve a higher
reaction stereoselectivity.
As has been shown by Krafft and Juliano [3], the
presence of coordinating heteroatoms in the starting
organic enyne in the intramolecular reaction not only
promotes the carbonylative cycloaddition but also en-
2. Results
2.1. Aminolysis reaction
Eight new allylamino carbene complexes displaying
differences in heteroatoms and their site in the allylic
chain were synthesized in generally good yields, as is
shown in Table 1. Only with two amines were the yields
* Corresponding author. Tel.: +34-93-4006115; fax: +34-93-
2045904.
E-mail address: srmqob@cid.csic.es (S. Ricart)
1 Also corresponding author.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00287-9

248
J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
In the case of silicon and tin substituted allylic sub-
strates (3f, 3g) a common cyclopentenone adduct 6f
(Table 2, entries 4 and 5) was obtained that would arise
most probably from the lability of the trimetylsilyl and
tributylstannil groups, respectively, possibly enhanced
by the stabilization of an adjacent a-keto carbanion
derived from the final cycloadduct.
rather low (entries 2, 3 and 8, Table 1): in the first case
this could be justified by the steric hindrance brought
about by the presence of the thiobenzyl unit on the
starting amine; in the second the neutralization of the
corresponding amine hydrochloride in the presence of a
hydroxyl group might have caused solubility problems.
In all cases the only product obtained corresponded
to the one with the allyl chain in trans arrangement to
the metal center (isomer E) [5]. The corresponding Z
isomer could be detected in some cases in the reaction
mixture but always in very low quantities (B3% of the
overall yield).
In entry 6 (Table 2) we obtained a mixture (3:1) of the
corresponding diastereomers 6h. At present we have no
good explanation for the lack of stereochemical control
when starting from allyl systems with a cis double bond,
but we cannot exclude the possibility of a previous
isomerization of the allylic double bond before the P–K
cyclization is accomplished. From the reaction of croty-
lamino carbene complexes, good stereoisomeric control
was obtained for the trans double bond, but the same
mixture of diastereomers was obtained from the cis
isomer [2]. The presence of the heteroatom (oxygen) in
the substituent of the double bond apparently would
not introduce any change in the reaction rates and
therefore in the product distribution of the mixture
obtained.
2.2. Reaction with Co2(CO)8
The cobalt carbonyl mediated cycloaddition (P–K
reaction) was tried with aminocarbene complexes 3
obtained as above. The results are gathered in Table 2.
From Table 2 we can observe that although the
cyclopentenone adduct 6 was obtained in all cases, the
presence of a heteroatom such as sulfur, in the internal
sp2 carbon atom of the allylic chain, produces a global
lowering in the final yields when compared with the
corresponding unsubstituted allylic carbene complexes.
Moreover, in the case of benzyl thio derivatives (entries
2 and 3) an isomerization of the allylic chain (from E to
Z position regarding the metal pentacarbonyl moiety)
[6] provided the formation of the tetracarbonyl adducts
(5b, 5c), pointing out the importance of steric hindrance
in these reactions as reported in a previous paper [2b].
No further reaction beyond this tetracarbonyl species
could be recorded.
2.3. Reaction with aminocarbenes 3d and 3e
The aminocarbenes 3d and 3e displayed an absolutely
different behavior under the same reaction conditions.
When the Co2(CO)8 was added to a THF solution of
these compounds no cyclopentenone adduct was ob-
tained. Instead, a new set of carbene complexes 7 and 8
was identified in both cases (Scheme 1).
These diene complexes seem to arise from a diversion
from the normal course of the P–K cycloaddition after
the first insertion has been accomplished. Prior to the
final carbonylation formal hydride transfer and decoor-
dination would be the preferred pathways to release the
cobalt moiety. A similar mechanism was already de-
scribed by Pauson [7] and Krafft [8] in the P–K reaction
of alkenes bearing an electron-withdrawing substituent.
Table 1
Preparation of alkynyl aminocarbene complexes 3 from complexes 1 and allylamines 2 a
Starting carbene
Amine
R1
R2
Yield (%) b
1
2
3
4
5
6
7
8
1a
1a
1b
1a
1b
1a
1a
1a
2a
2b
2b
2c
2c
2d
2e
2f c
SCH3
SCH2Ph
SCH2Ph
H
H
H
H
H
H
H
H
3a (92)
3b (44)
3c (52)
3d (74)
3e (60)
3f (93)
3g (92)
3h (20) b
SCH3
SCH3
Si(CH3)3
SnBu3
CH2OH
a Standard reaction conditions, THF, −78°C.
b Based on starting carbene 1.
c Starting from the corresponding hydrochloride.

J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
249
Table 2
Reaction of alkynyl aminocarbene complexes 3 with Co2(CO)8 to give compounds 4, 5 and 6 a
Starting compound
Yields b (%)
1
2
3
4
5
6
3a
3b
3c
3f
3g
3h
4a (21)
4b (trc.)
4c (trc.)
–
–
–
5a (trc.)
5b (5)
5c (18)
–
–
–
6a (13)
6b (26)
6c (24)
6f (56) c
6f (41)
6h (50) d
a Standard reaction conditions: Co2(CO)8 (1.1 equivalents), THF, r.t.
b Based on starting compounds 3.
c 6f R1=R2=H.
d Obtained as a mixture (3/1, cis/trans) of diastereomers.
In our case we suppose that the presence of the sulfur
center blocks the carbonylation step allowing alterna-
established by means of nOe measurements as is shown
in Fig. 1.
tive (b-elimination) processes to take place.
No allylic coupling was observed in these systems but
only a slight broadening of the singlets corresponding
to the vinyl protons (at 6.27 and 6.63 ppm, respectively
for compounds 7d and 8d).
1
A H-NMR study of compounds 7d and 8d led us to
assign unequivocally all the protons of the double
bonds. The stereochemistry of compounds 7 and 8 was
Scheme 1.
Fig. 1.

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J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
3. Conclusions
5.18 (d, J=1 Hz, 1H, CH2), 7.21–7.46 (m, 5H, Ph),
8.62 (bs, 1H, NH). 13C-NMR (CDCl3): l 14.6 (q), 57.2
(t), 91.5 (s), 108.8 (t), 121.3 (s), 128.6 (s), 128.7 (d),
130.8 (d), 132.4 (d), 140.7 (s), 198.2 (s), 203.7 (s), 233.8
(C=W). Anal. Calc. for C18H13O5NSW: C, 40.07; H,
2.41; N, 2.59; S, 5.93. Found: C, 40.15; H, 2.41; N,
2.59; S, 5.75%.
The results obtained with heterosubstituted allyl
amino carbene complexes confirm the importance of
the steric and coordinative effects in the P–K reaction
mediated by metal carbene complexes already pointed
elsewhere.
The formation of compounds 7 and 8 indicates that
the presence of a heteroatom with coordinative proper-
ties can not only stabilize the cobalt intermediates as
shown by Krafft in intramolecular systems, but also
lead to a diversion of the normal course of the mecha-
nism by a complete inhibition of the carbonyl insertion
step.
4.2. Preparation of the aminocarbene complex 3b
According to the general procedure 0.482 g (1 mmol)
of complex 1a were allowed to react with 0.260 g (1
mmol) of allylamine 2b. After purification by flash
chromatography 0.270 g (44% yield) of the correspond-
ing aminocarbene 3b were obtained as an orange solid.
3b. IR (CHCl3): 3375, 2167, 2061, 1974, 1920 cm−1
.
4. Experimental
1H-NMR (CDCl3): l 4.02 (s, 2H, SCH2), 4.38 (d,
J=5.8 Hz, 2H, NCH2), 5.15 (s, 1H, CH2), 5.38 (s, 1H,
CH2), 7.25–7.57 (m, 10H, Ph), 8.70 (bs, 1H, NH).
13C-NMR (CDCl3): l 36.7 (t), 57.2 (t), 91.7 (s), 112.9
(t), 121.4 (s), 127.7 (d), 128.8 (d), 131.0 (d), 132.4 (s),
132.5 (d), 135.8 (s), 139.0 (s), 198.3 (s), 203.7 (s), 234.2
(C=W). Anal. Calc. for C24H17O5NSW: C, 46.82; H,
2.76; N, 2.26; S, 5.20. Found: C, 46.61; H, 2.76; N,
2.24; S, 5.17%.
Unless otherwise stated all common reagents and
solvents were used as obtained from commercial suppli-
ers without further purification.
NMR spectra were recorded on a Varian Gemini-200
(200 MHz for 1H-NMR and 50 MHz for 13C) or a
1
Varian XL-300 apparatus (300 MHz for H-NMR and
75.4 MHz for 13C). All samples of carbene complexes
were filtered through a pad of Celite and EDTA prior
to recording the spectra. IR spectra were recorded on a
Bomem FT-IR M-120 spectrophotometer. Mass spectra
were obtained on an AutoSpec-Q mass spectrometer.
Elemental analyses were performed using a Carlo Erba
1106 apparatus.
4.3. Preparation of the aminocarbene complex 3c
According to the general procedure 0.700 g (2 mmol)
of complex 1b were allowed to react with 0.358 g (2
mmol) of allylamine 2b. After purification by flash
chromatography 0.495 g (52% yield) of the correspond-
ing aminocarbene 3c were obtained as an orange solid.
Flash column chromatography was performed with
‘flash grade’ silica (SDS 230–400 mesh).
Unless otherwise indicated all the reactions were
performed under Ar atmosphere.
Carbene complexes 1a,b [9] were prepared by litera-
ture procedures and yields of final products were not
optimized.
3c. IR (CHCl3): 3375, 2165, 2056, 1980, 1942 cm−1
.
1H-NMR (CDCl3): l 4.03 (s, 2H, SCH2), 4.47 (s, 2H,
NCH2), 5.17 (s, 1H, CH2), 5.40 (s, 1H, CH2), 7.38–7.57
(m, 10H, Ph), 8.85 (bs, 1H, NH). 13C-NMR (CDCl3): l
36.5 (t), 57.1 (t), 89.1 (s), 112.6 (t), 121.4 (s), 127.5 (d),
128.6 (d), 130.8 (d), 132.1 (s), 132.4 (d), 135.4 (s), 139.3
(s), 217.0 (s), 223.1 (s), 257.7 (C=W). Anal. Calc. for
C24H17O5NSCr: C, 59.62; H, 3.52; N, 2.89; S, 6.62.
Found: C, 59.54; H, 3.60; N, 2.85; S, 6.67%.
4.1. General procedure for aminolysis. Preparation of
the aminocarbene complex 3a
A total of 0.155 g of the corresponding allyl amine 2a
(1.5 mmol) were added over a stirred solution of 0.723
g of the alkoxy alkynyl carbene complex 1a (1.5 mmol)
in 20 ml of dry THF at −70°C. The reaction course
was monitored by thin-layer chromatography (4:1 hex-
ane–CH2Cl2). After the starting product had com-
pletely reacted, the solvent was removed and the
residue passed through a flash chromatography column
using the mentioned eluent, affording 0.744 g (92%
yield) of the amino complex 3a as an orange solid.
4.4. Preparation of the aminocarbene complex 3d
According to the general procedure 0.723 g (1.5
mmol) of complex 1a were allowed to react with 0.155
g (1.5 mmol) of allylamine 2c. After purification by
flash chromatography 0.600 g (74% yield) of the corre-
sponding aminocarbene 3d were obtained as an orange
solid.
3d. IR (CHCl3): 3379, 2167, 2061, 1974, 1936 cm−1
.
3a. IR (CHCl3): 3381, 2167, 2063, 1974, 1938 cm−1
.
1H-NMR (CDCl3): l 2.18 (s, 3H, CH3), 4.17 (td, J=
5.8, 1 Hz, 2H, NCH2), 5.45 (dt, J=9.4, 6.6 Hz, 1H,
1H-NMR (CDCl3): l 2.16 (s, 3H, SCH3), 4.27 (d,
J=5.8 Hz, 2H, NCH2), 4.78 (d, J=1 Hz, 1H, CH2),

J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
251
SCH), 6.12 (d, J=9.4 Hz, 1H, CH), 7.42–7.58 (m, 5H,
Ph), 8.46 (bs, 1H, NH). 13C-NMR (CDCl3): l 17.2 (q),
50.7 (t), 91.5 (s), 119.5 (d), 121.4 (s), 128.4 (s), 128.7 (d),
130.8 (d), 132.4 (s), 134.3 (d), 198.3 (s), 203.6 (s), 232.1
(C=W). Anal. Calc. for C18H13O5NSW: C, 40.07; H,
2.41; N, 2.59; S, 5.93. Found: C, 40.24; H, 2.39; N,
2.68; S, 5.88%.
6.41 (d, J=12.3 Hz, 1H, SnCH), 6.66 (dt, J=12.3, 6
Hz, 1H, CH), 7.40–7.58 (m, 5H, Ph), 8.47 (bs, 1H,
NH). 13C-NMR (CDCl3): l 10.4 (t), 13.6 (q), 27.2 (t),
29.0 (t), 57.6 (t), 91.7 (s), 121.4 (s), 128.5 (s), 128.7 (d),
130.8 (d), 132.3 (d), 138.9 (d), 139.4 (d), 198.3 (s), 203.5
(s), 232.1 (C=W). Anal. Calc. for C29H37O5NSnW: C,
44.56; H, 4.73; N, 1.80. Found: C, 44.60; H, 5.01; N,
1.96%.
4.5. Preparation of the aminocarbene complex 3e
4.8. Preparation of the aminocarbene complex 3h
According to the general procedure 0.700 g (2 mmol)
of complex 1b were allowed to react with 0.210 g (2
mmol) of allylamine 2c. After purification by flash
chromatography 0.480 g (60% yield) of the correspond-
ing aminocarbene 3e were obtained as an orange solid.
According to the general procedure 0.482 g (1 mmol)
of complex 1a were allowed to react with a mixture of
0.307 g (1 mmol) of the allylamine 2f hydrochloride and
0.252 g (2.5 mmol) of triethylamine. After purification
by flash chromatography 0.095 g (18% yield) of the
corresponding aminocarbene 3h were obtained as an
orange solid.
3e. IR (CHCl3): 3375, 2167, 2056, 1978, 1942 cm−1
.
1H-NMR (CDCl3): l 2.34 (s, 3H, CH3), 4.46 (m, 2H,
NCH2), 5.65 (m, 1H, SCH), 6.32 (d, J=9. Hz, 1H,
CH), 7.44–7.57 (m, 5H, Ph), 8.83 (bs, 1H, NH). 13C-
NMR (CDCl3): l 17.1 (q), 50.9 (t), 89.1 (s), 119.7 (d),
121.5 (s), 128.6 (s), 130.6 (d), 132.0 (d), 132.1 (s), 134.0
(d), 217.0 (s), 223.5 (s), 255.1 (C=Cr). Anal. Calc. for
C18H13O5NSCr: C, 53.07; H, 3.19; N, 3.44; S, 7.86.
Found: C, 53.02; H, 3.17; N, 3.44; S, 7.82%.
3h. IR (CHCl3): 3375, 2950, 2358, 2165, 2061, 1973,
1
1932 cm−1. H-NMR (CDCl3): l 4.34–4.31 (m, 4H,
NCH2, CH2OH), 5.76 (tt, J=11.1, 6.9, Hz, 1H, CH),
5.96 (tt, J=11.1, 6 Hz, 1H, CH), 7.35–7.56 (m, 5H,
Ph), 9.20 (bs, 1H, NH). 13C-NMR (CDCl3): l 49.7 (t),
58.6 (t), 91.3 (s), 121.4 (s), 125.1 (d), 127.6 (s), 128.7 (d),
130.7 (d), 132.2 (d), 133.7 (d), 198.4 (s), 203.6 (s), 230.8
(C=W). Anal. Calc. for C18H13O6NW: C, 41.33; H,
2.48; N, 2.67. Found: C, 41.45; H, 2.43; N, 2.61%.
4.6. Preparation of the aminocarbene complex 3f
According to the general procedure 0.723 g (1.5
mmol) of complex 1a were allowed to react with 0.193
g (1.5 mmol) of allylamine 2d. After purification by
flash chromatography 0.794 g (93% yield) of the corre-
sponding aminocarbene 3f were obtained as an orange
solid.
4.9. General procedure for cyclization. Reaction of
dicobalt octacarbonyl with complex 3a
A total of 0.400 g of Co2(CO)8 (1.2 mmol) were
added to 0.570 g of the (allylamino)carbene complex 3a
(1 mmol) in 20 ml of dry THF, and the reaction
mixture was left, under Ar, at room temperature (r.t.)
for 4 h. The reaction course was monitored by TLC
(1:1 hexane–EtOAc). After the starting product had
been consumed, the solvent was removed and the
residue passed through a flash chromatography column
using the mentioned eluent affording two different
complexes 0.184 g of 4a (21% yield) as a dark oil and
0.075 g of 6a (13% yield) as a red solid.
3f. IR (CHCl3): 3379, 2167, 2063, 1974, 1938 cm−1
.
1H-NMR (CDCl3): l 0.26 (s, 9H, CH3), 4.41 (td, J=
6.6, 1.1 Hz, 2H, NCH2), 6.03 (d, J=14 Hz, 1H, SiCH),
6.42 (dt, J=14, 6.6 Hz, 1H, CH), 7.40–7.63 (m, 5H,
Ph), 8.61 (bs, 1H, NH). 13C-NMR (CDCl3): l 0.10 (q),
54.3 (t), 91.5 (s), 121.3 (s), 128.5 (s), 128.7 (d), 130.8 (d),
132.2 (d), 137.4 (d), 138.7 (d), 198.3 (s), 203.6 (s), 231.9
(C=W). Anal. Calc. for C20H19O5NSiW: C, 42.48; H,
3.36; N, 2.48. Found: C, 42.50; H, 3.31; N, 2.46%.
4a. IR (CHCl3): 3238, 2096, 2032, 1978, 1932 cm−1
.
4.7. Preparation of the aminocarbene complex 3g
1H-NMR (CDCl3): l 2.34 (s, 3H, CH3), 4.70 (d, J=1
Hz, 2H, NCH2), 5.04 (s, 1H, CH2), 5.49 (s, 1H, CH2),
7.34–7.42 (m, 5H, Ph), 9.03 (bs, 1H, NH). 13C-NMR
(CDCl3): l 14.6 (q), 60.2 (t), 104.8 (s), 110.8 (t), 128.6
(d), 128.7 (s), 129.0 (d), 129.5 (d), 137.1 (s), 140.3 (s),
197–198 (bs), 198.2 (s), 201.4 (s), 244.9 (C=W). Anal.
Calc. for C24H13O11NSCo2W: C, 34.91; H, 1.57; N,
1.69; S, 3.88. Found: C, 34.70; H, 1.76; N, 1.70; S,
3.87%.
According to the general procedure 0.723 g (1.5
mmol) of complex 1a were allowed to react with 0.518
g (1.5 mmol) of allylamine 2e. After purification by
flash chromatography 1.09 g (92% yield) of the corre-
sponding aminocarbene 3g were obtained as an orange
solid.
3g. IR (CHCl3): 3377, 2165, 2063, 1974, 1940 cm−1
.
1H-NMR (CDCl3): l 0.90 (t, J=7.2 Hz, 9H, CH3),
0.98–1.04 (m, 6H, SnCH2), 1.30–1.37 (m, 6H, CH2),
1.48–1.56 (m, 6H, CH2), 4.26 (t, J=6 Hz, 2H, NCH2),
6a. IR (CHCl3): 3400, 2063, 1978, 1915 1718 cm−1
1H-NMR (CDCl3): l 2.08 (s, 3H, CH3), 2.97 (d, J=
.

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J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
18.3 Hz, 2H, CH2), 3.09 (d, J=18.3 Hz, 1H, CH2), 3.83
(d, J=12.6 Hz, 1H, NCH2), 3.91 (dd, J=12.6, 1.6 Hz,
1H, NCH2), 7.24–7.50 (m, 5H, Ph), 9.20 (bs, 1H, NH).
13C-NMR (CDCl3): l 12.8 (q), 47.8 (t), 55.9 (s), 65.0 (t),
128.4 (d), 128.8 (s), 129.7 (d), 130.3 (d), 137.1 (s), 143.7
(s), 175.4 (s), 197.0 (s), 201.8 (s), 205.2 (s), 239.6
(C=W). Anal. Calc. for C18H13O5NSW: C, 40.21; H,
2.29; N, 2.47; S, 5.64. Found: C, 40.25; H, 2.33; N,
2.38; S, 5.49%.
129.1 (d), 129.3 (d), 133.1 (d), 136.7 (s), 197–199 (bs),
217.5 (s), 222.2 (s), 254.5 (C=Cr).
6c. IR (CHCl3): 3288, 2054, 1949, 1932, 1905, 1697
1
cm−1. H-NMR (CDCl3): l 2.92 (d, J=18.4 Hz, 1H,
CH2), 3.08 (d, J=18.4 Hz, 1H, CH2), 3.70–3.92 (m,
4H, SCH2, NCH2), 7.26–7.46 (m, 5H, Ph), 9.12 (bs,
1H, NH). 13C-NMR (CDCl3): l 35.4 (t), 48.0 (t), 57.3
(s), 64.8 (t), 127.8 (d), 128.3 (s), 128.5 (d), 128.9 (d),
129.1 (d), 129.6 (d), 130.0 (d), 135.6 (s), 144.3 (s), 173.9
(s), 204.8 (s), 216.3 (s), 222.2 (s), 264.6 (C=Cr). Anal.
Calc. for C24H17O5NSCr: C, 58.70; H, 3.32; N, 2.74; S,
6.26. Found: C, 58.54; H, 3.41; N, 2.76; S, 6.22%.
4.10. Reaction of dicobalt octacarbonyl with complex 3b
After the reaction of 0.135 g of Co2(CO)8 (0.4 mmol)
and 0.220 g of the (allylamino)carbene complex 3b (0.35
mmol) under standard conditions, two new complexes
separated by flash chromatography (1:1 hexane–ethyl
acetate) were obtained from the reaction crude: com-
plex 6b as an orange–red solid (0.060 g, 26% yield) and
5b as a red oil (0.015 g, 5% yield).
4.12. Reaction of dicobalt octacarbonyl with complex
3f
After the reaction of 0.272 g of Co2(CO)8 (0.8 mmol)
and 0.500 g of the (allylamino)carbene complex 3f (0.64
mmol) under standard conditions and purification,
complex 5f [10] was obtained as a red solid (0.156 g,
56% yield).
5b. IR (CHCl3): 2958, 2063, 2044, 2030, 2002, 1940,
1
1919, cm−1. H-NMR (CDCl3): l 2.78 (d, J=15.9 Hz,
1H, CH2), 3.33 (d, J=14.1 Hz, 1H, SCH2), 3.65 (d,
J=12.9 Hz, 1H, NCH2), 3.73 (d, J=12.9 Hz, 1H,
NCH2), 4.22 (dd, J=15.9, 5.1 Hz, 1H, CH2), 7.30–7.58
(m, 5H, Ph), 8.52 (bs, 1H, NH). 13C-NMR (CDCl3): l
43.2 (t), 47.6 (t), 58.4 (s), 67.7 (t), 114.1 (s), 127.6 (d),
128.0 (s), 128.5 (d), 129.0 (d), 129.2 (d), 133.1 (d), 136.5
(s), 197–199 (bs), 198.3 (s), 201.5 (s), 244.3 (C=W).
6b. IR (CHCl3): 3338, 2061, 1984, 1971, 1930, 1895,
4.13. Reaction of dicobalt octacarbonyl with complex
3g
After the reaction of 0.272 g of Co2(CO)8 (0.8 mmol)
and 0.300 g of the (allylamino)carbene complex 3g (0.64
mmol) under standard conditions, and purification,
complex 5f [9] was obtained as a red solid (0.156 g, 41%
yield).
1
1718 cm−1. H-NMR (CDCl3): l 2.91 (d, J=18.4 Hz,
1H, CH2), 3.08 (d, J=18.4 Hz, 1H, CH2), 3.86 (m, 4H,
SCH2, NCH2), 7.25–7.47 (m, 5H, Ph), 9.05 (bs, 1H,
NH). 13C-NMR (CDCl3): l 35.6 (t), 48.1 (t), 57.4 (s),
65.2 (t), 127.8 (d), 128.1 (s), 128.4 (d), 128.9 (d), 129.0
(d), 129.7 (d), 130.3 (d), 135.6 (s), 143.9 (s), 175.5 (s),
197.1 (s), 201.7 (s), 204.5 (s), 240.0 (C=W). Anal. Calc.
for C24H17O5NSW: C, 46.65; H, 2.64; N, 2.17; S, 4.97.
Found: C, 46.52; H, 2.86; N, 2.07; S, 4.66%.
4.14. Reaction of dicobalt octacarbonyl with complex
3h
After the reaction of 0.096 g of Co2(CO)8 (0.28
mmol) and 0.093 g of the (allylamino)carbene complex
3h (0.18 mmol) under standard conditions a new com-
plex was obtained, which after purification by flash
chromatography (1:1 hexane–ethyl acetate), proved to
be a mixture (3/1) of diastereomers of the complex 6h
(0.050 g, 50% yield).
4.11. Reaction of dicobalt octacarbonyl with complex 3c
After the reaction of 0.510 g of Co2(CO)8 (1.5 mmol)
and 0.482 g of the (allylamino)carbene complex 3b (1
mmol) under standard conditions, two new complexes
separated by flash chromatography (1:1 hexane–ethyl
acetate) were obtained from the reaction crude. Com-
plex 6c as an orange–red solid (0.120 g, 24% yield) and
6c as a red oil (0.155 g, 18% yield).
6h. (major isomer) IR (CHCl3): 3388, 2063, 1976,
1
1940, 1915, 1720 cm−1. H-NMR (CDCl3): l 3.04 (td,
J=6.8, 4.8 Hz, 1H, CH), 3.66 (td, J=8.4, 6.8 Hz, 1H,
CH), 3.85–3.89 (m, 4H, NCH2), 7.32–7.44 (m, 5H,
Ph), 9.19 (bs, 1H, NH). 13C-NMR (CDCl3): l 45.5 (d),
49.9 (d), 55.5 (t), 62.1 (t), 128.3 (d), 129.3 (s), 129.5 (s),
130.2 (d), 143.7 (s), 178.7 (s), 197.2 (s), 201.7 (s), 208.6
(s), 238.8 (C=W). MS (FAB+, Xe, matrix NBA) m/e:
551 (M+ +1), 523, 467, 219, 154 (100%).
5c. IR (CHCl3): 3402, 2335, 2059, 2042, 2027, 1976,
1
1936, 1909, cm−1. H-NMR (CDCl3): l 2.82 (d, J=
15.2 Hz, 1H, CH2), 3.26 (d, J=12.8 Hz, 1H, SCH2),
3.32 (d, J=12.8 Hz, 1H, SCH2), 3.61 (d, J=13 Hz,
1H, NCH2), 3.70 (d, J=13 Hz, 1H, NCH2), 4.24 (dd,
J=15.2, 5 Hz, 1H, CH2), 7.30–7.58 (m, 5H, Ph), 8.68
(bs, 1H, NH). 13C-NMR (CDCl3): l 43.0 (t), 47.4 (t),
58.3 (s), 67.6 (t), 114.3 (s), 127.6 (d), 128.0 (s), 128.7 (d),
6h. (minor isomer) IR (CHCl3): 3180, 2061, 1982,
1
1938, 1905, 1741 cm−1. H-NMR (CDCl3): l 2.74 (dd,
J=9.3, 5.1 Hz, 1H, CH), 3.52–3.57 (m, 1H, CH),
3.98–4.04 (m, 2H, NCH2), 4.08–4.13 (m, 2H, CH2),

J. Pares et al. / Journal of Organometallic Chemistry 586 (1999) 247–253
253
7.37–7.44 (m, 5H, Ph), 9.10 (bs, 1H, NH). 13C-NMR
(CDCl3): l 45.5 (d), 48.1 (d), 54.2 (t), 60.4 (t), 128.3 (d),
129.4 (s), 129.5 (s), 130.1 (d), 143.3 (s), 177.6 (s), 197.1
(s), 201.8 (s), 208.3 (s), 238.3 (C=W).
(d), 130.1 (d), 135.9 (s), 143.4 (d), 144.5 (s), 218.2 (s),
222.7 (s), 266.2 (C=Cr). Anal. Calc. for
C18H13O5NSCr: C, 53.07; H, 3.19; N, 3.44; S, 7.86.
Found: C, 52.44; H, 3.42; N, 3.32; S, 7.60%.
1
8e. IR (CHCl3): 3411, 2054, 1930 cm−1. H-NMR
4.15. Reaction of dicobalt octacarbonyl with complex 3d
(CDCl3): l 2.15 (s, 3H, SCH3), 4.53 (s, 2H, NCH2),
6.53 (s, 1H, SCH), 7.33–7.55 (m, 5H, Ph), 7.76 (s, 1H,
CH), 8.84 (bs, 1H, NH). 13C-NMR (CDCl3): l 17.4 (q),
58.8 (t), 124.6 (s), 126.2 (d), 128.1 (d), 128.8 (d), 130.1
(d), 136.0 (s), 143.1 (d), 145.7 (s), 218.1 (s), 222.6 (s),
265.7 (C=Cr).
After the reaction of 0.372 g of Co2(CO)8 (1.1 mmol)
and 0.452 g of the (allylamino)carbene complex 3d (0.84
mmol) under standard conditions and separation of the
crude by flash chromatography, two new stereoisomeric
carbene complexes were obtained: 7d (0.215 g, 47%
yield) and 8d (0.077 g, 17% yield).
1
7d. IR (CHCl3): 3413, 2061, 1967, 1928 cm−1. H-
Acknowledgements
NMR (CDCl3): l 2.27 (s, 3H, SCH3), 4.49 (s, 2H,
NCH2), 6.27 (s, 1H, SCH), 7.32–7.44 (m, 5H, Ph), 7.85
(s, 1H, CH), 9.12 (bs, 1H, NH). 13C-NMR (CDCl3): l
19.4 (q), 61.1 (t), 124.4 (s), 127.6 (d), 128.1 (s), 128.7
(d), 130.2 (d), 135.8 (s), 144.8 (d), 145.4 (s), 198.3 (s),
202.4 (s), 245.7 (C=W). Anal. Calc. for
C18H13O5NSW: C, 40.07; H, 2.41; N, 2.59; S, 5.93.
Found: C, 40.21; H, 2.49; N, 2.53; S, 5.80%.
The authors acknowledge the financial support from
DGICYT (PB-97-0407-CO5-05) and Generalitat de
Catalunya (Grant 5G395-0439).
References
1
8d. IR (CHCl3): 3400, 2059, 1960, 1929 cm−1. H-
[1] (a) F. Camps, J.M. Moreto´, S. Ricart, J.M. Vin˜as, Angew.
Chem. Int. Ed. Engl. 30 (1991) 1470. (b) L. Jordi, S. Ricart, J.M.
Vin˜as, J.M. Moreto´, Organometallics 16 (1997) 2808.
[2] L. Jordi, J.M. Moreto´, S. Ricart, J.M. Vin˜as, M. Mejias, E.
Molins, Organometallics 11 (1992) 3507.
[3] M.E. Krafft, C.A. Juliano, J. Org. Chem. 57 (1992) 5106.
[4] (a) S.A. Burns, R.J.P. Corriu, H. Huynh, J.J.E. Moreau, J.
Organomet. Chem. 333 (1987) 281. (b) J. Barluenga, F.J.
Fan˜anas, F. Toubelo, M. Yus, J. Chem. Soc. Chem. Commun.
(1988) 1135. (c) J. Barluenga, R.M. Canteli, J. Flo´rez, J. Org.
Chem. 59 (1994) 602. (d) J. Barluenga, R.M. Canteli, J. Flo´rez,
J. Org. Chem. 59 (1994) 1586.
NMR (CDCl3): l 2.19 (s, 3H, SCH3), 4.34 (s, 2H,
NCH2), 6.63 (s, 1H, SCH), 7.35–7.58 (m, 5H, Ph), 7.72
(s, 1H, CH), 8.77 (bs, 1H, NH). 13C-NMR (CDCl3): l
20.2 (q), 61.5 (t), 122.9 (s), 125.8 (d), 128.1 (d), 128.7
(d), 130.1 (d), 135.2 (s), 143.5 (d), 144.9 (s), 198.7 (s),
201.8 (s), 245.7 (C=W).
4.16. Reaction of dicobalt octacarbonyl with complex 3e
After the reaction of 0.460 g of Co2(CO)8 (1.3 mmol)
and 0.455 g of the (allylamino)carbene complex 3e (0.97
mmol) under standard conditions and separation of the
crude by flash chromatography, two new stereoisomeric
carbene complexes were obtained: 7e (0.165 g, 33%
yield) and 8e (0.152 g, 30% yield).
[5] R. Sabate´, U. Schick, J.M. Moreto´, S. Ricart, Organometallics
15 (1996) 3611.
[6] C.P. Casey, N.W. Vollendorf, K.J. Haller, J. Am. Chem. Soc.
106 (1984) 3754.
[7] (a) I.U. Khand, P.L. Pauson, J. Chem. Soc. Chem. Commun.
(1974) 379. (b) I.U. Khand, P.L. Pauson, Heterocycles 11 (1978)
59.
[8] (a) M.E. Krafft, C.A. Juliano, J.L. Scott, C. Wright, M.D.
McEachin, J. Am. Chem. Soc. 113 (1991) 1693. (b) M.E. Krafft,
A.M. Wilson, O.A. Dasse, L.V.R. Bonaga, Y.Y. Cheung, Z. Fu,
B. Shao, I.L. Scott, Tetrahedron Lett. 39 (1998) 5911.
[9] K.H. Do¨tz, W. Kuhn, J. Organomet. Chem. 286 (1985) C23.
[10] This complex has been described in Ref. [1a].
1
7e. IR (CHCl3): 3413, 2054, 1971, 1932 cm−1. H-
NMR (CDCl3): l 2.24 (s, 3H, SCH3), 4.50 (s, 2H,
NCH2), 6.21 (s, 1H, SCH), 7.30–7.41 (m, 5H, Ph), 7.86
(s, 1H, CH), 8.83 (bs, 1H, NH). 13C-NMR (CDCl3): l
19.5 (q), 60.8 (t), 125.0 (s), 127.6 (d), 128.3 (d), 128.7
.
.