Syntheses of highly unsaturated isocyanides via organometallic pathways

Article abstract of DOI:10.1039/c1dt11382h

The carbon carbon coupling reaction by nucleophilic attack of (CO) ₅Cr(CN-CFCF₂) 1 by lithium or Grignard compounds 2a-i yields the isocyanide complexes (CO)₅Cr(CN-CFCF-R) 3a-i (a R = CHCH₂, b R = CHCF₂, c R = CCH, d R = CC-SiMe₃, e R = CC-Ph, f R = CC-C₆F₄OMe, g R = CC-C ₆H₃(CF₃)₂, h R = C₆F ₅, i R = C₆H₃(CF₃)₂) as mixtures of E and Z isomers. The dinuclear complexes 5a-c are obtained from the reaction of 1 with the dilithio or dimagnesium compound 4a-c as the Z,Z-, E,Z- and E,E-isomers, respectively. (CO)₅Cr(CN-CFCF-CC-CC-CFCF-NC)Cr(CO) ₅7 is obtained as a mixture of Z,Z-, Z,E- and E,E-isomers from (CO)₅Cr(CN-CFCF-CC-H 3d by Eglington-Glaser coupling. (CO) ₅Cr(CN-CFCF-CC-CFCF-NC)Cr(CO)₅6 and (CO) ₅Cr(CN-CFCF-CC-CC-CFCF-NC)Cr(CO)₅7 react with octacarbonyldicobalt forming the cluster compounds Z,Z-[{η²- μ₂-(CO)₅Cr(CN-CFCF-CC-CFCF-NC)Cr(CO) ₅}Co₂(CO)₆] Z,Z-8, E,Z-[{η²- μ₂-(CO)₅Cr(CN-CFCF-CC-CFCF-NC)Cr(CO) ₅}Co₂(CO)₆] E,Z-8 and E,E-[{η²- μ₂-(CO)₅Cr(CN-CFCF-CC-CFCF-NC)Cr(CO) ₅}Co₂(CO)₆] E,E-8 and Z,Z-[{η²- μ₂-(CO)₅Cr(CN-CFCF-CC-CC-CFCF-NC)Cr(CO) ₅}{Co₂(CO)₆}₂] Z,Z-9, E,Z-[{η²-μ₂-(CO)₅Cr(CN-CFCF-CC-CC-CFCF- NC)Cr(CO)₅}{Co₂(CO)₆}₂] E,Z-9 and E,E-[{η²-μ₂-(CO)₅Cr(CN-CFCF-CC-CC-CFCF- NC)Cr(CO)₅}{Co₂(CO)₆}₂] Z,Z-9, respectively. The crystal and molecular structures of E-3d, Z-3h, Z,Z-8, E,Z-8 and Z,Z-9 were elucidated by single-crystal X-ray crystallography.

Full text of DOI:10.1039/c1dt11382h

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PAPER
Syntheses of highly unsaturated isocyanides via organometallic pathways†
Monika Mujkica,b and Dieter Lentz*a
Received 22nd July 2011, Accepted 29th September 2011
DOI: 10.1039/c1dt11382h
The carbon carbon coupling reaction by nucleophilic attack of (CO)
Grignard compounds 2a–i yields the isocyanide complexes (CO) Cr(CN–CF CF–R) 3a–i (a R =
CH CH , b R = CH CF , c R = C CH, d R = C C–SiMe , e R = C C–Ph, f R = C C–C OMe,
g R = C C–C (CF , h R = C , i R = C (CF ) as mixtures of E and Z isomers. The dinuclear
complexes 5a–c are obtained from the reaction of 1 with the dilithio or dimagnesium compound 4a–c as
the Z,Z-, E,Z- and E,E-isomers, respectively. (CO) Cr(CN–CF CF–C C–C C–CF CF–NC)-
Cr(CO) 7 is obtained as a mixture of Z,Z-, Z,E- and E,E-isomers from (CO) Cr(CN–CF
CF–C C–H 3d by Eglington-Glaser coupling. (CO) Cr(CN–CF CF–C C–CF CF–NC)Cr(CO)
and (CO) Cr(CN–CF CF–C C–C C–CF CF–NC)Cr(CO) 7 react with octacarbonyldicobalt
Cr(CN–CF CF–C C–CF CF–NC)Cr-
Cr(CN–CF CF–C C–CF CF–NC)Cr(CO)
}-
Cr(CN–CF CF–C C–CF CF–NC)Cr(CO)
Cr(CN–CF CF–C C–C C–CF CF–NC)Cr(CO)
Cr(CN–CF CF–C C–C C–CF CF–NC)Cr(CO)
-(CO) Cr(CN–CF CF–C C–C C–CF CF–NC)-
] Z,Z-9, respectively. The crystal and molecular structures of E-3d, Z-3h,
5
Cr(CN–CF CF
2
) 1 by lithium or
5
2
2
3
6
F
4
6
H
3
3
)
2
6
F
5
6
H
3
)
3 2
5
5
5
5
5
6
5
5
2
forming the cluster compounds Z,Z-[{h -m
2
-(CO)
5
2
(CO)
5
}Co
2
(CO)
6
] Z,Z-8, E,Z-[{h -m
2
-(CO)
5
5
2
Co
Co
2
(CO)
(CO)
6
] E,Z-8 and E,E-[{h -m
2
-(CO)
5
5
}
2
2
6
] E,E-8 and Z,Z-[{h -m
2
-(CO)
-(CO)
5
5
}-
2
{
Co
Co
2
(CO)
(CO)
6
}
}
2
] Z,Z-9, E,Z-[{h -m
2
5
5
}
2
{
2
6
2
] E,Z-9 and E,E-[{h -m
2
5
Cr(CO)
5
}{Co
2
(CO)
6 2
}
Z,Z-8, E,Z-8 and Z,Z-9 were elucidated by single-crystal X-ray crystallography.
Introduction
on chloroethenyl isocyanides synthesized and stabilized at a
pentacarbonyl chromium fragment in 1989.
In 1991 we reported on the preparation, microwave spec-
troscopic study, and structure of the first alkynyl isocyanide,
ethynyl isocyanide, H–C C–NC, by vacuum pyrolysis of
14
1
Ethenyl isocyanide was prepared by Matteson and Bailey almost
00 years after the synthesis of the first isocyanides, ethyl iso-
1
2
3
cyanide by Gautier and phenyl isocyanide by Hofmann. Despite
the high potential in multicomponent reactions further examples
4
a suitable organometallic precursor molecule, (CO)
5
Cr(CN–
5
of alkenyl isocyanides like CH
3
–CH CH–NC, H
5
C
6
–CH CH–
15
CCl CCl(H). Shortly after the rotational constants of this
molecule were published, Kawaguchi et al. succeeded in de-
tecting H–C C–NC in TMC-1 (Taurus Molecular Cloud) by
6
7
NC, 1-isocyano-2-dimethylamino-alkenes or 1(S)-camphor-2-
8
cis-methylidene-isocyanide are still rare and CH
3
CH C(CH )–
3
9
CH CH–NC is the only one of these having conjugated
double bonds. Some of these have been used in polymerization
16
radioastronomy. H–C C–NC has been subsequently stud-
17
ied by HeI and HeII photoelectron spectroscopy, millimetre
10
experiments forming poly(vinyliminomethylenes) and in the
synthesis of heterocycles. 1-isocyano-2-dimethylamino-alkenes
or 1(S)-camphor-2-cis-methylidene-isocyanide have been success-
fully used as isocyanide in multicomponent reactions. The first
18
19
wave spectroscopy, high-resolution FTIR spectroscopy, and
11
7
20
NMR spectroscopy. Recently the very unstable CN–C C–CN
8
molecule, which had only been obtained before in an argon matrix
21
and characterised by IR spectroscopy, was synthesised, and
fluorinated ethenyl isoycanide, F
2
C
CF–NC, was synthesized
22
a broad study has been performed by a collaborative effort.
12
in 1992 and its structure was elucidated by low temperature
Propynyl isocyanide is the only further alkynyl isocyanide that
had been obtained thus far in preparative quantities and studied
13
single-crystal X-ray crystallography. Fehlhammer et al. reported
2
0,23
by various spectroscopic methods.
succeeded in generating H–(C C)
.1 to 1 picomol) along with large amounts of other com-
Recently, Thaddeus et al.
a
Fachbereich Biologie, Chemie, Pharmazie, Institut f u¨ r Chemie und
n
–NC (n = 2,3) (approximately
Biochemie-Anorganische und Analytische Chemie, Freie Universit a¨ t Berlin,
Fabeckstraße 34-36, D-14195, Berlin, Germany. E-mail: lentz@chemie.fu-
berlin.de; Fax: (+49)30-8382424
0
pounds by electrical discharge in a molecular beam of butadiyne,
b
24,25
present address: Tetramer Technologies, LLC, 657 S. Mechanic St.,
propynenitrile or others seeded in Ne.
The detection of the
Pendleton, SC 29670, USA
isocyanopolyyne molecules was based solely on Fourier transform
microwave spectroscopy in combination with ab initio calculations.
Fehlhammer et al. succeeded in synthesising and stabilising
†
CCDC reference numbers 179717–179718 and 836248–836250. For
crystallographic data in CIF or other electronic format see DOI:
0.1039/c1dt11382h
1
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H–C C–NC, Me
sition metal complex. However, no attempt has been made to
obtain the free isocyanides.
3
Si–C C–NC and C
6
H
5
–C C–NC in a tran-
nucleophilic attack of the complex 1 occurs exclusively at the
difluoromethylene group in the b position to the isocyanide
26
22,32
nitrogen atom, as observed earlier.
No by-products from the
Thus far, all methods for the preparation of halogenated
alkenyl isocyanides were based on the radical halogenation
of tetraethylammonium(pentacarbonyl)chromate in a suitable
halogenated alkane. This method requires halogenated alka-
nes and therefore is limited to molecules with relatively
small chain length. Consequently, only a few alkenyl and
alkynyl isocyanides could be prepared by the pyrolysis of (1,2-
dichloroalkenyl isocyanide)(pentacarbonyl)chromium complexes.
Although Fehlhammer’s method for the synthesis of metal
complex stabilised alkynyl isocyanides is promising it has been
demonstrated only on three examples and failed in an attempt
other possible reaction channels were observed so far although
pentacarbonyl(trifluoromethyl isocyanide)chromium is easily at-
tacked by nucleophiles resulting in the formation of carbene
33
complexes.
The trifluoroethenyl isocyanide complex 1 reacts readily with
Grignard and lithium compounds 2a–i yielding the isocyanide
complexes 3a–i, respectively. (Scheme 2) As expected, mixtures of
the two possible constitutional isomers E-3a–i and Z-3a–i were
3
19
19
formed. As the J( F- F) coupling constants of cis and trans
configurated fluoro alkenes differ by at least one to two orders of
3
3
34
magnitude, | Jcis| < | Jtrans|, the constitution and the isomeric
26
19
to synthesise (CO)
5
Cr(CN–C C–t-Bu) or (CO)
5
Cr(CN–C C–
ratio can be easily deduced from the F NMR spectra.
27
CF
which are not generally available.
3
). Furthermore, it requires alkynyl(phenyl)iodonium salts,
28
Pentacarbonyl(trifluoroethenyl isocyanide)chromium behaves
like a fluoroalkene. For example, it dimerizes on heating forming
29
a four membered ring. Highly fluorinated alkenes are very
electrophilic systems. Therefore, they can be easily attacked by
nucleophiles resulting in an intermediate carbanion, which can
30
undergo further reactions to the final products.
In principal there are several different possibilities for
a nucleophilic attack of pentacarbonyl(trifluoroethenyl iso-
cyanide)chromium (Scheme 1) including the carbonyl or iso-
31
cyanide carbon atoms, which would lead to carbene complexes
or the metal atom, forming substitution products. In recent
22,32
Scheme 2
publications
we have shown that the nucleophilic attack occurs
group of pentacarbonyl(trifluoroethenyl iso-
solely at the CF
2
cyanide)chromium and related compounds, allowing a systematic
variation of the substituent in the b position to the isocyano
group. In continuation of our work on unsaturated isocyanides
we report in detail on the synthesis and structural determination
of highly unsaturated halogenated alkenyl isocyanide complexes
with conjugated double and triple bonds.
Selected NMR spectroscopic data of 3a–i are listed in Table 1
together with the isomeric ratio. In most cases the Z isomer is the
expected prevailing one. This is in accordance with the so called
35
cis effect observed for example in the higher thermodynamical
stability of Z-1,2-difluoro ethene compared to the E isomer. In
general the E isomer is formed in slightly larger amounts if
the Grignard reagent is used as the nucleophile suggesting that
the isomeric ratio depends more strongly on kinetic effects than
thermodynamic stability. As observed earlier, the Z isomer is the
32,36
dominating one if organo lithium compounds are used.
Reaction of 1 with the dilithio or dimagnesio compounds 4a–c
yields an isomeric mixture, ZZ, EZ and EE, of the disocyanide
complexes 5a–c, as depicted in Scheme 3. The isomeric ratios have
been determined as ZZ : EZ : EE = 51 : 15 : 1 and 5 : 9 : 2 for 5a and
5
b, respectively, but can cannot be determined reliably for 5c as
1
9
the signals of the isomers could not be resolved in the F NMR
spectrum. This fact is probably due to the large distances between
the two ethenyl groups.
The highly unsaturated diisocyanide complex 6, in which two di-
fluoroethenyl isocyanide units are connected by one carbon carbon
triple bond, has already been obtained earlier by reaction of 1 with
tributylstannylethyne and butyllithium. In order to create longer
chain molecules a different synthetic strategy has to employed.
Scheme 1
36
Results and discussion
(CO)
5
Cr(CN–CF CF–C C–C C–CF CF–NC)Cr(CO)
5
7 is
formed in high yields by an Eglington-Glaser coupling reaction
Synthesis
37
using Hay conditions, as presented in Scheme 4.
1
9
Our synthetic strategy is based on the systematic modification of
trifluoroethenyl isocyanide. As very electrophilic systems, highly
fluorinated alkenes can be easily attacked by nucleophiles. The
According to the F NMR spectrum the ZZ-, EZ- and EE-
isomers are formed in a ratio of 9 : 3 : 1. Interestingly, the isomeric
ratio is independent from the one of 3c, even if pure Z-3c, which
30
8
40 | Dalton Trans., 2012, 41, 839–849
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19
Table 1
F NMR data of 3a–i
3
19
19
Compound
d(F1)/d(F2)
J( F1- F2)
Ratio Z/E reagent
Further data
Z-3a
E-3a
Z-3b
E-3b
Z-3c
E-3c
Z-3d
E-3d
Z-3e
E-3e
Z-3f
E-3f
Z-3g
E-3g
Z-3h
-121.2/-148.2
-138.1/-156.1
-120.3/-144.0
-137.45/-153.54
-108.3/-137.8
-127.4/-147.5
-112.1/-134.8
-128.2/-144.3
-110.7/-133.6
-128.4/-143.4
-106.1/-137.9
-124.6/-147.1
-106.6/-137.8
-124.9/-141.5
-108.5/-139.4
0
1 : 2
117
29.5
122
127
grignard reagent
20 : 1
lithium reagent
-72.62/-74.29 (CF
-73.37/-75.53 (CF
2
)
)
2
3
127
0
126.0
0
126.0
0
11 : 9/9 : 1
grignard/lithium
4 : 6/9 : 1
grignard/lithium
16 : 1
lithium
1 : 5/9 : 1
-64.2 (CF
-64.2 (CF
3
)
)
)
)
)
126.0
0
grignard/lithium
13 : 1
3
-133.5 (F
o
-
157.6 (F
144.7 (F
m
-
p
E-3h
-124.6/-141.5
129.7
lithium
-133.9(F
o
)
-
158.2(F
145.4(F
m
)
p
-
)
Z-3i
E-3i
-109.6/-142.9
-128.5/-151.3
0
36 : 1
lithium
-63.9 (CF
3
)
)
122.5
-63.9 (CF
3
Scheme 3
and to allow a separation of the isomers, 6 and 7 were treated
with octacarbonyl dicobalt forming the expected alkyne clus-
2
ter compounds [{h -m
2
-(CO)
5
Cr(CN–CF CF–C C–CF CF–
2
2
NC)Cr(CO)
5
}Co
2
(CO)
6
] 8 and [{h -m
2
-h -m
2
- (CO)
5
Cr(CN–
] 9,
CF CF–C C–C C–CF CF–NC)Cr(CO)
5
}{Co
2
(CO)
6 2
}
1
9
respectively. As can be seen from the F NMR spectra the isomeric
ratios are maintained during the reaction and 8 and 9 are again
formed as mixture of isomers. Column chromatography on silica
allowed at least the enrichment and crystallization of the most
abundant Z,Z isomers of 8 and 9 and the E,Z isomer of 8.
Again the different isomers can be easily distinguished by the
3
19
19
very different J( F- F) coupling constant of the constitutional
isomers.
Crystal structures
The crystal and molecular structures of E-3d, Z-3h, Z,Z-8, E,Z-
8
and Z,Z-9 were elucidated by single-crystal X-ray diffraction.
Selected bond lengths and angles are listed in Table 2 for compari-
son. ORTEP drawings of the molecules with the atomic numbering
scheme are given in Fig. 1, 2, 3 and 4. The crystallographic data
for E-3d, Z-3h, Z,Z-11, E,Z-11 and Z,Z-12 are summarised in
Table 3.
In all of the complexes studied by single-crystal X-ray crystal-
lography the chromium atom is coordinated almost octahedrally
by the five carbonyl ligands and the isocyanide ligand. The Cr–C
distances to the carbonyl ligands show only small variations and
Scheme 4
can be obtained by multiple sublimation of 3c, is used as a
starting material. Thus, we can conclude that the intermediate
compounds formed during the coupling reaction can undergo
isomerization of the C–C double bond. All attempts to separate the
isomers by chromatography using different eluents and stationary
phases failed. In order to stabilize the highly reactive alkynes,
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◦
Table 2 Selected bond lengths ( A˚ ) and angles ( ) of E-3d, Z-3h, Z,Z-8, E,Z-8, 9
Bond/angle E-3d
Z-3h
Z,Z-8
E,Z-8
Z,Z-9
Cr–Ctrans
Cr–Ccis
Cr–Cisocyanide
1.909(4)
1.900–1.922(4)
1.931(4)
1.912(3)
1.903–1.926(3)
1.925(3)
1.910(2), 1.904(2)
1.906(2)–1.925(2)
1.924(2), 1.931(2)
1.341(2), 1.338(2)
1.882(6), 1.884(6)
1.883(6)–1.903(6)
1.907(6), 1.913(6)
1.309(7), 1.325(7)
1.905(10)
1.901(10)–1.911(10)
1.936(10)
C
C
1.315(5))
1.313(5)
1.315(11)
C–F
1.327(5), 1.341(4) 1.338(4), 1.349(4) 1.340(2), 1.342(2), 1.340(2), 1.343(2) 1.325(6), 1.345(6), 1.359(5), 1.352(5) 1.356(9)
C–N–C
F1–C–N
F2–C–C
Co–C
176.1(3)
114.3(3)
117.8(3)
174.8(3)
113.9(3)
115.4(3)
167.0(2), 168.0(2)
114.7(2), 114.3(1)
116.3(1), 116.8(1)
169.5(6), 170.5(5)
114.2(5), 113.2(5)
117.0(4), 116.0(4)
158.1(9)
115.3(8)
113.7(7)
1.934(2), 1.978(2), 1.932(2), 1.980(2) 1.928(5), 1.933(5), 1.931(5), 1.963(5) 1.915(8), 1.975(8),
.950(8), 1.963(8)
1
2
h -C
C
1.362(2)
1.370(6)
1.353(11)
Table 3 Crystallographic data for E-3d, Z-3h, Z,Z-8, E,Z-8, 9
E-3d
Z-3h
Z,Z-8
E,Z-8
9
Chemical formula
Formula mass
C
377.30
13
H
9
CrF
2
NO
5
Si
C
447.15
14CrF
7
NO
5
C
24Co
2
Cr
2
F
4
N
2
O
16
C
870.12
Orthorhombic
13.6560(10)
12.1796(9)
36.970(3)
90.00
90.00
90.00
6149.0(8)
193(2)
Pbca
8
Mo-Ka
1.850
51 431
5439
24Co
2
Cr
2
F
4
N
2
O
16
C
32Co
4
Cr
2 4 2 22
F N O
870.12
Triclinic
10.0587(6)
12.0685(7)
13.6716(8)
107.4920(10)
93.9400(10)
103.9440(10)
1518.29(15)
193(2)
P1
2
Mo-Ka
1.873
21 046
10 576
0.0214
0.0288
0.0780
0.0357
0.0821
1.033
1180.06
Crystal system
Monoclinic
6.1314(18)
11.701(2)
23.613(6)
90.00
93.923(5)
90.00
1690.1(8)
173(2)
P2
4
Mo-Ka
0.788
19 666
3458
0.0491
0.0463
0.1094
0.0700
0.1219
1.054
Monoclinic
21.850(5)
6.184(2)
11.752(4)
90.00
98.566(10)
90.00
1570.2(9)
173(2)
P2
4
Mo-Ka
0.837
16 978
3220
0.0477
0.0405
0.0966
0.0634
0.1080
1.021
Orthorhombic
13.994(3)
11.837(3)
24.944(6)
90.00
90.00
90.00
a/A˚
b/A˚
c/A˚
◦
a/
◦
b/
◦
g /
Unit cell volume/A˚
T/K
3
4131.9(16)
193(2)
Pbca
¯
Space group
No. of formula units per unit cell, Z
Radiation type
Absorption coefficient, m/mm
No. of reflections measured
No. of independent reflections
1
/n
1
/c
4
Mo-Ka
2.181
32 362
3671
0.0420
0.0666
0.1720
0.0772
0.1783
1.224
-1
R
int
0.1272
0.0387
0.0606
0.0987
0.0679
1.034
Final R
Final wR(F ) values (I > 2s(I))
values (all data)
1
values (I > 2s(I))
2
Final R
1
2
Final wR(F ) values (all data)
2
Goodness of fit on F
40
Fig. 2 Molecular structure (ORTEP ) of Z-3h. Ellipsoids drawn at 50%
probability scale.
˚
A with the shortest distances observed for E,Z-8, which also has
the shortest Cr–CO distances, probably due to libration effects.
The C–C bond lengths of the ethenyl units are in a range observed
for C–C double bonds. In all of the cobalt clusters the C–C bond
of the coordinated triple bond is lengthened to between 1.353 and
40
Fig. 1 Molecular structure (ORTEP ) of E-3d. Ellipsoids drawn at 50%
probability scale.
˚
most importantly the distances show no significant dependence
on the position cis or trans to the isocyanide ligand. The Cr–C
distances to the isocyanide carbon atom vary from 1.907 to 1.936
1.370 A. As in other isocyanide complexes the isocyanide moiety
exhibits small deviations from linearity, which are probably due to
crystal packing effects.
8
42 | Dalton Trans., 2012, 41, 839–849
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due to the high reactivity of fluorine substituted isocyanides the
compounds can only be handled if stabilized at the metal centre.
In order to use them, for example, as reagents for multicomponent
reactions in situ, deprotection strategies need to be developed.
Experimental
General
All reactions were carried out under dry argon by using stan-
dard Schlenk and vacuum techniques. Volatile materials were
handled in a conventional glass vacuum line and amounts were
determined by PVT techniques. Moisture sensitive compounds
were handled in an automatic dry box (Braun) under dry
1
19
13
argon. H, F and C NMR spectra were recorded using a
JEOL LAMBDA 400 instrument with TMS or solvent signals
1
13
19
(
H, C) and CFCl
were taken on a Shimadzu, Nicolet 5SXC or a Bruker Vector
2 instrument. Raman spectra were recorded using a Bruker
3
( F) as the standards. Infrared spectra
2
RFS 100 instrument. Mass spectra were obtained on a Varian
MAT 711 (80 eV) instrument. Pentacarbonyl(trifluoroethenyl
1
2
38
isocyanide)chrom 1, pentafluorophenyltrimethylsilylethyne, 4-
39
36
methoxytetrafluorophenylethyne and 3c–e were prepared fol-
lowing the literature procedure.
Caution: Some fluoro alkenes like octafluoro-iso-butene or
41
hexafluorocyclobutene are extremely toxic. As the toxicity of
the compounds described below is unknown one should take care
to avoid contact with skin or incorporation of the materials. They
should be handled under a well ventilated hood.
3
,5-Bis(trifluoromethyl)phenylethynyltrimethylsilane
3
,5-Bis(trifluoromethyl)bromobenzene 5.86 g (20 mmol) and
40
Fig. 3 Molecular structure (ORTEP ) of ZZ-8 and EZ-8. Ellipsoids
drawn at 50% probability scale.
triphenylphosphine 100 mg (0.4 mmol) were dissolved in 60 mL
of triethylamine and 40 mL of toluene. The reaction mixture was
degassed by several freezing, pumping and argon venting cycles.
Trimethylsilylethyne 2.16 g (22 mmol), palladium acetate 20 mg
(
0.09 mmol) and copper iodide 20 mg (0.1 mmol) were added under
◦
a stream of argon. The reaction mixture was heated to 80 C for
12 h. After cooling to ambient temperature the reaction mixture
was filtered to remove insoluble by-products. The solvent was
removed under vacuum, the residue was dissolved in 100 mL of di-
ethylether, extracted with 100 mL of hydrochloric acid (10%), 100
mL of water, 100 mL of saturated sodium carbonate solution and
finally 100 mL of water. The organic phase was dried using mag-
nesium sulfate and the ether was removed under vacuum leaving
a yellow oil. Column chromatography on silica using pentane as
eluent yielded 3,5-bistrifluoromethylphenylethynyltrimethylsilane
40
Fig. 4 Molecular structure (ORTEP ) of Z,Z-9. Ellipsoids drawn at 50%
probability scale. Atom C4i is created by the crystallographic inversion
center by the symmetry operation 1 - x, -y, 1 - z.
(
6.05 g, 97%) after removal of the solvent under vacuum as a
Conclusion
colourless oil, which solidified to colourless needle shaped crystals
after standing for a while, m.p. 44 C. Further purification is
possible by vacuum sublimation (25 C, 10 mbar) onto a cold
finger kept at -20 C.
◦
Using the carbon carbon bond formation at the C–F acti-
vated carbon fluorine bond of pentacarbonylchromium stabilized
trifluorethenyl isocyanide allows the straightforward synthesis
of numerous highly unsaturated isocyanides. If lithium organic
compounds are used as nucleophiles the isomers with the fluorine
substituents in cis position at the double bond are the prevailing
one whereas the use of Grignard reagents results in a greater
amount of the trans configurated compound. There seem to be
no limitations in the nature of the nucleophilic reagent. However,
◦
-2
◦
1
9
F NMR (376 MHz, CDCl
3
, CFCl
3
intern): d = -64.0 (s, 6
1
F, CF
3
); H-NMR (CDCl
3
, 399.65 MHz): d = 7.88 (s, 2 H, ArH),
1
3
1
7.79 (s, 1 H, ArH), 0.27 (s, 9 H, Si(CH
100.4 MHz): d = 132.0 (qua, JCF = 34 Hz, 2 C, i-CAr–CF
(qua, JCF = 3.7 Hz, 2 C, CAr–H), 125.6 (s, 1 C, i-CAr–C C), 123.1
(qua, JCF = 273 Hz, 2 C, CF
3
)
3
). C{ H}-NMR (CDCl
3
,
2
3
), 131.9
3
1
3
3
), 121.8 (qua, JCF = 3.7 Hz, 1 C,
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 839–849 | 843

View Article Online
3
3
3
C
Ar–H), 101.5 (s, 1 C, Ar–C C), 98.7 (s, 1 C, C C–TMS), -0.46
J
HH = 11.5 Hz, JHH = 17.4 Hz, JHF = 26.1 Hz, 1 H, CH= CH
2
),
), 5.47 (ddd,
HH = 1.8 Hz, JHF = 3.6 Hz, JHH = 11.5 Hz, 1 H, CH CH );
-
1
2
3
(
s, 3 C, Si(CH
3
)
3
). IR (KBr): n (cm ) = 3812 w, 3748 w, 3660 w,
5.73 (dd, JHH = 1.8 Hz, JHH = 17.4 Hz, 1 H, CH CH
2
2
4
3
3091 m, 3064 w, 2967 s, 2903 m, 2857 w, 2798 w, 2652 w, 2308 w,
2268 w, 2233 w, 2174 m, 2128 w, 2109 w, 2069 m, 2016 w, 1981 w,
1950 w, 1906 w, 1866 w, 1835 w, 1807 w, 1787 w, 1711 w, 1617 m,
1610 m, 1593 w, 1562 w, 1529 w, 1514 w, 1497 vw, 1460 m, 1411
J
2
4
3
(Z)-Isomer: d = 6.36–6.22 (dddd, JHF = 1.8 Hz, JHH = 11.4 Hz,
3
3
2
J
HH = 17.2 Hz, JHF = 24.6 Hz, 1 H, CH CH
2
), 5.83 (dd, JHH
=
3
2
1.8 Hz, JHH = 17.2 Hz, 1 H, CH CH
Hz, JHH = 11.4 Hz, 1 H, CH CH
CDCl
2
1
), 5.58 (dd, JHH = 1.8
3
13
m, 116 s, 1332 w, 1315 w, 1279 s, 1253 s, 1172 vs, 1143 vs, 1108 s,
2
); C{ H}-NMR (100.4 MHz,
1
7
068 m, 1001 w, 979 w, 929 s, 914 s, 896 s, 844 vs, 762 s, 732 m,
00 s, 684 s, 654 m, 632 w, 623 w, 598 vw, 571 w, 559 w, 532 w, 509
3
): (E)-Isomer: d = 214.6 (s, 1 C, COtrans), 213.1 (s, 4 C, COcis),
1
2
197.3 (s, 1 C, CN), 146.6 (dd, JCF = 248 Hz, JCF = 51 Hz; 1 C,
-
1
1
2
vw, 431 m, 416 m, 406 w. IR (Pentan): n (cm ) = 1463 s, 1377 m,
279 s, 1148 s, 930 m, 899 w, 846 m, 733 w, 700 w, 684 m, 668 m;
CF CF–CH CH
C, CF CF–CH CH
1 C, CH CH ), 118.6 (dd, JCF = 5.3 Hz, JCF = 3.7 Hz, 1 C,
CH CH ); (Z)-Isomer: d = 214.3 (s, 1 C, COtrans), 213.0 (s, 4 C,
COcis), 195.9 (s, 1 C, CN), 144.0 (dd, JCF = 254 Hz, JCF = 25 Hz;
1 C, CF CF–CH CH
1 C, CF CF–CH CH
Hz, 1 C, CF CF–CH CH
2
), 128.7 (dd, JCF = 254 Hz, JCF = 43 Hz, 1
2
3
1
2
), 121.1 (dd, JCF = 19.0 Hz, JCF = 5.4 Hz,
3 4
-
1
Raman: nshift (cm ) = 3090 w, 2965 w, 2902 m, 2173 vs, 2129 w,
2
1611 m, 1412 w, 1376 m, 1265 w, 1211 m, 1186 w, 1132 w, 1107 w,
1000 s, 844 w, 760 w, 732 m, 701 w, 655 s, 630 m, 598 m, 531 w,
417 m, 348 w, 311 w, 295 w, 277 m, 212 m, 182 m,152 s, 107 vs. MS
2
1
2
1
2
2
), 127.2 (dd, JCF = 254 Hz, JCF = 43 Hz,
+
+
2
3
(
(
EI, 80 eV): m/z = 310 (M , 10.7%), 297 (M - CH, 5.1%), 296
M - CH
2
), 121.3 (dd, JCF = 19.2 Hz, JCF = 2.7
3 4
+
+
+
2
, 18.6%), 295 (M - CH
3
, 100%), 291 (M - F, 4.6%),
2
), 120.4 (dd, JCF = 12.8 Hz, JCF
=
+
-1
2
65 (M - 3 CH
3
, 4.3%), 219 (4.3%), 214 (5.6%), 155 (4.6%), 147
3.7 Hz, 1 C, CF CF–CH CH
2
); IR (Pentan): n (cm ) = 657 m,
(
(
5.1%), 138 (4.0%), 113 (4.0%), 77 (5.5%), 73 (Si(CH
)
3 3
, 9.4%), 43
1379 m, 1946 w, 1977 vs, 2019 m.
2
8
SiCH , 5.6%), 28 ( Si, 12.0%).
3
Pentacarbonyl(1,2,4,4-tetrafluorobuta-1,3-dienyl
isocyanide)chromium (3b)
3
,5-Bis(trifluoromethyl)phenylethyne 2g
A solution of 3,5-bistrifluoromethylphenylethynyltrimethyl-silane
in a 1 : 1 mixture of THF and methanol was treated with a 0.1 M
aqueous sodium hydroxide solution in water. The progress of the
reaction was followed by TLC. The reaction was complete after
about 1 h. After addition of about the same amount of water the
product was extracted into diethylether. After drying of the organic
A 250 mL Schlenk flask was charged with 10 mL of diethylether
and 10 mL of THF. After several freezing and pumping cycles
under cooling with liquid nitrogen 1.2 mmol of 1,1-difluoroethene
◦
were condensed to this mixture. After warming to -100 C the flask
was flushed with argon. 1 mL of t-butyllithium (1.5 M in hexane)
was added dropwise using a syringe. The colourless solution turned
yellow. After 0.5 h 300 mg (1 mmol) of 1 was added and the
reaction mixture was allowed to warm to ambient temperature
within 1 h. After filtration through a thin layer of silica the solvent
phase with MgSO
4
the solvent was removed under vacuum leaving
3
,5-bis(tri-fluoromethyl)phenylethyne as a colourless oil in almost
quantative yield. The product turned red after a short period of
time at ambient temperature due to decomposition and was used
immediately without further characterization.
◦
was removed of under vacuum at -20 C. Preparative thin layer
chromatography on silica using pentane as an eluent yielded 3b in
the first fraction. After removal of the solvent 200 mg (58%) of 3b
(
isomeric mixture Z : E = 20 : 1) is obtained as viscous yellow oil,
2
Pentacarbonyl(1,2-difluorobuta-1,3-dienylisocyanide)-chromium
-
which can be further purified by distillation under vacuum (10
mbar) at ambient temperature onto a cold finger cooled to -20 C.
(
3a)
◦
1
9
Ethenylmagnesiumbromide (1 M in THF) 2 mL (2 mmol) were
diluted by 30 mL of THF, the solution was cooled to -10
F-NMR (376 MHz, CDCl
3
, CFCl intern): (Z)-Isomer: d =
3
◦
2
3
5
4
C
-72.35 (dddd, JFF = 30.6 Hz, JHF = 22.1 Hz, JFF = 8.8 Hz, JFF
=
2
and pentacarbonyl(trifluoroethenyl isocyanide)chromium 1 was
added. The reaction mixture was allowed to warm to ambient
temperature with stirring. After an additional 30 min 50 mL
of n-pentane was added to the brown clear solution, which was
2.0 Hz, 1 F, CF CF–CH CF
CF CF–CH CF
1 F, CF CF–CH CF
2
), -73.70 (d, JFF = 29.6 Hz, 1 F,
3
5
2
), -120.31(dd, JFF = 29.5 Hz, JFF = 8.8 Hz,
3 3
2
), -143.95 (ddd, JFF = 29.5 Hz, JHF
=
4
19.5 Hz, JFF = 2.0 Hz, 1 F, CF CF–CH CF ); (E)-Isomer: d =
2
1
9
2
3
5
filtered through a thin pad of silica. F NMR analysis indicated
a quantitative conversion and an isomeric ratio of E/Z = 2/1.
The solvent volume was reduced to about 10 mL under vacuum
-73.01 (dddd, JFF = 32.9 Hz, JHF = 22.3 Hz, JFF = 11.5 Hz,
4
2
J
FF = 1.8 Hz, 1 F, CF CF–CH CF
2
), -74.72 (d, JFF = 32.9 Hz,
3
1 F, CF CF–CH CF
22.4 Hz, JFF = 11.6 Hz, JHF = 2.3 Hz, 1 F, CF CF–CH CF
2
), -137.45 (dddd, JFF = 122.0 Hz, JFF
=
◦
5
4
keeping the solution below -10 C. The residue was transferred
2
),
3
3
into sublimation apparatus, remaining solvent was removed under
-153.54 (dddd, JFF = 122.0 Hz, JFF = 31.4 Hz, JHF = 23.7 Hz,
◦
4
1
vacuum and cooling. Sublimation onto a receiver kept at -25 C
J
FF = 1.8 Hz, 1 F, CF CF–CH CF
CDCl ): (Z)-Isomer: d = 5.04 (m, JHF = 20.8 Hz, JHF = 1.2 Hz, 1
H); (E)-Isomer: d = 5.20 (m, JHF = 21.3 Hz, 1 H); C{ F}-NMR
(100.4 MHz, CDCl ): (Z)-Isomer: d = 214.0 (s, 1 C, COtrans), 212.9
(s, 4 C, COcis), 197.0 (s, 1 C, CN), 138.5 (CF CF–CH CF ),
), 70.90
2
). H-NMR (400 MHz,
under vacuum (10- mbar) at ambient temperature yielded 3a as a
3
3
◦
13
19
pale yellow solid (75–80%), which melts above -20 C forming a
yellow oil. The product readily polymerizes on further warming.
3
1
9
F NMR (376 MHz, CDCl
3
, CFCl
3
intern): (E)-Isomer: d =
), -156.1
dd, JHF = 25 Hz, JFF = 117 Hz, 1F, (E)-CF CF–CH CH );
), -148.2
); H NMR (400
2
3
-
138.1 (d, JFF = 117 Hz, 1F, (E)-CF CF–CH CH
2
128.1 (CF CF–CH CF
(CF CF–CH CF
2
), 72.6 (CF CF–CH CF
2
3
3
-1
(
(
(
2
2
); IR (CH
2
Cl
2
): n (cm ) = 2115 w, 2023 m,
Z)-Isomer: d = -121.2 (s, 1F, (Z)-CF CF–CH CH
2
1970 vs, 1781 w, 1733 m, 1390 w, 1149 w, 841 w, 657 s. Raman:
3
1
-1
d, JHF = 25 Hz, 1F, (Z)-CF CF–CH CH
2
n
shift (cm ) = 198 w, 260 w, 385 vs, 433 m, 550 w, 580 w, 614 w,
4
MHz, CDCl
3
): (E)-Isomer: d = 6.53–6.38 (dddd, JHF = 3.6 Hz,
666 w, 762 w, 841 w, 930 w, 1062 w, 1149 w, 1236 w, 1261 m, 1311
8
44 | Dalton Trans., 2012, 41, 839–849
This journal is © The Royal Society of Chemistry 2012

View Article Online
w, 1374 w, 1621 w, 1672 m, 1733 m, 2008 s, 2114 m. MS (EI, 80
temperature. A work-up as decribed above yielded 340 mg (66%)
◦
+
+
eV, 30 C): m/z (%) = 343 (12) [M ], 315 (1.3) [M - CO], 287 (4)
of 3g with an isomeric ratio of 3g (Z) : 3g (E) = 9 : 1.
+
+
+
19
[
2
7
M - 2 CO], 259 (2) [M - 3 CO], 247 (4), 231 (12) [M - 4 CO],
F-NMR (CDCl
3
, CFCl intern, 376.0 MHz): (Z)-Isomer: d =
3
+
03 (58) [M - 5 CO], 106 (10), 90 (4), 81 (15), 79 (15), 75 (10),
-64.19 (s, 6 F, CF
F, (Z)-CF CF–C); (E)-Isomer: d = -64.11 (s, 6 F, CF
3
), -106.37 (s, 1 F, (Z)-CF CF–C), -137.76 (s, 1
5
3
52
1 (26), 63 (11), 53 (11) [ Cr], 52 (100) [ Cr], 50 (6). Elemental
NO (342.9): C 35.01, H 0.29, N 4.08;
found: C 34.72, H 0.00, N 5.07%.
3
), -124.92
3
3
analysis calcd for C10HCrF
4
5
(d, JFF = 126 Hz, 1 F, (E)-CF CF–C), -147.42 (d, JFF = 126
1
Hz, 1 F, (E)-CF CF–C). H-NMR (CDCl
3
, 399.65 MHz): (Z)-
Isomer: d = 7.97 (s, 2 H, o-ArH), 7.94 (s, 1 H, p-ArH); (E)-Isomer:
1
3
1
19
d = 8.00 (s, 2 H, o-ArH), 7.95 (s, 1 H, p-ArH). C{ H, F}-NMR
CDCl , 100.4 MHz): (Z)-Isomer: d = 213.43 (s, 1 C, COtrans),
12.85 (s, 4 C, COcis), 197.74 (s, 1 C, CN), 134.54, 132.65, 131.64,
Pentacarbonyl(2,3,5,6-tetrafluoro-4-methoxyphenyl)but-1-en-3-
ynylisocyanid)chromium (3f)
(
2
3
2
04 mg (1.0 mmol) para-Methoxytetrafluorophenyl-acetylen 2f
128.87, 124.06, 123.76, 122.46, 121.34, 100.43; (E)-Isomer: d =
213.75 (s, 1 C, COtrans), 212.66 (s, 4 C, COcis), 191.19 (s, 1 C, CN),
were dissolved in 10 mL of diethylether. 0.4 mL (1.0 mmol) of n-
butyllithium (2.5 M in n-hexane) were added at -78 C. After
one hour at -78 C 300 mg (1.0 mmol) of 1 dissolved in a
minimum amount of diethylether was added and the solution was
◦
136.1, 132.65, 131.36, 125.61, 123.73, 122.81, 104.01. IR (CH
2
Cl ):
2
◦
-1
n (cm ) = 1085 m, 1145 s, 1177 s, 1392 m, 1960 vs, 2015 m. Raman:
-
1
nshift (cm ) = 2216 s, 2114 m, 2021 m, 2006 m, 1999 m, 1967 w,
allowed to warm to ambient temperature and stirred for additional
1674 m, 1615 w, 1391 w, 1317 w, 1271 m, 1181 m, 1082 w, 999
m, 906 w, 742 w, 702 w, 656 w, 626 w, 610 m, 579 w, 562 w, 530
w, 499 w, 455 w, 430 m, 389 vs, 326 w, 302 w, 278 w, 235 m, 150
1
5 min. After filtration over a plug of silica an intense yellow
solution was obtained, which was concentrated and purified by
+
TLC yielding 220 mg (46%) of 3f as a yellow, microcrystalline
m, 127 s, 109 vs. MS (EI, 80 eV): m/z = 517 (M , 19.3%), 474
◦
+
+
+
solid, mp. 52–53 C and an isomeric ratio of 3f (Z) : 3f (E) =
(61.3%), 461 (M - 2 CO, 5.4%), 433 (M - 3 CO, 9.3%), 405 (M
+
+
5
2
1
6 : 1.
- 4 CO, 20.7%), 377 (M - 5 CO, 89.3%), 325 (M - Cr(CO) ,
5
1
9
F-NMR (CDCl
3
, CFCl
3
intern, 376.0 MHz): (Z)-Isomer: d =
5.9%), 287 (66.4%), 268 (22.1%), 237 ((CF
3
)
2
C
6
H
3
C
2
, 13.8%),
5
2
-
106.07 (s, 1 F, (Z)-CF CF), -137.86 (s, 1 F, (Z)-CF CF), -
218 (16.0%), 213 ((CF
(22.0%), 155 (22.1%), 108 ( Cr(CO)
3
)
2
C
6
H
3
, 3.4%), 192 ( Cr(CO)
5
, 3.8%), 159
5
2
52
1
36.14 (m, 2 F, Ar–F), -157.63 (m, 2 F, Ar–F); (E)-Isomer: d =
2
, 6.8%), 80 ( Cr(CO), 21.0%),
3
3
52
-
124.59 (d, JFF = 126 Hz, 1 F, (E)-CF CF–C), -147.12 (d, JFF
=
78 (15.9%), 71 (16.7%), 52 ( Cr, 100%), 43 (10.3%), 28 (56.9%).
High resolution MS; calcd: 516.92883, found: 516.92749.
1
26 Hz, 1 F, (E)-CF CF–C), -136.28 (m, 2 F, Ar–F), -157.70 (m,
1
2
F, Ar–F). H-NMR (CDCl
Cl ) = 1498 m, 1506 m, 1972 vs, 2015 m.
Raman: nshift (cm ) = 2214 s, 2112 m, 2017 s, 2008 m, 1971 m,
950 w, 1662 m, 1644 s, 1456 w, 1428 w, 1339 w, 1290 m, 1257
s, 1197 w, 1148 w, 1096 w, 981 w, 907 w, 731 w, 657 w, 601 m,
3
, 399.65 MHz): d = 4.10 (s, 3 H, CH
3
–
O). IR (L o¨ sung): n (CH
2
2
Pentacarbonyl(1,2-difluor-2-pentafluorophenyl)ethenyl-
isocyanide)chromium (3h)
-
1
1
170 mg (0.7 mmol) of pentafluorbrombenzol were dissolved in
◦
5
5
64 w, 529 w, 425 m, 385 vs, 233 w, 159 m, 111 s. MS (EI, 80 eV,
20 mL of diethylether and cooled to -78 C and 0.45 mL (0.7
◦
+
+
0 C): m/z = 483 (M , 65.3%), 427 (M - 2 CO, 11.7%), 399
mmol) of n-Butyllithium (1.6 M in hexane) were added. After
+
+
+
◦
(
M - 3 CO, 30.5%), 371 (M - 4 CO, 39.9%), 343 (M - 5 CO,
stirring for 1 h at -78 C 200 mg (0.67 mmol) of 1 dissolved in a
+
52
1
3
00%), 291 (M - Cr(CO)
5
, 1.2%), 253 (CH
3
O–C
6
F
4
–C C–NC,
minimum amount of diethylether was added. The reaction mixture
was allowed to warm to ambient temperature and stirred for 1h.
After filtration over a plug of silica the solvent was removed under
+
+
1.2%), 238 ([253] - CH
3
, 8.2%)), 225 ([253] - CO, 13.4%), 223
+
+
(
[253] - CH O, 11.5%), 210 ([238] - CO, 7.6%), 204 (5.0%), 69
2
52
◦
(
3.0%), 52 ( Cr, 11.5%). High resolution MS; calcd: 482.92697,
vacuum at -20 C. The yellow residue was purified by chromatog-
found: 482.92477.
raphy on silica using pentane as eluent. Yield 230 mg (73%) of 3h
with an isomeric ratio of 3h (Z) : 3h (E) = 13 : 1. Crystallization
from n-pentane gave pure Z-3h as yellow platelet crystals, mp.
Pentacarbonyl(1,2-difluoro-4-(3,5-bis(trifluoromethyl)-phenyl)but-
◦
4
8–49 C.
F-NMR (CDCl
1
-en-3-ynylisocyanid)chromium (3g)
1
9
3
, CFCl intern, 376.0 MHz): (Z)-Isomer: d =
3
4
(
a) using the Grignard reagent:
-108.5 (s, 1 F, (Z)-CF CF–C), -130.4 (dt, 1 F, JFF = 8.5 Hz,
6
4
2
40 mg (1.0 mmol) of 3,5-bis(trifluormethyl)phenylacetylen 2g
J
J
FF = 2.5 Hz, (Z)-CF CF–C), -133.5 (m, 2 F, JFF = 8.5 Hz,
4
3
6
were dissolved in 10 mL of THF and 0.4 mL (1.0 mmol) of a
methylmagnesiumbromide solution (2.5 M in THF) was added at
ambient temperature. After 3 h 300 mg (1.0 mmol) of 1 dissolved
in diethylether was added and stirred for 15 min at ambient
temperature. After filtration over a plug of silica the solvent was
removed under vacuum The compound was purified by TLC on
silica yielding 300 mg (58%) of 3g as a yellow oil with an isomeric
ratio of 3g (Z) : 3g (E) = 1 :0 5.
FF = 3.1 Hz, Ar–Fortho), -144.7 (dt, 1 F, JFF = 21.0 Hz, JFF =
3 3
2.5 Hz, Ar–Fpara), -157.6 (m, 2 F, JFF = 21.0 Hz, JFF = 8.7 Hz,
3
5
Ar–Fmeta); (E)-Isomer: d = -124.6 (dt, JFF = 129.7 Hz, JFF = 14.0
5
4
Hz, 1 F, (E)-CF CF–C), -133.9 (m, JFF = 14.0 Hz, JFF = 8.3
Hz, 2 F, Ar–Fortho), -141.5 (ddt, JFF = 129.7 Hz, JFF = 8.3 Hz,
FF = 2.5 Hz, 1 F, (E)-CF CF–C), -145.4 (dt, JFF = 20.8 Hz, 1 F,
Ar–Fpara), -158.2 (m, JFF = 20.8 Hz, JFF = 9.5 Hz, JFF = 2.5 Hz,
3
4
5
3
J
3
3
5
1
3
19
2 F, Ar–Fmeta). C{ F}-NMR (CDCl
3
, 100.4 MHz): (Z)-Isomer:
b) using the lithium reagent:
d = 212.6 (s, 1 C, COtrans), 212.5 (s, 4 C, COcis), 197.4 (s, 1 C, CN),
144.7, 143.8, 138.0, 133.3, 130.8, 102.8; (E)-Isomer: d = 213.6 (s,
1 C, COtrans), 213.2 (s, 4 C, COcis), 201.0 (s, 1 C, CN), 144.3, 143.6,
2
40 mg (1.0 mmol) of 2g was dissolved in 10 mL of diethylether
and 0.4 mL (1.0 mmol) of n-butyl lithium (2.5 M in n-hexane) was
◦
-1
added at -78 C. After 1h 300 mg (1.0 mmol) of 1 in diethylether
137.9, 135.3, 130.9, 102.6. IR (KBr): n (cm ) = 3423 w, 2970 vw,
was added. The reaction mixture was allowed to warm to ambient
2930 w, 2120 m, 2041 s, 2007 m, 1997 m, 1931 vs, 1696 m, 1651
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 839–849 | 845

View Article Online
w, 1526 m, 1499 m, 1437 w, 1388 vw, 1344 w, 1278 m, 1233 m,
(EE) = 51 : 15 : 1. Yield 413 mg. (63%) as a yellow solid, mp.
◦
1153 w, 1128 m, 1045 w, 1033 vw, 1021 vw, 990 m, 830 m, 783 w,
86–87 C.
1
9
7
37 vw, 683 m, 645 s, 593 w, 581 w, 534 w, 497 w, 444 m, 430 m.
F-NMR (CDCl
3
, CFCl
3
intern, 376.0 MHz): (ZZ)-Isomer: d =
-
1
IR (CH
2
Cl ): n (cm ) = 2120 w, 2019 m, 1972 vs, 1708 w, 1651 w,
2
-119.7 (s, 2 F, (Z)-CF CF–C), -139.1 (s, 2 F, (Z)-CF CF–C);
3
1
524 m, 1505 m, 1439 w, 1348 w, 1281 w, 1269 vs, 1260 vs, 1232
(EZ)-Isomer: d = -119.8 (s, 1 F, (Z)-CF CF–C), -134.8 (d, JFF =
-
1
m, 1126 m, 995 m, 828 m. Raman: nshift (cm ) = 2118 m, 2051 m,
016 m, 1997 vs, 1953 m, 1695 m, 1651 w, 1526 vw, 1435 w, 1342
126 Hz, 1 F, (E)-CF CF–C), -139.1 (s, 1 F, (Z)-CF CF–C),
3
2
-150.7 (d, JFF = 126 Hz, 1 F, (E)-CF CF–C); (EE)-Isomer: d =
3
3
vw, 1275 m, 1231 w, 829 vw, 651 w, 637 w, 592 w, 581 w, 527 w, 497
w, 452 w, 431 w, 388 s, 366 w, 297 w, 228 w, 211 w, 196 w, 171 w,
-112.6 (d, JFF = 126 Hz, 2 F, (E)-CF CF–C), -157.6 (d, JFF
=
1
126 Hz, 2 F, (E)-CF CF–C). H-NMR (CDCl
3
, 399.65 MHz):
◦
+
52
13
1
19
1
(
10 vs. MS: (80 eV, EI, 60 C): m/z = 447 (M , Cr, 15.5%), 419
d = 7.75–7.50 (m, 4 H, Ar–H). C{ H, F}-NMR (CDCl
3
, 100.4
+
52
+
52
+
M - CO, Cr, 2.0%), 391 (M - 2 CO, Cr, 6.3%), 363 (M - 3
CO, Cr, 9.6%), 335 (M - 4 CO, Cr, 21.1%), 308 (M - 5 CO,
Cr, 20.6%), 307 (M - 5 CO, Cr, 100%), 255 (M - CrCO
.5%), 186 (C CN, 6.4%), 160 (C , 6.0%), 148 (C , 9.2%),
0 ( CrCO, 8.7%), 78 (7.0%), 53 ( Cr, 7.9%), 52 ( Cr, 76.5%), 32
MHz): d = 216.02, 214.31 (COtrans), 214.07, 212.81 (COcis), 179.60
(CN), 158.47, 155.99 (CF CF–C), 132.32, 130.75 (CF CF–C),
127.99, 127.30, 126. 69, 126.62, 114.75, 114.24 (CAr). IR (KBr): n
5
2
+
52
+
5
3
+
52
+
52
5
,
-
1
7
8
7
F
4
7
F
4
6
F
4
(cm ) = 3420 w, 2967 w, 2935 w, 2867 w, 2133 m, 2116 w, 2048 s,
2030 w, 2003 w, 1947 vs, 1934 vs, 1667 w, 1511 w, 1460 w, 1435 w,
1409 w, 1379 w, 1320 w, 1304 w, 1275 w, 1254 m, 1218 w, 1159 w,
5
2
53
52
(
7.9%). High resolution MS: calcd: 446.90698, found: 446.90733.
1149 w, 1131 w, 1117 w, 1082 w 1018 vw, 968 w, 946 vw, 894 w,
8
41 m, 832 w, 788 w, 752 w, 680 m, 651 s, 620 w, 599 w, 511 w, 479
Pentacarbonyl(1,2-difluor-2-(3,5-bistrifluoromethylphenyl)-
ethenylisocyanid)chromium (3i)
-
1
w, 446 m. IR (CH
2
Cl ): n (cm ) = 2115 w, 2050 m, 2023 w, 1963
1
2
-
s, 655 m. Raman: nshift (cm ) = 109 vs, 165 w, 224 w, 257 w, 287 w,
343 w, 389 s, 417 w, 450 m, 473 w, 502 w, 534 w, 581 w, 607 w, 628
w, 666 w, 730 w, 741 w, 828 w, 973 w, 1074 w, 1128 w, 1189 s, 1203
m, 1217 w, 1257 m, 1285 w, 1298 w, 1306 m, 1332 w, 2936 w.
3i was prepared analogously to 3h. The product was purified by
TLC on silica using pentane as eluent. Yield 230 mg (58%) as a
yellow oil with an isomeric ratio of 3i (Z) : 3i (E) = 36 : 1.
1
9
◦
+
F-NMR (CDCl
63.9 (s, –CF , 6 F), -109.6 (s, 1 F, (Z)-CF CF–C), -142.9 (s, 1 F,
Z)-CF CF–C), (E)-Isomer: d = -63.9 (s, –CF , 6 F), -128.5 (d,
3
, CFCl
3
intern, 376.0 MHz): (Z)-Isomer: d =
MS (EI, 80 eV, 90 C): m/z = 636 (M , 11%), 572 (26%), 534
+ +
-
3
(7%), 524 (M - 4 CO, 3%), 516 (11%), 496 (M - 5 CO, 19%),
+ +
(
3
488 (9%), 460 (15%), 440 (M - 7 CO, 8%), 432 (20%), 412 (M -
+ +
3
3
J
FF = 122.5 Hz, 1 F, (E)-CF CF–C), -151.3 (d, JFF = 122.5 Hz,
F, (E)-CF CF–C). H-NMR (CDCl
H, o-Ar–H), 7.95 (s, 1 H, p-Ar–H); (E)-Isomer: d = 8.19 (s, 2
H, o-Ar–H), 8.02 (s, 1 H, p-Ar–H). C{ H, F}-NMR (CDCl
00.4 MHz): (Z)-Isomer: d = 212.8 (s, 1 C, COtrans), 212.4 (s, 4 C,
COcis), 201.3 (s, 1 C, CN), 141.5, 133.4, 132.9, 129.2, 123.5, 121.4,
8 CO, 23%), 384 (M - 9 CO, 20%), 380 (31%), 356 (M - 10 CO,
25%), 304 (11%), 220 (11%), 178 (8%), 145 (12%), 108 (18%), 80
(34%), 53 (12%), 52 (100%), 41 (8%).
1
1
2
3
): (Z)-Isomer: d = 8.10 (s,
1
3
1
19
3
,
1
Decacarbonyl(1,4-bis(1,2-difluoro-2-isocyanoethenyl)-2,3,5,6-
tetrafluorobenzene)dichromium (5b)
1
2
18.7; (E)-Isomer: d = 213.8 (s, 1 C, COtrans), 213.2 (s, 4 C, COcis),
01.3 (s, 1 C, CN), 144.6, 132.8, 129.5, 121.8, 118.5. IR (KBr): n
Using 4b in a procedure as described above yields 5b, 404 mg
(57%) as a yellow microcrystalline solid in an isomeric ratio of 5b
(ZZ) : 5b (EZ) : 5b (EE) = 5 : 9 : 2, mp. 166 C (dec.).
-
1
(
cm ) = 3965 w, 3441 w, 3102 w, 2964 m, 2928 w, 2857 vw, 2778
vw, 2670 w, 2548 w, 2440 w, 2361 w, 2267 w, 2242 vw, 2117 m,
026 s, 1981 vs, 1947 vs, 1681 m, 1621 m, 1532 vw, 1514 w, 1470
◦
1
9
2
F-NMR (CDCl
3
, CFCl intern, 376.0 MHz): (ZZ)-Isomer: d =
3
m, 1452 w, 1434 vw, 1392 s, 1347 w, 1324 w, 1280 vs, 1255 vs, 1187
s, 1141 s, 1110 m, 1018 m, 947 w, 901 s, 848 m, 806 s, 757 vw, 740
w, 719 s, 700 m, 684 s, 653 vs, 622 s, 588 w, 561 vw, 531 w, 517 w,
-107.9 (s, 2 F, (Z)-CF CF–C), -133.7 (s, 4 F, Ar–F), -134.7 (s, 2
F, (Z)-CF CF–C); (EZ)-Isomer: d = -108.5 (s, 1 F, (Z)-CF CF–
5
3
C), -123.6 (dt, JFF = 15 Hz, JFF = 128 Hz, 1 F, (E)-CF CF–C),
-
1
4
3
4
98 w, 440 s, 420 m. Raman: nshift (cm ) = 2114 w, 2011 m, 1955
-134.1 (s, 1 F, (Z)-CF CF–C), -145.7 (dt, JFF = 9 Hz, JFF = 128
Hz, 1 F, (E)-CF CF–C), -134.0 (m, 4 F, Ar–F); (EE)-Isomer:
w, 1680 m, 1620 w, 1390 m, 1299 w, 1250 m, 1001 w, 718 w, 657 w,
5
3
6
4
3
3
21 w, 433 w, 383 vs, 314 w, 213 w, 154 m. MS (EI, 80 eV): m/z =
d = -123.8 (dt, JFF = 16 Hz, JFF = 128 Hz, 2 F, (E)-CF CF–C),
+
+
+
3
93 (M , 3.8%), 437 (M - 2 CO, 5.1%), 409 (M - 3 CO, 6.2%),
-145.4 (d, JFF = 128 Hz, 2 F, (E)-CF CF–C), -134.2 (s, 4 F,
+
+
13
19
81 (M - 4 CO, 17.5%), 353 (M - 5 CO, 60.8%), 333 (12.3%),
Ar–F). C{ F}-NMR (CDCl
3
, 100.4 MHz): (ZZ)-Isomer: d =
01 (5.0%), 282 (3.7%), 263 (100%), 244 (10.2%), 194 (12.3%), 80
213.3 (s, 2 C, COtrans), 212.5 (s, 8 C, COcis), 198.9 (s, 2 C, CN), 144.3
(s, 2 C, (Z)-CF CF–C), 133.4 (s, 2 C, (Z)-CF CF–C), 110.7
(s, 4 C, CAr–F), 110.2 (s, 2 C, i-C); (EZ)-Isomer: d = 213.0, 212.9
5
2
(
5.1%), 52 ( Cr, 24.3%). High resolution MS; calcd: 492.92886,
found: 492.92799.
(s, 1 C, COtrans), 212.4, 212.3 (s, 4 C, COcis), 202.4, 198.4 (s, 1 C,
CN), 144.0, 143.8, 133.0, 130.9, (s, 1 C, CF CF–C), 110.6, 110.3
Decacarbonyl(1,4-bis(1,2-difluoro-2-isocyanoethenyl)benzene)-
dichromium (5a)
-
1
(
s, 2 C, CAr–F), 110.0, 109.8 (s, 1 C, i-C). IR (KBr): n (cm ) =
421 m, 3220 w, 2961 vw, 2924 w, 2853 w, 2117 m, 2008 s, 1945
3
To 240 mg (1.0 mmol) of 1,4-Dibrombenzol 4a in 10 mL of
vs, 1698 w, 1496 m, 1473 m, 1346 w, 1274 m, 1186 m, 1119 w,
diethylether were added 2 equivalents of n-butyllithium (2.6 mL,
1066 w, 984 m, 874 w, 797 m, 651 s, 531 w, 444 m, 427 w. IR
◦
-1
1.6 M in hexane) at -78 C. After 1 h 600 mg (2.0 mmol) of 1
(CH
2
Cl
2
): n (cm ) = 2017 w, 1974 s, 1604 w, 1495 w, 1425 w, 897
-
1
dissolved in diethylether was added. The reaction mixture was
allowed to warm to ambient temperature. After filtration through
a plug of silica and purification by TLC 5a was obtained as a
mixture of the possible isomers in a ratio of 5a (ZZ) : 5a (EZ) : 5a
w. Raman: nshift (cm ) = 1580 w, 1649 s, 1695 s, 1943 w, 1956 m,
◦
1999 s, 2015 m, 2047 w, 2115 m. MS (EI, 80 eV, 80 C): m/z = 708
+
+
+
+
(M , 18%), 624 (M - 3 CO, 1.2%), 596 (M - 4 CO, 7%), 568 (M
+
+
- 5 CO, 29%), 540 (M - 6 CO, 6%), 512 (M - 7 CO, 18%), 484
8
46 | Dalton Trans., 2012, 41, 839–849
This journal is © The Royal Society of Chemistry 2012

View Article Online
+
+
+
19
(
M - 8 CO, 35%), 456 (M - 9 CO, 38%), 428 (M - 10 CO, 43%),
F-NMR (376.0 MHz, CDCl
3
, CFCl
3
intern): (ZZ)-Isomer:
+
52
+
52
3
1
7
(
76 (M - 10 CO, - Cr, 14%), 338 (M - 10 CO, - Cr, - 2 F,
0%), 214 (7%), 149 (16%), 142 (15%), 130 (7%), 108 ( Cr(CO)
%), 80 ( CrCO, 24%), 78 (10%), 71 (17%), 53 ( Cr, 11%), 52
Cr, 100%). Elemental analysis calcd C 37.31, N 3.96%; found:
d = -98.3 (s, 2 F, (Z)-CF CF–C), -140.9 (s, 2 F, (Z)-CF CF–
C); (EZ)-Isomer: d = -99.4 (s, 1 F, (Z)-CF CF–C), -120.3 (d,
FF = 126 Hz, 1 F, (E)-CF CF–C), -140.5 (s, 1 F, (Z)-CF CF–
C), -150.7 (d, JFF = 126 Hz, 1 F, (E)-CF CF–C); (EE)-Isomer:
5
2
2
,
5
2
53
3
J
5
2
3
3
C 36,57, N 3.53%.
d = -120.3 (d, JFF = 126 Hz, 2 F, (E)-CF CF–C), -150.4 (d,
3
13
19
J
FF = 126 Hz, 2 F, (E)-CF CF–C). C{ F}-NMR (100.4 MHz,
CDCl ): d = 213.3, 213.2, 213.0, 212.9 (COtrans), 212.4, 212.3, 212.2
COcis), 206.3, 202.5, 201.2, 195.4 (CN), 141.2, 136.6, 136.3, 134.6,
30.4, 129.9, 129.6, 129.5 (CF), 90.3, 90.1, 74.3, 73.9 (CF–C C–).
IR (CH
Raman: nshift (cm ) = 2194 s, 2112 w, 2013 m, 2004 m, 1990 m,
1979 m, 1946 w, 1655 s, 1392 w, 1275 m, 1140 w, 935 w, 603 w, 425
w, 385 s, 326 w, 117 w; MS (EI, 80 eV): m/z = 609 (30) [M , Cr],
608 (63) [M , Cr], 496 (13) [M - 4 CO], 469 (19) [M - 5 CO,
3
Decacarbonyl(1,4-bis(3,4-difluoro-4-isocyanobut-3en-4-yne-1-
yl)benzene)dichromium (5a)
(
1
-
1
1
30 mg (1.0 mmol) of 1,4-bis(ethynyl)benzene 4c were dissolved
2
Cl ): n (cm ) = 2120 w, 2038 m, 1966 s, 1269 vs, 1260 vs.
1
2
-
in 30 mL of tetrahydrofuran and two equivalents of methyl-
magnesiumbromide (0.8 mL, 2.5 M) were added at ambient
temperature. After 3h 600 mg (2.0 mmol) of 1 dissolved in
diethylether was added and the reaction mixture was stirred for 15
min. Chromatographic work up as described above yielded 294 mg
43%) of a yellow oil. Due to the small separation of the resonances
of the different isomers only a overall ratio of (E) : (Z) = 11 : 9 could
+
53
+
52
+
+
5
3
+
52
+
52
Cr], 468 (46) [M - 5 CO, Cr], 412 (21) [M - 7 CO, Cr], 385
+
53
+
52
(
(27) [M - 8 CO, Cr], 384 (100) [M - 8 CO, Cr], 357 (47), 356
+ 52 + 53
(99.6) [M - 9 CO, Cr], 329 (30) [M - 10 CO, Cr], 328 (94.5)
+ 52 + 52
be determined.
[M - 10 CO, Cr], 238 (43) [M - (CO) CrCNCFCF, Cr], 149
5
52
1
9
F-NMR (CDCl
3
, CFCl
3
intern, 376.0 MHz): (ZZ)-Isomer: d =
(15), 148 (30), 142 (26), 141 (23), 52 (27) [ Cr], 28 (58). Elemental
-
109.6 (s, 2 F, (Z)-CF CF–C), -134.4 (s, 2 F, (Z)-CF CF–C);
analysis calcd for C20Cr
C 40.12, N 3.37%.
2
F
4
2
N O10 (608.2): C 39.50, N 4.61; found:
3
(
EZ)-Isomer: d = -109.5 (s, 1 F, (Z)-CF CF–C), -127.4 (d, JFF
=
1
-
26.0 Hz, 1 F, (E)-CF CF–C), -134.4 (s, 1 F, (Z)-CF CF–C),
3
144.2 (d, JFF = 126.0 Hz, 1 F, (E)-CF CF–C); (EE)-Isomer:
Decacarbonyl(1,2,7,8-tetrafluoroocta-1,7-dien-3,5-(dodecacarbo-
nyl[l-(3,4-g: 3,4-g: 5,6-g: 5,6-g-diinyl)]tetracobalt)diisocyanide)-
dichromium (9)
3
d = -126.5 (d, JFF = 126.0 Hz, 2 F, (E)-CF CF–C), -144.9 (d,
3
-1
J
FF = 126.0 Hz, 2 F, (E)-CF CF–C). IR (KBr): n (cm ) = 3921
vw, 3414 w, 3306 w, 3293 m, 2960 w, 2925 m, 2854 w, 2543 vw,
447 vw, 2343 vw, 2205 m, 2117 m, 2015 s, 1956 vs, 1668 m, 1505
w, 1494 w, 1463 w, 1404 w, 1384 w, 1350 w, 1274 s, 1263 s, 1184 m,
161 m, 1103 w, 1083 vw, 1067 m, 1017 w, 953 w, 862 w, 835 s, 803
m, 752 m, 647 vs, 582 m, 544 m, 492 w, 445 m, 433 m. Raman: nshift
2
Toasolutionof 700mg (1.1mmol) of (CO)
5
Cr(CNCFCFC
2
2
C CF-
CFNC)Cr(CO) 7 in 10 mL of a pentane/dichloromethane
5
1
mixture (1 : 1) 980 mg (2.9 mmol) of octacarbonyldicobalt was
added under argon atmosphere. During stirring of the solution
the reaction was observed by TLC. After there was no remaining
7 detectable the solution was filtered, the solvent and surplus
octacarbonyldicobalt were removed in vacuum. The residue was
-
1
(cm ) = 3068 vw, 2849 vw, 2530 w, 2432 vw, 2203 vs, 2157 w, 2111
m, 2039 m, 1992 m, 1952 w, 1671 s, 1599 vs, 1496 vw, 1334 w, 1275
m, 1168 m, 1067 w, 601 w, 531 vw, 481 w, 431 w, 388 m, 108 m.
+
52
+
52
◦
MS (EI, 80 eV): m/z = 684 (M , Cr, 2.4%), 628 (M - 2 CO, Cr,
recrystallized in a pentane/dichloromethane mixture. At -30 C
+
52
+
52
0
5
(
.5%), 600 (M - 3 CO, Cr, 0.7%), 572 (M - 4 CO, Cr, 2.5%),
44 (M - 5 CO, Cr, 7.3%), 516 (M - 6 CO, Cr, 1.9%), 488
M - 7 CO, Cr, 3.6%), 460 (M - 8 CO, Cr, 5.3%), 432 (M - 9
CO, Cr, 4.6%), 405 (M - 10 CO, Cr, 17.1%), 404 (M - 10 CO,
Cr, 10.5%), 349, (12.0%), 321 (8.7%), 293 (28.2%), 266 (21.1%),
65 (100%), 175 (26.9%), 168 (26.3%), 109 ( Cr(CO)
CrCO, 3.7%), 80 ( CrCO, 3.1%), 78 (Ph, 2.7%), 57 (10.8%), 52
Cr, 30.7%).
710 mg (55% yield) of dark brown crystals of 9 were obtained,
+
52
+
52
◦
m.p. 166 C (dec.).
+
52
+
52
+
19
F-NMR (376.0 MHz, CDCl
3
, CFCl intern): (ZZ)-Isomer:
3
5
2
+
53
+
d = -101.8 (s, 2 F, (Z)-CF CF–C), -120.9 (s, 2 F, (Z)-CF CF–
C); (EZ)-Isomer: d = -102.1 (s, 1 F, (Z)-CF CF–C), -120.9
5
2
5
3
3
2
2
, 3.4%), 81
(s, 1 F, (Z)-CF CF–C), -123.8 (d, JFF = 126 Hz, 1 F, (E)-
5
3
52
3
(
(
CF CF–C), -126.2 (d, JFF = 126 Hz, 1 F, (E)-CF CF–C);
5
2
3
(EE)-Isomer: d = -124.0 (d, JFF = 125 Hz, 2 F, (E)-CF CF–
3
13
19
C), -126.4 (d, JFF = 125 Hz, 2 F, (E)-CF CF–C). C{ F}-
NMR (100.4 MHz, CDCl ): (ZZ)-Isomer: d = 212.8 (COtrans),
12.5 (COcis), 200.4 (CN), 196.9 (Co(CO) ), 142.7, 129.8 (CF),
3.6, 73.1 (C C); (EZ)-Isomer: d = 214.2 (COtrans), 213.7 (COcis),
), 147.2, 129.5 (CF), 91.1, 72.0 (C C).
): n (cm ) = 2093 w, 2074 m, 2064 s, 2054 s, 1971
3
Decacarbonyl(1,2,7,8-tetrafluoroocta-1,7-dien-3,5-
diynyldiisocyanide)-dichromium (7)
2
9
3
1
0 mg of CuBr, one drop of triethylamine and TMEDA were
added to 175 mg (0.57 mmol) of pentacarbonyl(1,2-difluorobut-1-
en-3-inylisocyanide)chromium ((CO) Cr(CNCFCFC H) 3c in 10
203.0 (CN), 196.9 (Co(CO)
IR (CH
3
-
1
2
Cl
2
◦
+
5
2
m, 1858 m. MS (EI, 80 eV, 70 C): m/z (%) = 960 (0.1) [M -
5
2
+
52
+
52
mL of acetone. The suspension was vigorously stirred at ambient
temperature in an open flask allowing air contact. After 1 h no
reactant could be detected by TLC. The reaction mixture was
filtered through a thin pad of silica to remove insoluble materials.
After column chromatography on silica and pentane as eluent and
crystallization 140 mg (81%) 5 were obtained as a mixture of the
three possible isomers in a ratio of (ZZ) : (EZ) : (EE) = 6 : 3 : 1. The
Cr(CO)
6
], 932 (0.5) [M - Cr(CO)
7
], 820 (0.1) [M - Cr(CO)11],
+
52
+
52
792 (0.5) [M
(0.5) [M
-
Cr(CO)12], 764 (0.4) [M
Cr(CO)14], 708 (0.4) [M
-
Cr(CO)13], 736
Cr(CO)15], 680 (0.2)
+
52
+
52
-
-
+
52
+
52
+
[M - Cr(CO)16], 652 (0.4) [M - Cr(CO)17], 624 (0.4) [M -
5
2
59
59
Cr(CO)18], 572 (53) [ Co
4
(CO)12], 544 (55) [ Co
4
(CO)11], 516 (9)
(CO) ], 432 (89)
(CO) ], 348
(CO) ],
], 192 (11)
5
9
59
59
[ Co
4
(CO)10], 488 (8) [ Co
4
(CO)
9
], 460 (45) [ Co
4
8
5
9
59
59
[ Co
4
59
(CO)
7
], 404 (31) [ Co
4
59
(CO)
6
], 376 (18) [ Co
4
5
◦
59
isomeric mixture forms a microcrystalline solid with mp. 105 C
(22) [ Co
264 (25) [ Co
4
9
(CO)
4
], 320 (38) [ Co
CO], 236 (33) [ Co
4
(CO)
3
], 292 (28) [ Co
4
2
5
59
52
(
dec).
4
4
], 220 (69) [ Cr(CO)
6
This journal is © The Royal Society of Chemistry 2012
Dalton Trans., 2012, 41, 839–849 | 847

View Article Online
5
2
52
52
[
Cr(CO)
5
], 177 (20), 164 (6) [ Cr(CO)
4
], 136 (7) [ Cr(CO)
3
], 118
paper have been deposited with the Cambridge Crystallographic
Data Centre and are available as ESI.†
5
9
52
59
(
(
12), 115 (3) [ Co(CO)
19) [ CrCO], 80 (100) [ CrCO], 59 (11), 53 (7), 52 (78).
2
], 108 (97) [ Cr(CO)
2
], 87 (6) [ CoCO], 81
5
3
52
Acknowledgements
Decacarbonyl(1,2,5,6-tetrafluorohex-1,5-dien-3-(hexacarbonyl[l -
2
Support by the Deutsche Forschungsgemeinschaft (DFG) is
gratefully acknowledged.
2
2
(
3,4-g : 3,4-g -inyl)]dicobalt)-diisocyanide)dichromium (8)
Analogously to the syntheses of 9, 108 mg (0.18 mmol) of
(
CO) Cr(CNCFCFC CFCFNC)Cr(CO) 6 was dissolved in 10
5
2
5
Notes and references
mL of a pentane/dichloromethane mixture (1 : 1) under argon
atmosphere at ambient temperature. After addition of 210 mg
(
1
2
D. S. Matteson and R. A. Bailey, J. Am. Chem. Soc., 1968, 90, 3761.
A. Gautier, Justus Liebigs Ann. Chem., 1867, 142, 289; A. Gautier,
Justus Liebigs Ann. Chem., 1868, 146, 124.
0.61 mmol) of octacarbonyldicobalt the solution was stirred for
.5 h. After filtration and removal of the solvents the isomers 8 were
1
3 A. W. Hofmann, Justus Liebigs Ann. Chem., 1867, 144, 114; A. W.
Hofmann, Justus Liebigs Ann. Chem., 1868, 146, 107.
4 (a) A. D o¨ mling and I. Ugi, Angew. Chem., Int. Ed., 2000, 39, 3168;
isolated by fractionated column chromatography and fractionated
crystallization from petrolether at -30 C. The yield was 74 mg
◦
(
b) J. Zhu, H. Bienaym e´ , Multicomponent Reactions, WILEY-VCH,
◦
(
47%) of dark red crystals of 8, m.p. (ZZ)-8: 138–139 C; (EZ)-8:
Weinheim, 2005;; (c) A. D o¨ mling, Chem. Rev., 2006, 106, 17; (d) I.
◦
1
19–121 C.
Akritopoulou-Zanze, Curr. Opin. Chem. Biol., 2008, 12, 324.
1
9
5 T. Saegusa, I. Murase and Y. Ito, Tetrahedron, 1971, 27, 3795–3801.
F-NMR (376.0 MHz, CDCl
3
, CFCl intern): (ZZ)-Isomer:
3
6
U. Sch o¨ llkopf, D. Stafforst and K. Jentsch, Liebigs Ann. Chem., 1977,
d = -104.4 (s, 2 F, (Z)-CF CF–C), -120.9 (s, 2 F, (Z)-CF CF–
C); (EZ)-Isomer: d = -105.3 (s, 1 F, (Z)-CF CF–C), -120.9
(
CF CF–C), -128.4 (d, JFF = 125 Hz, 1 F, (E)-CF CF–C);
(
1
167–1173.
7
A. D o¨ mling and K. Illgen, Synthesis, 2005, 662–667.
3
d, JFF = 125 Hz, 1 F, (E)-CF CF–C), -121.5 (s, 1 F, (Z)-
8 H. Bock and I. Ugi, J. Prakt. Chem., 1997, 339, 385–389.
9 R. B. King and L. Borodinsky, Tetrahedron, 1985, 41, 3225–3240.
0 R. B. King and L. Borodinsky, Macromolecules, 1985, 18, 2117–2120.
1 R. Aumann, E. Kuckert, C. Kr u¨ ger and K. Angermund, Angew. Chem.,
Int. Ed. Engl., 1987, 26, 563.
3
1
1
3
EE)-Isomer: d = -122.2 (d, JFF = 125 Hz, 2 F, (E)-CF CF–
3
13
19
C), -129.3 (d, JFF = 125 Hz, 2 F, (E)-CF CF–C). C{ F}-
NMR (CDCl , 100.4 MHz): (ZZ)-Isomer: d = 213.0 (COtrans),
11.9 (COcis), 206.6 (Co(CO) ), 202.5 (CN), 141.8, 125.9(CF), 96.2
); (EZ)-Isomer: d = 213.6, 212.9 (COtrans), 212.3, 212.2 (COcis),
01.9, 198.3 (CN), 195.7 (Co(CO) ), 145.4, 141.6, 128.1, 125.8
Cl ): (ZZ)-Isomer: n (cm ) = 2111
s, 2080 s, 2065 s, 2045 s, 2028 m, 2002 s, 1969 vs. (CO), 1945 vs,
644 w (C C), 1250 m (CF), 835 w, 660 s, 647 s; (EZ)-Isomer: n
1
1
2 D. Lentz and D. Preugschat, J. Chem. Soc., Chem. Commun., 1992,
3
1
523.
2
(
2
3
3 J. Buschmann, S. Kleinhenz, D. Lentz, P. Luger, K. V. Madappat, D.
C
Preugschat and J. S. Thrasher, Inorg. Chem., 2000, 39, 2807–2812.
14 W. P. Fehlhammer and G. Beck, J. Organomet. Chem., 1989, 379, 97.
15 M. Kr u¨ ger, H. Dreizler, D. Preugschat and D. Lentz, Angew. Chem.,
3
-
1
(
CF), 96.3, 85.0 (C ). IR (CH
2
2
1
991, 103, 1674, (Angew. Chem., Int. Ed. Engl., 1991, 30, 1644).
1
6 K. Kawaguchi, M. Ohishi, S.-I. Ishikawa and N. Kaifu, Astrophys. J.,
1992, 386, L51.
1
-
1
(cm ) = 2110 s, 2075 s, 2046 s, 2037 m, 2019 m, 1954 vs. (CO), 1660
17 L. Zanathy, H. Bock, D. Lentz, D. Preugschat and P. Botschwina, J.
Chem. Soc., Chem. Commun., 1992, 403.
w, 1571 w (C C), 1259 m (CF), 1172 m, 1107 w, 657 s. Raman:
1
8 A. Guarnieri, R. Hinze, M. Kr u¨ ger, H. Zerbe-Foese, D. Lentz and D.
Preugschat, J. Mol. Spectrosc., 1992, 156, 39; A. Huckauf, A. Guarnieri,
D. Lentz and A. Fayt, J. Mol. Spectrosc., 1998, 188, 109.
9 H. B u¨ rger, S. Sommer, D. Lentz and D. Preugschat, J. Mol. Spectrosc.,
1992, 156, 360.
0 H. B u¨ rger, D. Lentz, B. Meisner, N. Nickelt, D. Preugschat and M.
Senzlober, Chem.–Eur. J., 2000, 6, 3377–3385.
-
1
(
ZZ)-Isomer: nshift (cm ) = 2109 w, 2074 vw, 2055 vw, 2038 vw,
030 vw, 2016 w, 2004 vs, 1967 w, 1951 vw, 1938 w, 1660 s, 1646
m, 1592 vw, 1262 m, 1245 m, 1195 w, 1044 vw, 655 vw, 612 w, 434
2
1
2
-
1
w, 384 s, 197 w, 106 s; (EZ)-Isomer: nshift (cm ) = 2107 w, 2049 vw,
017 m, 2002 m, 1946 w, 2016 w, 1665 vs, 1571 w, 1301 m, 1272
m, 1249 w, 1168 vw, 852 vw, 683 vw, 655 vw, 619 w, 527 vw, 433
2
21 A. M. Smith, G. Schallmoser, A. Thoma and V. E. Bondybey, J. Chem.
Phys., 1993, 98, 1776.
+
52
w, 386 m, 275 vw. MS (EI, 80 eV): m/z (%) = 870 (6) [M , Cr],
¨
2
2 C. Bartel, P. Botschwina, H. B u¨ rger, A. Guarnieri, A. Heyl, A. Huckauf,
+
+
+
8
6
5
1
42 (14) [M - CO], 786 (5) [M - 3 CO], 702 (10) [M - 6 CO],
D. Lentz, T. Merzliak and El B. Mkadmi, Angew. Chem., 1998, 110,
+
+
+
46 (9) [M - 8 CO], 618 (7) [M - 9 CO], 590 (11) [M - 10 CO],
3036, (Angew. Chem., Int. Ed., 1998, 37, 2879).
+
+
+
2
2
3 J. Gripp, A. Guarnieri, W. Stahl and D. Lentz, J. Mol. Struct., 2000,
526, 81–96.
34 (10) [M - 12 CO], 506 (12) [M - 13 CO], 478 (13) [M -
5
2
4 CO], 220 (100) [ Cr(CO)
6
], 28 (32). Elemental analysis calcd
4 P. Thaddeus, M. C. McCarthy, M. J. Travers, C. A. Gottlieb and W.
for C24Co
.39%.
2
Cr 16 (870.1): C 33.13, N 3.22; found: C 33.83, N
2
F
4
N O
2
Chen, Faraday Discuss., 1998, 109, 121.
¨
3
25 P. Botschwina, A. Heyl, W. Chen, M. C. McCarthy, J.-U. Grabow, M.
J. Travers and P. Thaddeus, J. Chem. Phys., 1998, 109, 3108.
6 R. Kunz and W. P. Fehlhammer, Angew. Chem., 1994, 106, 331, (Angew.
Chem., Int. Ed. Engl., 1994, 33, 330).
2
Crystallography
2
2
7 D. Bergemann, Diplomarbeit Freie Universit a¨ t Berlin.
8 P. J. Stang, in Modern Acetylene Chemistry, ed. P. J. Stang, F. Diederich,
VCH, Weinheim, New York, Basel, Cambridge, Tokyo, 1995, p. 67.
Crystal data and details of the structure determinations are
presented in Table 3. The intensity data were collected using a
Bruker AXS Smart CCD diffractometer: corrections for Lorentz
polarisation and absorption effects (SADABS) were applied to
the data. The structures were solved by Patterson and direct meth-
29 D. Lentz, F. Nowak, D. Preugschat and M. Wasgindt, Angew. Chem.,
1
993, 105, 1547, (Angew. Chem., Int. Ed. Engl., 1993, 32, 1456).
3
0 (a) R. D. Chambers, in Synthetic Fluorine Chemistry, ed. G. A. Olah, R.
D. Chambers, G. K. S. Prakash, Wiley-Interscience, New York, 1992;
(b) R. D. Chambers, J. F. S. Vaughan, Topics in Current Chem. 1997,
192, 1.
42
43
ods (SHELXS-97) Anisotropic thermal parameters were applied
to all non-hydrogen atoms. Refinement for all structures on F were
2
31 (a) K. H. D o¨ tz, in Reactions of Coordinated Ligands, Ed. P. S.
Bratermann, Plenum Press, New York, 1986; (b) B. Crociani, in
Reactions of Coordinated Ligands, Ed. P. S. Bratermann, Plenum Press,
New York, 1986.
42
achieved using the SHELXL-97 system. Crystallographic data
excluding structure factors) for the structures reported in this
(
8
48 | Dalton Trans., 2012, 41, 839–849
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2 D. Lentz, M. Mujkic and S. Roth, Eur. J. Inorg. Chem., 2008, 2967–
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41 C. M. Timperley, J. Fluorine Chem., 2004, 125, 685–693.
42 SADABS: Area-Detector Absorption Correction, Siemens Industrial
Automation, Inc., Madison, WI, 1996.
2
3 (a) D. Lentz and R. Marschall, Chem. Ber., 1990, 123, 751; (b) D. Lentz,
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3
3, 1315).
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3
3
4 S. Berger, S. Braun, H.-O. Kalinowski, NMR-Spektroskopie von
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Dalton Trans., 2012, 41, 839–849 | 849