Novel nickel-catalyzed reactions of nitriles with 1,2-bis(dimethylsilyl)carborane

Article abstract of DOI:10.1021/om0008629

The nickel-catalyzed reaction of 1,2-bis(dimethylsilyl)carborane (1) with propionitrile afforded an N-silyl enamine. The dehydrogenative double silylation of nitriles without α-H such as isobutyronitrile, benzonitrile, p-tolunitrile, and 1-cyanonaphthalene yielded six-membered cyclic imines. In contrast, the reaction of 1 with 9-anthracenecarbonitrile under the same reaction conditions gave a five-membered N,N-bis(silyl) amine. Interestingly, the reaction of 1 with nitriles having an α-hydrogen such as benzyl cyanide, diphenylacetonitrile, and hydrocinnamonitrile afforded N,N-bis(silyl) enamines.

Full text of DOI:10.1021/om0008629

Organometallics 2001, 20, 937-944
937
Novel Nick el-Ca ta lyzed Rea ction s of Nitr iles w ith
1,2-Bis(d im eth ylsilyl)ca r bor a n e
J insik Kim,† Youngjin Kang,‡ J unghyun Lee,‡ Young Kun Kong,†
Myong Seon Gong,§ Sang Ook Kang,*,‡ and J aejung Ko*,‡
Departments of Chemistry, Korea University, Chochiwon, Chungnam 339-700, Korea,
Kyonggi University, Suwon, Kyonggido, 440-760, Korea, and Dankook University, Cheonan,
Chungnam 330-714, Korea
Received October 10, 2000
The nickel-catalyzed reaction of 1,2-bis(dimethylsilyl)carborane (1) with propionitrile
afforded an N-silyl enamine. The dehydrogenative double silylation of nitriles without R-H
such as isobutyronitrile, benzonitrile, p-tolunitrile, and 1-cyanonaphthalene yielded six-
membered cyclic imines. In contrast, the reaction of 1 with 9-anthracenecarbonitrile under
the same reaction conditions gave a five-membered N,N-bis(silyl) amine. Interestingly, the
reaction of 1 with nitriles having an R-hydrogen such as benzyl cyanide, diphenylacetonitrile,
and hydrocinnamonitrile afforded N,N-bis(silyl) enamines.
In tr od u ction
photochemical9 double silylation using a silyliron car-
bonyl complex have been developed as a method for the
preparation of silyl-substituted nitriles.
Transition-metal-catalyzed double silylation of al-
kynes,1 alkenes,2 1,3-dienes,3 and carbonyl compounds4
has been developed in the last 30 years. In contrast to
the above well-developed reactions, little is known about
double silylation of the carbon-nitrogen triple bond,
because the cyano group has been believed to be inert.
For example, rhodium-,5 molybdenum-,6 and cobalt-
catalyzed7 hydrosilylation and chemoselective8 and
Recently, we10 reported the double-silylation reactions
of a variety of unsaturated organic substrates with
(Ph3P)2Pt[o-(SiMe2)2C2B10H10] (A), which contains an
o-carboranylene unit. Interestingly, its reaction with
fumaronitrile yielded the cyclization product B, which
contains two types of disilyl moieties, an imine and N,N-
bis(silyl)amine.
† Kyonggi University.
‡ Korea University.
§ Dankook University.
(1) (a) Sharma, H. K.; Pannel, K. H. Chem. Rev. 1995, 95, 1351. (b)
Suginome, M.; Ito, Y. Chem. Rev. 2000, 100, 3221. (c) Sakurai, H.;
Kamiyama, Y.; Nakadaira, Y. J . Am. Chem. Soc. 1975, 97, 931. (d)
Tamao, K.; Hayashi, T.; Kumada, M. J . Organomet. Chem. 1976, 114,
C19. (e) Watanabe, H.; Kobayashi, M.; Higuchi, K.; Nagai, Y. J .
Organomet. Chem. 1980, 186, 51. (f) Watanabe, H.; Kobayashi, M.;
Saito, M.; Nagai, Y. J . Organomet. Chem. 1981, 216, 149. (g) Matsu-
moto, H.; Matsubara, I.; Kato, T.; Shono, K.; Watanabe, H.; Nagai, Y.
J . Organomet. Chem. 1980, 199, 43. (h) Seyferth, D.; Goldmam, E. W.;
Escudie´, J . J . Organomet. Chem. 1984, 217, 337. (i) Naka, A.; Okazaki,
S.; Hayashi, M.; Ishikawa, M. J . Organomet. Chem. 1995, 499, 35.
(2) (a) Hayashi, T.; Kobayashi, T.; Kawamoto, A. M.; Yamashita,
H.; Tanaka, M. Organometallics 1990, 9, 280. (b) Murakami, M.;
Anderson, P. G.; Suginome, M.; Ito, Y. J . Am. Chem. Soc. 1991, 113,
3987. (c) Ozawa, F.; Sugawara, M.; Hayashi, T. Organometallics 1994,
13, 3237. (d) Ishikawa, M.; Naka, A.; Ohshita, J . Organometallics 1993,
12, 4987.
(3) (a) Sakurai, H.; Kamiyama, Y.; Nakadaira, Y. Chem. Lett. 1975,
887. (b) Carlson, C. W.; West, R. Organometallics 1983, 2, 1801. (c)
Tsuji, Y.; Largo, R. M.; Tomohiro, S.; Tsuneishi, H. Organometallics
1992, 11, 2353. (d) Obora, Y.; Tsuji, Y.; Kawamura, T. Organometallics
1993, 12, 2853. (e) Tamao, K.; Okazaki, S.; Kumada, M. J . Organomet.
Chem. 1978, 146, 87. (f) Sakurai, H.; Kamiyama, Y.; Nakadaira, Y.
Chem. Lett. 1975, 887.
(4) (a) Uchimaru, Y.; Lautenschlager, H.-J .; Wynd, A. J .; Tanaka,
M.; Goto, M. Organometallics 1992, 11, 2639. (b) Hayashi, T.; Matsu-
moto, Y.; Ito, Y. J . Am. Chem. Soc. 1988, 110, 5579. (c) Tamao, K.;
Okazaki, S.; Kumada, M. J . Organomet. Chem. 1978, 146, 87.
(5) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-Sat, M. J . Organomet.
Chem. 1882, 228, 301.
(6) Keinan, E.; Perez, D. J . Org. Chem. 1987, 52, 2576.
(7) (a) Murai, T.; Sakane, T.; Kato, S. Tetrahedron Lett. 1985, 26,
5145. (b) Murai, T.; Sakane, T.; Kato, S. J . Org. Chem. 1990, 55, 449.
(8) (a) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-Sat, M. J . Org.
Chem. 1981, 46, 3372. (b) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-
Sat, M. Organometallics 1985, 4, 623.
Tanaka and co-workers11 reported that platinum-
catalyzed double silylation of nitriles with o-bis(dimeth-
ylsilyl)benzene afforded N-silyl enamines and imines.
The unusal reactivity of 1,2-bis(dimethylsilyl)carborane
(1) has allowed novel transformations of some nitriles.
In addition, the double silylation of nitriles by the cyclic
bis(silyl)platinum complex A was a stoichiometric pro-
cess and was quite limited. Accordingly, we have started
a systematic study of the double silylation of nitriles
catalyzed by a nickel complex. Here we report the
double-silylation reactions of a variety of nitriles with
1,2-bis(dimethylsilyl)carborane.
(9) (a) Corriu, R. J . P.; Moreau, J . J . E. J . Chem. Soc., Chem.
Commun. 1980, 278. (b) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-Sat,
M. J . Org. Chem. 1981, 46, 3372.
(10) (a) Kang, Y.; Kang, S. O.; Ko, J . Organometallics 1999, 18, 1818.
(b) Kang, Y.; Kang, S. O.; Ko, J . Organometallics 2000, 19, 1216.
(11) Reddy, N. P.; Uchimaru, Y.; Lautenschlager, H.-J .; Tanaka, M.
Chem. Lett. 1992, 45.
10.1021/om0008629 CCC: $20.00 © 2001 American Chemical Society
Publication on Web 01/27/2001

938 Organometallics, Vol. 20, No. 5, 2001
Kim et al.
singlets (-0.62 and -1.42 ppm) in the 13C NMR
spectrum of 3 could be assigned to the methyl groups
on the silicon atoms. The 29Si NMR spectrum of 3
exhibited two resonances at -12.4 and -8.8 ppm arising
from the nonequivalent silicon atoms. We are tenta-
tively assigned the Z configuration due to the steric
hindrance. Such N-silyl enamines have been prepared
using a platinum complex as the catalyst with o-bis-
(dimethylsilyl)benzene.11
The results of the nickel-complex-catalyzed reactions
of 1 with nitriles that do not contain an R-hydrogen are
presented in Table 2.
Reaction of benzonitrile and 1 in the presence of a
catalytic amount of 2 in refluxing toluene afforded a six-
membered cyclic imine (Table 2) in moderate yield (eq
2). In a similar fashion, the nickel-catalyzed reactions
Ta ble 1. Cr ysta l Da ta of Com p ou n d s 8 a n d 12
8
12
empirical formula
mol wt
cryst syst
space group
a, Å
C
21H33B10NSi2
C15H28B10NSi2
386.66
monoclinic
P21/c
11.7883(9)
14.4327(11)
13.8304(11)
90
102.681(2)
90
2295(3)
4
463.76
monoclinic
P21/c
18.332(3)
13.196(2)
23.452(3)
90
107.414(10)
90
5413(1)
8
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
D
calcd, g cm-3
1.138
1.119
F(000)
1952
0.143
ω
9733
812
0.156
ω
14 807
5520
0.0609
0.1493
1.008
µ, cm-1
)
scan type
no. of rflns measd
no. of obsd rflns, I > 2σ(I)
R1
3711
0.0856
0.1897
1.103
wR2a
goodness of fit
wR2 ) ∑[w(Fo - Fc2)2]/∑[w(Fo2)2]1/2
.
a
2
Resu lts a n d Discu ssion
Although the cyclic bis(silyl)platinum complex is not
a catalyst for the double silylation of nitriles with 1,2-
bis(dimethylsilyl)carborane (1), due to its strong Pt-Si
bonds and the relative inertness of the cyano group, the
cyclic bis(silyl)nickel complex 212 was found to be a good
catalyst for the dehydogenative double silylation of
nitriles. The nickel-catalyzed double silylation can be
carried out either by reacting 1 and the nitrile in the
presence of Ni(PEt3)4 or by reacting 1 and the nitrile in
the presence of a catalytic amount of the cyclic bis(silyl)-
nickel complex 2. Because the former procedure in some
cases gave complex product mixtures, the latter proce-
dure is preferred.
of 1 with other nitriles such as isobutyronitrile, p-
tolunitrile, and 1-cyanonaphthalene in refluxing toluene
yielded the respective six-membered cyclic insertion
products. Such a nitrile insertion reaction has been
reported using a platinum complex as catalyst and o-bis-
(dimethylsilyl)benzene.11
Propionitrile readily reacted with 1 in the presence
12
of a catalytic amount of (PEt3)2Ni[o-(SiMe2)2C2B10H10
]
(2) in refluxing toluene to give the N-silyl enamine 3
(Table 2) in good yield (eq 1).
Compounds 4-7 were identified on the basis of their
1H, 13C, and 29Si NMR spectra, their mass spectra, and
elemental analyses. The 1H NMR spectrum of 5 showed
the phenyl and methyl resonances in the expected 5:12
ratio. In the 13C NMR spectrum of 5, a resonance at
141.81 ppm could be assigned to the imino carbon atom.
The 29Si NMR spectrum of 5 showed two resonances at
-11.6 and -7.2 ppm.
In contrast to the double silylation of the above
nitriles by 1, when 9-anthracenecarbonitrile was em-
ployed in the reaction with 1 under the same reaction
conditions (eq 3), the five-membered cyclic N,N-bis(silyl)
amine 8 (Table 2) was isolated as colorless crystals in
76% yield.
The 1H, 13C, and 29Si NMR spectra and the mass
spectrum of compound 3 were consistent with the
proposed structure. A parent ion in the mass spectrum
1
A key feature in the H NMR spectrum of 8 includes
a singlet at 4.96 ppm assigned to the methylene protons.
A high-frequency 13C NMR resonance at 29.42 ppm
provides evidence for a methylene carbon atom, in
addition to a resonance at -2.64 ppm assigned to the
methyl carbon. The value is close to that of the N,N-
bis(silyl) amine reported by Tanaka and co-workers.11
To confirm the structure of 8, a single-crystal X-ray
diffraction study was undertaken. The molecule struc-
ture of 8 is shown in Figure 1. A summary of cell
1
was observed at m/z 312. The H NMR spectrum of 3
contained a broad N-H resonance (3.92 ppm) and an
olefinic proton resonance (4.97 ppm). Two singlets (0.35
and 0.33 ppm) in the 1H NMR spectrum and two
(12) (a) Kang, Y.; Lee, J .; Kong, Y. K.; Kang, S. O.; Ko, J . Chem.
Commun. 1998, 2343. (b) Kang, Y.; Lee, J .; Kong, Y. K.; Kang, S. O.;
Ko, J . Organometallics 2000, 19, 1722.

Nickel-Catalyzed Reactions of Nitriles
Organometallics, Vol. 20, No. 5, 2001 939
Ta ble 2. Nick el-Ca ta lyzed Rea ction s of Nitr iles w ith 1,2-Bis(d im eth ylsilyl)ca r bor a n e

940 Organometallics, Vol. 20, No. 5, 2001
Kim et al.
Ta ble 2 (Con tin u ed )
constants and data collection parameters is included in
Table 1. A five-membered ring containing a carboranyl
unit, two silicon atoms, and an amine fragment was
shown to be present. There are two crystallographically
independent molecules in an asymmetric unit. This is
why the unit cell has a Z value of 8. These two molecules
are essentially identical within experimental error. The
anthracene group is almost perpendicular to the mol-
ecule plane defined by the two silicon atoms, the two
carborane carbon atoms, and the nitrogen atom with
dihedral angles of 88.1(1)°. The N(1)-C(7) bond distance
(1.478(7) Å) is typical of the nitrogen-carbon single
bond (1.47 Å).13 The N(1)-C(7)-C(8) bond angle
(116.0(5)°) is slightly wider than the usual value for an
sp3 carbon center due to the steric hindrance of the
anthracene group.
The formation of 8 is interesting, because the sequen-
tial hydrosilylation of the carbon-nitrogen triple bond
by the Si-H bond in 1 must have occurred during the
course of the reaction. A similar hydrosilylation has
been observed in the rhodium5- and platinum-cata-
lyzed11 double silylation of nitriles with a bis(hydrosi-
lane).
A preliminary study of the reactivity of cyclic bis-
F igu r e 1. ORTEP drawing of 8 showing the atom-labeling scheme with 50% probability thermal ellipsoids. Selected
bond lengths (Å) and angles (deg): Si(1)-N(1) ) 1.730(7), Si(1)-C(1) ) 1.909(6), Si(2)-N(1) ) 1.734(4), Si(2)-C(2) )
1.894(6), N(1)-C(7) ) 1.478(7); N(1)-Si(1)-C(B) ) 98.5(2), N(1)-Si(2)-C(2) ) 99.4(2), Si(1)-N(1)-Si(2) ) 120.6(3),
C(2)-C(1)-Si(1) ) 111.1(4), C(1)-C(2)-Si(2) ) 110.3(4), N(1)-C(7)-C(8) ) 116.0(5), C(7)-N(1)-Si(1) ) 124.7(4),
C(7)-N(1)-Si(2) ) 114.4(3).

Nickel-Catalyzed Reactions of Nitriles
Organometallics, Vol. 20, No. 5, 2001 941
reaction (9-11) may be proposed (Scheme 1). In the first
stage, insertion of the cyano group into one Ni-Si bond
gives a seven-membered intermediate (C). The migra-
tion of the other silicon atom to the nitrogen affords the
carbene intermediate D. The σ-vinyl complex E can be
obtained via a migration of one hydrogen atom R to the
cyano group of the nitrile to the carbon R to the nitrogen
atom. The N,N-bis(silyl) enamine is then formed in a
reductive elimination step.
To further prove the above proposed mechanism, we
have carried out the reaction of 2,3-(1,1,4,4-tetrameth-
yldisilanediyl)carborane with 3 equiv of benzyl cyanide
in the presence of a catalytic amount of 2 in toluene at
60-70 °C. It gave compound 9 in 76% yield (eq 5). This
is additional evidence for the mechanism proposed
above.
(silyl)nickel complex 2 showed that its catalytic reac-
tions with nitriles that have an R-hydrogen produce
N,N-bis(silyl) enamines (Table 1), providing easy access
to a variety of N,N-bis(silyl) enamines, which recently
were shown to be precusors of substituted 2-aza-1,3-
butadienes.14 Thus, treatment of 1 with 4 equiv of
benzyl cyanide in the presence of a catalytic amount of
2 in refluxing toluene-d8 resulted in the diminishment
of the methylene peak and new signals at 6.53 and 5.82
ppm grew in (eq 4). The 1H NMR spectrum of the
Surprisingly, when cinnamonitrile was employed in
the catalytic reaction with 2, a five-membered cyclo-
pentanone enamine (Table 2) was isolated as colorless
crystals in 68% yield (eq 6). A key feature in the 1H
isolated product 9 exhibited two olefinic proton reso-
nances at 6.53 and 5.82 ppm (both doublets). The IR
spectrum of compound 9 showed a new absorption due
to the νCdC stretch at 1592 cm-1, concomitant with the
disappearance of the original strong absorption at 2240
cm-1, assigned to the cyano group of the ligand. The
29Si NMR spectrum of 9 showed two resonances at 2.4
and -3.2 ppm, indicative of the presence of two chemi-
cally nonequivalent silicon atoms. The chemical shifts
in the 29Si NMR spectrum of 9 are in the range of
those of the other five-membered-ring compounds.15
Such selective conversion of nitriles into N,N-bis(silyl)
enamines has been observed previously in the iron-
catalyzed double silylation.15
NMR spectrum of 12 includes a doublet at 3.34 ppm
assigned to the methylene and a triplet at 5.98 ppm
assigned to the vinyl proton. A characteric high-field 13
C
NMR resonance at 35.89 ppm provides evidence for
formation of a methylene group. The structure of the
product was not deduced on the basis of spectroscopic
data; therefore, a single-crystal X-ray diffraction study
was undertaken. The molecular structure of 12 is shown
in Figure 2. Crystallographic data are given in Table 1.
To our surprise, the X-ray study of 12 showed it to be
the cyclic enamine. The C(1)-C(9) bond length (1.393-
(5) Å) in the ring is in the range of a double bond,
demonstrating the presence of an enamine. Such a
transformation of nitrile to enamine has been observed
in the photochemical reaction of iron with 4-cyanobut-
1-ene.16
On the basis of our results and some other related
results,15 a plausible reaction pathway for the present
(13) Huheey, J . E.; Keiter, E. A.; Keiter, R. L. Inorg. Chem.; Harper
Collins: A30.
(14) (a) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-Sat, M. J . Org.
Chem. 1990, 55, 2878. (b) Corriu, R. J . P.; Huynh, V.; Moreau, J . J .
E.; Pataud-Sat, M. J . Organomet. Chem. 1983, 255, 359. (c) Corriu, R.
J . P.; Huynh, V.; Moreau, J . J . E.; Pataud-Sat, M. Tetrahedron Lett.
1982, 23, 3257.
(15) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen,
A. G.; Taylor, R. J . Chem. Soc., Perkin Trans. 1987, 1, 51.

942 Organometallics, Vol. 20, No. 5, 2001
Kim et al.
Sch em e 1
A reasonable mechanism for the formation of 12
involves the initial insertion of the cyano group into one
of the nickel-silicon bonds, leading to the seven-
membered intermediate C. The migration of the silicon
atom to the nitrogen atom in our case then would afford
hydride intermediate G. The nickelacyclohexene thus
formed can liberate the cyclic enamine by reductive
elimination with extrusion of Ni(PEt3)2. Such a forma-
tion of a nickel carbene intermediate is supported by
the isolation of iron carbene complexes as reported by
Gladysz and co-workers.17
The reaction of (trimethylsilyl)acetonitrile gave the
acylsilane enamine 13. Two characteristic doublets at
1
5.52 and 5.46 ppm in the H NMR spectrum of 13 were
assigned to the vicinal olefinic protons. Such a formation
of an enamine due to the migration of a trimethylsilyl
group has been observed previously.18
In earlier work,10 we attempted the stoichiometric
reaction of the cyclic bis(silyl)platinum complex with
fumaronitrile. An X-ray study revealed the product to
be a cyclization product, B, which contained two types
of disilyl moieties, imine and N,N-bis(silyl) amine. To
determine whether the nickel-catalyzed double silyla-
tion of fumaronitrile proceeds in a similar direction, we
attempted the double silylation under the same reaction
conditions.
an amine and the carbene F . The intramolecular
aromatic C-H activation would occur to give the nickel
Fumaronitrile was found to react with 1 in the
F igu r e 2. ORTEP drawing of 12 showing the atom-labeling scheme with 50% probability thermal ellipsoids. Selected
bond lengths (Å) and angles (deg): C(1)-C(9) ) 1.393(5), C(1)-C(2) ) 1.494(5), C(2)-C(3) ) 1.489(6), C(3)-C(8) ) 1.393(5),
C(9)-C(9) ) 1.471(4), C(12)-C(13) ) 1.681(4), N-C(9) ) 1.430(4), Si(1)-N ) 1.740(2), Si(1)-C(13) ) 1.903(3),
Si(2)-C(12) ) 1.901(3); Si(1)-N-Si(2) ) 121.60(14), Si(1)-N-C(9) ) 118.55(18), N-C(9)-C(1) ) 127.4(3), C(9)-C(1)-
C(2) ) 111.4(4).

Nickel-Catalyzed Reactions of Nitriles
Organometallics, Vol. 20, No. 5, 2001 943
Hz, CH), 0.94 (d, 6H, J HH ) 7.02 Hz, CH3), 0.43 (s, 6H, Si-
CH3), 0.41 (s, 6H, Si-CH3). 13C{1H} NMR (CDCl3): δ 107.83
(CN), 41.25 (CHMe2), 19.14 (CHCH3), -1.40 (2C, Si-CH3),
-2.24 (2C, Si-CH3). 29Si NMR (CDCl3): δ -7.6, -12.8. MS:
m/z 328 [M+]. IR (KBr pellet; cm-1): 3068 (m), 2963 (m), 2592
(s), 2576 (s), 1658 (w), 1545 (w), 1261 (s), 1208 (w), 1095 (s),
1020 (s), 982 (w), 932 (w), 803 (s), 716 (w), 583 (w). Anal. Calcd
for C10H29B10NSi2: C, 36.69; H, 8.86. Found: C, 36.22; H, 8.52.
Com p ou n d 5 fr om t h e R ea ct ion w it h Ben zon it r ile.
Compound 5 was prepared using the same procedure as
described for 3. The pure yellow product 5 was obtained by
repeated recrystallization from hexane at -30 to -40 °C in
presence of a catalytic amount of 2 to afford the
cyclization product 14. Four singlets (0.29, 0.35, 0.44,
and 0.63 ppm) in the 1H NMR spectrum and four
singlets (-0.03, 0.40, 0.93, and 2.20 ppm) in the 13C
NMR spectrum of 14 could be assigned to the methyl
groups, which indicated that the four methyl groups are
not equivalent. The spectral data for 14 were identical
with those of the authentic sample obtained in the
reaction of the platinum complex with fumaronitrile.
In summary, the nickel-catalyzed double silylation of
nitriles allowed easy access to bis(silyl)carboranyl prod-
ucts. The disilanickela complex 2 is an effective catalyst
for the selective conversion of nitriles to bis(silyl)
products. The reactions are quite sensitive to the
substituent of the nitriles. The present reaction provides
a new route to a novel class of heterocyclic compounds.
1
52% yield. Mp: 96-98 °C. H NMR (CDCl3): δ 7.62-7.32 (m,
5H, Ph), 0.60 (s, 6H, Si-CH3), 0.54 (s, 6H, Si-CH3). 13C{1H}
NMR (CDCl3): δ 141.81, 129.48, 127.11, 124.95, 102.76, -1.84,
-2.79. 29Si NMR (CDCl3): δ -7.2, -11.6. MS: m/z 362 [M+].
IR (KBr pellet; cm-1): 3084 (w), 3064 (w), 3036 (w), 2966 (m),
2595 (s), 2561 (s), 1616 (s), 1591 (m), 1579 (m), 1447 (w), 1403
(w), 1311 (w), 1257 (s), 1203 (m). 1172 (m), 1087 (s), 1072 (w),
1024 (w), 1001 (w), 983 (m), 932 (m), 868 (s), 820 (s), 789 (s),
688 (m), 666 (m), 627 (m), 588 (w), 452 (m). Anal. Calcd for
Exp er im en ta l Section
All experiments were performed under a nitrogen atmo-
sphere in a Vacuum Atmospheres drybox or by standard
Schlenk techniques. Toluene, benzene, and diethyl ether were
freshly distilled from sodium benzophenone. Hexane was dried
C
13H27B10NSi2: C, 43.20; H, 7.47. Found: C, 42.89; H, 7.22.
Com p ou n d 6 fr om th e Rea ction w ith p-Tolu n itr ile.
Compound 6 was prepared using the same procedure as
described for 3. The pure product 6 was isolated by chromato-
graphic workup (eluent benzene/hexane (1/4), Rf ) 0.58) in 74%
yield. Mp: 102-104 °C. 1H NMR (CDCl3): δ 7.26-7.06 (m,
4H, Ph), 2.17 (s, 3H, CH3), 0.17 (s, 12H, Si-CH3). 13C{1H}
NMR (CDCl3): δ 137.27, 129.27, 127.94, 123.87, 96.98, 30.93,
-1.28. MS: m/z 376 [M+]. IR (KBr pellet; cm-1): 3038 (w),
2957 (w), 2926 (w), 2858 (w), 2600 (s), 2578 (s), 1641 (w), 1512
(w), 1405 (w), 1361 (w), 1258 (s), 1089 (m), 1067 (s), 1027 (w),
987 (w), 943 (w), 904 (w), 880 (m), 820 (s), 786 (m), 722 (w),
1
and distilled from CaH2. H, 13C, and 29Si NMR spectra were
recorded on a Varian Gemini 300 spectrometer operating at
300.00, 75.44, and 59.60 MHz, respectively. Chemical shifts
are referenced relative to TMS. IR spectra were recorded on a
Biorad FTS-165 spectrometer. Mass spectra were recorded on
a Shimadzu Model QP-1000 spectrophotometer, and elemental
analyses were performed with a Carlo Erba Instruments
CHNS-O EA 1108 analyzer.
o-Carborane was purchased from Callery Chemical Co. and
used without purification. The starting materials Ni(COD)2,
PEt3, and SiMe2HCl were purchased from Strem Chemicals.
The nitriles were purchased from Aldrich. 1,2-Bis(dimethyl-
697 (w), 668 (w), 515 (w), 473 (w). Anal. Calcd for C14H29B10
NSi2: C, 44.79; H, 7.73. Found: C, 44.92; H, 7.58.
-
Com p ou n d 7 fr om th e Rea ction w ith 1-Cya n on a p h -
th a len e. Compound 7 was prepared using the same prodedure
as described for 6, except 1-cyanonaphthalene was used
instead of p-tolunitrile. Pure 7 was isolated by chromato-
graphic workup (eluent benzene/hexane (1/4), Rf ) 0.52). Yield:
72%. Mp: 104-106 °C. 1H NMR (CDCl3): δ 8.08-7.16 (m, 7H,
naphthyl), 0.34 (s, 6H, Si-CH3), 0.33 (s, 6H, Si-CH3). 13C-
{1H} NMR (CDCl3): δ 134.05, 131.52, 130.01, 129.23, 127.50,
127.28, 126.43, 126.39, 124.87, 124.39, 1.99, 0.60. MS: m/z 412
[M+]. IR (KBr pellet; cm-1): 3153 (w), 3072 (w), 2960 (s), 2927
(w), 2864 (w), 2594 (s), 1467 (w), 1382 (w), 1261 (s), 1091 (s),
1039 (w), 908 (s), 804 (m), 734 (s), 651 (w), 543 (m), 449 (m),
423 (m). Anal. Calcd for C17H29B10NSi2: C, 49.63; H, 7.05.
Found: C, 49.28; H, 6.87.
Com p ou n d 8 fr om th e Rea ction w ith 9-An th r a cen e-
ca r bon itr ile. Compound 8 was prepared using the same
procedure as described for 3. Pure 8 was isolated by chro-
matographic workup (benzene/hexane (1/1), Rf ) 0.62) in 76%
yield. Mp: 269-271 °C. 1H NMR (CDCl3): δ 8.49-7.52 (m,
9H, anthracene), 4.96 (s, 2H, CH2), -0.09 (s, 12H, Si-CH3).
13C{1H} NMR (CDCl3): δ 127.80, 127.38, 127.04, 124.93,
124.76, 123.72, 122.60, 118.24, 29.42, -2.64 (Si-CH3). 29Si NMR
(CDCl3): δ -11.6. MS: m/z 464 [M+]. IR (KBr pellet; cm-1):
3056 (w), 2973 (w), 2882 (w), 2579 (s), 1626 (w), 1525 (w), 1496
(w), 1473 (w), 1446 (m), 1404 (m), 1368 (m), 1343 (m), 1258
(s), 1181 (w), 1160 (m), 1073 (s), 1039 (s), 978 (m), 950 (s), 898
(w), 882 (s), 876 (s), 831 (w), 817 (s), 784 (s), 732 (s), 700 (m),
670 (m), 649 (w), 564 (w), 514 (w), 408 (m). Anal. Calcd for
C21H33B10NSi2: C, 54.42; H, 7.12. Found: C, 53.95; H, 6.84.
Com p ou n d 9 fr om th e Rea ction w ith Ben zyl Cya n id e.
A mixture of 0.11 g (0.25 mmol) of 2 and 0.117 g (1 mmol) of
benzyl cyanide in toluene (10 mL) was heated at reflux for 6
h. The solvent was removed in vacuo and chromatographed
using hexane/benzene (4/1) as eluent. Recrystallization from
hexane (10 mL) at -20 °C afforded 9 as colorless crystals in
86% yield. Mp: 103 °C. 1H NMR (CDCl3): δ 7.27-7.14 (m,
silyl)carborane,12 Ni(PEt3)4,19 and (PEt3)2Ni[o-(SiMe2)2-C2B10
-
12
H10
]
were prepared according to the known procedures.
Nick el-Ca ta lyzed Rea ction of 1 w ith Va r iou s Nitr iles.
Gen er a l P r oced u r e. Compounds 3-14 were prepared by the
reaction of 1 with the corresponding nitriles in the presence
of a catalytic amount of 2. In a typical synthesis, a mixture of
propionitrile (0.27 mL, 6.35 mmol), 1 (0.1 g, 0.38 mmol), and
2 (0.01 g, 0.018 mmol) in toluene (15 mL) was heated at reflux
for 12 h. The solvent was removed in vacuo. The solid residue
was extracted with three portions (10 mL) of hexane. The pure
product (3) was obtained by sublimation as air-sensitive
colorless crystals in 66% yield. Mp: 88-92 °C. 1H NMR
(CDCl3): δ 4.97 (q, 1H, J HH ) 6.60 Hz, CH), 3.92 (br, 1H, NH),
1.54 (d, 3H, J HH ) 6.60 Hz, CH3), 0.35 (s, 6H, Si-CH3), 0.33
(s, 6H, Si-CH3). 13C{1H} NMR (CDCl3): δ 116.15 (NC), 97.00
(CCH3), 10.52 (CCH3), -0.62 (2C, Si-CH3), -1.42 (2C, Si-
CH3). 29Si NMR (CDCl3): δ -8.8, -12.4. MS: m/z 312 [M+].
IR (KBr pellet; cm-1): 3329 (w), 3052 (w), 2961 (s), 2599 (s),
1607 (w), 1425 (w), 1335 (m), 1258 (s), 1145 (m), 1090 (s), 1078
(m), 1012 (sh), 878 (m), 815 (s), 722 (w), 680 (m), 583 (m), 542
(w), 492 (w), 422 (m). Anal. Calcd for C9H26B10NSi2: C, 34.61;
H, 8.32. Found: C, 34.16; H, 8.04.
Com p ou n d 4 fr om th e Rea ction w ith Isobu tyr on itr ile.
Compound 4 was prepared using the same procedure as
described for 3, except isobutyronitrile was used instead of
propionitrile. Pure 4 was obtained by sublimation in 66% yield.
Mp: 92-95 °C. 1H NMR (CDCl3): δ 2.91 (sept, 1H, J HH ) 7.02
(16) Corriu, R. J . P.; Moreau, J . J . E.; Pataud-Sat, M. Organome-
tallics 1985, 4, 623.
(17) Nakazawa, H.; J ohnson, D. L.; Gladysz, J . A. Organometallics
1983, 2, 1846.
(18) Bassindale, A. R.; Brook, A. G.; J ones, P. F.; Stewart, J . A. G.
J . Organomet. Chem. 1978, 152, C25.
(19) Browning, J .; Cundy, C. S.; Green, M.; Stone, F. G. A. J . Chem.
Soc. A 1969, 20.

944 Organometallics, Vol. 20, No. 5, 2001
Kim et al.
5H, Ph), 6.53 (d, 1H, J HH ) 14.4 Hz, dCH), 5.82 (d, 1H, J HH
)
Com p ou n d 13 fr om th e Rea ction w ith (Tr im eth ylsi-
lyl)a ceton itr ile. A mixture of (trimethylsilyl)acetonitrile (0.16
mL, 1.19 mmol), 1 (4.15 mL, 1.08 mmol), and 2 (0.03 g, 0.054
mmol) in toluene (20 mL) was heated at 60-80 °C for 12 h.
The volatiles were removed in vacuo. The product was
extracted with hexane (30 mL). The pure product 13 was
obtained by crystallization from pentane at -20 °C in 75%
yield. Mp: 134-136 °C. 1H NMR (CDCl3): δ 5.52 (d, 1H,
J HH ) 2.42 Hz, dCH), 5.46 (d, 1H, J HH ) 2.42 Hz, dCH), 0.27
(s, 12H, Si-CH3), 0.12 (s, 9H, Si-(CH3)3). 13C NMR (CDCl3):
δ 129.05, 128.99, 0.45 (s, Si-CH3), -0.95 (s, Si-(CH3)3). 29Si
NMR (CDCl3): δ 8.6, 1.4, -4.9. MS: m/e 372 [M+]. IR (KBr
pellet; cm-1): 3075 (w), 2960 (m), 2900 (w), 2599 (s), 2578 (s),
2080 (w), 1549 (s), 1450 (w), 1400 (w), 1260 (s), 1175 (m), 1090
(m), 1078 (m), 1006 (s), 960 (m), 905 (s), 880 (m), 805 (s), 780
(m), 750 (w), 695 (m), 680 (m), 450 (w), 430 (w). Anal. Calcd
for C11H33B10NSi3: C, 35.57; H, 8.88. Found: C, 35.08; H, 8.61.
14.4 Hz, dCH), 0.48 (s, 12H, Si-CH3). 13C{1H} NMR (CDCl3):
δ 130.49, 128.67, 128.22, 126.10, 124.77, 124.52, 114.67, 97.21,
-1.40. 29Si NMR (CDCl3): δ 2.4, -3.2. MS: m/z 376 [M+]. IR
(KBr pellet; cm-1): 3031 (w), 2960 (w), 2587 (s), 1597 (w), 1592
(m), 1401 (w), 1335 (w), 1259 (m), 1227 (m), 1158 (s), 1089 (s),
987 (w), 958 (s), 930 (m), 883 (m), 848 (m), 822 (s), 788 (w),
749 (w), 695 (w), 674 (w), 647 (w), 545 (w). Anal. Calcd for
C
14H29B10NSi2: C, 44.79; H, 7.73. Found: C, 44.42; H, 7.52.
Com p ou n d 10 fr om th e Rea ction w ith Dip h en yla ceto-
n itr ile. Compound 10 was prepared using the same procedure
as described for 9, except diphenylacetonitrile was used intead
of benzyl cyanide. Pure 10 was isolated by chromatographic
workup (eluent hexane/benzene (3.5/1), Rf ) 0.48). Yield: 65%.
Mp: 106 °C. 1H NMR (CDCl3): δ 7.36-7.10 (m, 10H, Ph), 6.48
(d, 1H, J HH ) 2.3 Hz, HCd), 4.77 (dd, 1H, J HH ) 2.3 and 6.6
Hz, dCH), 0.96 (d, 1H, J HH ) 6.6 Hz, CH). 0.32 (s, 12H, Si-
CH3). 13C{1H} NMR (CDCl3): δ 145.60, 128.66, 127.44, 126.92,
126.04, 125.38, 29.85, -2.03. 29Si NMR (CDCl3): δ 8.8, -1.4.
MS: m/e 452 [M+]. IR (KBr pellet; cm-1): 3064 (w), 3028 (w),
2974 (m), 2594 (s), 1596 (m), 1490 (s), 1454 (s), 1411 (w), 1259
(s), 1149 (s), 1076 (m), 1035 (m), 914 (m), 777 (m), 748 (s), 698
(s), 650 (m), 628 (w), 538 (m), 453 (m). Anal. Calcd for
Com p ou n d 14 fr om th e Rea ction w ith F u m a r on itr ile.
A mixture of fumaronitrile (0.126 g, 1.6 mmol), 1 (4.15 mL,
1.08 mmol), and 2 (0.03 g, 0.054 mmol) was heated at 60-80
°C for 8 h. The solvent was removed in vacuo. The crude
product was chromatographed, with benzene and hexane
(1/1) as eluent, and recrystallized from pentane at -20 °C in
75% yield. Mp: 158-162 °C. All spectral data for product 14
were identical with those of an authentic sample.2e
C
21H35B10NSi2: C, 54.19; H, 7.52. Found: C, 53.76; H, 7.38.
Com p ou n d 11 fr om th e Rea ction w ith Hyd r ocin n a -
m on itr ile. Compound 11 was prepared using the same
procedure as described for 9. Yield: 71%. Mp: 139 °C. 1H NMR
(CDCl3): δ 7.36-7.21 (m, 5H, Ph), 5.85 (d, 1H, J HH ) 13.8 Hz,
dCH), 5.02 (dt, 1H, J HH ) 13.8 Hz, J HH ) 6.9 Hz, dCH), 3.24
(d, 2H, J HH ) 6.9 Hz, CH2), 0.38 (s, 12H, Si-CH3). 13C{1H}
NMR (CDCl3): δ 138.06, 137.84, 128.86, 128.26, 127.22,
127.04, 126.84, 126.52, 31.54, 5.70, 1.03. MS: m/z 390 [M+].
IR (KBr pellet; cm-1): 3075 (w), 3042 (w), 2964 (s), 2948 (m),
2906 (w), 2618 (s), 2578 (s), 1952 (w), 1675 (w), 1610 (m), 1509
(w), 1462 (s), 1418 (w), 1265 (s), 1092 (m), 1078 (m), 1032 (w),
918 (m), 805 (s), 784 (w), 756 (m), 725 (s), 698 (m), 472 (m),
447 (w). Anal. Calcd for C15H31B10NSi2: C, 46.26; H, 7.96.
Found: C, 45.84; H, 7.68.
X-r a y Cr ysta llogr a p h y. Details of the crystal data and a
summary of intensity data collection parameters for 8 and 12
are given in Table 1. Crystals of 8 and 12 were grown from
hexane at -20 °C, mounted in thin-walled glass capillaries,
and sealed under argon. The data sets of 8 and 12 were
collected on a Siemens P4 diffractometer equipped with a Mo
X-ray tube and a graphite crystal monochromator. Mo KR
radiation (λ ) 0.7107 Å) was used for all structures. Each
structure was solved by the application of direct methods using
the SHELX-96 program. All non-hydrogen atoms in com-
pounds 8 and 12 were refined anisotropically. All other
hydrogen atoms were included in calculated positions.
Com p ou n d 12 fr om th e Rea ction w ith Cin n a m on itr ile.
Compound 12 was prepared using the same procedure as
described for 9. Yield: 68%. Mp: 124 °C. H NMR (CDCl3): δ
Ack n ow led gm en t. We wish to acknowledge the
financial support of the Korean Research Foundation
made in the program year of 2000 (2000-015-DP0296).
1
7.44-7.19 (m, 4H, Ph), 5.98 (t, 1H, J HH ) 3.82 Hz, dCH), 3.34
(d, 2H, J HH ) 3.8 Hz, CH2), 0.29 (s, 6H, Si-CH3), 0.27 (s, 6H,
Si-CH3). 13C{1H} NMR (CDCl3): δ 138.42, 129.28, 128.34,
127.51, 126.34, 125.57, 124.20, 119.21, 35.89, 1.16, -0.98. 29Si
NMR (CDCl3): δ 11.05. MS: m/e 338 [M+]. IR (KBr pellet;
cm-1): 3146 (w), 2997 (w), 2934 (w), 2592 (s), 2566 (s), 1976
(m), 1665 (w), 1594 (m), 1537 (w), 1455 (w), 1404 (w), 1266
(s), 1076 (w), 1055 (m), 1044 (m), 943 (w), 922 (w), 895 (m),
834 (s), 807 (m), 754 (w), 742 (w), 724 (s), 487 (w), 468 (w).
Anal. Calcd for C15H29B10NSi2: C, 46.50; H, 7.49. Found: C,
46.26; H, 7.24.
Su p p or tin g In for m a tion Ava ila ble: Tables listing crys-
tallographic information, atomic coordinates and Beq values,
anisotropic thermal parameters, and intramolecular bond
distances, angles, and torsion angles for 8 and 12. This
material is available free of charge via the Internet at
http://pubs.acs.org.
OM0008629