Catalytic Carbon-Carbon and Carbon-Silicon Bond Activation and Functionalization by Nickel Complexes

Article abstract of DOI:10.1021/om990457l

The nickel alkyne complexes (dippe)Ni(Me₃SiC=CSiMe₃), 1, (dippe)Ni(Me₃CC≡CSiMe₃), 2, and (dippe)Ni(MeC≡CSiMe₃), 3, were synthesized (dippe = bis(diisopropylphosphino)-ethane) and characterized by ¹H, ³¹P, and ¹³C{¹H} NMR spectroscopy. Complex 1 was characterized by X-ray crystallography. Heating complex 1,2, or 3 with excess biphenylene and alkyne results in the catalytic formation of several novel organic compounds, several of which have been characterized by X-ray crystallography. These reactions are proposed to proceed by a competition between β-silyl migration from an acetylene insertion intermediate and elimination of phenanthrene. Mechanistic schemes are presented for these reactions.

Full text of DOI:10.1021/om990457l

4660
Organometallics 1999, 18, 4660-4668
Ca ta lytic Ca r bon -Ca r bon a n d Ca r bon -Silicon Bon d
Activa tion a n d F u n ction a liza tion by Nick el Com p lexes
Brian L. Edelbach, Rene J . Lachicotte, and William D. J ones*
Department of Chemistry, University of Rochester, Rochester, New York 14627
Received J une 11, 1999
The nickel alkyne complexes (dippe)Ni(Me3SiCtCSiMe3), 1, (dippe)Ni(Me3CCtCSiMe3),
2, and (dippe)Ni(MeCtCSiMe3), 3, were synthesized (dippe ) bis(diisopropylphosphino)-
ethane) and characterized by 1H, 31P, and 13C{1H} NMR spectroscopy. Complex 1 was
characterized by X-ray crystallography. Heating complex 1, 2, or 3 with excess biphenylene
and alkyne results in the catalytic formation of several novel organic compounds, several of
which have been characterized by X-ray crystallography. These reactions are proposed to
proceed by a competition between â-silyl migration from an acetylene insertion intermediate
and elimination of phenanthrene. Mechanistic schemes are presented for these reactions.
In tr od u ction
tuted phenanthrenes and/or products derived from
addition of the C-Si bond across the C-C bond of
biphenylene. Catalytic cycles are proposed for the vari-
ous systems that were evaluated.
The cleavage of C-Si bonds by transition metal
compounds has not been systematically studied.9 How-
ever, several examples of C-Si bond cleavage in alkyn-
ylsilanes have been reported.10 One common mechanism
involves 1,2-silyl migration to form vinylidene complexes
(eq 1).11 Another mechanism of C-Si bond cleavage is
Homogeneous catalytic C-C bond activation and
functionalization by transition metal complexes is cur-
rently an active area of research in organometallic
chemistry.1 Catalytic hydrogenolysis of biphenylene to
2
biphenyl has been reported using (C5Me5)Rh(PMe3)H2
and several platinum, palladium, and nickel phosphine
complexes.3 Milstein and co-workers reported the cata-
lytic hydrogenolysis and hydrosilation of a strong C-C
bond using a rhodium complex.4 Ito and co-workers
treated cyclobutanone under hydrogen with a catalytic
amount of a rhodium(I) complex to generate the ring-
opened alcohol.5 J un and Lee recently reported homo-
geneous catalytic C-C bond cleavage of unstrained
ketones.6 Nickel(0) complexes have been employed in
the formation of substituted phenols by cleaving the
C-C bonds of cyclobutenones with subsequent [4+2]
addition of alkynes.7
We have recently used (dippe)Ni(RCtCR) complexes
as catalyst precursors for the formation of 9,10-disub-
stituted phenanthrenes.8 The phenanthrene products
are formed catalytically by heating (dippe)Ni(RCtCR)
in the presence of biphenylene, the appropriate alkyne,
and a small amount of O2 to accelerate the reaction. In
the present work we demonstrate that nickel complexes
can catalytically functionalize biphenylene with tri-
methylsilyl-substituted alkynes to give 9,10-disubsti-
â-silyl migration from a metal alkyl group to the metal
center.12 This is believed to be a key step in the catalytic
dehydrogenative silylation of olefins (Scheme 1).12f
Resu lts a n d Discu ssion
P r ep a r a tion a n d Ch a r a cter iza tion of Nick el
Alk yn e P h osp h in e Com p lexes. Several different tri-
methylsilylalkyne-nickel(0) complexes were prepared
(9) Some examples include: (a) Steenwinkel, P.; J ames, S. L.; Grove,
D. M.; Kooijman, H.; Spek, A. L.; van Koten, G. Organometallics 1997,
16, 513. (b) Hoffman, P.; Heiss, H.; Neiteler, P.; Mu¨ller, G.; Lachmann,
J . Angew. Chem., Int. Ed. Engl. 1990, 29, 880. (c) Schubert, U. Angew.
Chem., Int. Ed. Engl. 1994, 33, 419, and references therein.
(10) (a) Poist, J . E.; Kraihanzel C. S. Chem. Commun. 1968, 60 (b)
Ciriano, M.; Howard, J . A. K.; Spencer, J . L.; Gordon, F.; Stone, A.;
Wadepohl. J . Chem. Soc., Dalton Trans. 1979, 1749.
(11) (a) Bantel, H.; Powell, A. K.; Vahrenkamp, H. Chem. Ber. 1990,
123, 661. (b) Rappert, T.; Nu¨rnberg, O.; Werner, H. Organometallics
1993, 12, 1359. (c) Werner, H.; Baum, M.; Schneider, D.; Windmu¨ller,
B. Organometallics 1994, 13, 1089. (d) Werner, H.; Lass, R. W.; Gevert,
O.; Wolf, J . Organometallics 1997, 16, 4077.
(12) (a) Randolph, C. L.; Wrighton, M. S. J . Am. Chem. Soc. 1986,
108, 3366. (b) Wakatsuki, Y.; Yamazaki, H.; Nakano, M.; Yamamoto,
Y. J . Chem. Soc., Chem. Commun. 1991, 703. (c) Marciniec B.;
Pietraszuk, C. J . Chem. Soc., Chem. Commun. 1995, 2003. (d)
Wakatsuki, Y.; Yamazaki, H. J . Organomet. Chem. 1995, 500, 349. (e)
LaPointe, A. M.; Rix, F. C.; Brookhart, M. J . Am. Chem. Soc. 1997,
119, 906. (f) Kakiuchi, F.; Yamada, A.; Chatani, N.; Murai, S.
Organometallics 1999, 18, 2033.
(1) Two reviews on carbon-carbon bond activation have recently
been published: (a) Rybtchinski, B.; Milstein, D. Angew. Chem., Int.
Ed. 1999, 38, 870. (b) Murakami, M.; Ito, Y. In Topics in Organome-
tallic Chemistry; Murai, S., Ed.; Springer-Verlag: New York, 1999;
Vol. 3, pp 96-129.
(2) Perthuisot, C.; J ones, W. D.; J . Am. Chem. Soc. 1994, 116, 3647.
(3) Edelbach, B. L.; Vicic, D. A.; Lachicotte, R. J .; J ones, W. D.
Organometallics 1998, 17, 4784.
(4) Liou, S.-Y,; van der Boom, M. E.; Milstein D. Chem. Commun.
1998, 687-688.
(5) Murakami, M.; Amii, H.; Shigeto, K.; Ito, Y. J . Am. Chem. Soc.
1996, 118, 8285.
(6) J un, C.-H.; Lee, H. J . Am. Chem. Soc. 1999, 121, 880.
(7) Huffman, M. A.; Liebeskind, L. S. J . Am. Chem. Soc. 1991, 113,
2771.
(8) Edelbach, B. L.; Lachicotte, R. J .; J ones, W. D. Organometallics
1999, 18, 4040.
10.1021/om990457l CCC: $18.00 © 1999 American Chemical Society
Publication on Web 10/07/1999

Catalytic C-C and C-Si Bond Activation
Organometallics, Vol. 18, No. 22, 1999 4661
F igu r e 2. ORTEP drawing of 2-(ethynyl)-2′-(trimethylsi-
lyl)biphenyl, 7.
F igu r e 1. ORTEP drawing of (dippe)Ni(Me3SiCtCSiMe3),
1. Selected distances (Å): Ni(1)-P(1), 2.154(2); Ni(1)-P(2),
2.153(2); Ni(1)-C(1), 1.907(6); Ni(1)-C(2), 1.916(6); C(1)-
C(2), 1.298(8).
Sch em e 2
Sch em e 1
by addition of the alkyne to (dippe)Ni(COD) or [(dippe)-
NiH]2. The following new compounds were synthe-
sized: (dippe)Ni(Me3SiCtCSiMe3), 1, (dippe)Ni(Me3-
CCtCSiMe3), 2, and (dippe)Ni(MeCtCSiMe3), 3. These
compounds 2-(trimethylsilylethynyl)-2′-(trimethylsilyl)-
biphenyl, 4, 9-trimethylsilyl-10-(2-(2′-trimethylsilylphen-
yl)phenyl)phenanthrene, 5, and bis(2-(2′-trimethylsi-
lylphenyl)phenyl)acetylene, 6, were produced in an
approximate 12:4:1 ratio (based on GC/MS). A small
amount of tetraphenylene is also observed. Compounds
4 and 5 were isolated by thick layer chromatography.
Compound 4 was isolated as a yellow oil (41%, 13 turn-
overs), which was characterized by 1H and 13C{1H}
1
compounds were characterized by H, 31P, and 13C{1H}
NMR spectroscopy. The 13C{1H} resonances of the
alkyne carbons are similar to those reported for other
bis(phosphine)nickel(0) acetylene complexes.13 Com-
pound 1 was also characterized by X-ray crystallography
(Figure 1). This compound is a distorted square planar
complex (the alkyne is in the plane) with a carbon-
carbon triple-bond distance of 1.298(8) Å, similar to
those reported for other nickel(0) alkyne complexes with
electron-donating chelating phosphines.14
F u n ction a liza tion of Bip h en ylen e w ith Silyla ted
Acetylen es. To our knowledge the compound 9,10-bis-
(trimethylsilyl)phenanthrene has never been synthe-
sized. Given the ability to functionalize the trimethyl-
silyl groups, we thought it desirable to attempt the
preparation of this compound by heating compound 1
in the presence of biphenylene and bis(trimethylsilyl)-
acetylene at 120 °C. While 9,10-di(trimethylsilyl)phen-
anthrene was not produced, several other organic
products were formed catalytically (Scheme 2). The
1
NMR spectroscopy and GC/MS. The H NMR spectrum
indicated the presence of two different silyl methyl
groups. The 13C{1H} NMR spectrum revealed the pres-
ence of two different acetylenic carbons. To confirm that
the trimethylsilyl group and the acetylenic groups were
on different benzene rings, 4 was converted to the pale
yellow solid 2-(ethynyl)-2′-(trimethylsilyl)biphenyl, 7,
with potassium carbonate in methanol. An X-ray crystal
structure of compound 7 confirmed that the locations
of the trimethylsilyl and acetylenic groups were as
indicated (Figure 2).
Compound 5 was isolated as a white solid (14%) and
characterized by 1H and 13C{1H} NMR spectroscopy and
GC/MS. The structure of the molecule was established
by X-ray crystallography (Figure 3). Compound 6 is a
yellow liquid, but could not be isolated in pure form, as
compound 5 was always present in small amounts. The
1H NMR spectrum indicates the presence of only one
trimethylsilyl resonance in an 9:8 ratio with the aro-
matic protons. The 13C{1H} NMR spectrum displays
(13) Bartik, T.; Happ, B.; Iglewsky, M.; Bandmann, H.; Boese, R.;
Heimbach, P.; Hoffmann, T.; Wenschuh, E. Organometallics 1992, 11,
1235.
(14) (a) Bonrath, W. Ph.D. Dissertation, University of Bochum, 1988.
(b) Po¨rschke, K. R.; Mynott, R.; Angermund, K.; Kru¨ger, C. Z.
Naturforsch. B: Anorg. Chem., Org. Chem. 1985, 40, 199. (c) Po¨rschke,
K. R. Angew. Chem., Int. Ed. Engl. 1987, 26, 1288. (d) Bonrath, W.;
Po¨rschke, K. R.; Wilke, G.; Angermund, K.; Kru¨ger, C. Angew. Chem.,
Int. Ed. Engl. 1988, 27, 833.

4662 Organometallics, Vol. 18, No. 22, 1999
Edelbach et al.
Sch em e 3
intensity doublets is observed in the 31P{1H} NMR
spectrum at δ 76.0 (J ) 53.3 Hz) and δ 71.4 (J ) 53.3
Hz) early in the catalysis. This is consistent with the
formation of a (dippe)Ni(0) complex coordinated to an
asymmetric acetylene. Compound 4 is the only nonsym-
metrical alkyne observed in the reaction mixture,
providing evidence that the new doublets in the 31P-
{1H} NMR spectrum arise from 4 coordinating in an η2
fashion to (dippe)Ni(0) to give complex 8 (see Scheme
3). The identity of this compound was confirmed by
independent synthesis. Addition of 4 to (dippe)Ni(COD)
produces compound 8, which has a 31P{1H} NMR
spectrum identical to the compound observed in the
catalytic reaction. Compound 8 was characterized by 1H
and 31P{1H} NMR spectroscopy and elemental analysis.
The 1H NMR spectrum displays two trimethylsilyl
resonances at δ 0.073 (s, 9 H) and -0.216 (s, 9 H). The
structure of compound 8 was confirmed by X-ray
crystallography (Figure 4). Heating compound 8 with
excess 4 and biphenylene leads to the formation of
compounds 5 and 6. Third, when the non-phosphorus-
containing species Ni2(COD)2(PhCtCPh) is combined
with 16 equiv of bis(trimethylsilyl)acetylene and 5 equiv
of biphenylene and heated at 85 °C, the major products
in the reaction are tetraphenylene and compound 4. No
F igu r e 3. ORTEP drawing of 9-trimethylsilyl-10-(2-(2′-
trimethylsilylphenyl)phenyl)phenanthrene, 5.
only one type of acetylenic carbon and 12 different
aromatic carbons. A GC/MS of the mixture reveals an
M+ peak at 474. These results are consistent with the
formulation of compound 6 as bis(2-(2′-trimethylsilyl-
phenyl)phenyl)acetylene.
Earlier studies with alkyl and aryl acetylenes showed
that small quantities of added O2 can accelerate these
reactions.8 The role of the O2 was believed to be to
oxidize the phosphine ligand to the phosphine oxide,
generating vacant sites on the Ni0 intermediate. Greater
than 50 mol % O2 was found to have a deleterious effect
upon the reaction, presumably as reaction of the O2 with
the Ni0 now interfered with the catalysis.
There is evidence that the reaction with the disilyl-
acetylene proceeds without added air, although higher
temperatures (120 °C) are required to achieve a reason-
able rate of catalysis. First, if the reaction is run at 110
°C with 6 mol % O2 (via addition of air), the reaction
proceeds at only twice the rate as the reaction run in
the absence of air. Second, the formation of two equal
1
compound 5 or 6 is observed in the H NMR spectrum.
These results suggest that the phosphine complex 8 is
responsible for the formation of compounds 5 and 6.
However, it is likely that some of compound 4 is formed
via a non phosphine nickel compound upon addition of
O2 since a rate acceleration is observed. The mechanism
depicted in Scheme 3 is proposed for the formation of
compounds 4, 5, 6, and 8.
The first step is reversible loss of bis(trimethylsilyl)-
acetylene from compound 1 or reversible loss of alkyne

Catalytic C-C and C-Si Bond Activation
Organometallics, Vol. 18, No. 22, 1999 4663
Sch em e 4
elimination. To our knowledge, there is no reported case
of â-silyl migration from a silyl-vinyl complex.
Path B involves two possible orientations of insertion
of 4 into the nickel carbon bond of (dippe)Ni(2,2′-
biphenyl). First, insertion resulting in the trimethylsilyl
group nearest the metal center gives compound Y.
Reductive elimination of phenanthrene 5 regenerates
(dippe)Ni(0). Second, insertion resulting in the biphenyl
group nearest the metal center gives compound Z. Rapid
1,3 trimethylsilyl migration followed by reductive elimi-
nation gives compound 6 and (dippe)Ni(0). Insertion
with the trimethylsilyl group nearest the metal center
is less sterically demanding and explains the higher
yield of 5 relative to 6.
A mechanism involving oxidative addition of a Si-
C(sp) bond to the nickel center and subsequent oxidative
addition of the C-C bond of biphenylene via a Ni(IV)
species cannot be ruled out. Caulton and co-workers
have demonstrated that the cleavage of the Si-C(sp)
bond of Me3SiCtCSiMe3 to a Ru center proceeded via
oxidative addition.16 Earlier work by Stone et al.
demonstrated oxidative addition of both C-Si bonds of
Me2Si(CtCPh)2 by (PR3)2Pt(C2H4)2.10b While an oxida-
tive addition mechanism appears viable, we favor the
â-silyl migration mechanism since these reactions have
been demonstrated to proceed under very mild condi-
tions and avoid a Ni(IV) intermediate.
One explanation for the lack of formation of 9,10-bis-
(trimethylsilyl)phenanthrene is that trimethylsilyl mi-
gration in complex X is more rapid than reductive
elimination of 9,10-bis(trimethylsilyl)phenanthrene. An-
other possibility may be that juxtaposition of two
trimethylsilyl groups in the 9 and 10 positions is too
sterically demanding, making 9,10-bis(trimethylsilyl)-
phenanthrene an unstable compound. To examine this
latter possibility, we attempted to synthesize 9-tert-
butyl-10-(trimethylsilyl)phenanthrene, a compound with
nearly the same steric requirements as 9,10-bis(trimeth-
ylsilyl)phenanthrene. Acetylene compound 2 was dis-
solved in THF and heated at 120 °C in the presence of
biphenylene and 1-trimethylsilyl-3,3-dimethyl-1-butyne.
Three organic products were formed (Scheme 4): 9-tert-
butyl-10-(trimethylsilyl)phenanthrene, 9, 2-(tert-butyl-
ethynyl)-2′-(trimethylsilyl)biphenyl, 10, and 9-tert-butyl-
10-(2-(2′-trimethylsilylphenyl)phenyl)phenanthrene, 11,
in a 4:1:1 ratio (based on GC/MS).
F igu r e 4. ORTEP drawing of (dippe)Ni(2-(trimethylsilyl-
ethynyl)-2′-(trimethylsilyl)biphenyl), 8. Selected distances
(Å): Ni(1)-P(1), 2.1601(4); Ni(1)-P(2), 2.1642(4); Ni(1)-
C(1), 1.9334(14); Ni(1)-C(2), 1.8873(14); C(1)-C(2), 1.283-
(2).
4 from compound 8 to give (dippe)Ni(0). Subsequent
carbon-carbon bond activation of biphenylene by
(dippe)Ni(0) gives (dippe)Ni(2,2′-biphenyl). This com-
pound is observed in small amounts in the 31P{1H} NMR
spectrum during the catalysis. Compounds 1 and 8 are
the major resting state species observed in the 31P{1H}
NMR spectrum during the course of the reaction. This
observation is consistent with recoordination of the
alkynes to (dippe)Ni(0) being more rapid than C-C
cleavage of biphenylene. Reaction of (dippe)Ni(2,2′-
biphenyl) with biphenylene could account for the small
amount of tetraphenylene produced.15 Two pathways
are now available. Path A involves insertion of bis-
(trimethylsilyl)acetylene into the Ni-C bond of (dippe)-
Ni(2,2′-biphenyl) to give the putative cycloheptatriene
compound X. The necessity for high temperatures to
affect reasonable rates of catalysis may result from the
requisite loss of one phosphine in order to accommodate
alkyne coordination in the plane of the biphenyl group
prior to insertion. Rapid [1,3] trimethylsilyl migration
to the nickel center followed by reductive elimination
of 4 regenerates the (dippe)Ni(0) fragment. The 1,3-
trimethylsilyl migration must be more rapid than
reductive elimination of 9,10-bis(trimethylsilyl)phenan-
threne from X since the phenanthrene compound is not
observed.
Precedent for [1,3] silyl group migration (so-called
â-silyl migration) from an alkyl ligand to a metal center
with concomitant loss and or coordination of alkene has
been established.12 Brookhart et al. established that
rapid, reversible â-silyl migration occurred at -70 °C
using cationic Pd(II) compounds.12e Recently, Murai and
co-workers synthesized vinylsilanes from olefins using
a Ru catalyst and allylsilanes as the source of organosi-
lyl group.12f The key step in this reaction was the
generation of a metal-silyl species via â-silyl group
(15) Tetraphenylene is formed catalytically upon heating a mixture
of (dippe)Ni(2,2′-biphenyl) with biphenylene in THF-d8. See: Edelbach,
B. L.; Lachicotte, R. J .; J ones, W. D. J . Am. Chem. Soc. 1998, 120,
2843.
(16) Huang, D.; Heyn, R. H.; Bollinger, J . C.; Caulton, K. G.
Organometallics 1997, 16, 292.

4664 Organometallics, Vol. 18, No. 22, 1999
Edelbach et al.
Sch em e 5
F igu r e 5. ORTEP drawing of 9-tert-butyl-10-(trimethyl-
silyl)phenanthrene, 9, showing disorder of tert-butyl and
trimethylsilyl groups.
The organic compound 9-methyl-10-(trimethylsilyl)-
phenanthrene, 12, was produced in an analogous fash-
ion by reacting a THF solution containing (dippe)Ni-
(MeCtCSiMe3), 3, excess biphenylene, and 1-(trimethyl-
silyl)propyne at 120 °C. The two main organic products
generated were 9-methyl-10-(trimethylsilyl)phenan-
threne, 12, and 9-methyl-10-(2-(2′-trimethylsilylphenyl)-
phenyl)phenanthrene, 13, in a 2:1 ratio (isolated yield)
(Scheme 5). A minor product was also detected by GC/
F igu r e 6. ORTEP drawing of 9-tert-butyl-10-(2-(2′-tri-
methylsilylphenyl)phenyl)phenanthrene, 11.
1
MS and H and 13C{1H} NMR, although it could not be
isolated free from compound 3. A GC/MS trace of this
compound displayed an ion peak at 264, consistent with
the molecular weight of 2-(1-propynyl)-2′-(trimethylsi-
lyl)biphenyl, 14. The 13C{1H} NMR spectrum displayed
two singlets at 90.0 and 79.9 ppm, corresponding to the
acetylenic carbons. Other 1H and 13C{1H} NMR spec-
troscopy data are also consistent with the formulation
of 14 as 2-(1-propynyl)-2′-(trimethylsilyl)biphenyl. Fur-
ther support for the production of compound 14 comes
from the 31P{1H} NMR spectrum upon completion of the
reaction. Two new doublets were observed at δ 79.7
(J P-P ) 49.8 Hz) and 75.4 (J P-P ) 49.7 Hz). This
observation is consistent with the formation of (dippe)-
Ni[(2-(1-propynyl)-2′-(trimethylsilyl)biphenyl)], which is
analogous to compound 8. Compound 12 is an off-white
Compound 9 was characterized by 1H and 13C{1H}
NMR spectroscopy, GC/MS, and elemental analysis. An
X-ray crystal structure (Figure 5) confirmed the loca-
tions of the trimethylsilyl and tert-butyl groups, al-
though these two groups were disordered. Compound
10 was characterized by 1H and 13C{1H} NMR spec-
troscopy and GC/MS. The 13C{1H} shows two separate
acetylenic carbons and one type of trimethylsilyl carbon.
1
The aromatic region in the H NMR is similar to that
1
of compound 4. Compound 11 was characterized by H
and 13C{1H} NMR spectroscopy, GC/MS, and elemental
analysis. The structure of the molecule was established
by X-ray crystallography (Figure 6).
We propose a mechanism for the formation of com-
pounds 9-11 similar to that of their bis(trimethylsilyl)
analogues depicted in Scheme 2. In this case however,
insertion of 1-trimethylsilyl-3,3-dimethyl-1-butyne into
the M-C bond of (dippe)Ni(2,2′-biphenyl) can occur with
different regiochemistries, with either the tert-butyl
group or the trimethylsilyl group on the carbon nearest
the metal center. If the tert-butyl group is nearest the
metal center, [1,3] trimethylsilyl migration and subse-
quent reductive elimination generates compound 10. If
the trimethylsilyl group is nearest the metal center,
reductive elimination generates (dippe)Ni(0) and phenan-
threne 9. Compound 11 is formed via the same path-
ways as compound 5. In this reaction no analogue of
compound 6 is observed.
1
oil, which was characterized by GC/MS and H and 13C-
{1H} NMR. To further confirm the structure of 12,
bromine was added to a hexane solution containing
compound 12 and refluxed for 1.5 h. Two compounds
were isolated: 9-bromo-10-methylphenanthrene and
9-bromomethyl-10-bromophenanthrene in an ∼50:50
1
ratio. The H NMR spectrum and GC/MS of 9-bromo-
10-methylphenanthrene matched those reported in the
1
literature.17 The H NMR spectrum of 9-bromomethyl-
10-bromophenanthrene matched that reported in the
literature.18 Compound 13 was characterized by 1H and
13C{1H} NMR spectroscopy, GC/MS, and elemental
(17) Lambert, J . B.; Fabricius, D. M.; Hoard, J . A. J . Org. Chem.,
1979, 44, 1480.

Catalytic C-C and C-Si Bond Activation
Organometallics, Vol. 18, No. 22, 1999 4665
over sieves, freeze-pump-thaw-degassed three times, and
vacuum distilled prior to use.
All NMR spectra were recorded on a Bruker AMX400 or
1
Avance400 spectrometer. All H chemical shifts are reported
in ppm (δ) relative to tetramethylsilane and referenced using
chemical shifts of residual solvent resonances (THF-d8, δ 1.73,
toluene-d8, δ 2.09). 31P NMR spectra were referenced to
external 30% H3PO4 (δ 0.0). GC/MS was conducted on a 5890
Series II gas chromatograph fitted with an HP 5970 Series
mass selective detector. Analyses were obtained from Desert
Analytics. A Siemens SMART system with
a CCD area
detector was used for X-ray structure determination.
P r ep a r a tion of (d ip p e)Ni(Me3SiCtCSiMe3), 1. (dippe)-
Ni(COD) (150 mg, 0.35 mmol) was dissolved in an round-
bottom flask with 20 mL of benzene. Bis(trimethylsilyl)-
acetylene (0.8 mL, 3.5 mmol) was added dropwise to the
(dippe)Ni(COD) solution and heated to reflux for 12 h, during
which time the solution slowly turned golden. The mixture was
filtered, and the solvent, excess COD, and bis(trimethylsilyl)-
acetylene were removed under vacuum with heating. The
yellow powder was washed with cold MeOH. (Yield: 140 mg,
85%). X-ray quality crystals were grown by dissolving the solid
in a minimum of acetone and cooling to -30 °C. NMR data
for 1: 1H NMR (THF-d8) δ 2.161 (sept, CHMe2, J H-H ) 7.8
Hz, 4 H), 1.612 (d, PCH2CH2P, J H-P ) 7.9 Hz, 4 H), 1.144-
1.000 (m, CHMe2, 24 H), 0.218 (s, 18 H); 31P{1H} NMR (THF-
d8) δ 75.60 (s). 13C{1H} NMR (THF-d8): δ 157.1 (t, tC-TMS,
J P-C ) 9.5 Hz), 26.8 (t, J P-C ) 9.7 Hz), 22.2 (t, J P-C ) 19.0
Hz), 21.2 (t, J P-C ) 5.0 Hz), 19.1 (s), 2.2 (s). Anal. Calcd for
F igu r e 7. ORTEP drawing of 9-methyl-10-(2-(2′-trimeth-
ylsilylphenyl)phenyl)phenanthrene, 13.
analysis. The structure of 13 was established by X-ray
crystallography (Figure 7).
Con clu sion s
C
22H50P2Si2Ni: C, 53.76; H, 10.25. Found: C, 53.35; H, 10.72.
The catalytic functionalization of biphenylene with
disubstituted alkynes (RCtCR′, R ) TMS, R′ ) TMS
or alkyl group) to give either addition products of the
alkyne-Si bond across the C-C bond of biphenylene
or 9,10-disubstituted phenanthrenes has been demon-
strated using (dippe)Ni(RCtCR) complexes. The array
of organic products produced can be explained by alkyne
insertion into a Ni(2,2′-biphenyl) bond and subsequent
[1,3] trimethylsilyl migration from a vinyl ligand to a
metal center versus rapid reductive elimination of the
organic product. The orientation of insertion dictates
which of these processes occur. In the case where the
trimethylsilyl group inserts away from the metal center,
[1,3] trimethylsilyl migration is more rapid than reduc-
tive elimination. These results compare with earlier
biphenylene functionalizations using alkyl- and aryl-
substituted acetylenes in that the latter tended to give
phenanthrenes as the major products.8
P r ep a r a tion of (d ip p e)Ni(Me3CCtCSiMe3), 2. (dippe)-
Ni(COD) (200 mg, 0.47 mmol) and tert-butylethynyltrimeth-
ylsilane (0.49 mL, 360 mg, 2.33 mmol) were combined in an
ampule with 10 mL of THF. The mixture was heated at 100
°C for 12 h. The solvent, excess COD, and alkyne were removed
under vacuum. The solid was washed with cold MeOH and
cold acetone, giving a green/yellow solid (yield: 95 mg, 43%).
NMR data for 2: 1H NMR (THF-d8) δ 2.157 (sept, CHMe2,
J H-H ) 6.7 Hz, 4 H), 1.658-1.521 (m, 4 H), 1.285 (s, 9 H),
1.180-1.036 (m, CHMe2, 24 H), 0.195 (s, 9 H); 31P{1H} NMR
(THF-d8) δ 74.51 (d, J P-P ) 51.4 Hz), 73.88 (d, J P-P ) 51.3
Hz); 13C{1H} NMR (THF-d8) δ 172.4 (d, tC-tert-butyl,
J P-C ) 35.3 Hz), 157.1 (d, tC-TMS, J P-C ) 29.6 Hz), 34.6
(dd, J P-C ) 10.1, 7.4 Hz), 33.9 (s), 27.5 (dd, J P-C ) 13.8, 5.9
Hz), 26.8 (dd, J P-C ) 13.1, 5.3 Hz), 22.7 (t, J P-C ) 20.2 Hz),
21.5 (m), 19.3 (d, J P-C ) 9.0 Hz), 3.0 (s). Anal. Calcd for
C
23H50P2Si2Ni: C, 58.11; H, 10.60. Found: C, 57.85; H, 10.55.
P r ep a r a tion of (d ip p e)Ni(MeCtCSiMe3), 3. The com-
pound (dippe)NiCl2 (295 mg, 0.754 mmol) was suspended in
20 mL of hexanes, and 1 M Superhydride (0.69 mL, 0.69 mmol)
was added dropwise at room temperature. The resulting purple
solution of [(dippe)NiH]2 was stirred for 0.5 h and decanted
into a separate round-bottom flask. 1-Trimethylsilylpropyne
(95.4 mg, 0.126 mL, 0.85 mmol) was added dropwise. Within
a few minutes the solution turned a dark orange/brown. The
solution was stirred for 15 min, and the solvent was removed
under vacuum, giving a brown/orange oil (yield: 78 mg, 52%).
NMR data for 3: 1H NMR (THF-d8) δ 2.609, (d, J H-P ) 7.2
Hz, 3 H), 2.086 (sept, CHMe2, J H-H ) 7.2 Hz, 4 H), 1.571 (d,
PCH2CH2P, J H-P ) 9.3 Hz, 4 H), 1.184-0.976 (m, CHMe2, 24
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All manipulations were per-
formed under an N2 atmosphere, either on a high-vacuum line
using modified Schlenk techniques or in a Vacuum Atmo-
spheres Corporation glovebox. Tetrahydrofuran and toluene
were distilled from dark purple solutions of benzophenone
ketyl. Alkane solvents were made olefin-free by stirring over
H2SO4, washing with aqueous KMnO4 and water, and distilling
from dark purple solutions of tetraglyme/benzophenone ketyl.
Tetrahydrofuran-d8 and toluene-d8 were purchased from Cam-
bridge Isotope Lab., distilled under vacuum from dark purple
solutions of benzophenone ketyl, and stored in ampules with
Teflon-sealed vacuum line adapters. The preparations of
biphenylene,19 dippe,20 Ni2(COD)2(PhCtCPh),21 and [(dippe)-
NiH]2,22 have been previously reported. All of the alkynes were
purchased from Aldrich Chemical Co. The liquids were stirred
H), 0.149 (s, 9 H); 31P{1H} NMR (THF-d8) δ 79.61 (d, J P-P
)
53.3 Hz), 76.54 (d, J P-P ) 53.3 Hz); 13C{1H} NMR (THF-d8) δ
154.6 (dd, tC-methyl, J P-C ) 36.5, 7.0 Hz), 123.9 (dd, tC-
TMS, J P-C ) 31.6, 5.6 Hz), 26.2 (m), 22.6 (dt, J P-C ) 19.9, 7.6
(20) Cloke, F. G. N.; Gibson, V. C. Green, M. L. H.; Mtetwa, V. S.
B.; Prout, K. J . Chem. Soc., Dalton Trans. 1988, 2227.
(21) Muetterties, E. L.; Pretzer, W. R.; Thomas, M. G.; Beier, B. F.;
Thorn, D. L.; Day, V. W.; Anderson, A. B. J . Am. Chem. Soc. 1978,
100, 2090.
(18) Yamamoto, K., Kitsuki, T.; Okamoto, Y. Bull. Chem. Soc. J pn.
1986, 59, 1269.
(19) Yates, P. Organic Synthesis; Wiley: New York, 1968; Collect.
Vol. 48, p 12.
(22) Edelbach, B. L.; Vicic, D. A.; Lachicotte, R. J . Organometallics
1998, 17, 4784.

4666 Organometallics, Vol. 18, No. 22, 1999
Edelbach et al.
Hz), 20.8 (d, J P-C ) 9.7 Hz), 20.3 (d J P-C ) 8.8 Hz), 19.1 (s),
17.9(dd, J P-C ) 15.0, 7.8 Hz), 1.6 (s).
(J ) 53.3 Hz) and δ 71.4 (J ) 53.3 Hz). Anal. Calcd for
C34H58P2Si2Ni: C, 63.45; H, 9.08. Found: C, 63.48; H, 9.28.
Ch a r a cter iza tion Da ta for 2-(Tr im eth ylsilyleth yn yl)-
2′-(tr im eth ylsilyl)bip h en yl, 4. 1H NMR (C6D6): δ 7.633-
7.580 (m, 1 H), 7.500-7.462 (m, 1 H), 7.246-7.193 (m, 3 H),
7.133-7.094 (m, 1 H), 6.295 (dq, J H-H ) 6.9, 2 Hz, 2 H), 0.078
(s, 9 H), 0.009 (s, 9 H). 13C{1H} NMR (C6D6): δ 147.9 (s), 138.6
(s), 134.7 (s), 131.9 (s), 130.3 (s), 130.1 (s), 128.4 (s), 127.8 (s),
127.4 (s), 126.8 (s), 124.1 (s), 117.6 (s), 105.4 (tC-Ph),
98.7 (tC-TMS), -0.49 (s), -0.25 (s). MS, 322 (M+). 9-Tr i-
m eth ylsilyl-10-(2-(2′-tr im eth ylsilylp h en yl)p h en yl)p h en -
a n th r en e, 5. 1H NMR (CD2Cl2): δ 8.711-8.667 (m, 1 H),
8.575-8.537 (m, 1 H), 8.418-8.369 (m, 1 H), 7.649-7.598 (m
2 H), 7.574-7.424 (m, 6 H), 7.398-7.360 (m, 1 H), 7.208 (t,
J H-H ) 6.7, 1.2 Hz, 1 H), 7.141 (bd, J H-H ) 8.0 Hz, 1 H), 6.974
(t, J H-H ) 7.4, 1.1 Hz, 1 H), 6.754 (t, J H-H ) 7.3, 1.5 Hz, 1 H),
0.271 (s, 9 H) 0.235 (s, 9 H). 13C{1H} NMR (CD2Cl2): δ 146.9
(s), 146.8 (s), 142.6 (s), 141.5 (s), 139.8 (s), 137.0 (s), 136.3 (s),
135.2 (s), 133.7 (s), 132.4 (s), 130.7 (s), 130.5 (s), 130.2 (s), 129.9
(s), 129.7 (s), 128.8 (s), 128.1 (s), 127.8 (s), 127.1 (s), 127.0 (s),
126.1 (s), 126.04 (s), 126.03 (s), 125.8 (s), 123.4 (s), 122.3 (s),
2.62 (s), 2.06 (s). MS, 474 (M+). Anal. Calcd for C33.5H35.5Si2
(benzene in the lattice): C, 81.40; H, 7.24; Si, 11.35. Found:
C, 81.45; H, 7.37; Si, 11.18. Bis(2-(2′-tr im eth ylsilylp h en yl)-
Rea ction of (d ip p e)Ni(Me3SiCtCSiMe3) w ith Bip h en -
ylen e a n d Bis(tr im eth ylsilyl)a cetylen e. An ampule was
charged with (dippe)Ni(Me3SiCtCSiMe3) (25 mg, 0.050 mmol),
biphenylene (240 mg, 1.58 mmol), and bis(trimethylsilyl)-
acetylene (281 mg, 1.58 mmol). The mixture was dissolved in
5 mL of THF and heated at 120 °C for 3 days in an ampule
sealed with a Teflon valve to avoid entry of air, after which
only a trace of biphenylene and bis(trimethylsilyl)acetylene
remained. The reaction mixture was applied to a thick layer
SiO2 chromatography (TLC) plate, and a 12:1 (v/v) solution of
hexanes-CH2Cl2 was used as eluent. Three major bands were
observed under UV light. The product of band 1 (Rf ≈ 0.5) was
extracted with CH2Cl2. The isolated product was a yellow oil
(207 mg, 41%) and identified as 2-(trimethylsilylethynyl)-2′-
1
(trimethylsilyl)biphenyl, 4, by H, 13C{1H} NMR spectroscopy
and GC/MS. 4 was also characterized by derivatization to 7
as described below.
Bands 2 and 3 (Rf ≈ 0.4 and 0.35, respectively) were isolated.
1H NMR spectroscopy displayed a mixture of products. There-
fore the contents of the two bands were combined and applied
to a TLC plate. A 300:20:2 (v/v/v) solution of hexanes-CHCl3-
ethyl acetate was used as eluent. Two bands were observed
under UV light. A GC trace of band 1 (Rf ≈ 0.45) contained
three compounds. One compound was isolated by adding ∼2
mL of hexanes. A white solid precipitated (56 mg). The white
solid was identified as 9-trimethylsilyl-10-(2-(2′-trimethylphen-
yl)phenyl)phenanthrene, 5, by 1H NMR, GC/MS, elemental
analysis, and X-ray crystallography. A GC trace of the remain-
ing yellow solution displayed 5 as well as two other compounds.
Another 49 mg of 5 was precipitated by dissolving the yellow
solid in hot ethanol and cooling to -30 °C. The solvent was
removed from the remaining yellow liquid, giving 67 mg of
yellow solid. GC/MS revealed a small amount of 5, tetraphen-
ylene, and one other compound. The tetraphenylene was
isolated by applying the mixture to a TLC plate and using a
300:12 (v/v) hexanes-CH2Cl2 solution as eluent. Tetraphen-
ylene (8 mg) was isolated from an Rf ≈ 0.3 band. One other
band with Rf ≈ 0.4 was isolated, giving a yellow solid (60 mg).
GC/MS of this band revealed a 2.5:1 mixture of 5 and bis(2-
(2′-trimethylsilylphenyl)phenyl)acetylene, 6, which could not
1
p h en yl)a cetylen e, 6. H NMR (CD2Cl2): δ 7.640-7.600 (m,
2 H), 7.40-7.14 (m, 14 H, overlapping 5). 13C{1H} NMR (CD2-
Cl2): δ 147.7 (s), 146.3 (s), 141.8 (s), 134.7 (s), 132.1 (s), 130.5
(s), 130.0 (s), 129.4 (s), 128.4, 127.9 (s), 127.6 (s), 127.4 (s),
92.9 (s, tC-Ph), 0.312 (s). MS: 474 (M+).
2-(E t h yn yl)-2′-(t r im et h ylsilyl)b ip h en yl, 7. 1H NMR
(C6D6): δ 7.624-7.597 (m, 1 H), 7.495-7.452 (m, 1 H), 7.293-
7.250 (m, 1 H), 7.236-7.191 (m, 2 H), 7.115-7.075 (m, 1 H),
6.914 (dq, J H-H ) 7.1, 2.7 Hz, 2 H), 2.976 (s, 1 H), 0.075 (s, 9
H). 13C{1H} NMR (CD2Cl2): δ 146.7 (s), 146.4 (s), 138.2 (a),
134.1 (s), 132.2 (s), 130.0 (s), 129.2 (s), 127.7 (s), 127.5 (s), 126.8
(s), 126.1 (s), 121.6 (s), 82.4 (s, tC-Ph), 80.0 (s, tC-H), -0.54
(s). MS: 250 (M+). Anal. Calcd for C17H18Si: C, 81.54; H, 7.25;
Si, 11.22. Found: C, 81.14; H, 7.17; Si, 12.08.
Rea ction of (d ip p e)Ni(Me3CCtCSiMe3) w ith Bip h en -
ylen e a n d 1-Tr im eth ylsilyl-3,3-d im eth yl-1-bu tyn e. An
ampule was charged with (dippe)Ni(Me3CCtCSiMe3) (50 mg,
0.11 mmol), biphenylene (200 mg, 1.31 mmol), and 1-trimeth-
ylsilyl-3,3-dimethyl-1-butyne (203 mg, 0.275 mL, 1.31 mmol).
The mixture was dissolved in 5 mL of THF and heated at 120
°C for 4 days as before. The solvent was removed under
vacuum, and the mixture dissolved in a minimum of CH2Cl2
and applied to a thick layer chromatography (TLC) plate. A
6:1 (v/v) solution of hexanes-CH2Cl2 was used as eluent. Two
major bands were observed under UV light. The product of
band 1 (Rf ≈ 0.8) was extracted with CH2Cl2, giving 315 mg of
a viscous yellow oil. GC/MS revealed two compounds in a 4:1
ratio, each with a molecular weight of 306. The major product
was isolated as a white solid by dissolving the mixtures in a
minimum of hexanes and cooling to -30 °C. The solid was
washed with cold methanol. X-ray quality crystals were grown
by dissolving in C6H6, layering with methanol, and cooling to
-30 °C. This compound was characterized by 1H NMR
spectroscopy, GC/MS, elemental analysis, and X-ray crystal-
lography and determined to be 9-tert-butyl-10-(trimethylsilyl)-
phenanthrene, 9. The filtrate was stripped of solvent, redis-
solved in a minimum of CH2Cl2, and applied to a thin layer
chromatography plate. A 30:1:0.1 (v/v/v) solution of hexanes-
acetonitrile-ethyl acetate was used as eluent. Two bands were
observed. Band 1a (Rf ≈ 0.85) yielded an oil identified as
2-(tert-butylethynyl)-2′-(trimethylsilyl)biphenyl, 10, and char-
acterized by 1H and 13C{1H} NMR spectroscopy as well as GC/
MS. Band 1b was compound 9.
1
be separated. 6 was identified by GC/MS and H and 13C{1H}
NMR spectroscopy.
P r ep a r a tion of 2-(Eth yn yl)-2′-(tr im eth ylsilyl)bip h en yl,
7. A 25 mL round-bottom flask was charged with 8 (207 mg,
0.64 mmol), potassium carbonate (364 mg, 2.64 mmol), and
15 mL of methanol. The mixture was stirred at room temper-
ature for 1.5 h. The excess potassium carbonate was filtered,
and the product was extracted from the filtrate with pentane.
The pentane was removed under vacuum, giving a yellow solid
(138 mg, 86%). X-ray quality crystals were grown by dissolving
in hot ethanol and slow cooling to room temperature.
P r ep a r a tion of (d ip p e)Ni[(2-(tr im eth ylsilyleth yn yl)-2′-
(tr im eth ylsilyl)bip h en yl)], 8. (dippe)Ni(COD) (232 mg, 0.54
mmol) and 2-(trimethylsilylethynyl)-2′-(trimethylsilyl)biphen-
yl, 4 (192 mg, 0.596 mmol), were combined in an ampule with
3 mL of THF. The mixture was heated at 60 °C for 48 h. The
solvent and excess COD were removed under vacuum, giving
a brown oil. The oil was dissolved in a minimum of acetone
and cooled to -30 °C. The resulting yellow powder was filtered
and washed with cold acetone (yield: 230 mg, 66%). X-ray
quality crystals were grown by dissolving the yellow powder
in a minimum of acetone and cooling to -30 °C. NMR data
for 8: 1H NMR (THF-d8) δ 7.570 (d, J H-H ) 7.4 Hz, 1 H), 7.446
(d, J H-H ) 7.3 Hz, 1 H), 7.263 (d, J H-H ) 7.3 Hz, 1 H), 7.184-
6.989 (m, 4 H), 6.948 (t, J H-H ) 7.8 Hz, 1 H), 2.117 (sept,
CHMe2, J H-H ) 7.6 Hz, 2 H), 2.09-1.94 (m, 2 H), 1.65-1.51
(m, 2 H), 1.21-0.98 (m, CHMe2, 24 H), 0.75-0.43 (bs, 2 H),
0.073 (s, 9 H), -0.216 (s, 9 H); 31P{1H} NMR (THF-d8) δ 76.0
Band 2 (Rf ≈ 0.65) was extracted with CH2Cl2. The solvent
was removed under vacuum to give 75 mg of a white solid.
This compound was further purified by dissolving in hot
ethanol and cooling to -30 °C. X-ray quality crystals were

Catalytic C-C and C-Si Bond Activation
Organometallics, Vol. 18, No. 22, 1999 4667
Ta ble 1. X-r a y Da ta Collection a n d Refin em en t P a r a m eter s for 1, 5, 7, 8, 9, 11, a n d 13
1
5
7
8
9
11
13
chem formula
fw
C
22H50P2Si2Ni C33.5H35.5Si2
C17H18Si
250.40
C34H58P2Si2Ni C21H26Si
C33H34Si
458.69
C30H28Si
416.61
491.45
494.3
643.63
306.51
cryst syst
space group, Z
a, Å
b, Å
c, Å
triclinic
P1h, 2
triclinic
P1h, 4
monoclinic
P21/n, 8
19.4741(8)
7.3014(3)
21.1731(8)
90
96.2460(10)
90
2992.7(2)
-80
11646
monoclinic
P21/n, 4
12.68430(10)
19.6756(2)
15.16810(10
90
92.4660(10)
90
3782.02(5)
-80
22758
orthorhombic
P212121, 4
8.97110(10)
12.15930(10)
16.1896(2)
90
triclinic
P1h, 2
monoclinic
C2/c, 8
24.5023(10)
13.0864(5)
17.9748(7)
90
125.8500(10)
90
4671.7(3)
-80
9905
10.2830(9)
10.7457(9)
14.6014(12)
109.5490(10)
95.350(2)
102.166(2)
1462.6(2)
-80
10.4834(2)
12.9347(2)
22.4424(3)
75.9890
88.1280
75.5630
2858.17
-80
9.5282(2)
10.316 A
14.1657(3)
70.0820(10)
86.0750(10)
89.0570(10)
1306.03(4)
-80
R, deg
â, deg
90
90
γ, deg
vol, Å3
1766.00(3)
-80
7683
temp, °C
no. of data
collected
6010
12093
5661
no. of unique data 3833
7679
4146
8785
2520
3607
3330
2
R1(Fo), wR2(Fo
(I > 2σ(I))
)
0.0623, 0.1300 0.0461, 0.1081 0.0512, 0.1116 0.0300, 0.0730 0.0428, 0.0942 0.0595, 0.1432 0.0368, 0.0866
R1(Fo), wR2(Fo2),
all data
0.0923, 0.1434 0.0597, 0.1159 0.0756, 0.1234 0.0379, 0.0768 0.0545, 0.0990 0.0731, 0.1509 0.0462, 0.0916
goodness of fit
1.000
1.025
1.013
1.013
0.988
0.968
1.060
grown by dissolving in hot ethanol and slowly cooling to room
temperature. The resulting solid was washed with cold metha-
nol to give 9-tert-butyl-10-(2-(2′-trimethylsilylphenyl)phenyl)-
phenanthrene, 11. This compound was characterized by 1H
NMR spectroscopy, GC/MS, elemental analysis, and X-ray
crystallography.
Ch a r a cter iza tion Da ta for 9-ter t-Bu tyl-10-(tr im eth yl-
silyl)p h en a n th r en e, 9. 1H NMR (CD2Cl2): δ 8.592-8.440 (m,
3 H), 8.155-8.100 (m, 1 H), 7.600-7.476 (m, 4 H), 1.730 (s, 9
H), 0.506 (s, 9 H). 13C{1H} NMR (CD2Cl2): δ 157.7 (s), 137.9
(s), 137.6 (s), 132.9 (s), 131.8 (s), 129.5-129.6 (m), 128.7 (s),
127.0 (s), 125.8 (s), 125.4 (s),125.3 (s), 123.6 (s), 122.9 (s), 39.7
(s), 34.3 (s), 5.6 (s). MS: 306 (M+). Anal. Calcd for C21H26Si:
C, 82.29; H, 8.55; Si, 9.16. Found: C, 82.21; H, 8.61; Si, 8.99.
2-(ter t-Bu t ylet h yn yl)-2′-(t r im et h ylsilyl)bip h en yl, 10.
1H NMR (CDCl3): δ 7.609-7.562 (m, 1 H), 7.408-7.133 (m, 7
H), 0.947 (s, 9 H), -0.033 (s, 9 H). 13C{1H} NMR (CDCl3): δ
148.2 (s), 147.1 (s), 138.6 (s), 134.4 (s), 131.2 (s), 130.0 (s),
129.96 (s), 128.3 (s), 127.3 (s), 126.7 (s), 126.4 (s), 124.7 (s),
102.8 (tC-Ph), 78.7 (tC-tert-butyl), 30.5 (s), 14.1 (s), 0.21
(s). MS: 306 (M+). 9-ter t-Bu tyl-10-(2-(2′-tr im eth ylsilyl-
p h en yl)p h en yl)p h en a n th r en e, 11. 1H NMR (THF-d8): δ
8.744-8.735 (m, 1 H), 8.610 (d, J H-H ) 8.2 Hz, 1 H), 8.543 (d,
J H-H ) 7.2 Hz, 1 H), 7.566-7.477 (m, 5 H), 7.446-7.363 (m, 4
H), 7.199 (bs, 2 H), 6.918 (dt, J H-H ) 7.2, 1.6 Hz, 1 H), 6.590
(bs, 1 H), 1.480 (bs, 9 H), 0.263 (s, 9 H). 13C{1H} NMR (330 K,
THF-d8): δ 147.4 (s), 143.3 (s), 142.7 (s), 142.4 (s), 140.5 (s),
136.8 (s), 136.5 (s), 134.8 (s), 133.2 (s), 132.9 (s), 132.4 (s), 130.6
(s), 130.43 (s), 130.39 (s), 129.7 (s), 129.2 (s), 127.9 (s), 127.7
(s), 127.1 (s), 126.6 (s), 126.5 (s), 126.1 (s), 125.3 (s), 124.2 (s),
122.7 (s), 122.66 (s), 39.2 (s), 35.6 (s), 2.5 (s). MS: 458 (M+).
Anal. Calcd for C33H34Si: C, 86.41; H, 7.47; Si, 6.12. Found:
C, 86.49; H, 7.44; Si, 5.93.
known compound23 9-methyl-10-(trimethylsilyl)phenanthrene,
12, by 1H, 13C{1H} NMR spectroscopy and GC/MS. Band 3
(Rf ≈ 0.5) was isolated and determined to be tetraphenylene
(∼15 mg). Band 4 was extracted with CH2Cl2; the resulting
viscous oil was dissolved in hot ethanol and cooled to -30 °C.
The resulting white solid (150 mg) of 9-methyl-10-(2-(2′-tri-
methylsilylphenyl)phenyl)phenanthrene, 13, was washed with
cold methanol and characterized by 1H NMR spectroscopy, GC/
MS, elemental analysis, and X-ray crystallography.
Ch a r a cter iza tion Da ta for 9-Meth yl-10-(tr im eth ylsi-
lyl)p h en a n th r en e, 12. 1H NMR (C6D6): δ 8.512-8.419 (m,
2 H), 8.233 (d, J H-H ) 8 Hz, 1 H), 7.912-7.855 (m, 1 H), 7.435-
7.342, (m, 4 H), 2.580 (s, 3 H), 0.477 (s, 9 H). 13C{1H} NMR
(C6D6): δ 144.2 (s), 136.0 (s), 134.5 (s), 132.4 (s), 131.5 (s), 130.1
(s), 129.2 (s), 126.9 (s), 126.7 (s), 125.7 (s), 125.4 (s), 124.8 (s),
123.5 (s), 123.0 (s), 21.9 (s), 4.2 (s). MS, 264 (M+). 9-Meth yl-
10-(2-(2′-tr im eth ylsilylp h en yl)p h en yl)p h en a n th r en e, 13.
1H NMR (THF-d8): δ 8.726-8.633 (m, 2 H), 7.996 (bd, J H-H
)
7.2 Hz, 1 H), 7.590-7.277 (m, 10 H), 6.866 (t, J H-H ) 7.2 Hz,
1 H), 6.7449 (bd, J H-H ) 7.2 Hz, 1 H), 6.564 (t, J H-H ) 7.2 Hz,
1 H), 1.730 (bs, 9 H), 0.515 (s, 9 H). 13C{1H} NMR (336 K,
THF-d8): δ 145.3 (s), 142.4 (s), 138.3 (s), 137.4 (s), 135.1 (bs),
134.0 (s), 130.1 (s), 130.8 (s), 129.1 (s), 129.0 (bs), 128.5 (s),
128.0 (s), 126.4 (s), 126.0 (s), 125.73 (s), 125.70 (s), 125.2 (s),
124.8 (bs), 124.7 (s), 124.5 (s), 124.1 (s), 123.6 (s), 121.6 (s),
121.2 (s), 16.2 (s), 0.08 (s). MS: 416 (M+). Anal. Calcd for
C
30H28Si: C, 86.49; H, 6.77; Si, 6.74. Found: C, 86.41; H, 7.46;
Si, 6.79.
2-(1-P r op yn yl)-2′-(tr im eth ylsilyl)bip h en yl, 14. 1H NMR
(C6D6): δ 1.423 (s, 9 H), 0.129 (s, 3 H). The aromatic protons
were obscured by compound 12. 13C{1H} NMR (C6D6): δ 90.0
(s), 79.9 (s), 0.61 (s). The other carbon resonances were
obscured by compound 12. MS: 264 (M+).
Rea ction of (d ip p e)Ni(MeCtCSiMe3) w ith Bip h en -
ylen e an d 1-Tr im eth ylsilylpr opyn e. An ampule was charged
with (dippe)Ni(MeCtCSiMe3) (130 mg, 0.30 mmol), biphen-
ylene (250 mg, 1.64 mmol), and 1-trimethylsilylpropyne (184
mg, 0.243 mL, 1.64 mmol). The mixture was dissolved in 5
mL of THF and heated at 120 °C for 7 days as before. The
solvent was removed under vacuum, and the mixture was
dissolved in a minimum of CH2Cl2 and applied to a thick layer
chromatography (TLC) plate. A 25:1 (v/v) solution of hexanes-
CH2Cl2 was used as eluent. Four major bands were observed
under UV light. The product of band 1 (Rf ≈ 0.7) was extracted
with CH2Cl2. The isolated product was determined to be
residual biphenylene (∼15 mg). Band 2 (Rf ≈ 0.6) was a yellow
oil (217 mg), which was dissolved in hot ethanol and isolated
by cooling to -30 °C. The orange solid melts as it is warmed
to room temperature. This material was identified as the
X-r a y Str u ctu r a l Deter m in a tion of 1, 5, 7, 8, 9, 11, a n d
13. All of the crystals were mounted on glass fibers under
Paratone-8277 (Exxon) and immediately placed in a cold
nitrogen stream at -80 °C on the X-ray diffractometer. The
X-ray intensity data were collected on a standard Siemens
SMART CCD area detector system equipped with a normal
focus molybdenum-target X-ray tube operated at 2.0 kW (50
kV, 40 mA). A total of 1321 frames of data (1.3 hemispheres),
using a detector-to-crystal distance of 5.094 cm (maximum 2θ
angle of 56.52°), were collected using a narrow frame method
with scan widths of 0.3° in ω and exposure times of 30 s/frame
for all of the crystals except for 5, which was collected at 10 s
exposures. The total data collection time was approximately
(23) Marcinow, A.; Clawson, D. K.; Rabideau, P. W. Tetrahedron
1989, 45, 5441.

4668 Organometallics, Vol. 18, No. 22, 1999
Edelbach et al.
13 h for 30 s exposures and 7 h for 10 s exposures. Frames
were integrated either to 0.75 Å or to 0.90 Å with the Siemens
SAINT program. The unit cell parameters for all of the crystals
were based upon the least-squares refinement of three-
dimensional centroids of >2000 reflections.24 Data were cor-
rected for absorption using the program SADABS.25 The space
group assignments were made on the basis of systematic
absences and intensity statistics by using the XPREP program.
The structure solutions were achieved by direct methods and
refined employing full-matrix least-squares on F2 (Siemens,
SHELXTL,26 version 5.04). There was nothing unusual about
the solution and refinement of any of the structures, with the
exceptions of 5, 7, and 9: Both 5 (P (#2), Z ) 4) and 7 (P21/n,
Z ) 8) contain two independent molecules in the asymmetric
unit; the TMS and t-Bu groups exhibit disorder in 9, and the
disordered atoms were refined isotropically. For all of the
structures except 9, the non-hydrogen atoms were refined with
anisotropic thermal parameters. Hydrogens were included in
idealized positions, except H1 and H2 were located and their
positions and isotropic thermal parameter refined for 7.
Further experimental details of the X-ray diffraction studies
are provided in Table 1. Full experimental details of the X-ray
diffraction studies, as well as positional parameters, aniso-
tropic thermal parameters, bond lengths and angles, and fixed
hydrogen positional parameters are given in the Supporting
Information. In all ORTEPS, ellipsoids are shown at the 30%
level and hydrogen atoms have been omitted for clarity.
Ack n ow led gm en t is made to the U.S. Department
of Energy (Grant FG02-86ER13569) for their support
of this work.
(24) It has been noted that the integration program SAINT produces
cell constant errors that are unreasonably small, since systematic error
is not included. More reasonable errors might be estimated at 10×
the listed value.
(25) The SADABS program is based on the method of Blessing: see
Blessing, R. H. Acta Crystallogr., Sect A 1995, 51, 33.
(26) SHELXTL: Structure Analysis Program, version 5.04; Siemens
Industrial Automation Inc.: Madison, WI, 1995.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic data including atomic coordinates, thermal param-
eters, and bond distances and angles. This material is available
free of charge via the Internet at http://pubs.acs.org.
OM990457L