Star-shaped molecules containing polyalkynyl groups with metal moieties on benzene and triphenylene cores

Article abstract of DOI:10.1002/ejoc.200600380

A series of star-shaped molecules with a silyl group and an aromatic core surrounded by extended π conjugative arms has been synthesized by the use of Sonogashira coupling methods. They show excellent fluorescence intensity with high quantum yield. These

Full text of DOI:10.1002/ejoc.200600380

FULL PAPER
DOI: 10.1002/ejoc.200600380
Star-Shaped Molecules Containing Polyalkynyl Groups with Metal Moieties on
Benzene and Triphenylene Cores
Chiung-Cheng Huang,[a] Ying-Chih Lin,*[a] Ping-Yu Lin,[b] and Yu-Ju Chen[b]
Keywords: Alkynes / Palladium / Platinum / Gold / Heterometallic complexes / Luminescence
A series of star-shaped molecules with a silyl group and an
aromatic core surrounded by extended π conjugative arms
has been synthesized by the use of Sonogashira coupling
methods. They show excellent fluorescence intensity with
high quantum yield. These molecules undergo desilylation
in the presence of nBu4NF to give terminal polyalkynyl com-
pounds. By incorporating metal moieties such as palladium,
platinum and gold into these compounds, star-shaped mole-
cules can be obtained. Photophysical properties of these
molecules are investigated spectroscopically in solution.
These star-shaped molecules are characterized by IR, NMR
(1H, 31P and 13C) spectroscopy, as well as MALDI-TOF mass
spectrometry.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2006)
amenable to study. Recent interest in alkynylpalladium(II)
and -platinum(II) chemistry has been extended toward
platinum-containing hyperbranched molecules and organo-
metallic dendrimers. Stang[8] and Takahashi[9] have shown
that 1,3,5-triethynylbenzene could be used as a building
block for organoplatinum dendrimers. Yam and her co-
workers[10] have explored the luminescence properties of a
series of branched alkynyl palladium(II) and alkynylplati-
num(II) complexes. With regard to hexaethynylbenzene,
Vollhardt et al. first reported its synthesis and derivatives at
high-temperature Sonogashira conditions in 1986.[11] Re-
cently, Beck[12] have utilized hexaethynylbenzene as a build-
ing block to construct star-shaped molecules containing
hexa-platinum and hexa-iron. Despite the growing interests
and extensive studies in alkynylmetal compounds in the
past decade or so, relatively less attention was focused on
the exploration and exploitation of dendritic molecules con-
taining more metal moieties as luminescent materials.
Herein, we report the properties of a series of organic star-
shaped molecules with four, five and six arms, and then
incorporate palladium, platinum and gold metal moieties
into them to extend the polyethynylbenzenes in the direc-
tion of the long conjugated polyyne system to investigate
the properties of these metal acetylide molecules.
Introduction
Since the past decade, there has been a blooming growth
in the development of the chemistry of carbon-rich metal-
containing systems, in particular those with long sp carbon
chain.[1] Such a rapid growth is partly assisted by the urgent
demand for new materials in molecular electronics as a re-
sult of the inherent limit of the present semiconductor tech-
nology. The alkynyl group, with its linear geometry, struc-
tural rigidity, extended π-electron delocalization, and ability
to interact with metal centers through pπ–dπ overlap, has
been an attractive candidate to serve as building blocks for
the construction of carbon-rich metal-containing materials
that possess potential applications as optical nonlinearity,[2]
electrical conductivity,[3] luminescence[4] and liquid crystal-
linity.[5]
Early works on metal alkynes involve those of polymeric
nature, which precluded further purification and characteri-
zation. Hagihara and co-workers reported the first soluble
polyynylplatinum and -palladium complexes.[6] Subsequent
reports on metal-containing polyynes provided important
contributions in this area.[7] Despite all these important
works, studies on these polymeric systems present difficult-
ies such as the exact arrangement of the structure, molecu-
lar-weight distribution, heterogeneity of samples, reprodu-
cibility, and many others. All of these would render a direct
understanding of the structure–property relationship and
the fundamental understanding on the spectroscopic origin
of these chromophores less straightforward and less
Results and Discussion
Synthetic methodologies used for the construction of
poly(silylethynyl)benzenes rely on two approaches described
as divergent and convergent strategies. The compounds 1–
4 could be prepared by convergent method by a simple one-
pot reaction involving Pd-catalyzed alkynylation of haloge-
nated arenes with 1-ethynyl-4-[2-(triisopropylsilyl)ethynyl]-
benzene (A)[13] under the condition of Sonogashira coup-
[a] Department of Chemistry, National Taiwan University,
Taipei, Taiwan
[b] Institute of Chemistry, Academia Sinica,
Nankang, Taipei, Taiwan
Fax: +886-2-23636359
E-mail: yclin@ntu.edu.tw
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Star-Shaped Molecules with Polyalkynyl Groups and Metal Moieties
FULL PAPER
Scheme 1.
ling reaction.[14] The inverse cross-coupling reaction of (4-
iodophenyl)ethynyltrimethylsilane with ethynylated arenes
also afforded the desired poly(silylethynyl)benzenes com-
pound on divergent approach. However, the intermediate
obtained in the divergent method, hexaethynylbenzene
could turns brown slowly in the absence of air and rapidly
in its presence.[11] Therefore, it is not convenient to utilize
it as good precursors for subsequent Sonogashira coupling
reaction to form poly(silylethynyl)benzenes. For this reason,
the poly(silylethynyl)benzenes 1–4 were efficiently prepared
by the convergent approach. The preparation of 1–4 com-
menced with tetra-, penta- or hexa-halogenated arenes and
excess A as outlined in Scheme 1. Compared with the re-
ported preparation of the similar molecules,[15] our prepara-
tion uses only 1.1–1.25 equiv. of A, and the poly(silylethyn-
yl)arenes 1–4 are obtained in 50–90% yield. Desilylation
of poly(silylethynyl)benzene 1 and 4 with nBu4NF gave the
compounds 5 and 6, respectively, mostly in quantitative
yield with multiple terminal alkynyl groups.
In the reaction of 5 and 6 with trans-Pd(PR3)2Cl2 (R =
Et, Bu), only a four- or sixfold equivalent of Pd complex
was dissolved in THF in the reaction mixture for the forma-
tion of the desired product. Multiple Pd metal moieties
were added to all terminal carbon atoms of alkyne. The
reaction was carried out in the presence of CuCl catalyst
and Et2NH to yield the palladium acetylide complex 7. Af-
ter stirring at room temperature overnight the reaction mix-
ture was processed by chromatography to yield the expected
air- and moisture-stable palladium complex in good yield
(Ͼ 70%). We note that Yam and her co-workers[10] have
reported that excess trans-M(PEt3)2Cl2 (M = Pd, Pt) was
required in the preparation of the branched palladium ace- Scheme 2.
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C.-C. Huang, Y.-C. Lin, P.-Yu Lin, Y.-J. Chen
FULL PAPER
tylide complexes in the presence of copper() catalyst in or- δ = 103–104 (2JC–P = 24 Hz) ppm, which are assigned to
der to decrease the formation of undesirable insoluble the α- and β-carbon atoms of the acetylide ligand, respec-
oligomeric materials. They carried out these reactions in tively.[17] The 31P NMR spectra of 9 and 10 reveal singlet
CH2Cl2. In our cases, the reaction in CH2Cl2 gave incom- resonances at δ = 56.8 and 56.9 ppm, respectively, which
plete incorporation of the metal moieties affording three- slightly shift downfield from that of Au(PCy3)Cl at δ =
or four-substituted product. However, the reaction in THF 55.2 ppm.
generally gave much better yield because the organic start-
The IR spectra of all organic compounds containing silyl
ing material has a higher solubility in THF. Using the prep- and terminal alkynyl groups show one stretching band at
aration method of gold acetylide in the literature,[16] the around 2190 cm–1 (νCϵC) and terminal acetylenic ends
gold complexes 9 and 10 are obtained in THF solution (ϵCH) near 3286 cm–1. Additionally, after incorporating
from compound 5 and 6, respectively with a four- or sixfold metal moieties, these compounds exhibit other stretching
of (Cy3P)AuCl in the presence of a strong base KOH. Con- band at around 2090 cm–1. It is probably due to π back-
sequently, we believe that the solvent plays a crucial role in bonding from metal centers to reduce the stretching fre-
the preparation of alkynylmetal. In addition, complexes 11– quency of the CϵC bond adjacent to the transition metal.
14 with triphenylene as the core have been synthesized by With regard to the mass spectra of these metal acetylide
similar preparation method (Scheme 2).
complexes, 8 and 10 with four arms show parent ion [M +
H]+ consistent with their formulation in the FAB mass spec-
tra. Nevertheless, metal acetylide complexes with six arms
can not been detected by FAB or MALDI-TOF mass.
Spectroscopic Characterization
These star-shaped molecules are characterized by 1H,
13C, 31P NMR, mass and IR spectroscopy and give satisfac-
tory elemental analysis. The high symmetry of compound
1, with twelve acetylenic groups and six silyl groups, is man-
Heterometallic Polynuclear Complexes
1
ifested by simple signals in the H and 13C NMR spectra.
Platinum acetylide complex 15 was prepared by the reac-
1
In the H NMR spectrum of 1, there is only one set of two tion of compound A and cis-Pt(PEt3)2Cl2 in the presence
doublet resonance at δ = 7.51 and 7.47 ppm with JH–H
=
of CuCl catalyst in Et3N/toluene.[18] Subsequent reaction of
8.5 Hz in the aromatic region. In addition to the 13C NMR 5 with excess of 15 in the presence of a CuCl catalyst in
signals of the triisopropylsilyl group typically at δ = 18.7, THF/diethylamine generated the pure complex 16, which
11.3 ppm, five signals (one for the benzene core and four undergoes deprotection in the presence of tetrabutylammo-
for the C6H4 groups) are observed in the region of δ = 134– nium fluoride to afford complex 17 containing six terminal
124 and four signals for the acetylide carbon atoms are ob- alkynes. The reaction of 17 with 6 equiv. of (Cy3P)AuCl in
served at δ = 106.5, 99.4, 93.6 and 88.8 ppm indicating the the presence of excess of KOH give the heterometallic com-
C6 symmetry. Mass spectra of star-shaped molecules with plex 18 containing six gold and six platinum metal atoms
triisopropylsilyl groups can not be determined by tradi- (Scheme 3).
tional techniques such as FAB and EI. Therefore, MALDI-
The 31P NMR spectra of 16 and 17 show both a singlet
TOF technique is used to obtain the mass spectra of these resonance at δ = 11.78 and 11.80 ppm, respectively, indica-
compounds. MALDI-TOF mass spectra were obtained tive of highly symmetrical structure of the molecules. Plati-
using DHB (2,5-dihydroxybenzoic acid) as matrix. The pro- num satellites with 1JPt–P = 2359 Hz, which is characteristic
tonated molecular ion [M + H]+ appeared as the parent ion of a trans-P–Pt–P configuration, are observed in the 31P
1
in the spectra of compounds 1–4 and 11.
NMR spectrum.[19] In the H NMR spectrum of 17, four
The 1H NMR spectrum of palladium complexes 7 shows sets of coupled doublet resonances at δ = 7.45–7.17 ppm
only one set of two doublet resonance at δ = 7.48 and 7.21 with JH–H = 8.2 Hz are located in the aromatic region and
ppm with JH–H = 8.2 Hz in the aromatic region and four the singlet resonance of the terminal alkyne protons is ob-
3
broad resonances in the region of δ = 2.0–0.9 ppm are served at δ = 3.09 ppm. In the IR spectra, the νCϵC stretch-
rationally assigned to the butyl protons on the PnBu3 li- ing band appears at 2093, 2195 cm–1 and the absorption at
gands. No signal for acetylenic proton was detected, elimin- 3286 cm–1 is assigned to the νH–Cϵ stretching vibration.
ating the possibility of the existence of partially substituted
In the 31P NMR spectrum of 18 incorporating gold moi-
molecules. In the 31P NMR spectrum, only one singlet sig- eties, the resonance at δ = 11.76 ppm (s, JPt–P = 2366 Hz)
nal was observed at δ = 10.80 ppm. The 13C resonances of was almost consistent with that of complex 17, and the sin-
the alkynyl carbon atoms bound to the palladium are at δ glet peak at δ = 56.91 ppm is assigned to the tricyclohexyl-
2
2
1
= 106.27 ppm with JC–P = 5.3 Hz and 101.62 JC–P
=
phosphane of the gold acetylide moiety. In the H NMR
15.6 Hz, respectively. Two singlet resonances of internal spectrum similar patterns with complex 17 are observed in
alkynyl carbon atoms are located at δ = 99.68 and 88.55 the aromatic region. No signals for acetylenic proton are
ppm. These data are consistent with other palladium ace- detected, eliminating the possibility of partial substitution.
tylide complexes in the literature.[10a]
However, the mass spectra of these metal acetylide com-
The 13C NMR spectra of the gold complexes 9 and 10 plexes can not obtained by FAB or MALDI mass tech-
display two doublets at δ = 140–139 (2JC–P = 131 Hz) and nique.
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Star-Shaped Molecules with Polyalkynyl Groups and Metal Moieties
FULL PAPER
in determining the quantum yield. The wavelength at the
intersection point of the absorption spectra of the sample
and the reference is taken as the excitation wavelength in
determining the quantum yield.
The electronic absorption spectra of triisopropylsilyl-
substituted benzene system 1–4a show that the absorption
maximum (λmax) for the lowest π–π* transition increases
from 340 to 373 nm as the number of arms around the ben-
zene core increases. The photophysical properties of the
molecules presented in this report will likely arise from the
extended π conjugation and enhanced electron delocaliza-
tion of these star-shaped systems. The trend is consistent
with the phenylethynyl-substituted benzene system[20] and
is evidence of extended π conjugation through the benzene
core. However, 4b and 4c show a shoulder at around 398–
400 nm due to the electron-donation effect of the methyl
group and the alkoxyl group, respectively. This phenome-
non was observed for (1,4-diphenylethynyl-2,5-dialkoxy)-
benzene.[21] The absorption band of compound 11 with tri-
phenylene as the core displays much higher extinction coef-
ficient with 2.9·105 dm3 mol–1 cm–1 and a blue shift relative
to that of compound 1 with benzene as the core. (Table 1)
In general, the introduction of metal moieties makes ab-
sorption peaks (275–420 nm) shift to longer wavelength and
displays higher extinction coefficient relative to that of 5
with terminal alkyne groups (247–392 nm) in THF. Much
higher extinction coefficients of the absorption bands in
complex 7 and 16 than their precursor complex, trans-
M(PEt3)2Cl2 (M = Pd, Pt),[22] and the close similarity of its
absorption patterns and extinction coefficients with that of
compound 1 and 5 are indicative of transitions of predomi-
nantly organic complex character. Spectroscopic studies on
Scheme 3.
Photophysical Properties
Table 1 summarizes the photophysical data of star- trans-[L2M(CϵCR)2] (L = tertiary phosphane or stibane,
shaped molecules containing triisopropylsilyl group, palla- M = Ni, Pd, Pt)[23] and trinuclear palladium or platinum
dium and platinum metal moieties. The emission spectra of acetylide complexes,[9d,10] in which the absorption bands at
these compounds are obtained by excitation at their longest ca. 300–370 nm were assigned as metal-to-alkynyl MLCT
wavelength with absorption maximums. The quantum transitions have been reported. It is likely that the electronic
yields were determined while the absorbance is set in the absorption bands of these metal acetylide complexes would
range of 0.1–0.2 to avoid the interference of reabsorption also involve metal-to-alkynyl MLCT character.
Table 1. Photophysical properties.
Compounds
Absorption spectra λmax [nm] (10–4 ε/–1 cm–1)
Emission spectra λmax [nm] Quantum yield Φem
1
294 (4.75), 373[a] (16.01), 399 sh (8.04)
466
460
438
411
417
470
461
480
475
432
429
439
436
486
487
487
0.11
0.51
0.46
0.92
0.83
0.52
0.17
0.14
0.34
0.21
0.29
0.09
0.52
0.06
0.05
2
288 (3.04), 354[a] (12.36)
3
288 (2.68), 355[a] (12.09)
4a
4b
4c
5
340[a] (12.54), 374 sh (1.25)
247 (1.11), 339[a] (11.96), 398 (1.57)
263 (2.20), 336[a] (11.69), 400 (3.02)
280 (1.24), 366[a] (11.95), 392 sh (5.64)
275 (6.28), 307 (4.45), 398[a] (13.76), 420 (9.36)
305 (2.93), 388[a] (8.55)
7
9
11
12
13
14
16
17
18
268 (3.83), 325 sh (8.79), 361[a] (28.97), 384 sh (19.01)
261 sh (1.92), 320 sh (5.56), 356[a] (20.13), 378 sh (12.04)
277 (13.66), 312 sh (7.22), 378[a] (35.16), 400 sh (28.42)
372[a] (36.72), 395 sh (25.12)
300 (20.78), 334 (23.55), 407[a] (30.08)
297 (19.90), 333 (24.36), 392[a] (28.62)
344 (25.90), 409[a] (25.00)
[b]
–
[a] Excitation wavelength for the emission spectra. [b] Not observed with very low quantum effciency.
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C.-C. Huang, Y.-C. Lin, P.-Yu Lin, Y.-J. Chen
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As in the case for the absorption spectra, the emission of appropriate base. Heterometallic polynuclear complex 18
spectra of triisopropylsilyl-substituted benzene system 1–4 containing Pt and Au metals has also been prepared.
also display an analogous red shift as the number of arms
increases. Compound 4c shows the emission data with red
shift about 50–60 nm in comparison to those of 4a and 4b Experimental Section
as a result of incorporating the electron-donating alkoxy
groups. Similar to the trend of absorption spectra, the emis-
sion spectrum of 11 with triphenylene core is blue-shifted
relative to those with benzene core. Compound 4a shows
General Procedures: All manipulations were performed under nitro-
gen using vacuum-line, dry box, and standard Schlenk techniques.
CH2Cl2 was distilled from CaH2 and diethyl ether and THF from
Na/diphenyl ketyl. All other solvents and reagents were of reagent
grade and were used as received. NMR spectra were recorded with
excellent fluorescence intensity with the highest quantum
yield (Φem Ϸ 0.92). Due to incorporating the two electron- Bruker AC-300 and DMX-500 FT-NMR spectrometers at room
temperature (unless states otherwise) and are reported in units of
δ with residual protons in the solvents as a standard (CDCl3, δ =
7.24 ppm; CD2Cl2, δ = 5.32; [D8]THF, δ = 1.73; 3.58). FAB mass
donating alkoxy groups, complex 4c show the emission data
with red shift about 60 nm and lower quantum yield (Φem
Ϸ 0.52) in comparison to those of 4a and 4b.
On the whole, with incorporation of metal into multiple
alkynyl compounds, the emission spectra of metal com-
plexes show a red shift relative to those of alkynyl and silyl
compounds. The tendency of wavelength shifts in emission
spectra is similar to that of their corresponding absorption
spectra due to the same electronic factors.[10b] For example,
spectra were recorded with
MALDI-mass spectra were collected Voyager DE-PRO (Applied
Biosystem, Houston, USA) equipped with nitrogen laser
a JEOL SX-102A spectrometer.
a
(337 nm) and operated in the delayed extraction reflector mode.
1-Ethynyl-4-[2-(triisopropylsilyl)ethynyl]benzene, (A) was prepared
according to the literature methods[13] as were Au(PCy3)Cl[24] and
2,3,6,7,10,11-hexabromotriphenylene.[25] The complex trans-dichlo-
after incorporation of palladium moieties, the low quantum robis(triethylphosphane)palladium(II) was obtained from Aldrich
Chemical Co. Absorption spectra were obtained using HP 8453
diode array spectrophotometer. Emission spectra were taken using
Hitachi F-4500 luminescence spectrometer. Luminescence quan-
tum yield (Φem) were calculated relative to quinine sulfate dihydrate
in 1  H2SO4(aq) (Φem = 0.52).[26] Elemental analyses were carried
with Perkin–Elmer 2400 CHN elemental analyzer.
yield for 13 with triphenylene as a core decreases to 0.09
relative to that for 5 with 0.29. In addition, a red shift in
the emission energies is observed for metal complexes on
going from the palladium complexes to the platinum ana-
logs; this is indicative of the involvement of the triplet
metal-to-alkynyl MLCT character in emissive states.[10a] For
the platinum complexes, the emission spectra of 16–18 show
nearly the same band at 487 nm. Accordingly, the introduc-
tion of six electron-rich Cy3PAu moieties or triisopropylsilyl
groups into the platinum acetylide complex seems to have
almost no influence on the emission energy. Complexes 16
and 17 display lower quantum efficiency (Φem Ϸ 0.05) than
that of 7 with palladium moieties (Φem Ϸ 0.14). Moreover,
when the terminal alkynyl protons of complex 17 are substi-
tuted by gold moieties to form complex 18, the quantum
efficiency (ca. 0.005) is even lower. However, gold complex
14 show the highest quantum efficiency (Φem Ϸ 0.52) in
these metal acetylide complexes.
Synthesis of 1,2,3,4,5-Pentabromo-6-dodecyloxybenzene (B): 2-But-
anone (20 mL) was added to a 50-mL Schlenk flask containing
pentabromophenol (977 mg, 2 mmol), 1-bromododecane (700 mg,
2.8 mmol) and K2CO3 (553 mg, 4 mmol). The mixture was heated
at reflux for 24 h. After cooling to room temperature, the solvent
was removed under vacuum. The residue was extracted with EtOAc
(2×40 mL), and the solution was dried with MgSO4. After fil-
tration, the organic solution was concentrated under reduced pres-
sure. Column chromatography (silica gel, hexane/EtOAc, 9:1) of
the residue removed excess 1-bromododecane and gave 1,2,3,4,5-
pentabromo-6-dodecyloxybenzene as a white powder in 60% yield
(788 mg) by the eluent with hexane/EtOAc (1:1). Spectroscopic
3
data of B: 1H NMR (CDCl3): δ = 3.97 (t, JH–H = 6.6 Hz, 2 H,
OCH2), 1.90–1.80 (m, 2 H, CH2), 1.54–1.44 (m, 18 H, CH2), 0.86
(t, 3JH–H = 6.6 Hz, 3 H, CH3) ppm. 13C NMR (CDCl3): δ = 154.6,
128.3, 124.4, 121.9 (Ph), 73.7 (OCH2), 31.9, 29.9, 29.6, 29.6, 29.6,
29.4, 29.3, 25.8, 22.7 (CH2), 14.1 (CH3) ppm. MS (FAB): m/z =
652 [M+, Br = 79.9]. C18H20Br5O (651.87): calcd. C 33.16, H 3.09;
found C 33.28, H 3.07.
Conclusions
We use benzene and triphenylene as cores to synthesize a
series of star-shaped molecules with extended π conjugative
system by Sonogashira reaction. Palladium acetylide com-
plexes can be obtained by appropriate incorporation of the
(PR3)2PdCl moiety. The photophysical data of metal ace-
tylide complexes show that introduction of electron-rich
palladium or triisopropyl groups makes absorption peaks
shift to longer wavelength and higher extinction coefficients
relative to that of organic molecules. However, the quantum
yields of palladium complexes are decreased in comparison
with free organic molecules. In organic molecules, the blue-
emitting compounds 4a and 4b show excellent fluorescence
intensity with high quantum yield (Φem 4a = 0.92). In ad-
dition, gold acetylide complexes can also be obtained from
Synthesis of 1,2,4,5-Tetrabromo-3,6-dibutoxybenzene (C): Synthesis
of C followed the same procedure as that used for the preparation
of B. Their spectroscopic data are the same as that of literature.[27]
Synthesis of 1,2,4,5-Tetrabromo-3,6-dodecyloxybenzene (D): Syn-
thesis of D followed the same procedure as that used for the prepa-
ration of B, with 77% yield. Spectroscopic data of D: 1H NMR
3
(CDCl3): δ = 3.94 (t, JH–H = 6.5 Hz, 4 H, OCH2), 1.89–1.80 (m,
3
4 H, CH2), 1.54–1.25 (m, 36 H, CH2), 0.86 (t, JH–H = 6.5 Hz, 6
H, CH3) ppm. 13C NMR (CDCl3): δ = 152.0 (C-2), 121.4 (C1),
73.6 (OCH2), 31.9, 29.9, 29.7, 29.6, 29.4, 25.8, 22.7 (CH2), 14.1
(CH3) ppm. C30H50Br4O2 (762.33): calcd. C 47.27, H 6.61; found
C 47.30, H, 6.58.
Preparation of Compound 1: Compound A (2.82 g, 10 mmol) was
terminal alkynyl ligands with (Cy3P)AuCl in the presence added to a stirred suspension of hexabromobenzene (0.732 g,
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Star-Shaped Molecules with Polyalkynyl Groups and Metal Moieties
1.33 mmol), PdCl2(PPh3)2 (93 mg, 0.13 mmol), CuI (25 mg, (s, 2 H, Ph), 7.46 (s, 16 H, Ph), 1.12 (m, 84 H, TIPS) ppm. 13C
FULL PAPER
0.13 mmol), and PPh3 (174 mg, 0.67 mmol) in Et3N (60 mL) under
nitrogen. The mixture was stirred at 100 °C for 48 h. After cooling
to room temperature, the solvent was removed under vacuum and
the resulting residue was washed with hexanes and H2O/EtOH (1:2)
to give the yellow product (1.96 g, 84% yield). Spectroscopic data
of 1: 1H NMR (CDCl3): δ = 7.51 (d, 3JH–H = 8.5 Hz, 12 H, C6H4),
7.47 (d, 3JH–H = 8.5 Hz, 12 H, C6H4), 1.13 (m, 126 H, TIPS) ppm.
13C NMR (CDCl3): δ = 132.2, 131.5, 127.4, 124.2, 122.7 (Ph),
106.5, 99.4, 93.6, 88.8 (C=C), 18.7 (CH3), 11.3 (CH) ppm.
MALDI-TOF-MS (DHB): m/z = 1761.23 [M+ + 1]. IR (KBr,
NMR (CDCl3): δ = 134.9, 132.1, 131.4, 125.3, 124.0, 122.6 (Ph),
106.5, 99.1, 93.3, 89.1 (C=C), 18.7 (CH3), 14.1 (CH3), 11.3 (CH)
ppm. IR (KBr, cm–1): ν = 2144 (νCϵC). MS (MALDI-TOF): m/z
˜
= 1199.7 [M+]. C82H102Si4 (1200.03): calcd. C 82.07, H 8.57; found
C 82.30, H, 8.66.
Preparation of Compound 4b: Compound A (496 mg, 1.76 mmol)
was added to a stirred suspension of 2,3,5,6-tretabromo-p-xylene
(169 mg, 0.4 mmol), PdCl2(PPh3)2 (22 mg, 0.032 mmol), CuI (6 mg,
0.032 mmol), and PPh3 (14 mg, 0.02 mmol) in Et3N (30 mL) under
nitrogen. The mixture was heated to reflux for 36 h. After cooling
to room temperature, the solvent was removed and the resulting
residue was extracted with THF (3×10 mL). The solvent was re-
moved and the residue was passed through a silica gel column using
n-hexane as the eluent to remove excess A. The product 4b was
eluted with THF/n-hexane (1:2). The solvent was removed and the
residue washed with EtOH (20 mL) to give green-yellow solid 4b
in 51% yield (251 mg) Spectroscopic data of 4b: 1H NMR (CDCl3):
cm–1): ν = 2144 (νCϵC). C120H150Si6 (1760.99): calcd. C 81.85, H
˜
8.59; Found C 81.90, H 8.53.
Preparation of Compound 2: Compound A (338 mg, 1.2 mmol) was
added to
a stirred suspension of B (131 mg, 0.2 mmol),
PdCl2(PPh3)2 (14 mg, 0.02 mmol), CuI (3.8 mg, 0.02 mmol), and
PPh3 (14 mg, 0.02 mmol) in Et3N (15 mL) under nitrogen. The
mixture was stirred at 100 °C for 48 h. After cooling to room tem-
perature, the solvent was removed and the resulting residue was
extracted with THF (3×10 mL). The solvent was evaporated and
the residue was passed through silica gel using hexanes as the eluent
to remove the excess A. The crude product was eluted with EtOAc/
hexanes (1:1). The solvent was removed under vacuum and the resi-
due washed with EtOH (20 mL) to give bright-yellow solid 2.
3
3
δ = 7.47 (d, JH–H = 8.6 Hz, 8 H, Ph), 7.44 (d, JH–H = 8.6 Hz, 8
H, Ph), 2.70 (s, 6 H, CH3), 1.12 (m, 84 H, TIPS) ppm. 13C NMR
(CDCl3): δ = 139.9, 132.1, 131.3, 125.4, 123.8, 123.0 (Ph), 106.6,
98.7, 93.2, 89.2 (C=C), 19.8 (CH3), 18.7 (CH3), 11.3 (CH) ppm. IR
(KBr, cm–1): ν = 2144 (νCϵC). MS (MALDI-TOF): m/z = 1227.7
˜
[M+]. C84H106Si4 (1228.08): calcd. C 82.15, H 8.07; found C 82.33,
H 8.15.
1
(229 mg, 69% yield). Spectroscopic data of 2: H NMR (CDCl3):
3
δ = 7.51–7.44 (m, 20 H, Ph), 4.34 (t, JH–H = 6.3 Hz, 2 H, OCH2),
Preparation of Compound 4c: Compound A (271 mg, 0.2 mmol)
was added to a stirred suspension of 1,2,4,5-tetrabomo-3,6-dibu-
1.94–1.84 (m, 2 H, CH2), 1.55–1.22 (m, 18 H, CH2), 1.12 (m, 105
3
H, TIPS), 0.86 (t, JH–H = 6.6 Hz, 3 H, CH3) ppm. 13C NMR
toxybenzene
(108 mg,
0.2 mmol),
PdCl2(PPh3)2
(11 mg,
(CDCl3): δ = 160.7, 132.2, 132.1, 131.5, 131.3, 128.9, 124.2, 124.0,
123.9, 123.8, 123.1, 122.8, 122.7, 120.1 (Ph), 106.5, 99.4, 99.3, 97.1,
93.5, 93.4, 93.3, 88.9, 88.5, 86.1 (C=C), 75.1 (OCH2), 31.9, 30.6,
29.6, 29.3, 26.3, 22.67 (CH2), 18.7 (CH3), 14.1 (CH3), 11.3 (CH)
ppm. MALDI-TOF-MS (DHB): m/z = 1665.95 [M+ + 1]. IR (KBr,
0.016 mmol), CuI (3 mg, 0.016 mmol), and PPh3 (21 mg,
0.08 mmol) in THF/NEt3 (30 mL, 1:1) under nitrogen. The mixture
was stirred at 100 °C for 36 h. After cooling to room temperature,
the solvent was removed and the resulting residue was extracted
with n-hexane (3×20 mL). The solvent was removed and the resi-
due was passed through a silica gel packed column using n-hexane
as the eluent to remove excess A. Elution with THF/n-hexane gave
yellow solid compound 4c (180 mg, 67% yield). Spectroscopic data
cm–1): ν = 2144 (νCϵC). C113H150OSi5 (1644.83): calcd. C 81.52, H,
˜
9.08; found C 81.70, H 9.01.
Preparation of Compound 3: Compound A (451 mg, 1.2 mmol) was
added to a stirred suspension of 2,3,4,5,6-pentabromotoluene
(97 mg, 0.2 mmol), PdCl2(PPh3)2 (14 mg, 0.02 mmol), CuI (3.8 mg,
0.02 mmol), and PPh3 (14 mg, 0.02 mmol) in Et3N (15 mL) under
nitrogen. The mixture was stirred at 100 °C for 48 h. After cooling
to room temperature, the solvent was removed under vacuum and
the resulting residue was extracted with THF (3×10 mL). The sol-
vent was removed and the residue was passed through silica gel
using hexane as the eluent to remove excess A. The desired product
was then eluted with EtOAc/hexane (1:1). The solvent was removed
and the residue was washed with EtOH (20 mL) to give bright-
yellow solid 3 (188 mg, 63% yield). Spectroscopic data of 3: 1H
NMR (CDCl3): δ = 7.51–7.44 (m, 20 H, Ph), 2.74 (s, 3 H, CH3),
1.12 (m, 105 H, TIPS) ppm. 13C NMR (CDCl3): δ = 142.3, 132.1,
131.4, 127.4, 125.9, 125.5, 124.0, 123.8, 123.0, 122.9, 122.8(Ph),
106.6, 99.2, 98.8, 93.4, 93.2, 89.5, 88.8, 88.5 (C=C), 20.2 (CH3),
18.7 (CH3), 11.3 (CH) ppm. MALDI-TOF-MS (DHB): m/z =
1
3
of 4c: H NMR (CDCl3): δ = 7.47 (s, 16 H, Ph), 4.27 (t, JH–H
=
6.6 Hz, 4 H, OCH2), 1.92–1.83 (m, 4 H, CH2), 1.68–1.56 (m, 4 H,
CH2), 1.12 (m, 84 H, TIPS), 0.86 (t, J = 6.3 Hz, 3 H, CH3) ppm.
13C NMR (CDCl3): δ = 157.4, 132.1, 131.3, 123.9, 122.9, 121.1
(Ph), 106.5, 99.1, 93.3, 86.3 (C=C), 74.6 (OCH2), 32.5, 19.5 (CH2),
18.7 (CH ), 14.0 (CH ), 11.3 (CH) ppm. IR (KBr, cm–1): ν = 2144
˜
3
3
(νCϵC). MS (MALDI-TOF): m/z = 1343.9 [M+]. C90H118O2Si4
(1344.24): calcd. C 80.41, H 8.85; found C 80.73, H 8.91.
Preparation of Compound 4d: Synthesis of 4d followed the same
procedure as that used for the preparation of 4c, with 72% yield.
Spectroscopic data of 4d: 1H NMR (CDCl3): δ = 7.45 (s, 16 H,
3
Ph), 4.25 (t, JH–H = 6.3 Hz, 4 H), 1.93–1.83 (m, 4 H, CH2), 1.61–
1.21 (m, 18 H, CH2), 1.12 (m, 84 H, TIPS), 0.86 (t, 3JH–H = 6.6 Hz,
6 H, CH3) ppm. 13C NMR (CDCl3): δ = 157.4, 132.1, 131.3, 123.9,
122.9, 121.1 (Ph), 106.5, 99.1, 93.3, 86.3 (C=C), 75.0 (OCH2), 31.9,
30.5, 29.6, 29.3, 26.4, 22.7(CH2), 18.7 (CH3), 14.1 (CH3), 11.3 (CH)
ppm. MS (MALDI-TOF): m/z = 1568.8 [M+]. C106H150O2Si4
(1568.67): calcd. C 81.16, H, 9.64; found C 81.34 H 9.74.
1495.0 [M+]. IR (KBr, cm–1): ν = 2144 (νCϵC). C102H128Si5
˜
(1494.54): calcd. C 81.97, H 8.63; found C 81.75, H 8.53.
Preparation of Compound 4a: A mixture of tetrabromobenzene
(157 mg, 0.4 mmol) and A (496 mg, 1.76 mmol) in 30 mL of Et3N
was stirred in the presence of PdCl2(PPh3)2 (22 mg, 0.032 mmol)
and CuI (6 mg, 0.032 mmol) as catalyst at 100 °C for 36 h. After
cooling to room temperature, the solvent was removed and excess
A was removed by washing with n-hexane (2×10 mL) and ethyl
alcohol (2×10 mL) to give the product as yellow solid (317 mg,
Preparation of Compound 5: A mixture of 1 (1.96 g, 1.11 mmol) in
THF (20 mL) and nBu4NF (1 M THF solution, 13.32 mL) was
stirred at 45 °C overnight. The solvent was removed and EtOH
(50 mL) was added to give yellow solid which was filtered and dried
under vacuum to give 5 (907 mg, 99% yield). Spectroscopic data
3
of 5: 1H NMR ([D8]THF): δ = 7.62 (d, JH–H = 8.3 Hz, 12 H,
3
C6H4), 7.52 (d, JH–H = 8.3 Hz, 12 H, C6H4), 3.77 (s, 6 H, C=CH)
1
66% yield). Spectroscopic data of 4a: H NMR (CDCl3): δ = 7.73
ppm. 13C NMR ([D8]THF): δ = 133.3, 132.8, 128.6, 124.7, 124.0
Eur. J. Org. Chem. 2006, 4510–4518
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
4515

C.-C. Huang, Y.-C. Lin, P.-Yu Lin, Y.-J. Chen
FULL PAPER
(Ph), 100.5, 89.4, 83.9, 81.7 (C=C) ppm. IR (KBr, cm–1): ν = 3286
(νCϵC). C138H204Cl6P12Pd6 (3086.02): calcd. C 53.71, H 6.66; found
C 53.90, H 6.61.
˜
(νH–Cϵ), 2195 (νCϵC). Mass (FAB): m/z = 823 [M+ + 1]. HRMS
cacld for C66H30: 822.2347; found 822.2352. C66H30 (822.94): C
96.33, H 3.67; found C 96.37, H 3.66.
Preparation of Complex 8a: A mixture of trans-Pd(PEt3)2Cl2
(125 mg, 0.30 mmol), 6a (43 mg, 0.075 mmol) and CuCl (2 mg) was
Preparation of Compound 6a: A mixture of 4a (340 mg, 0.28 mmol) dissolved in THF (10 mL) then Et2NH (5 mL) was added. The re-
and nBu4NF (1.13 mL, 1  in THF) in THF (10 mL) was stirred action mixture stirred overnight at room temperature under nitro-
at room temperature for 1 h. The solvent was removed and EtOH
(20 mL) was added to give yellow solid which was filtered and dried
under vacuum to give 6a (160 mg, 99% yield). Spectroscopic data
gen. The solvent was then removed under reduced pressure. After
the residue was extracted with n-hexane, the solvent was then con-
centrated under reduced pressure. The residues was passed through
a short column of basic aluminum oxide using CH2Cl2/petroleum
1
3
of 6a: H NMR ([D8]THF): δ = 7.82 (s, 2 H, Ph), 7.56 (d, JH–H
8.1 Hz, 8 H, C6H4), 7.50 (d, JH–H = 8.1 Hz, 8 H, C6H4), 3.72 (s, ether (boiling range 40–65 °C), 1:1, as the eluent to remove excess
=
3
4 H, CϵCH) ppm. 13C NMR ([D8]THF): δ = 136.1, 133.2, 132.6, trans-Pd(PEt3)2Cl2. The tetranuclear complex 8a was eluted with
126.5, 124.4, 124.0 (Ph), 96.2, 89.9, 83.9, 81.4 (CϵC) ppm. IR
THF and the solvent was removed by a rotary evaporator to give
(KBr, cm–1): ν = 3286 (νH–Cϵ), 2195 (νCϵC). Mass (FAB): m/z = complex 8a as a yellow solid (136 mg, 87% yield). Spectroscopic
˜
574.2 [M+]. HRMS cacld for C46H22: 574.1722; found 574.1719.
C46H22 (574.67): calcd. C 96.14, H 3.86; found C 96.21, H 3.86.
data of 8a: 31P NMR (CDCl3): δ = 18.86 ppm. H NMR (CDCl3):
1
3
δ = 7.70 (s, 2 H, Ph), 7.40 (d, JH–H = 8.4 Hz, 8 H, C6H4), 7.21 (d,
3JH–H = 8.4 Hz, 8 H, C6H4), 2.01–1.92 (m, 48 H, CH2), 1.25–1.13
(m, 72 H, CH3) ppm. 13C NMR (CDCl3): δ = 134.8, 131.5, 130.7,
Preparation of Compound 6c: A mixture of 6c (269 mg, 0.2 mmol)
and nBu4NF (0.8 mL, 1  in THF) in THF (10 mL) was stirred at
room temperature for 1 h. The solvent was removed and EtOH
(20 mL) was added to give yellow solid and dried under vacuum
3
128.3, 125.1, 119.8 (Ph), 106.8 (t, JC–P = 5.6 Hz, Cβ), 99.8 (t,
2JC–P = 15.8 Hz, Cα), 95.8, 88.4 (CϵC), 15.5 (t, JC–P = 14.0 Hz,
CH2), 8.3 (CH3) ppm. Mass (FAB): m/z = 2081 [M+, Cl = 35].
C94H138Cl4P8Pd4 (2083.38): calcd. C 54.19, H 6.68; found C 54.00,
H 6.73.
1
(141 mg, 98% yield). Spectroscopic data of 6c: H NMR (CDCl3):
3
3
δ = 7.62 (d, JH–H = 8.5 Hz, 12 H, C6H4), 7.52 (d, JH–H = 8.5 Hz,
3
12 H, C6H4), 4.27 (t, JH–H = 6.3 Hz, 4 H, OCH2), 3.19 (s, 4 H,
C=CH), 1.89–1.83 (m, 4 H, CH2), 1.64–1.54 (m, 4 H, CH2), 0.95 Preparation of Complex 8c: Et2NH (5 mL) was added to a mixture
(t, 3JH–H = 6.6 Hz, 6 H, CH3) ppm. 13C NMR (CDCl3): δ = 157.4, of trans-Pd(PEt3)2Cl2 (83 mg, 0.100 mmol), 6c (36 mg, 0.025 mmol)
132.2, 131.4, 123.5, 122.5, 121.1 (Ph), 98.8, 86.4, 83.1, 79.3 (C=C),
and CuCl (1 mg) dissolved in THF (5 mL). The reaction mixture
was stirred overnight at room temperature under nitrogen. The sol-
vent was then removed under reduced pressure. The residue was
passed through a short column of basic aluminum oxide using
CH2Cl2/petroleum ether (boiling range 40–65 °C), 1:1, as the eluent
to remove excess trans-Pd(PEt3)2Cl2. The tetranuclear complex 8c
was eluted with THF and the solvent was removed by rotary evapo-
rator to give complex 8c as orange solid. (35 mg, 62% yield). Spec-
74.7 (OCH ), 32.5, 19.5 (CH ), 14.0 (CH ) ppm. IR (KBr,cm–1): ν
˜
2
2
3
= 3276 (νH–Cϵ), 2195 (νCϵC). Mass (FAB): m/z = 718 [M+]. HRMS
calcd. for C54H38O2: 718.2872; found 718.2877. C54H38O2 (718.88):
calcd. C 90.22, H 5.33; found C 90.37, H 5.44.
Preparation of Compound 7a: trans-Pd(PBu3)2Cl2 (174 mg,
0.3 mmol) was dissolved in HNEt2 (10 mL) containing CuI (2 mg).
Compound 5 (41 mg, 0.05 mmol) in THF (10 mL) was added and
the reaction mixture stirred for 8 h at room temperature under ni-
trogen. The solvent was then removed under reduced pressure. The
residue was extracted with diethyl ether/n-hexane (1:1) and the
solution was dried with anhydrous MgSO4 followed by filtration
with celite. The filtrate was then concentrated under reduced pres-
sure and passed through a short column of basic aluminum oxide
using petroleum ether (boiling range 40–65 °C) as the eluent to
remove excess trans-Pd(PBu3)2Cl2. The hexanuclear complex 7a
was eluted with EtOAc and the solvent was removed by rotary
evaporator to give pale yellow solid 7a (162 mg, 79% yield). Spec-
troscopic data of 7a: 31P NMR (CDCl3): δ = 10.80. 1H NMR
1
troscopic data of 8c: 31P NMR (CDCl3): δ = 18.86 ppm. H NMR
3
(CDCl3): δ = 7.41 (d, J = 8.2 Hz, 8 H, C6H4), 7.21 (d, JH–H
=
3
8.2 Hz, 8 H, C6H4), 4.24 (t, JH–H = 6.3 Hz, 4 H, OCH2), 2.01–
1.91 (m, 48 H, CH2), 1.88–1.83 (m, 4 H, CH2), 1.64–1.57 (m, 4 H,
CH2), 1.25–1.13 (m, 72 H, CH2), 0.95 (t, J = 6.6 Hz, 6 H, CH3)
ppm. 13C NMR (CDCl3): δ = 157.2 (O–C, C6H4), 131.3, 130.7,
3
128.2, 120.8, 120.1 (Ph), 106.7 (t, JC–P = 5.6 Hz, Cβ), 99.7 (t,
2JC–P = 14.3 Hz, Cα), 99.8, 85.8 (CϵC), 74.4 (OCH2), 32.5, 19.5
(CH2), 15.4 (t, JC–P = 14.0 Hz, CH2), 14.0 (CH3), 8.4 (s, CH3) ppm.
IR (KBr, cm–1): ν = 2195, 2103 (νCϵC). Mass (FAB): m/z = 2227
˜
[M+, Cl = 35.45]. C102H154Cl4O2P8Pd4 (2227.59): calcd. C 55.00, H
6.97; found C 55.31, H 6.79.
3
3
(CDCl3): δ = 7.48 (d, JH–H = 8.2 Hz, 2 H, Ph), 7.21 (d, JH–H
=
8.2 Hz, 2 H, Ph), 1.94–1.88 (m, 6 H, CH2), 1.57–1.37 (m, 12 H,
Preparation of Complex 9a: A mixture of 5 (41 mg, 0.05 mmol),
CH2), 0.91 (t, 3JH–H = 7.2 Hz, 9 H, CH3) ppm. 13C NMR (CDCl3): NaOH (36 mg, 0.9 mmol) dissolved in EtOH (2 mL) and
3
δ = 131.5, 130.6, 128.7, 127.1, 119.9 (Ph), 106.3 (t, JC–P = 5.3 Hz, Au(PCy3)Cl (154 mg, 0.3 mmol) dissolved in THF (10 mL) was
2
Cβ), 101.6 (t, JC–P = 15.6 Hz, Cα), 99.6, 88.3 (CϵC), 26.4 (CH2), stirred at room temperature under nitrogen for 3 h. The solvent
2
24.4 (t, JC–P = 6.6 Hz, CH2), 22.9 (t, JC–P = 13.6 Hz, CH2), 13.8
was then removed, and the residue was washed with EtOH/H2O
(1:1, 10 mL) and acetone to give the yellow solid 9a (153 mg, 83%
yield). Spectroscopic data of 9a: 31P NMR (CDCl3): δ = 56.81 ppm.
(CH3) ppm. IR (KBr, cm–1):
ν = 2195 and 2103 (νCϵC).
˜
C210H348Cl6P12Pd6 (4095.93): calcd. C 90.22, H 5.33; found C
90.37, H 5.44.
3
1H NMR (CDCl3): δ = 7.47 (d, JH–H = 8.7 Hz, 12 H, C6H4), 7.43
(d, 3JH–H = 8.7 Hz, 12 H, C6H4), 2.01–1.24 (m, 180 H, PCy3) ppm.
13C NMR (CDCl3): δ = 139.9 (d, 2JP–C = 131.2 Hz, Cα (AuCϵC)),
Preparation of Compound 7b: Synthesis of 7b followed the same
procedure as that used for the preparation of 7a in 73% yield. Spec-
troscopic data of 7b: 31P NMR (CD2Cl2): δ = 18.95. 1H NMR
3
132.3, 131.4, 127.2, 125.9, 121.0 (Ph), 103.5 (d, JP–C = 24.5 Hz,
Cβ, (AuCϵC)), 99.7, 88.6, (CϵC), 33.2 (d, JP–C = 24.5 Hz, Cy3P),
3
(CD2Cl2): δ = 7.51 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.27 (d,
30.7 (s, Cy3P), 27.7 (d, 2JP–C = 11.8 Hz, Cy3P), 25.9 (s, Cy3P) ppm.
3JH–H = 8.2 Hz, 12 H, C6H4), 2.02–1.93 (m, 72 H, CH2), 1.26–1.16
IR (KBr, cm–1): ν = 2195, 2103 (νCϵC). C174H222Au6P6 (3681.27):
˜
(m, 108 H, CH3) ppm. 13C NMR (CD2Cl2): δ = 132.10, 131.40,
calcd. C 56.77, H 6.08; found C 56.91, H 6.21.
3
129.46, 127.62, 120.20 (Ph), 107.24 (t, JC–P = 5.6 Hz, Cβ), 101.72
2
(t, JP–C = 15.8 Hz, Cα), 100.39, 88.62 (CϵC), 16.00 (t, JC–P
=
Preparation of Complex 10c: A mixture of 6c (36 mg, 0.05 mmol),
NaOH (8 mg, 2 mmol) dissolved in EtOH (1.2 mL) and Au-
14.0 Hz, CH ), 8.70 (CH ) ppm. IR (KBr, cm–1): ν = 2195, 2103
˜
2
3
4516
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© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2006, 4510–4518

Star-Shaped Molecules with Polyalkynyl Groups and Metal Moieties
FULL PAPER
(PCy3)Cl (103 mg, 0.2 mmol) dissolved in THF (10 mL) was stirred
at room temperature under nitrogen for 5 h. The solvent was re-
moved under vacuum then the residue was washed with EtOH/H2O
(1:1, 10 mL) to give a yellow solid identified as 10c (106 mg, 81%
H, CH3) ppm. 13C NMR (CD2Cl2): δ = 132.0, 131.3, 129.4, 129.2,
3
128.0, 125.4, 120.1 (Ph), 106.6 (t, JC–P = 5.5 Hz, Cβ), 102.7 (t,
2JC–P = 15.7 Hz, Cα), 95.5, 89.5 (CϵC), 27.0 (s, CH2), 25.0 (t,
JC–P = 6.6 Hz, CH2), 23.5 (t, JC–P = 6.6 Hz, CH2), 14.2 (s, CH3)
yield). Spectroscopic data of 10c: 31P NMR (CDCl3): δ = 56.88.
ppm. IR (KBr, cm–1): ν = 2205, 2103 (νCϵC). C222H354Cl6P12Pd6
˜
3
1H NMR (CDCl3): δ = 7.41 (d, JH–H = 8.4 Hz, 8 H, C6H4), 7.21 (4246.11): calcd. C 62.80, H 8.40; found C 62.65, H 8.51.
3
3
(d, JH–H = 8.4 Hz, 8 H, C6H4), 4.22 (t, JH–H = 6.3 Hz, 4 H,
Preparation of Complex 14: A mixture of 13 (49 mg, 0.05 mmol),
NaOH (36 mg, 0.9 mmol) in EtOH (2 mL) and Au(PCy3)Cl
(154 mg, 0.3 mmol) in THF (10 mL) was stirred at room tempera-
ture under nitrogen for 3 h. The solvent was then removed, and
then the residue was washed with EtOH/H2O (1:1, 10 mL) and ace-
tone to give a yellow solid (153 mg, 80% yield). Spectroscopic data
3
OCH2), 2.05–1.19 (m, 128 H, CH2, Cy3P), 0.91 (t, JH–H = 6.6 Hz,
6 H, CH3) ppm. 13C NMR (CDCl3): δ = 157.2 (Ph), 139.8 (d,
2JC–P = 131.3 Hz, AuCϵC), 132.3, 131.2, 125.7, 121.2, 120.9 (Ph),
2
103.3 (d, JC–P = 23.8 Hz, AuCϵC), 99.5, 85.8 (CϵC), 74.4
2
2
(OCH2), 33.2 (d, JC–P = 27.8 Hz, Cy), 32.5 (CH2), 27.1 (d, JC–P
= 11.7 Hz, Cy), 25.9 (s, Cy), 19.5 (CH2), 13.9 (CH3) ppm. Mass
(FAB): m/z = 2624.1 [M+, Au = 197]. C126H166Au4O2P4 (2624.43):
calcd. C 57.66, H 6.38; found: C 56.88, H 6.31.
1
of 14: 31P NMR (CDCl3): δ = 56.86 ppm. H NMR (CDCl3): δ =
3
8.73 (s, 6 H, triphenylene), 7.52 (d, JH–H = 8.5 Hz, 12 H, C6H4),
3
7.48 (d, JH–H = 8.5 Hz, 12 H, C6H4), 2.02–1.24 (m, 180 H, PCy3)
2
ppm. 13C NMR (CDCl3): δ = 139.7 (d, JP–C = 132 Hz, AuCϵC),
Preparation of Compound 11: Compound A (2.83 g, 7.5 mmol) was
added to a stirred suspension of 2,3,6,7,10,11-hexabromotripheny-
lene (0.702 g, 1 mmol), PdCl2(PPh3)2 (70 mg, 0.1 mmol), CuI
(19 mg, 0.1 mmol), and PPh3 (131 mg, 0.57 mmol) in THF/Et3N
(50 mL, 1:1) under nitrogen. The mixture was stirred at 100 °C for
48 h. After cooling to room temperature, the solvent was removed
and the resulting residue was extracted with THF (3×10 mL). The
solvent was removed under vacuum and excess A was washed with
hexanes (2×10 mL) and ethyl alcohol (2×10 mL) to give a yellow
solid (1.74 g, 85%). Spectroscopic data of 11: 1H NMR ([D8]THF):
δ = 8.99 (s, 6 H, triphenylene), 7.65 (d, 3JH–H = 8.3 Hz, 2 H, C6H4),
7.55 (d, 3JH–H = 8.3 Hz, 12 H, C6H4), 1.19 (m, 126 H, TIPS) ppm.
13C NMR ([D8]THF): δ = 133.1, 132.5, 129.8, 128.6, 125.7, 124.6,
124.3 (Ph), 108.1, 95.1, 93.3, 91.3 (CϵC), 19.2 (CH3), 12.4 (CH)
3
132.3, 131.4, 128.5, 127.2, 125.7, 124.9, 120.9 (Ph), 103.5 (d, JP–C
1
= 24 Hz, AuCϵC), 95.0, 89.4, (CϵC), 33.2 (d, JP–C = 28 Hz,
2
Cy3P), 30.7 (s, Cy3P), 27.1 (d, JP–C = 12 Hz, Cy3P), 25.9 (s, Cy3P)
ppm. IR (KBr, cm–1): ν = 2205, 2103 (νCϵC). C186H228Au6P6
˜
(3831.44): calcd. C 58.31, H 6.00; found C 58.55, H 6.11.
Synthesis of Cl(Et3P)2Pt(CϵCC6H4CϵCTIPS) (15): trans-Dichlo-
robis(triethylphosphane)platinum (201 mg, 0.40 mmol) was treated
with compound A (113 mg, 0.4 mmol) in the presence of 2 mg of
CuCl as catalyst in 20 mL of toluene/Et3N (1:1) at 90 °C. After
24 h the solvent was removed under vacuum, and the residue was
extracted with hexanes. Then the solvent was removed to afford
oily residue. The residue was passed through a short column of
basic aluminum oxide using hexanes as the eluent to give a colorless
oily product 15 (284 mg, 95% yield). Spectroscopic data of 15: 31P
NMR (CDCl3): δ = 15.47 (s, JPt–P = 2379 Hz) ppm. 1H NMR
ppm. IR (KBr, cm–1): ν = 2144 (νCϵC). MALDI-TOF-MS (DHB):
˜
m/z = 1913.6 [M+ + 2]. C132H156Si6 (1191.16): calcd. C 82.96, H
8.23; found C 83.06, H 8.31.
3
3
(CDCl3): δ = 7.30 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.13 (d, JH–H
2
= 8.2 Hz, 12 H, C6H4), 2.08–1.98 (m, 72 H, CH2), 1.17 (dt, JP–H
Preparation of Compound 12: A mixture of 11 (1.74 g, 0.85 mmol)
and nBu4NF (10.2 mL, 1  in THF) in THF (20 mL) was stirred
at 45 °C overnight. The solvent was removed under vacuum and
EtOH (50 mL) was added to give yellow solid which was filtered
and dried under vacuum to give 12 (907 mg, 99%). Spectroscopic
3
= 16.0 Hz, JH–H = 8.0 Hz, 108 H, CH3), 1.10 (m, 126 H, TIPS)
ppm. 13C NMR (CDCl3): δ = 131.7, 130.5, 128.8, 120.0 (Ph), 107.5
3
(CϵCSi), 101.9 (s, CϵCPt), 90.9 (CϵCSi), 85.7 (t, JC–P = 29 Hz,
CϵCPt), 18.7 (CH3), 14.5 (t, JC–P = 18 Hz, CH2), 11.3 (CH), 8.0
(CH3) ppm. MS (FAB): m/z
3
= = 35.45).
748.3 [M+] (Cl
1
data of 12: H NMR ([D8]THF): δ = 8.91 (s, 6 H, triphenylene),
C31H55ClP2PtSi (748.33): calcd. C 49.75, H 7.41; found C 49.88, H
7.51.
3
3
7.61 (d, JH–H = 8.1 Hz, 12 H, C6H4), 7.51 (d, JH–H = 8.1 Hz, 12
H, C6H4), 3.77 (CϵCH) ppm. 13C NMR ([D8]THF): δ = 133.1,
132.6, 129.3, 128.1, 125.5, 124.6, 124.5 (Ph), 94.9, 91.4, 83.9, 81.1
Preparation of Complex 16: A mixture of 5 (41 mg, 0.05 mmol) in
THF (15 mL) and 15 (299 mg, 0.40 mmol) in Et2NH (10 mL) was
stirred at room temperature in the presence of CuCl (2 mg) for
24 h. The solvent was then removed under vacuum. The residue
was passed through alumina column using CH2Cl2/hexanes (1:4)
as the eluent to remove excess 15. The complex 16 was eluted with
EtOAc and the solvent was removed by rotary evaporator to give
the yellow solid 16 (211 mg, 83% yield). Spectroscopic data for 16:
(CϵC) ppm. IR (KBr, cm–1): ν = 3286 (νH–Cϵ), 2205 (νCϵC). Mass
˜
(FAB): m/z = 974 [M+ + 1]. HRMS cacld for C78H36: 973.2896;
found 973.2913. C78H36 (973.12): calcd. C 96.27, H 3.73; found C
963.21, H 3.71.
Preparation of Complex 13: trans-Pd(PBu3)2Cl2 (174 mg, 0.3 mmol)
was dissolved in Et2NH (10 mL) containing CuCl (2 mg). Com-
pound 12 (49 mg, 0.05 mmol) in THF (10 mL) was added and the
reaction mixture stirred overnight at room temperature under ni-
trogen. The solvent was then removed under reduced pressure. The
residue was extracted with diethyl ether/hexanes (1:1), the resulting
solution was dried with anhydrous MgSO4 following by filtration
using Celite. The filtrate was concentrated under reduced pressure
and passed through a short column of basic aluminum oxide using
petroleum ether (boiling range 40–65 °C) as the eluent to remove
excess trans-Pd(PBu3)2Cl2. The product 13 was eluted with EtOAc
and the solvent was removed by rotary evaporator to give a pale
yellow solid identified as 13 (159 mg, 75% yield). Spectroscopic
data of 13: 31P NMR (CD2Cl2): δ = 10.67 ppm. 1H NMR
1
31P NMR (CDCl3): δ = 11.80 (s, JPt–P = 2359 Hz) ppm. H NMR
3
3
(CDCl3): δ = 7.47 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.31 (d, JH–H
3
= 8.2 Hz, 12 H, C6H4), 7.25 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.18
3
(d, JH–H = 8.2 Hz, 12 H, C6H4), 2.22–2.12 (m, 72 H, CH2), 1.22
(dt, 2JP–H = 16.0 Hz, 3JH–H = 8.0 Hz, 108 H, CH3), 1.10(m, 126 H,
TIPS) ppm. 13C NMR (CDCl3): δ = 131.7, 131.5, 130.9, 130.6,
2
129.3, 128.8, 127. 0, 119.8, 119.5 (Ph), 112.0 (t, JC–P = 28 Hz,
CϵCPt), 110.8 (t, JC–P = 28 Hz, CϵCPt), 110.0 (CϵCPt), 109.9
2
3
(CϵCPt), 107.6, 99.9, 90.8, 88.3 (CϵC), 18.7 (CH3), 16.4 (t, JC–P
= 18 Hz, CH ), 11.3 (CH), 8.3 (CH ) ppm. IR (KBr, cm–1): ν =
˜
2
3
2093, 2195 (νCϵC). C252H354P12Pt6Si6 (5094.17): calcd. C 59.41, H
7.00; found C 59.37, H 7.02.
3
(CD2Cl2): δ = 8.84 (s, 6 H, triphenylene), 7.55 (d, JH–H = 8.2 Hz,
3
12 H, C6H4), 7.29 (d, JH–H = 8.2 Hz, 12 H, C6H4), 1.97–1.91 (m,
Preparation of Complex 17: Complex 16 (211 mg, 0.041 mmol) was
36 H, CH2), 1.60–1.44 (m, 72 H, CH2), 0.95 (t, 3JH–H = 7.2 Hz, 54 dissolved in THF (10 mL), and nBu4NF (0.4 mL, 1  in THF) was
Eur. J. Org. Chem. 2006, 4510–4518
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
4517

C.-C. Huang, Y.-C. Lin, P.-Yu Lin, Y.-J. Chen
FULL PAPER
trical Properties (Ed.: H. S. Nalwa), Wiley: New York, 1997; p.
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added. The mixture was stirred at room temperature for 2 h and
then the solvent was removed under vacuum. The residue was puri-
fied by washing with EtOH to afford the deprotected alkyne 17 as
yellow solid (171 mg, 99% yield). Spectroscopic data for 17 are as
1
follows: 31P NMR (CDCl3): δ = 11.77 (JPt–P = 2359 Hz) ppm. H
3
NMR (CDCl3): δ = 7.47 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.32 (d,
3JH–H = 8.2 Hz, 12 H, C6H4), 7.25 (d, 3JH–H = 8.2 Hz, 12 H, C6H4),
3
7.19 (d, JH–H = 8.2 Hz, 12 H, C6H4), 3.09 (s, CϵCH), 2.19–
2.14(m, 72 H, CH2), 1.22 (dt, JP–H = 16.0 Hz, JH–H = 8.0 Hz, 108
H, CH3) ppm. 13C NMR (CDCl3): δ = 131.8, 131.5, 130.9, 130.7,
2
129.4, 127.0, 119.5, 118.2 (Ph), 112.0 (t, JC–P = 30 Hz, CϵCPt),
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3981–3987.
2
111.2 (t, JC–P = 30 Hz, CϵCPt), 110.0 (CϵCPt), 109.9 (CϵCPt),
107.6, 99.9, 88.2, 84.1 (CϵC), 77.2 (CϵCH), 16.4 (t, JC–P = 18 Hz,
CH ), 8.3 (CH ) ppm. IR (KBr, cm–1): ν = 3286 (νH–Cϵ), 2185,
˜
2
3
2093 (νCϵC). C198H234P12Pt6 (4156.13): calcd. C 57.22, H 5.67;
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found C 57.47, H 5.82.
Preparation of Complex 18: To
a mixture of 17 (20 mg,
4.8×10–3 mL) and Au(PCy3)Cl (15 mg, 0.029 mmol) in THF
(10 mL) was added excess NaOH (2 mg,0.048 mmol) in EtOH
(1 mL). The mixture was stirred at room temperature for 3 h. The
solvent was removed under vacuum and the residue was washed
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(29 mg, 86% yield). Spectroscopic data for 18: 31P NMR (CDCl3):
δ = 56.91 (Cy3PAu), 11.76 (JPt–P = 2366 Hz) ppm. 1H NMR
3
3
(CDCl3): δ = 7.45 (d, JH–H = 8.2 Hz, 12 H, C6H4), 7.32 (d, JH–H
3
= 7.8 Hz, 12 H, C6H4), 7.23 (d, JH–H = 7.8 Hz, 12 H, C6H4), 7.10
3
(d, JH–H = 7.8 Hz, 12 H, C6H4), 2.17–1.15 (m, 360 H, PCy3 and
PEt3) ppm. IR (KBr, cm–1):
ν
˜
=
2185, 2083 (νCϵC).
C306H426Au6P18Pt6 (7014.45): calcd. C 52.40, H 6.12; found C
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Acknowledgments
Financial support provided by the National Science Council of
Taiwan is grateful acknowledged. Funding for the Instrumentation
Facility of the Department of Chemistry of NTU has also been
provided in part by the National Science Council of Taiwan.
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Received: May 1, 2006
Published Online: July 28, 2006
4518
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Eur. J. Org. Chem. 2006, 4510–4518