Stereoselective hydroboration of diynes and triyne to give products containing multiple vinylene bridges: A versatile application to fluorescent dyes and light-emitting copolymers

Article abstract of DOI:10.1021/om049832m

The Rh(I)-catalyzed hydroboration of a variety of aromatic diynes and a triyne afforded bis(boryl)- and tris(boryl)vinyl products. The hydroboration products underwent Suzuki cross-coupling reactions with a variety of substrates containing chromophore units to give fluorescent dye-substituted products. The hydroboration product also reacted with dibromoarenes to afford an oligomer with a vinylene unit along the oligomer backbone.

Full text of DOI:10.1021/om049832m

Organometallics 2004, 23, 4569-4575
4569
Ster eoselective Hyd r obor a tion of Diyn es a n d Tr iyn e to
Give P r od u cts Con ta in in g Mu ltip le Vin ylen e Br id ges: A
Ver sa tile Ap p lica tion to F lu or escen t Dyes a n d
Ligh t-Em ittin g Cop olym er s
Taegweon Lee, Chul Baik, Il J ung, Kyu Ho Song, Sanghoon Kim,
Duckhyun Kim, Sang Ook Kang,* and J aejung Ko*
Department of Chemistry, Korea University, J ochiwon, Chungnam 339-700, Korea
Received March 8, 2004
The Rh(I)-catalyzed hydroboration of a variety of aromatic diynes and a triyne afforded
bis(boryl)- and tris(boryl)vinyl products. The hydroboration products underwent Suzuki cross-
coupling reactions with a variety of substrates containing chromophore units to give
fluorescent dye-substituted products. The hydroboration product also reacted with dibro-
moarenes to afford an oligomer with a vinylene unit along the oligomer backbone.
In tr od u ction
polymerization,10 and Suzuki coupling reaction,11 start-
ing boranes such as 4 and 5 should be useful in the
synthesis of fluorescent dyes and light-emitting copoly-
mers using this methodology.
Organic molecules bearing extended π-conjugated
systems have received considerable attention due to
their applications in molecular electronics1 and photon-
ics.2 In particular, oligophenylenevinylene derivatives
have been investigated extensively for applications in
the fields of photo- and electroluminescence,3 photovol-
taics,4 or nonlinear optics.5 Although 1-alkenylboron
derivatives are useful intermediates in organic synthesis
on the basis of their applications in the Pd-catalyzed
cross-coupling reaction with a variety of organic elec-
trophiles,6 little is known about the synthetic applica-
tions of such boron derivatives to the preparation of
polymers or oligomers containing alternate vinylene
units.7 Although various polymerization methods for the
synthesis of such polymers have been developed that
include the Wittig reaction,8 Heck reaction,9 Gilch
Hydroboration provides a useful entry for the syn-
thesis of vinylic boron compounds.12 Although there has
been significant progress using a variety of metal-
catalyzed reactions to provide vinylboron derivatives of
type 1, 2, or 3,13 aromatic compounds containing two14
or three vinylborane substituents have received only
little attention. We report here the preparation of a
number of such compounds and their use in Suzuki
cross-coupling reactions to prepare fluorescent dyes and
light-emitting polymers.
* Corresponding authors. Fax: 82 41 867 5396. Tel: 82 41 860 1337.
E-mail: jko@korea.ac.kr.
(1) (a) Roncali, J . Chem. Rev. 1997, 97, 173. (b) Tour, J . M. Chem.
Rev. 1996, 96, 537.
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A. J . Mater. Chem. 1997, 7, 2175.
Resu lts a n d Discu ssion
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Chem. Res. 1999, 32, 257. (b) Wong, M. S.; Li, Z. H.; Shek, M. F.; Chow,
K. H.; Tao, Y.; D’Iorio, M. J . Mater. Chem. 2000, 10, 1805.
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Echegoyen, L.; Barigelletti, F.; Armaroli, N.; Ouali, L.; Krasnikov, V.;
Hadziioannou, G. J . Am. Chem. Soc. 2000, 122, 7467. (b) Gu, T.; Ceroni,
P.; Marconi, G.; Armaroli, N.; Nierengarten, J .-F. J . Org. Chem. 2001,
66, 6432.
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J .-Y.; Lee, G. J .; Kang, T. I.; Lee, Y. K.; Cho, M.; J eon, S.-J . Chem.
Mater. 2001, 13, 1438. (b) Cho, B. R.; Park, S. B.; Lee, S. J .; Son, K.
H.; Lee, S. H.; Lee, M.-J .; Yoo, J .; Lee, Y. K.; Lee, G. J .; Kang, T. I.;
Cho, M.; J eon, S.-J . J . Am. Chem. Soc. 2001, 123, 6421. (c) Brunel, J .;
Ledoux, I.; Zyss, J .; Blanchard-Desce, M. Chem. Commun. 2001, 923.
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Ishiyama, T.; Nishijima, K.; Miyaura, N.; Suzuki, A. J . Am. Chem.
Soc. 1993, 115, 7219. (c) Miyaura, N.; Ishiyama, T.; Sasaki, H.;
Ishikawa, M.; Satoh, M.; Suzuki, A. J . Am. Chem. Soc. 1989, 111, 314.
(d) Ishiyama, T.; Matsuda, N.; Miyaura, N.; Suzuki, A. J . Am. Chem.
Soc. 1993, 115, 11018.
Our initial experiment on the hydroboration of 1,3,5-
triethynylbenzene with pinacolborane in the presence
of Wilkinson’s catalyst resulted in (E)-1,3,5-tris(borylvi-
nyl)benzene 6 in very low yield (Table 1). Significant
improvement in yield was achieved using Rh(CO)-
(10) Gilch, H. G.; Wheelwright, W. L. J . Polym. Sci. Part A: Polym.
Chem. 1966, 4, 1337.
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(b) Schlu¨ter, A. D. J . Polym. Sci. Part A: Polym. Chem. 2001, 39, 1533.
(12) (a) Takagi, J .; Takahashi, K.; Ishiyama, T.; Miyaura, N. J . Am.
Chem. Soc. 2002, 124, 8001. (b) J uliette, J . J . J .; Rutherford, D.;
Horva´th, I. T.; Gladysz, J . A. J . Am. Chem. Soc. 1999, 121, 2696. (c)
He, X.; Hartwig, J . F. J . Am. Chem. Soc. 1996, 118, 1696. (d) Rubina,
M.; Rubin, M.; Gevorgyan, V. J . Am. Chem. Soc. 2003, 125, 7198.
(13) (a) Pereira, S.; Srebnik, M. Organometallics 1995, 14, 3127. (b)
Pereira, S.; Srebnik, M. Tetrahedron Lett. 1996, 37, 3283. (c) Tucker,
C. E.; Davidson, J .; Knochel, P. J . Org. Chem. 1992, 57, 3482.
(14) (a) Chen, Y. K.; Lurain, A. E.; Walsh, P. J . J . Am. Chem. Soc.
2002, 124, 12225. (b) Corriu, R. J .-P.; Deforth, T.; Douglas, W. E.;
Guerrero, G.; Siebert, W. S. Chem. Commun. 1998, 963.
(7) Terao, T.; Tang, A.; Michels, J . J .; Krivokapic, A.; Anderson, H.
L. Chem. Commun. 2004, 56.
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(9) J ung, S.-H.; Kim, H. K.; Kim, S.-H.; Kim, Y. H.; J eoung, S. C.;
Kim, D. Macromolecules 2000, 33, 9277.
10.1021/om049832m CCC: $27.50 © 2004 American Chemical Society
Publication on Web 08/28/2004

4570 Organometallics, Vol. 23, No. 20, 2004
Lee et al.
Ta ble 1. Ca ta lyzed Hyd r obor a tion of
reacted to give 100% trans product. The trans configu-
1,3,5-Tr ieth yn ylben zen ea a n d Ca ta lyst Scr een in g
ration was assigned on the basis of the characteristic
large coupling constant of the vinylene unit (3J H-H
18.6-18.9 Hz).
)
To demonstrate the synthetic application of the
obtained bis(borylvinyl) and tris(borylvinyl) products,
compound 6 was chosen for a study of the Suzuki cross-
coupling reaction with aryl bromides containing a
chromophore unit. As expected, tris(borylvinyl)benzene
is an efficient precursor for the cross-coupling reaction
under mild conditions (Scheme 1). The Suzuki reaction
of 6 with 9-bromoanthracene in the presence of Pd-
(PPh3)4 and aqueous K2CO3 afforded the trianthryl-
substituted vinyl compound 13 in 55% yield. Compound
13 was obtained in 50% yield using a PdCl2(PPh3)2-dppf,
K3PO4 base, and DMF solvent system developed by
Miyaura et al.17 Compound 6 also reacted readily with
1-bromopyrene to afford 14. The structures of com-
pounds 13 and 14 were readily assigned by a combina-
entry
catalyst
Rh(PPh3)3Cl
solvent
MC
yield (%)b
1
2
3
4
5
6
7
8
9
5
35
88
8
5
0
Rh(CO)(PPh3)2Cl
[Rh(cod)Cl]2-4PiPr3
[Rh(cod)Cl]2-4PCy3
[Rh(cod)Cl]2-4PtBu3
[Rh(cod)Cl]2-4PPh3
[Rh(cod)Cl]2-(t)-BINAP
[Ir(cod)Cl]2-4PiPr3
Pd(PPh3)4
MC
cyclohexane
cyclohexane
cyclohexane
cyclohexane
THF
cyclohexane
THF
MC
0
45
15
0
1
tion of MS and H and 13C NMR spectroscopies and by
10
Cp2ZrHCl
comparison with analogous compounds.18 A parent ion
in the mass spectrum of 13 and 14 was observed at m/z
684 and 756, respectively. Two doublets and large
coupling constants (16.8-17.4 Hz) in the 1H NMR
spectra of 13 and 14 are consistent with trans-vinylic
hydrogens. The 13C NMR spectra of 13 and 14 also
exhibited the expected resonances. The amorphous N,N-
bis(9,9-dimethylfluoren-2-yl)-4-bromoaniline19 under-
went the Suzuki cross-coupling reaction with 6 to give
15. The compound was purified by silica gel column
chromatography and identified by NMR spectroscopy
and elemental analysis. Furthermore, we found that 6
reacted with 2-(4-bromophenyl)-5-(4-tert-butylphenyl)-
1,3,4-oxadiazole20 to provide the starburst product 16,
whose structure was confirmed by NMR spectroscopy
and elemental analysis. Such π-electron starburst mol-
ecules have been extensively explored as either light-
emitting materials or host materials in organic LEDs
due to their good film-forming properties.21 The absorp-
tion and emission spectra of 13-15 taken in methylene
chloride, depicted in Figure 1, reveal the varying geo-
metrical differences between the electronic ground state
and the fluorescent singlet excited state (Table 3). The
absorption spectra of 13 and 14 exhibit intense absorp-
tion bands at 390 and 384 nm, indicating that the
electronic transitions are mostly πfπ*, originating from
the π-conjugation chain extending from the anthryl and
pyrenyl units. Compounds 13 and 14 exhibit fluores-
cence emission in the blue (478 and 457 nm) wavelength
region. Since the vinylene groups and the chromophore
units are planar, their fluorescence spectra are charac-
terized by a small Stokes shift (88 and 73 nm). The
a
To a solution of catalyst and 1,3,5-triethynylbenzene was
added pinacolborane. The mixture was stirred at room tempera-
b
ture for 8 h. Isolated yield.
(PPh3)2Cl as the catalyst (entry 2). The catalyst gener-
ated in situ from [Rh(cod)Cl]2 and PiPr3 (4 equiv) gave
6 in excellent yield (entry 3). The use of Et3N was found
to be essential to achieve good yields and trans-selectiv-
ity in the case of some substrates. Use of different
i
amines such as piperidine, pyrrolidine, Et2NH, and Pr2-
NH resulted in unsatisfactory yields and gave a mixture
of E- and Z-isomers. Screening a number of phosphine
ligands during the hydroboration of 1,3,5-triethynyl-
benzene showed PiPr3 to be superior in terms of yield
and reaction rate (entries 4-7). An iridium catalyst, [Ir-
(cod)Cl]2-4PiPr3, was also effective, but led to a lower
yield. The solvent is crucial in order to obtain a high
yield and stereoselectivity, and cyclohexane was found
to be the best solvent.
A variety of diynes and triynes were investigated. The
data for the hydroboration in Table 2 were obtained with
the Rh(I)-PiPr3 catalyst under the optimum reaction
conditions. The Rh-catalyzed hydroboration of 1,4-
diethynylbenzene afforded (E)-bis(borylvinyl)benzene in
high yield (entry 2). There is no great difference in trans-
selectivity for the diynes and triyne studied (entries
1-4). Hydroboration of terminal alkynes using the same
catalyst has been reported to give cis-1-alkenylbor-
onates.15 However, the hydroboration of 3,6-diethynyl-
9-hexylcarbazole and 9,10-diethynylanthracene resulted
in a mixture of products, E- and Z-isomers (entries 5,
6). Moreover, the 1,3-diethynylazulene underwent a
hydroboration to form only the Z-isomer (entry 7).
Although it has been well documented that the hy-
droboration of terminal or internal alkynes affords a
variable product distribution depending on the nature
of the catalyst and substrate,16 it is quite remarkable
that some of the diynes used in the present study
(17) Takagi, J .; Takahashi, K.; Ishiyama, T.; Miyaura, N. J . Am.
Chem. Soc. 2002, 124, 8001.
(18) (a) Hamaguchi, H.; Tasumi, M.; Karatsu, T.; Arai, T.; Toku-
maru, K. J . Am. Chem. Soc. 1986, 108, 1698. (b) Gopal, V. R.; Rao, V.
J .; Saroja, G.; Samanta, A. Chem. Phys. Lett. 1997, 270, 593.
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2004, 68. (b) Doi, H.; Kinoshita, M.; Okumoto, K.; Shirota, Y. Chem.
Mater. 2003, 15, 1080. (c) Shirota, Y.; Kinoshita, M.; Noda, T.;
Okumoto, K.; Ohara, T. J . Am. Chem. Soc. 2000, 122, 11021.
(20) Lee, D. W.; Kwon, K.-Y.; J in, J .-I.; Park, Y.; Kim, Y.-R.; Hwang
I.-W. Chem. Mater. 2001, 13, 565.
(21) (a) Kuwabara, Y.; Ogawa, H.; Inada, N.; Noma, N.; Shirota, Y.
Adv. Mater. 1994, 6, 677. (b) Wu, I.-Y.; Lin, J . T.; Tao, Y.-T.;
Balasubramaniam, E. Adv. Mater. 2000, 12, 668. (c) Gao, Z.; Lee, C.
S.; Bello, I.; Lee, S. T.; Chen, R.-M.; Luh, T.-Y.; Shi, J .; Tang, C. W.
Appl, Phys. Lett. 1999, 74, 865.
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2000, 122, 4990.
(16) (a) Harrison, K. N.; Marks, T. J . J . Am. Chem. Soc. 1992, 114,
9220. (b) Gridnev, I. D.; Miyaura, N.; Suzuki, A. Organometallics 1993,
12, 589. (c) Hayashi, T.; Matsumoto, Y.; Ito, Y. J . Am. Chem. Soc. 1989,
111, 3426. (d) Pergament, I.; Srebnik, M. Org. Lett. 2001, 3, 217. (e)
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Kinoshita, M.; Okumoto, K.; Shirota, Y. Chem. Mater. 2003, 15, 1080.

Stereoselective Hydroboration of Diynes
Organometallics, Vol. 23, No. 20, 2004 4571
Ta ble 2. Hyd r obor a tion of Diyn es a n d a Tr iyn e Ca ta lyzed by Rh (I)
a
hr ) reaction time; yield ) isolated yield.
absorption and emission spectroscopic properties of 15
and 16 are basically similar to those of 13 and 14,
suggesting that the loss of fine structures results from
the conjugation of the phenyl groups with the vinylene
chromophore units. The somewhat large Stokes shift
(120 nm) of 15 most likely stems from the excited-state-
induced coplanarity of the amorphous chromophore
substituents.
Another synthetic utility of the hydroboration product
was demonstrated by transformation of 2,2′-diethoxy-
6,6′-bis(borylvinyl)-1,1′-binaphthalene 9 to chiral ditopic
ligands. Compound 17 was prepared by Suzuki coupling

4572 Organometallics, Vol. 23, No. 20, 2004
Lee et al.
Sch em e 1a
a
Reaction conditions: (i) 9-bromoanthracene, 55% yield; (ii) 1-bromopyrene, 61% yield; (iii) N,N-bis(9,9-dimethylfluorene-2-
yl)-4-bromoaniline, 47% yield; (iv) 2-(4-bromophenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 48% yield. All the reactions were
carried out in the presence of Pd(PPh3)4 and K2CO3 in THF.
18 (Scheme 2). Many binuclear Ru(II) and Os(II)
complexes containing two bipyridine units connected by
various bridges have been reported.23
Preliminary results with the well-established synthe-
sis of alternating copolymers using the Suzuki coupling
reaction24 encouraged us to extend the new synthetic
methodology to copolymers containing vinylene units
along the polymer backbone. Most remarkably, the
Suzuki coupling reaction of 2,2′-diethoxy-6,6′-bis(boryl-
vinyl)-1,1′-binaphthalene 9 with 9,10-dibromoanthracene
afforded the fully conjugated oligomer 19 in 35% yield
(Scheme 3). The molecular weight and the polydispersity
of the oligomer, determined by gel-permeation chroma-
tography using a polystyrene standard, were in the
ranges 2450-2550 and 1.9, respectively. The oligomer
was soluble in common solvents such as CHCl3, CH2-
F igu r e 1. UV-visible spectra and PL spectra of 13-15.
Cl2, and THF. The 1H NMR spectrum of 19 shows a
resonance at 6.18 ppm with a large coupling constant
(J H-H ) 18.6 ppm) due to a vinylic hydrogen. The 13C
NMR spectrum of the oligomer shows the expected
resonances in the aromatic region. Such multiple C-C
bond formation by the stepwise Suzuki cross-coupling
reaction, providing a route to PPV-based molecular
wires, was recently reported by Anderson and co-
workers.25
Ta ble 3. P h otop h ysica l Da ta for 13-16 in CH2Cl2
a t Room Tem p er a tu r ea
UV-vis
emission
compound λmax (nm) ꢀ (dm3 mol-1 cm-1
)
Eem (nm) Φem
b
13
14
15
16
390
384
376
349
6240
12 420
19 240
18 840
478
457
496
406
0.12
0.22
0.26
0.34
In summary, the first hydroboration of a variety of
diynes and a triyne to afford bis- and trisboryl-
substituted vinyl compounds with high stereoselectivity
a
Concentration of compounds is in the range 10-4-10-5 mol
dm-3
.
Quinine sulfate in 1 M H2SO4 (Φf1 ) 0.55) was used as
b
quantum yield standard.
reaction between 9 and 4-bromopyridine hydrochloride
in 32% yield. The compound had been synthesized
earlier by Heck coupling reaction between 4-vinylpyri-
dine and 6,6′-dibromo-2,2′-diethoxy-1,1′-binaphthalene
by Lin.22 Also the bis(borylvinyl)binaphthalene ligand
9 readily reacted with 5-bromo-2,2′-bipyridine to give
(22) Cui, Y.; Lee, S. J .; Lin, W. J . Am. Chem. Soc. 2003, 125, 6014.
(23) Kaes, C.; Katz, A.; Hosseini, M. W. Chem. Rev. 2000, 100, 3553.
(24) (a) Morin, J .-F.; Leclerc, M. Macromolecules 2002, 35, 8413. (b)
Lim, E.; J ung, B.-J .; Shim, H.-K. Macromolecules 2003, 36, 4288. (c)
Miyaura, N.; Yanagi, T.; Suziki, A. Synth. Commun. 1981, 11, 513.
(25) Terao, J .; Tang, A.; Michels, J . J .; Krivokapic, A.; Anderson,
H. L. Chem. Commun. 2004, 56.

Stereoselective Hydroboration of Diynes
Organometallics, Vol. 23, No. 20, 2004 4573
Sch em e 2a
a
Reaction conditions: (i) 4-bromopyridine, Pd(PPh3)4, K2CO3, toluene, reflux, 24 h, 32% yield; (ii) 5-bromo-2,2′-pyridine, Pd(PPh3)4,
K2CO3, toluene, reflux, 24 h, 19% yield.
Sch em e 3
trometer, respectively. Pinacolborane, PiPr3, 1-bromopyrene,
is presented. The hydroboration products underwent the
9-bromoanthracene, 9,10-dibromoanthracene, and 4-bromopyr-
idine hydrochloride were purchased from Aldrich Chemical Co.
[Rh(cod)Cl]2,26 1,4-diethynylbenzene,27 1,3,5-triethynylben-
zene,28 2,7-diethynyl-9,9-dimethylfluorene,29 3,6-diethynyl-9-
hexylcarbazole,30 2,2′-diethynyl-9,9′-spirobifluorene,31 1,3-
diethynylazulene,32 9,10-diethynylanthracene,33 2,2′-diethoxy-
6,6′-diethynyl-1,1′-binaphthalene,34 N,N-bis(9,9-dimethylfluorene-
2-yl)-4-bromoaniline,19 2-(4-bromophenyl)-5-(4-tert-butylphenyl)-
Suzuki cross-coupling reaction with a variety of sub-
strates containing chromophore units to give tris-
chromophore-substituted products. The mild and easy
access of the isomerically distinct hydroboration protocol
opens access to a host of potential subsequent trans-
formations toward the construction of a large number
of emitting copolymers. Additional investigations into
the photophysical properties and novel synthesis of a
variety of copolymers are now being undertaken in this
laboratory.
(26) Giordano, G.; Crabtree, R. H. Inorg. Synth. 1990, 28, 88.
(27) Takahashi, S.; Kuroyama, Y.; Sonogashira, K.; Hagihara, N.
Synthesis 1980, 627.
(28) Leininger, S.; Stang, P. J .; Huang, S. Organometallics 1998,
17, 3981.
Exp er im en ta l Section
(29) Thomas, K. R. J .; Lin, J . T.; Lin, Y.-Y.; Tsai, C.; Sun, S.-S.
Organometallics 2001, 20, 2262.
(30) Beginn, C.; Garzˇulevicˇius, J . V.; Strohriegl, P.; Simmerer, J .;
Haarer, D. Macromol. Chem. Phys. 1994, 195, 2353.
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2002, 67, 4924.
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Lett. 2000, 41, 2855.
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A: Polym. Chem. 1990, 28, 2641.
All experiments were performed under a nitrogen atmo-
sphere in a Vacuum Atmospheres drybox or by standard
Schlenk techniques. Toluene, THF, and cyclohexane were
1
freshly distilled from sodium benzophenone. The H, 13C, and
11B NMR spectra were recorded on a Varian Mercury 300
spectrometer operating at 300.00, 75.44, and 96.00 MHz,
respectively. The absorption and photoluminescence spectra
were recorded on a Perkin-Elmer Lambda 25 UV-visible
spectrophotometer and a Perkin-Elmer LS fluorescence spec-
(34) Onitsuka, K.; Harada, Y.; Takei, F.; Takahashi, S. Chem.
Commun. 1998, 643.

4574 Organometallics, Vol. 23, No. 20, 2004
Lee et al.
1,3,4-oxadi-azole,20 and 5-bromo-2,2′-bipyridine35 were prepared
according to procedures reported in the literature.
140.9, 139.2, 138.5, 135.1, 134.0, 133.7, 127.9, 124.5, 83.1, 24.7.
11B NMR (CDCl3): δ 18.4. MS: m/z 432 [M+]. Anal. Calcd for
C
26H34O4B2: C, 72.26; H, 7.93. Found: C, 72.08; H, 7.80.
1,3,5-Tr is[2-(a n th r yl)vin yl]ben zen e (13). To a stirred
Gen er a l P r oced u r e for Hyd r obor a tion of Diyn es a n d
a Tr iyn e. To a stirred cyclohexane solution (10 mL) of [Rh-
(cod)Cl]2 (0.022 g, 0.045 mmol), NEt3 (0.7 mL, 5 mmol), PiPr3
(0.035 mL, 0.18 mmol), and pinacolborane (0.44 mL, 3 mmol)
was added 1,3,5-triethynylbenzene (0.15 g, 1 mmol) dissolved
in cyclohexane (10 mL) at room temperature. The solution was
stirred for 8 h at that temperature. The solvent was removed
in vacuo. The pure product 6 was obtained by silica gel column
chromatography (eluent: methylene chloride/hexane, 2:1) as
a white solid in 88% yield.
THF solution (25 mL) of 6 (0.15 g, 0.28 mmol), 9-bromoan-
thracene (0.24 g, 0.93 mmol), and Pd(PPh3)4 (0.05 g, 0.043
mmol) was added degassed K2CO3(aq) (2 M, 2.1 mL, 4.2 mmol).
The solution was heated at reflux for 24 h. After cooling the
solution, H2O (10 mL) was added. The organic layer was
separated and dried with MgSO4. The solvent was removed
in vacuo. The pure product 13 was obtained by silica gel
chromatography (eluent: methylene chloride/hexane, 1:5) as
1
a white solid in 55% yield. Mp: 262 °C dec. H NMR (CDCl3):
1,3,5-Tr is[2-(p in a colbor yl)vin yl]ben zen e (6). Mp: 225
1
δ 8.48-8.44 (m, 6H, anthryl), 8.13 (d, 3H, J ) 17.4 Hz, CHd),
8.07-8.03 (m, 9H, anthryl), 7.98 (s, 3H, Ph), 7.54-7.50 (m,
12H, anthryl), 7.13 (d, 3H, J ) 17.4 Hz, dCH). 13C{1H} NMR
(CDCl3): δ 138.4, 134.2, 133.6, 132.6, 131.6, 129.8, 128.8, 127.5,
127.2, 125.9, 125.5. MS: m/z 684 [M+]. Anal. Calcd for
°C. H NMR (CDCl3): δ 7.53 (s, 3H, Ph-H), 7.37 (d, 3H, J )
18.9 Hz, CHd), 6.16 (d, 3H, J ) 18.9 Hz, dCH-B), 1.32 (s,
36H, CH3). 13C{1H} NMR (CDCl3): δ 148.7, 138.2, 126.1, 116.9,
83.5, 24.8. 11B NMR (CDCl3): δ 15.8. MS: m/z 534 [M+]. Anal.
Calcd for C30H45O6B3: C, 67.46; H, 8.49. Found: C, 67.18; H,
8.24.
C
54H36: C, 94.70; H, 5.30. Found: C, 94.46; H, 5.21.
1,3,5-Tr is[2-(p yr en yl)vin yl]ben zen e (14). Compound 14
1,4-Bis[2-(p in a colbor yl)vin yl]ben zen e (7). Mp: 195 °C.
1H NMR (CDCl3): δ 7.45 (s, 4H, Ph-H), 7.36 (d, 2H, J ) 18.6
Hz, CHd), 6.17 (d, 2H, J ) 18.6 Hz, dCH-B), 1.31 (s, 24H,
CH3). 13C{1H} NMR (CDCl3): δ 148.4, 138.3, 128.4, 119.6, 83.6,
24.9. 11B NMR (CDCl3): δ 16.4. MS: m/z 382 [M+]. Anal. Calcd
for C22H32O4B2: C, 69.15; H, 8.44. Found: C, 68.97; H, 8.26.
2,7-Bis[2-(p in a colbor yl)vin yl]-9,9′-sp ir obiflu or en e (8).
Mp: 208 °C. 1H NMR (CDCl3): δ 7.83 (d, 2H, J ) 7.8 Hz),
7.76 (d, 2H, J ) 7.2 Hz), 7.50 (d, 2H, J ) 7.8 Hz), 7.34 (t, 2H,
J ) 7.5 Hz), 7.24 (d, 2H, J ) 18.9 Hz, CHd), 7.08 (t, 2H, J )
7.5 Hz), 6.86 (s, 2H), 6.71 (t, 2H, J ) 7.2 Hz), 5.96 (d, 2H, J )
18.9 Hz, dCH-B), 1.22 (s, 24H, CH3). 13C{1H} NMR (CDCl3):
δ 149.8, 149.2, 148.8, 142.0, 141.7, 137.4, 128.4, 128.1, 127.1,
125.0, 124.4, 123.4, 120.1, 119.8, 83.1, 26.8. 11B NMR
was prepared using the same procedure as that described for
13 except that 1-bromopyrene was used instead of 9-bromoan-
thracene. The pure product 14 was isolated by silica gel
chromatography (eluent: ethyl acetate/hexane, 1:1) as a white
1
solid in 61% yield. Mp: 238 °C dec. H NMR (CDCl3): δ 8.57
(d, 3H, J ) 8.7 Hz, pyrenyl), 8.38 (d, 3H, J ) 8.7 Hz, pyrenyl),
8.32 (d, 3H, J ) 16.8 Hz, CHd), 8.22-8.02 (m, 21H, pyrenyl),
7.70 (s, 3H, Ph), 7.45 (d, 3H, J ) 16.8 Hz, dCH). 13C{1H} NMR
(CDCl3): δ 157.9, 157.1, 148.1, 138.6, 132.0, 131.8, 131.6, 131.2,
131.0, 128.6, 127.9, 127.6, 127.2, 126.5, 126.2, 125.3, 125.1,
124.4, 124.1, 122.3. MS: m/z 756 [M+]. Anal. Calcd for
C
60H36: C, 95.21; H, 4.79. Found: C, 94.88; H, 4.67.
1,3,5,-T r is {2-[N ,N -b is (9,9-d im e t h y lflu o r e n -2-y l)-4-
(CDCl3): δ 16.0. MS: m/z 620 [M+]. Anal. Calcd for C41H42
-
a n ilin yl]vin yl}ben zen e (15). Compound 15 was prepared
using the same procedure as that described for 13 except that
N,N-bis(9,9-dimethylfluoren-2-yl)-4-bromoaniline was used
instead of 9-bromoanthracene. The pure product 15 was
isolated by silica gel chromatography (eluent: methylene
chloride/hexane, 1:3) as a pale yellow solid in 47% yield. Mp:
O4B2: C, 79.38; H, 6.82. Found: C, 79.19; H, 6.65.
2,2′-Dieth oxy-6,6′-bis[2-(pin acolbor yl)vin yl]-1,1′-bin aph -
1
th a len e (9). Mp: 198 °C. H NMR (CDCl3): δ 7.91 (d, 2H, J
) 9.0 Hz), 7.85 (s, 2H), 7.53 (d, 2H, J ) 18.6 Hz, CHd), 7.48
(d, 2H, J ) 9.0 Hz), 7.39 (s, 2H), 7.08 (d, 2H, J ) 9.0 Hz), 6.15
(d, 2H, J ) 18.6 Hz, dCH-B), 4.04 (m, 4H, OCH2), 1.31 (s,
24H, CH3), 1.05 (t, 6H, J ) 6.9 Hz, OCH2CH3). 13C{1H} NMR
(CDCl3): δ 154.7, 148.9, 137.8, 136.4, 134.0, 132.9, 129.4, 126.5,
126.2, 125.3, 123.8, 120.7, 83.2, 65.3, 25.3, 15.1. 11B NMR
1
230 °C. H NMR (CDCl3): δ 7.65-7.16 (m, 60H), 7.14 (d, 3H,
J ) 16.8 Hz, dCH), 1.43 (s, 36H, C-CH3). 13C{1H} NMR
(CDCl3): δ 155.2, 153.6, 147.7, 147.2, 139.0, 138.5, 138.1, 134.4,
131.5, 127.8, 127.4, 127.1, 126.7, 126.1, 123.8, 123.2, 122.9,
120.9, 120.6, 119.4, 46.9, 27.1. Anal. Calcd for C120H99N3: C,
91.04; H, 6.30. Found: C, 90.83; H, 6.21.
(CDCl3): δ 15.8. MS: m/z 646 [M+]. Anal. Calcd for C40H48
-
B2O6: C, 74.32; H, 7.48. Found: C, 74.12; H, 7.35.
1,3,5-T r is {2-[p h e n y l-5-(4-t er t -b u t y lp h e n y l)-1,3,4-
oxa d ia zolyl]vin yl}ben zen e (16). Compound 16 was pre-
pared using the same procedure as that described for 13 except
2-(4-bromophenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole was
used instead of 9-bromoanthracene. The pure product 16 was
isolated by silica gel chromatography (eluent: ethyl acetate/
hexane, 1:3) as a white solid in 48% yield. Mp: 195 °C. 1H
NMR (CDCl3): δ 8.12 (d, 6H, J ) 8.1 Hz), 8.02 (d, 3H, J )
16.8 Hz, CHd), 7.96 (d, 6H, J ) 8.1 Hz), 7.67 (d, 6H, J ) 8.1
Hz), 7.59 (s, 3H, Ph), 7.52 (d, 6H, J ) 7.5 Hz), 7.53 (d, 6H, J
3,6-Bis[2-(p in a colbor yl)vin yl]-9-h exylca r ba zole (10).
Mp: 167 °C. H NMR (CDCl3): δ 8.12 (s, 2H, Ph-H), 7.60 (d,
1
2H, J ) 8.4 Hz), 7.34 (d, 2H, J ) 18.9 Hz, CHd), 7.27 (d, 2H,
J ) 8.4 Hz), 6.14 (d, 2H, J ) 18.9 Hz, dCH-B) {cis-10, 6.02
(d, J ) 15.0 Hz, dCH-B)}, 4.18 (t, 2H, J ) 6.6 Hz, NCH2),
1.49-0.85 (m, 11H), 1.23 (s, 24H, CH3). 13C{1H} NMR
(CDCl3): δ 150.5, 141.3, 140.8, 130.0, 129.1, 125.0, 123.0, 119.8,
82.8, 45.8, 31.4, 28.9, 24.6, 23.3, 22.4, 16.2. 11B NMR (CDCl3):
δ 16.8. MS: m/z 555 [M+]. Anal. Calcd for C34H47O4NB2: C,
73.53; H, 8.53. Found: C, 73.26; H, 8.40.
9,10-Bis[2-(pin acolbor yl)vin yl]an th r acen e (11). Mp: 201
°C. 1H NMR (CDCl3): δ 8.35 (m, 4H, anthryl), 7.47 (m, 4H,
anthryl), 7.45 (d, 2H, J ) 18.6 Hz, CHd), 5.61 (d, 2H, J )
18.6 Hz, dCH-B) {cis-11, 6.02 (d, J ) 14.1 Hz, dCH-B)}, 1.28
(s, 24H, CH3). 13C{1H} NMR (CDCl3): δ 140.7, 133.9, 131.7,
129.0, 126.3, 125.4, 83.7, 25.3. 11B NMR (CDCl3): δ 16.0. MS:
m/z 482 [M+]. Anal. Calcd for C30H36O4B2: C, 74.72; H, 7.52.
Found: C, 74.53; H, 7.37.
t
) 7.5 Hz), 7.12 (d, 3H, J ) 16.8 Hz, dCH), 1.37 (s, 27H, Bu).
13C{1H} NMR (CDCl3): δ 164.7, 164.4, 155.5, 145.5, 140.7,
137.2, 134.5, 127.5, 127.0, 126.8, 126.3, 126.0, 122.9, 121.2.
31.3, 25.0. MS: m/z 985 [M+]. Anal. Calcd for C66H60N6O3: C,
80.46; H, 6.14. Found: C, 80.22; H, 6.02.
2,2′-Diet h oxy-1,1′-b in a p h t h a len e-6,6′-b is(4-vin ylp yr i-
d in e) (17). Compound 17 was prepared using the same
procedure as that described for 13 except that compound 9
and 2 equiv of 4-bromopyridine hydrochloride were used
instead of compound 6 and 3 equiv of 9-bromoanthracene. The
pure product 17 was isolated by silica gel chromatography
(eluent: ethyl acetate/hexane, 2:1 (Rf ) 0.1)) in 32% yield. The
spectroscopic data of 17 were identical to those of Lin.21
2,2′-Diet h oxy-1,1′-b in a p h t h a len e-6,6′-b is(5-vin yl-2,2′-
bip yr id in e) (18). Compound 18 was prepared using the same
procedure as that described for 17 except that 5-bromo-2,2′-
1,3-Bis[2-(p in a colbor yl)vin yl]a zu len e (12). Mp: 175 °C.
1H NMR (CDCl3): δ 8.70 (s, 1H, Ph-H), 8.31 (d, 2H, J ) 10.2
Hz), 7.77 (d, 2H, J ) 15.0 Hz, CHd), 7.53 (t, 1H, J ) 9.6 Hz),
7.11 (dd, 2H, J ) 10.2 Hz, J ) 9.6 Hz), 5.65 (d, 2H, J ) 15.0
Hz, dCH-B), 1.23 (s, 24H, CH3). 13C{1H} NMR (CDCl3): δ
(35) Schwab, P. F. H.; Fleischer, F.; Michl, J . J . Org. Chem. 2002,
67, 443.

Stereoselective Hydroboration of Diynes
Organometallics, Vol. 23, No. 20, 2004 4575
bipyridine was used instead of 4-bromopyridine hydrochloride.
The pure product 18 was isolated by silica gel chromatography
(eluent: ethyl acetate/hexane, 2:1 (Rf ) 0.1)) as a pale yellow
it was refluxed for 10 h, the reaction mixture was cooled to
about 40 °C and added to a stirred mixture of MeOH (100 mL)
and 6 mL of 1 N aqueous HCl. The oligomer was collected by
filtration and reprecipitated from MeOH and acetone. The
oligomer was extracted by a Soxhlet in acetone for 1 day. The
extract was dried in vacuo. The final product 19 was obtained
1
solid in 19% yield. Mp: 253 °C. H NMR (CDCl3): δ 8.78 (s,
2H), 8.68 (d, 2H, J ) 3.6 Hz), 8.40 (d, 2H, J ) 8.4 Hz), 8.39 (d,
2H, J ) 8.4 Hz), 8.00 (d, 2H, J ) 8.4 Hz), 7.86 (d, 2H, J ) 9.0
Hz), 7.94 (s, 2H), 7.81 (dd, 2H, J ) 8.4 Hz, J ) 1.8 Hz), 7.50
(d, 2H, J ) 9.0 Hz), 7.44 (d, 2H, J ) 9.0 Hz), 7.38 (d, 2H, J )
17.1 Hz, vinyl), 7.32 (dd, 2H, J ) 3.6 Hz, J ) 1.8 Hz), 7.17 (d,
2H, J ) 9.0 Hz), 7.15 (d, 2H, J ) 17.1 Hz, vinyl), 4.08 (m, 4H,
OCH2), 1.09 (t, 6H, J ) 6.9 Hz, OCH2CH3). 13C{1H} NMR
(CDCl3): δ 156.1, 155.0, 154.9, 149.5, 148.1, 137.0, 134.2, 133.5,
132.08, 129.7, 129.43, 128.5, 127.5, 126.0, 124.0, 123.5, 122.4,
121.3, 121.0, 120.7, 116.3, 115.9, 65.3, 15.0. MS: m/z 702 [M+].
Anal. Calcd for C48H38N4O2: C, 82.03; H, 5.45. Found: C,
81.87; H, 5.32.
Oligo(2,2′-d iet h oxy-6,6′-d ivin yl-1,1′-b in a p h t h a len yl-
9,10-a n th r a cen e) (19). 2,2′-Diethoxy-6,6′-bis(borylvinyl)-1,1′-
binaphthalene (0.24 g, 0.37 mmol) and 9,10-dibromoan-
thracene (0.12 g, 0.37 mmol) were dissolved in THF (20 mL).
The palladium complex Pd(PPh3)4 (0.03 g) and degassed K2-
CO3 (5.25 mL, 1 M) were added to the mixture. The reaction
mixture was heated at reflux for 48 h. An excess of bromoben-
zene (0.040 g, 0.25 mmol) was added as an end-capper. After
1
as a yellow solid in 35% yield. Mp: 277 °C. H NMR (CDCl3):
δ 7.92-7.06 (m, 20H, aromatic and vinyl), 6.18 (d, 2H, J )
18.6 Hz, vinyl), 4.12 (m, 4H, OCH2), 1.05 (m, 6H, OCH2CH3).
13C{1H} NMR (CDCl3): δ 155.0, 137.3, 134.1, 132.7, 132.3,
131.6, 130.6, 129.5, 128.3, 127.4, 126.8, 126.4, 126.0, 125.2,
124.6, 122.7, 120.8, 117.2, 115.2, 65.2, 16.1. Anal. Calcd for
(C42H32O2)n: C, 88.51; H, 5.71. Found: C, 88.17; H, 5.58. The
number-average molecular weights (Mn) was determined by
gel permeation chromatography (GPC) with an HPLC Waters
510 using a series of monodisperse polystyrenes as standard
in THF. The number-average molecular weight (Mn) was 2500
(Mw/Mn ) 1.9).
Ack n ow led gm en t. This work was supported by a
Korea Research Foundation Grant (KRF-2002-070-C00055).
OM049832M