Synthesis and structural analysis of oligo(naphthalene-2,3-diyl)s

Article abstract of DOI:10.1246/bcsj.78.142

Oligo(naphthalene-2,3-diyl)s are synthesized by the palladium-catalyzed cross-coupling reactions of 2-naphthyl-zinc compounds with 2-bromonaphthalene derivatives. An NMR analysis together with an X-ray diffraction study supports the conjecture that the helical secondary structure is a common feature of the assemblies in which naphthalene-like aromatic units are linked together between the β-positions in series.

Full text of DOI:10.1246/bcsj.78.142

142 Bull. Chem. Soc. Jpn., 78, 142–146 (2005)
ꢀ 2005 The Chemical Society of Japan
Synthesis and Structural Analysis of Oligo(naphthalene-2,3-diyl)s
Takahisa Motomura, Hideko Nakamura, Michinori Suginome,
y
ꢀ;
Masahiro Murakami, and Yoshihiko Ito
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering,
Kyoto University, Katsura, Kyoto 615-8510
Received June 10, 2004; E-mail: murakami@sbchem.kyoto-u.ac.jp
Oligo(naphthalene-2,3-diyl)s are synthesized by the palladium-catalyzed cross-coupling reactions of 2-naphthyl-
zinc compounds with 2-bromonaphthalene derivatives. An NMR analysis together with an X-ray diffraction study sup-
ports the conjecture that the helical secondary structure is a common feature of the assemblies in which naphthalene-like
aromatic units are linked together between the ꢀ-positions in series.
Previous papers from this laboratory have described aroma-
Br
Br
Br
tizing polymerization of 1,2-diisocyanoarenes catalyzed by or-
ganopalladium complexes giving poly(quinoxaline-2,3-diyl)s.1
An X-ray structural study of a quinoxaline pentamer suggested
that the main chain of poly(quinoxaline-2,3-diyl) would have a
helical secondary structure. Actually, we succeeded in the syn-
thesis of poly(quinoxaline-2,3-diyl)s that are optically active
due to their helical secondary structures.2 These previous stud-
ies brought forth the possibility that a similar helical secondary
structure might be a common feature of the assemblies in
which aromatic units analogous to quinoxaline are linked to-
gether between the 2- and 3-positions in series. This conjecture
led us to study the structural features of assemblies of naphtha-
lene-like aromatic units. In the first place, naphthalene itself
was chosen as the simplest constituent unit for a model assem-
bly.
As for the atropisomerism of naphthalene assemblies, 1,10-
binaphthyl derivatives has attracted much attention, particular-
ly due to their successful applications to chiral ligands for
enantioselective reactions.3 Accordingly, a variety of reactions
to form C–C bonds between two ꢁ-positions of naphthalene
derivatives have been reported.4 In contrast, much less atten-
tion has been directed to the atropisomerism of 2,20-binaph-
thyl, and thus synthetic methods of 2,20-binaphthyl are not as
well developed. In this paper, the synthetic study and structural
analyses of oligo(naphthalene-2,3-diyl)s are described.
0.55 equiv BuLi
THF, -78 °C
1
Br
79%
2
Scheme 1. Synthesis of 3,30-dibromo-2,20-binaphthyl (2).
naphthyl dibromide with 2-metallonaphthalene in order to
synthesize naphthalene tetramers.
3,30-Dibromo-2,20-binaphthyl (2), a suitable starting plat-
form for the synthesis of quater(naphthalene-2,3-diyl), was suc-
cessfully prepared in 79% yield from 2,3-dibromonaphthalene
(1) according to the procedure reported for the synthesis of 2,20-
dibromobiphenyl from 1,2-dibromobenzene (Scheme 1).6
The dibromo derivative 2 was reacted with 2-metallonaph-
thalenes (2.0–2.2 equiv), which were generated in situ by
transmetallation from 2-naphthylmagnesium bromide, in the
presence of a palladium catalyst (Table 1). 2-Naphthyltin
and -boron derivatives afforded naphthalene trimer 3 as the
major product (Runs 1 and 2). The desired naphthalene tetra-
mer 4 was obtained only in low yield even when the isolated
3 was subjected to a second coupling reaction with these 2-
metallonaphthalenes. On the other hand, 2-naphthylzinc halide
generated by transmetallation of 2-naphthylmagnesium bro-
mide with ZnCl2 underwent the double coupling reaction with
2 efficiently to furnish 4 in 55% yield (Run 3). Naphthalene
trimer 3b, concomitantly formed in 45% yield through a single
coupling reaction, possessed a chlorine atom instead of a bro-
mine atom. It is likely that halogen exchange on the aromatic
ring was also mediated by the palladium catalyst. The decreas-
ed reactivity of the resultant chloro derivative 3b toward oxi-
dative addition to palladium(0) retarded the second coupling
reaction. In fact, the use of ZnBr2 instead of ZnCl2 for the
transmetallation improved the yield of 4 to 74% (Run 4).
2-Bromo-3-methoxynaphthalene (8) and 2-bromo-3-methyl-
naphthalene (12) were employed as the precursors of 2-metal-
lonaphthalenes for the cross-coupling reaction. The 2-bromo-
naphthalene derivative 8 was prepared from 3-hydroxy-2-
naphthoic acid 5 via 6 according to the reaction sequences
Results and Discussion
Synthesis of Oligo(naphthalene-2,3-diyl)s.
Transition
metal-catalyzed cross-coupling reactions of two aromatic units
have been well studied and utilized for the preparation of aro-
matic materials.5 We envisaged that making a bond between
the ꢀ-positions of naphthalene units by a cross-coupling reac-
tion would be a staightforward and suitable method for the
construction of oligo(naphthalene-2,3-diyl)s. Thus, we exam-
ined the palladium-catalyzed cross-coupling reaction of bi-
y Present address: Department of Molecular Science and
Technology, Faculty of Engineering, Doshisha University,
Kyotanabe, Kyoto 610-0321
Published on the web January 13, 2005; DOI 10.1246/bcsj.78.142

T. Motomura et al.
Bull. Chem. Soc. Jpn., 78, No. 1 (2005)
143
Table 1. Cross-Coupling Reactions of 2-Metallonaphthalenes with 2
Metal
Pd catalyst
2
+
X
3a : X = Br
3b : X = Cl
4
Run
Metal
Catalyst
Solvent
Conditions
ꢁ
3, %
4, %
1
2
3
4
–SnBu3
–B(OH)2
–ZnXaÞ
Pd(PPh3)4, LiCl
Pd(PPh3)4, Na2CO3
PdCl2(dppp)
DMF
THF
THF
THF
100 C, 5 d
3b, 66
3a, 38
3b, 45
3a, 12
0
7
55
74
reflux, 21 h
reflux, 13 h
reflux, 31 h
–ZnBrbÞ
PdCl2(dppp)
a) Prepared by transmetallation of 2-naphthylmagnesium bromide with ZnCl2. b) Prepared by
transmetallation of 2-naphthylmagnesium bromide with ZnBr2.
OH
OMe
OMe
ZnBr
OMe
MeI, K2CO3
DMF
aq. NaOH
ZnBr2
Mg
8
CO2H
CO2Me
MgBr
5
6 92%
OMe
8
N
S
OMe
OMe
Br
ONa
SOCl2
PdCl2(dppp)
CO2H
13 94%
CBrCl3, AIBN
MeO
7
91%
8 64%
Scheme 4. Synthesis of 3,30-dimethoxy-2,20-binaphthyl (13).
Scheme 2. Synthesis of 2-bromo-3-methoxynaphthalene (8).
OMe
OMe
OMe
Me
LiAlH4
THF
H2 / Pd−C
6
PdCl2(dppp)
THF
OMe
ZnBr
AcOEt
CH2OH
1
+
9
99%
10 97%
Br
OH
(2.5 equiv)
Ph3PBr2
HBr
AcOH
OMe
14 40%
Me
Me
11 84%
12 40%
Scheme 5. Synthesis of symmetrical naphthalene trimer 14.
Scheme 3. Synthesis of 2-bromo-3-methylnaphthalene (12).
OMe
OMe
shown in Scheme 2.
2-Bromo-3-methylnaphthalene (12) was also prepared from
the intermediate 6 (Scheme 3).
ZnBr
1
Symmetrical naphthalene dimer and trimer with both ends
substituted by two methoxy groups were synthesized using
the building block 8. Initially, the bromonaphthalene (8) was
converted to the corresponding 2-naphthylzinc bromide via
the Grignard reaction and the following transmetallation with
ZnBr2. (3-Methoxy-2-naphthyl)zinc bromide was then subject-
ed to the palladium-catalyzed coupling reactions. Coupling
with 8 in the presence of PdCl2(dppp) afforded the symmetri-
cal 3,30-dimethoxy-2,20-binaphthyl (13) in 94% yield
(Scheme 4).
PdCl2(dppp)
15 74%
Br
Me
Mg
ZnBr2
OMe
15
12
PdCl2(dppp)
ZnBr
16 77%
Me
On the other hand, the double coupling reaction of 1 with
(3-methoxy-2-naphthyl)zinc bromide (2.5 equiv) furnished
the symmetrical naphthalene trimer 14 in 40% yield
(Scheme 5). The homo-coupling dimer 13 and the mono-cou-
pling product, e.g., bromobinaphthyl 15, were also formed as
the side products.
Scheme 6. Synthesis of unsymmetrical naphthalene trimer 16.
(Scheme 6). The bromonaphthalene 12 was converted to the
corresponding 2-naphthylzinc bromide via the Grignard re-
agent. Bromobinaphthyl 15 was prepared by a controlled cou-
pling reaction of 2,3-dibromonaphthalene (1) with (3-me-
Unsymmetrical naphthalene trimer was also synthesized

144 Bull. Chem. Soc. Jpn., 78, No. 1 (2005)
Synthesis and Structure of Oligo(2,3-naphthylene)s
thoxy-2-naphthyl)zinc bromide (1.1 equiv). The successive
cross-coupling reaction of 15 with (3-methyl-2-naphthyl)zinc
bromide furnished the unsymmetrical naphthalene trimer 16
in 77% yield.
Finally, naphthalene pentamer 18 was synthesized
(Scheme 7). Bromobinaphthyl 17 was produced by a single
coupling reaction of (3-methyl-2-naphthyl)zinc bromide (1.1
equiv) with 2,3-dibromonaphthalene (1). The palladium-cata-
lyzed double coupling reaction of 1 with the 2-naphthylzinc
derivative generated from 17 (2.5 equiv) successfully pro-
duced naphthalene pentamer 18.
Structural Analysis of Ter(naphthalene-2,3-diyl)s in
Solution. The 1H NMR studies on the naphthalene monomer,
dimer, and trimers provided a basis for deduction of the struc-
tures of oligo(naphthalene-2,3-diyl)s in solution (Fig. 1). 2-
Methoxynaphthalene and 3,30-dimethoxy-2,20-binaphthalene
(13) showed their methoxy signals at ꢂ 3.92 and 3.90, respec-
tively. On the other hand, the methoxy groups of the ter(naph-
thalene-2,3-diyl)s 14 and 16 resonated at ꢂ 3.50 and 3.52, re-
spectively. These large high-field shifts peculiar to naphtha-
lene trimers are reasonably ascribed to their folded conforma-
tions where the methoxy group of the head (first) naphthalene
is disposed over the tail (third) naphthalene ring. The signal of
the methoxy group of 14 was significantly broadened, suggest-
ing that the flipping of the naphthalene units is occurring at the
rate comparable to the NMR time-scale (200 MHz) at room
temperature.
In addition, a distinct NOE was observed between the me-
thoxy group on the head naphthalene and the methyl group
on the tail naphthalene of 16. This result also indicates that
the three naphthalene units are not extended but folded, and
that both ends are brought in close proximity to each other.
These results of the NMR studies suggest clearly that naph-
thalene trimers take a helical secondary structure in solution.
Crystal Structure of Quater(naphthalene-2,3-diyl) (4).
Recrystallization of quater(naphthalene-2,3-diyl) (4) from hex-
ane provided single crystals and so an X-ray structural analysis
was conducted. The ORTEP view is shown in Fig. 2. The three
serial naphthalene units A–C constitute almost one cycle of the
helical structure, which was similar to that observed with a
quinoxaline pentamer.2a The terminal D ring is oriented
out of the helical array. The dihedral angles between two ad-
jacent naphthalene units are as follows: C1{C10{C11{C20 ¼
48:3ꢁ, C11{C20{C21{C30 ¼ 61:8ꢁ, C21{C30{C31{C40 ¼
ꢂ135:3ꢁ.2b
Thus, a helical folding was observed also in the crystal
structure of 4. However, we have been unsuccessful so far in
obtaining single crystals of the naphthalene pentamer 18.
Me
Me
Mg
ZnBr2
1
12
PdCl2(dppp)
Br
ZnBr
Me
17 89%
Mg
ZnBr2
1
PdCl2(dppp)
18 57%
Me
Scheme 7. Synthesis of naphthalene pentamer 18.
OMe
MeO
MeO
δ 3.92
δ 3.90
13
OMe
MeO
Me
MeO
NOE
δ 3.50
δ 3.52
14
16
Fig. 1. Chemical shifts of 2-methoxy-substituted naphtha-
lene derivatives.
Fig. 2. Crystal structure of naphthalene tetramer 4.

T. Motomura et al.
Bull. Chem. Soc. Jpn., 78, No. 1 (2005)
145
3-hydroxy-2-naphthoic acid (15.1 g, 80 mmol) and K2CO3 (33.4
g, 241 mmol) in DMF (120 mL) at room temperature was added
MeI (68.4 g, 482 mmol). The reaction mixture was stirred at 50 ꢁC
for 4 d. After removal of DMF at a reduced pressure, the residue
was subjected to aqueous extractive workup. Column chromatog-
raphy of the organic extracts (silica gel, ether:hexane = 2:1) af-
forded 6 as yellow oil (15.9 g, 92%): 1H NMR ꢂ 3.96 (s, 3H),
4.00 (s, 3H), 7.21 (s, 1H), 7.33–7.43 (m, 1H), 7.47–7.57 (m,
1H), 7.70–7.87 (m, 2H), 8.31 (s, 1H).8
3-Methoxy-2-naphthoic Acid (7). A mixture of 6 (4.19 g,
19.4 mmol) and NaOH (1.71 g, 42.8 mmol) in H2O (20 mL)
was stirred at 100 ꢁC for 90 min. After being cooled, the reaction
mixture was neutralized with HCl (1 mol Lꢂ1), extracted with
CH2Cl2, and dried. Evaporation followed by crystallization from
EtOH afforded 7 as white solid (3.58 g, 91%): 1H NMR ꢂ 4.18
(s, 3H), 7.31 (s, 1H), 7.40–7.52 (m, 1H), 7.55–7.65 (m, 1H),
7.76–7.84 (m, 1H), 7.88–7.97 (m, 1H), 8.79 (s, 1H), 10.62–
11.30 (br, 1H).9
2-Bromo-3-methoxynaphthalene (8). A mixture of 7 (3.05 g,
15.1 mmol) and SOCl2 (10 mL, 137 mmol) was stirred at room
temperature for 2 h to afford crude 3-methoxy-2-naphthoyl chlo-
ride. A mixture of 3-methoxy-2-naphthoyl chloride thus prepared,
CBrCl3 (30 mL), and 2,20-azobis(isobutyronitrile) (AIBN, 0.5 g,
3.0 mmol) was added to a refluxing suspension of sodium salt
of 2-mercaptopyridine N-oxide (2.75 g, 18.5 mmol) in CBrCl3
(30 mL) over 30 min. The reaction mixture was stirred for an ad-
ditional 15 min, cooled, and subjected to aqueous extractive work-
up. Column chromatography of the organic extracts (silica gel,
ether:CH2Cl2 = 2:1) afforded 8 as white solid (2.30 g, 64%):
13C NMR ꢂ 56.7, 107.2, 113.9, 125.0, 127.1, 127.2, 129.9,
132.8, 134.0, 154.1.9
Conclusion
The palladium-catalyzed cross-coupling reactions of 2-
naphthylzinc bromide with 2-bromonaphthalene derivatives
offered straightforward synthetic pathways leading to oligo-
(naphthalene-2,3-diyl)s. The present structural studies on the
naphthalene trimers in solution and on the naphthalene tetra-
mer in crystal provided a convincing support for the conjecture
that organic assemblies in which naphthalene-like aromatic
units are linked together between the ꢀ-positions would
have the helical secondary structures similar to those of poly-
(quinoxaline-2,3-diyl)s.
Experimental
Column chromatography was performed with silica gel 60 (E.
Merck, Darmstadt), 230–400 mesh. Preparative thin-layer chro-
matography (TLC) was performed with silica gel 60 PF254 (E.
Merck, Darmstadt). 1H and 13C NMR spectra were acquired in
chloroform-d at 200 MHz and 50 MHz, respectively. The carbon
chemical shifts were recorded relative to chloroform-d (ꢂ 77.0).
Na2SO4 was used to dry the organic layers after extraction. All
of the reactions were performed under a dry nitrogen atmosphere.
Unless otherwise noted, all materials were obtained from commer-
cial sources. THF was distilled from sodium diphenylketyl. Di-
chloromethane was distilled under N2 over CaH2. 2,3-Dibromo-
naphthalene (1) was prepared according to the literature proce-
dure.7
3,30-Dibromo-2,20-binaphthyl (2). To a stirred solution of 1
(4.00 g, 14.0 mmol) in THF (100 mL) at ꢂ78 ꢁC was added a so-
lution of butyllithium in hexane (4.90 mL, 7.74 mmol) over 3 min.
After the reaction mixture was stirred for 10 min, MeOH (1 mL)
was added. The mixture was subjected to aqueous extractive
workup. Evaporation and the following recrystallization of the or-
ganic extracts from benzene–EtOH afforded 2 as white needles
(3-Methoxy-2-naphthyl)methanol (9). To a suspension of
ꢁ
LiAlH4 (1.90 g, 50.1 mmol) in ether (40 mL) at 0 C was added
a solution of 6 (10.8 g, 50.1 mmol) in ether (20 mL) over 30 min.
The reaction mixture was stirred at reflux for 12 h and then cooled
in an ice bath. Water (1.9 mL), 15% aqueous NaOH (1.9 mL), and
water (5.7 mL) were added successively in a dropwise manner.
Removal of the resultant precipitates by filtration and the follow-
ing evaporation of the filtrate afforded 9 as white solid (9.34 g,
(2.28 g, 79%): IR (KBr) 3056, 748, 740 cmꢂ1; H NMR ꢂ 7.50–
1
7.64 (m, 4H), 7.80–7.92 (m, 6H), 8.23 (s, 2H); 13C NMR ꢂ
122.3, 127.2, 127.3, 127.7, 128.5, 130.6, 131.5, 132.5, 134.5,
140.0. Found: C, 58.55; H, 3.09; Br, 38.82%. Calcd for
C20H12Br2: C, 58.29; H, 2.93; Br, 38.78%.
1
99%): H NMR ꢂ 2.42–2.69 (bs, 1H), 3.96 (s, 3H), 4.83 (s, 2H),
Quarter(naphthalene-2,3-diyl) (4). To a stirred solution of
ZnBr2 (455 mg, 2.0 mmol) in THF (3 mL) at room temperature
was added a solution of 2-naphthylmagnesium bromide in THF
(2.6 mL, 2.0 mmol). After the reaction mixture was stirred for
30 min, 2 (206 mg, 0.50 mmol) and PdCl2(dppp) (15 mg, 26
mmol) was added. The mixture was stirred at 80 ꢁC for 31 h,
and then cooled. Aqueous HCl (1 mol Lꢂ1, 5 mL) was added to
the mixture, which was then subjected to aqueous extractive work-
up. After evaporation, the mixture was separated by GPC to afford
4 (188 mg, 74%) and 3a (28 mg, 12%) as white solids. 3a:
1H NMR ꢂ 7.34–7.53 (m, 4H), 7.44 (s, 1H), 7.53–7.66 (m, 2H),
7.59 (s, 1H), 7.66–7.82 (m, 4H), 7.83–8.06 (m, 6H), 8.10 (s,
1H); 13C NMR ꢂ 122.3, 127.2, 127.3, 127.7, 128.5, 130.6,
131.5, 132.5, 134.5, 140.0. 4: 1H NMR ꢂ 6.20–6.70 (m, 2H),
6.71–6.80 (m, 2H), 7.02–7.11 (m, 2H), 7.18–7.33 (m, 4H),
7.35–7.45 (m, 2H), 7.52–7.61 (m, 4H), 7.61–7.74 (m, 2H), 7.63
(s, 2H), 7.81–7.90 (m, 2H), 7.97–8.10 (m, 2H), 8.24 (s, 2H);
13C NMR ꢂ 125.37, 125.43, 126.2, 126.3, 127.1, 127.3, 127.7,
127.8, 128.0, 128.1, 129.0, 130.8, 131.6, 132.7, 133.0, 133.1,
138.3, 139.2, 139.5. HRMS Found: m=z 506.2045. Calcd for
C40H26: M, 506.2034.
7.13 (s, 1H), 7.31–7.51 (m, 2H), 7.73 (s, 1H), 7.70–7.88 (m, 2H).8
2-Methoxy-3-methylnaphthalene (10). A mixture of 9 (8.52
g, 45.3 mmol) and 5% Pd on carbon (1.0 g) in AcOEt (50 mL) was
stirred under hydrogen atmosphere for 7.5 h. The reaction mixture
was filtered through Celite, washed with ether, and evaporated to
give 10 as white solid (7.59 g, 97%).10
3-Methyl-2-naphthol (11). A mixture of 10 (6.91 g, 40.1
mmol) and 48% aqueous HBr (25 mL) in AcOH (200 mL) was
stirred at 130 ꢁC for 6.5 h. After the reaction mixture was cooled,
AcOH was evaporated and the residue was extracted with ether.
The organic extracts were washed with water, aqueous Na2S2O3,
and saturated NaCl. The organic layer was dried and evaporated.
Recrystallization of the residue from xylene afforded 11 as a pale
brown solid (5.34 g, 84%).11
2-Bromo-3-methylnaphthalene (12). To a stirred solution of
ꢁ
PPh3 (28.8 g, 110 mmol) in CH3CN (50 mL) at 0 C was added
Br2 (5.5 mL, 110 mmol) over 20 min. After the temperature
was raised to room temperature, 11 (14.7 g, 100 mmol) in ꢁCH3CN
(50 mL) was added. Then CH3CN was distilled off at 70 C. The
ꢁ
temperature was then raised to 310 C. The reaction mixture was
ꢁ
heated at that temperature for 90 min and then cooled to 240 C,
ꢁ
Methyl 3-Methoxy-2-naphthoate (6). To a stirred mixture of
where Celite (100 g) was added. At 80 C, benzene (20 mL) and

146 Bull. Chem. Soc. Jpn., 78, No. 1 (2005)
Synthesis and Structure of Oligo(2,3-naphthylene)s
ane): C, 93.25; H, 6.75%.
hexane (150 mL) were added. The reaction mixture was heated at
reflux overnight, cooled, and filtered. The filtrate was passed
through a short column of silica gel. The filtrate was evaporated
and the residue was recrystallized from ethanol to give 12 as pale
yellow solid (8.43 g, 40%).12
3,30-Dimethoxy-2,20-binaphthyl (13). The title compound
was prepared from 2-bromo-3-methoxynaphthalene (8) and 3-me-
thoxy-2-naphthylmagnesium bromide (1.1 equiv) by a procedure
similar to that used for 4 (94%): 1H NMR ꢂ 3.90 (s, 6H), 7.26
(s, 2H), 7.37–7.47 (m, 2H), 7.47–7.57 (m, 2H), 7.80 (s, 4H),
7.85 (s, 2H); 13C NMR ꢂ 55.7, 105.3, 123.7, 126.2, 126.4,
127.7, 128.7, 129.9, 130.3, 134.4, 156.3. Found: C, 83.93; H,
5.58%. Calcd for C22H18O2: C, 84.05; H, 5.77%.
X-ray Crystallographic Analysis of 4. Crystal data: C40H26,
M ¼ 506:4, orthorhombic, space group P21cn, a ¼ 16:650ð3Þ,
ꢀ
ꢀ 3
b ¼ 20:223ð3Þ, c ¼ 7:989ð1Þ A, U ¼ 2690:1ð8Þ A , Z ¼ 4, Dc ¼
1:25 g/cm3, ꢃ ¼ 4:63 cmꢂ1. Intensity data were measured on a
Mac Science MXC3 diffractometer using !–2ꢄ scan technique
with graphite monochromated Cu K radiation (ꢅ ¼ 1:54178
ꢁ
ꢁ
ꢀ
A). 2079 unique reflections within 3 ꢃ 2ꢄ ꢃ 120 were collected.
No decay correction was applied. The data were corrected for
Lorentz and polarization effects. The structure was solved by a
direct method and refined by the full-matrix least-squares to R ¼
0:051 (Rw ¼ 0:058) for 1752 reflections [F > 3:0ꢆðFÞ], using a
Crystan GM package program. The non-hydrogen atoms were re-
fined anisotropically. Hydrogen atoms were found on a difference
Fourier map. The thermal parameter of each hydrogen atom was
assumed to be isotropic and to be equal to that of the bonded atom.
Dimethoxyternaphthalene (14). The title compound was pre-
pared from 2,3-dibromonaphthalene (1) and 3-methoxy-2-naph-
thylmagnesium bromide (2.5 equiv) by a procedure similar to that
1
used for 4 (40%): H NMR ꢂ 3.32–3.65 (br, 6H), 6.76–6.90 (br,
Supporting Information
2H), 7.22–7.44 (m, 4H), 7.46–7.85 (m, 8H), 7.86–8.06 (m, 2H),
7.96 (s, 2H); 13C NMR ꢂ 55.4, 105.3, 124.0, 126.4, 126.6,
126.8, 128.0, 128.4, 129.0 (br s), 129.8, 131.1, 133.2, 133.4,
134.5, 137.8 (br s), 155.8. HRMS Found: m=z 440.1787. Calcd
for C32H24O2: M, 440.1776.
3-Bromo-30-methoxy-2,20-binaphthyl (15). The title com-
pound was prepared from 2,3-dibromonaphthalene (1) and 3-me-
thoxy-2-naphthylmagnesium bromide (1.1 equiv) by a procedure
similar to that used for 4 (74%): 1H NMR ꢂ 3.92 (s, 3H), 7.26
(s, 1H), 7.36–7.56 (m, 6H), 7.74 (s, 1H), 7.80–7.88 (m, 3H),
8.20 (s, 1H); 13C NMR ꢂ 56.1, 106.0, 123.0, 124.5, 126.9,
127.06, 127.10, 127.26, 127.30, 128.3, 128.4, 129.0, 130.7,
131.3, 132.66, 132.72, 134.3, 135.1, 138.1, 156.2. HRMS Found:
m=z 362.0308. Calcd for C21H15BrO: M, 362.0307.
Crystallographic coordinates for 4. This material is available
free of charge on the Web at: http//www.csj.jp/journals/bcsj/.
References
1
a) Y. Ito, E. Ihara, M. Murakami, and M. Shiro, J. Am.
Chem. Soc., 112, 6446 (1990). b) Y. Ito, E. Ihara, T. Uesaka,
and M. Murakami, Macromolecules, 25, 6711 (1992).
2
a) Y. Ito, E. Ihara, and M. Murakami, Angew. Chem., Int.
Ed. Engl., 31, 1509 (1992). b) Y. Ito, E. Ihara, M. Murakami, and
M. Sisido, Macromolecules, 25, 6810 (1992). c) Y. Ito, Y. Kojima,
and M. Murakami, Tetrahedron Lett., 34, 8279 (1993). d) Y. Ito,
T. Miyake, S. Hatano, R. Shima, T. Ohara, and M. Suginome,
J. Am. Chem. Soc., 120, 11880 (1998). e) Y. Ito, T. Miyake,
and M. Suginome, Macromolecules, 33, 4034 (2000). f) M.
Suginome, S. Collet, and Y. Ito, Org. Lett., 4, 351 (2002).
2-Methoxy-30-methylter(naphthalene-2,3-diyl) (16). The ti-
tle compound was prepared from 15 and 3-methyl-2-naphthyl-
magnesium bromide (1.1 equiv) by a procedure similar to that
1
used for 4 (77%): H NMR ꢂ 2.27 (br s, 3H), 3.52 (s, 3H), 6.81
3
a) R. Noyori and H. Takaya, Chem. Scr., 25, 83 (1985). b)
(s, 1H), 7.27–7.43 (m, 4H), 7.58 (s, 1H), 7.46–7.78 (m, 7H),
7.81 (s, 1H), 7.85 (s, 1H), 7.87 (m, 2H), 8.00 (s, 1H); 13C NMR
ꢂ 21.4, 55.3, 105.5, 124.2, 125.4, 126.0, 126.4, 126.8, 126.9,
127.3, 127.9, 128.0, 128.1, 128.3, 128.4, 129.1, 129.5, 129.8,
130.3, 131.3, 131.9, 133.0, 133.2, 133.3, 134.7, 135.3, 137.6,
140.4, 140.7, 155.6. Found: C, 90.38; H, 5.64%. Calcd for
C32H24O: C, 90.53; H, 5.70%.
R. Noyori, ‘‘Asymmetric Catalysis in Organic Synthesis,’’ Wiley,
New York (1994).
4
a) T. Hattori, H. Hotta, T. Suzuki, and S. Miyano, Bull.
Chem. Soc. Jpn., 66, 613 (1993). b) G. Bringmann, R. Walter,
and R. Weirich, Angew. Chem., Int. Ed. Engl., 29, 977 (1990),
and references cited therein.
5
D. W. Knight, ‘‘Comprehensive Organic Synthesis,’’ ed by
3-Bromo-30-methyl-2,20-binaphthyl (17).
The title com-
pound was prepared from 2-bromo-3-methylnaphthalene (12)
B. M. Trost and I. Fleming, Pergamon Press, Oxford (1991),
Vol. 3, p. 481.
and 3-methyl-2-naphthylmagnesium bromide (1.1 equiv) by a pro-
1
6
7
H. Gilman and B. J. Gaj, J. Org. Chem., 22, 447 (1957).
D. H. R. Barton, B. Lacher, and S. Z. Zard, Tetrahedron,
cedure similar to that used for 4 (89%): H NMR ꢂ 2.29 (s, 3H),
7.41–7.62 (m, 4H), 7.67–7.90 (m, 7H), 8.22 (s, 1H). HRMS
Found: m=z 346.0355. Calcd for C21H15Br: M, 346.0358.
43, 4321 (1987).
8
Nakazaki, Bull. Chem. Soc. Jpn., 58, 3633 (1985).
9
(1984).
10 F. B. Mallory, M. J. Rudolph, and S. M. Oh, J. Org. Chem.,
54, 4619 (1989).
´
11 G. Coll, J. Morey, A. Costa, and J. M. Saa, J. Org. Chem.,
53, 5345 (1988).
12 J. G. Smith, P. W. Dibble, and R. E. Sandborn, J. Org.
Chem., 51, 3762 (1986).
K. Yamamoto, H. Fukushima, H. Yumioka, and M.
Naphthalene Pentamer 18. The title compound was prepared
from 2,3-dibromonaphthalene (1) and the Grignard reagent pre-
pared from 17 (2.5 equiv) by a procedure similar to that used
for 4 (57%): 1H NMR ꢂ 0.70–1.94 (m, 6H), 6.05–6.48 (br, 1H),
6.50–7.25 (m, 6H), 7.42 (s, 1H), 7.26–8.40 (m, 22H); 13C NMR
ꢂ 20.7, 21.0, 125.2, 126.1, 126.3, 126.4, 126.9, 127.7, 127.8,
128.0, 128.2, 128.5, 129.3, 129.9, 130.4, 131.0, 131.8, 132.2,
132.4, 132.7, 132.8, 133.1, 136.1, 137.7, 138.9, 139.5, 140.0,
140.2. Found: C, 93.08; H, 6.71%. Calcd for C58H50 (18 + hex-
J. M. Wilson and D. J. Cram, J. Org. Chem., 49, 4930