Oxidative C - C bond formation (Scholl Reaction) with DDQ as an efficient and easily recyclable oxidant

Article abstract of DOI:10.1021/ol901331p

DDQ in the presence of an acid is known to oxidize a variety of aromatic donors to the corresponding cation radicals. Herein, we now demonstrate that the DDQ/H⁺ system can be effectively utilized for the oxidative C - C bond formations or biaryl synthesis. The efficient preparation of a variety of polyaromatic hydrocarbons including graphitic hexa-peri-hexabenzocoronenes, ease of isolation of the clean products, and ready regeneration of DDQ from easily recovered reduced DDQ-H₂ advances the use of DDQ/H⁺ for Scholl reactions.

Full text of DOI:10.1021/ol901331p

SUPPORTING INFROMATION FOR
Oxidative C-C Bond Formation (Scholl Reaction)
Using DDQ as an Efficient and Easily Recyclable Oxidant
Linyi Zhai, Ruchi Shukla, and Rajendra Rathore*
Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI-53201
Email: Rajendra.Rathore@marquette.edu
General Experimental Methods and Materials. All reactions were performed under
argon atmosphere using conventional vacuum-line techniques unless otherwise noted. All
commercial reagents were used without further purification unless otherwise noted.
Anhydrous tetrahydrofuran (THF) was prepared by refluxing the commercial tetrahydro-
furan (Aldrich) over lithium tetrahydroaluminate under an argon atmosphere for 24 hours
followed by distillation. It was stored under an argon atmosphere in a Schlenk flask
equipped with a Teflon valve fitted with Viton O-rings. Dichloromethane (Aldrich) was
repeatedly stirred with fresh aliquots of conc. Sulfuric acid (~10% by volume) until the
acid layer remained colorless. After separation it was washed successively with water,
aqueous sodium bicarbonate, water, and saturated aqueous sodium chloride and dried
over anhydrous calcium chloride. The dichloromethane was distilled twice from P2O5
under an argon atmosphere and stored in a Schlenk flask equipped with a Teflon valve
fitted with Viton O-rings. The hexanes and toluene were distilled from P2O5 under an
S1

argon atmosphere and then refluxed over calcium hydride (~12 hrs). After distillation
from CaH2, the solvents were stored in Schlenk flasks under argon atmosphere.
Syntheses of o-terphenyls, hexaarylbenzenes, and bichromophoric diarylpropanes
as Scholl precursors. The Suzuki couplingS1 provided a general route for the
preparation of various substituted o-terphenyls (1a-e and 1k). The hexaarylbenzene
derivatives (1l-1n) were synthesized according to a previously known literature
procedure.S2 Bichromophoric 2,2-bis(3,4-dimethoxyphenyl)propane (1f),S3 9,9-bis(3,4-
dimethoxyphenyl)fluorene (1g),S4 and 1,3-bis(3,4-dimethoxyphenyl)propane (1h)S4 were
available from literature procedures. The details of the synthesis and spectral data for
various Scholl precursors, utilized in this study, are summarized below:
General Method for Suzuki Reaction (Method A). Synthesis of 3,3",4,4"-tetrameth-
oxy-o-terphenyl (1a).
O
O
Br
Br
O
O
Pd(PPh3)4
+
Na2CO3 (20% in H2O)
DME
(HO)2B
O
O
A solution of sodium carbonate (5 g) in water (20 mL) was prepared in a Schlenk flask
and degassed (3x) and kept under argon atmosphere. In a separate Schlenk flask, 1,2-di-
bromobenzene (1.65 g, 7.0 mmol), 3,4-dimethoxyphenylboronic acid (3.82 g, 21 mmol),
and DME (35 mL) were added under an argon atmosphere and the Schlenk flask was
degassed (5x). Under an argon flow, a catalytic amount of Pd(PPh3)4 (35 mg) was added
S2

and the flask was covered by aluminum foil and degassed (3x). Into this mixture, the
aqueous sodium carbonate solution was transferred with the aid of a syringe and the
reaction was degassed again (3x). The resulting mixture was heated to reflux for ~24
hours, cooled to room temperature and poured onto 5% aqueous hydrochloric acid. The
resulting mixture was extracted with dichloromethane (3 x 25 mL). The combined
dichloromethane extracts were washed with water, brine, and dried over anhydrous
MgSO4. Removal of the solvent in vacuo afforded a crude solid which was purified by
column chromatography on silica gel using a 95:5 mixture of hexanes: ethyl acetate as
the eluent to afford pure 3,3",4,4"-tetramethoxy-o-terphenyl as white solid. Yield: 2.05 g,
1
84%; mp 138-139 oC; H NMR (CDCl3) δ: 3.61 (s, 6H), 3.86 (s, 6H), 6.61 (s, 2H), 6.78
(d, 4H), 7.41 (m, 4H); 13C NMR (CDCl3) δ: 55.83, 56.02, 110.94, 113.64, 122.01,
127.46, 130.52, 134.53, 140.37, 147.88, 148.39.
Synthesis of 3',4'-dimethyl-3,4,3",4"-tetramethoxy-o-terphenyl (1b)
O
O
O
O
Pd(PPh3)4
Br
Br
+
(HO)2B
Na2CO3 (20% in H2O)
DME
O
O
According to Method A, 1,2-dibromo-4,5-dimethylbenzene (1.1 g, 4.2 mmol) and 3,4-
dimethoxyphenylboronic acid (2.3 g, 12.5 mmol) were mixed in 1,2-dimethoxyethane (25
mL) under argon atmosphere, followed by successive addition of a catalytic amount of
Pd(PPh3)4 (35 mg) and aqueous sodium carbonate solution (20%, 20 mL). The resulting
mixture was degassed and heated to reflux for 15h. Standard aqueous work up afforded
S3

the crude product which was purified by a column chromatography on silica gel using
10% ethyl acetate in hexanes as the eluent to furnish 3',4'-dimethyl-3,4,3",4"-
o
1
tetramethoxyl-o-terphenyl (1b) as white solid. Yield: 1.5 g, 94%; mp 139-140 C; H
NMR (CDCl3) δ: 2.36 (s, 6H), 3.62 (s, 6H), 3.86 (s, 6H), 6.62 (s, 2H), 6.77 (s, 2H), 6.78
13
(s, 2H), 7.23 (s, 2H); C NMR (CDCl3) δ: 19.55, 55.79, 55.99, 110.91, 113.66, 121.92,
131.78, 134.50, 135.83, 137.81, 147.68, 148.32.
General in situ Suzuki Reaction (Method B): Synthesis of 3',4'-dimethyl-3,5,3",5"-
tetramethoxy-o-terphenyl (1c).
O
Br
O
(i) n-BuLi/THF/-78 oC/2h
Br
O
O
(ii) trimethylborate/-78 oC/12h
Na2CO3 (20% in H2O)
Br
O
toluene, ethanol
Pd(PPh3)4
O
In a oven dried Schlenk flask, a solution of 1-bromo-3,5-dimethoxybenzene (3.25 g, 15
o
mmol) in anhydrous THF (30 mL) was cooled to -78 C (dry ice-acetone bath) under
argon atmosphere and n-butyllithium (2.5 M in hexane, 8 mL, 20 mmol) was added
o
dropwise. After 2h of stirring at -78 C, trimethylborate (1.5 equiv) was added dropwise
with the aid of a syringe and the temperature was allowed to gradually rise to room
temperature during an 8h period. To the resulting mixture were added 1,2-dibromo-4,5-
dimethylbenzene (1.32 g, 5 mmol), anhydrous toluene (30 mL), dry ethanol (30 mL),
aqueous Na2CO3 (7.5 g dissolved in 30 mL H2O), and Pd(PPh3)4 (40 mg) successively.
The flask containing the resulting mixture was repeatedly evacuated and filled with argon
(3x), covered by aluminum foil and refluxed for 24 h. The reaction mixture was cooled to
S4

room temperature and then poured into 5% aqueous HCl solution. The organic layer was
separated and the aqueous layer was extracted with dichloromethane (3 x 25 mL). The
combined organic extracts were washed with water, brine and dried over anhydrous
MgSO4. Removal of the solvent in vacuo afforded the crude product which was purified
by column chromatography on silica gel using 2% ethyl acetate in hexanes as the eluent
to afford 3',4'-dimethyl-3,5,3",5"-tetramethoxy-o-terphenyl (1c) as colorless oil. Yield:
1
0.75 g, 40%; H NMR (CDCl3) δ: 2.38 (s, 6H), 3.66 (s, 12H), 6.35 (t, J = 2.26 Hz, 2H),
6.39 (dd, J1 = 2.26 Hz, J2 = 0.86 Hz, 4H), 7.28 (s, 2H); 13C NMR (CDCl3) δ: 19.58,
55.41, 99.10, 107.99, 131.65, 136.21, 138.08, 143.66, 160.35.
Synthesis of 3,3"-dimethoxy-3',4'-dimethyl-o-terphenyl (1d)
O
Br
O
(i) n-BuLi/THF/-78 oC/2h
Br
(ii) trimethylborate/-78 oC/12h
Na2CO3 (20% in H2O)
Br
toluene, ethanol
Pd(PPh3)4
O
According to Method B, n-butyllithium (2.5M in hexane) (3.3 mL, 8.2 mmol) was added
o
to a solution of m-bromoanisole (1.74 g, 9.3 mmol) in THF (20 mL) at -78 C under
argon atmosphere. After 2h, trimethylborate (1 mL, 9.4 mmol) was added and the
mixture was allowed to warm to room temperature during a 12h period. 1,2-Dibromo-
4,5-dimethylbenzene (0.42 g, 1.6 mmol), anhydrous toluene (20 mL), dry ethanol (20
mL), aqueous Na2CO3 (5 g dissolved in 20 mL H2O), and Pd(PPh3)4 (40 mg) were added.
The reaction mixture was refluxed for 16 h. Standard work up afforded a crude product
which was purified by column chromatography on silica gel with hexanes as the eluent to
S5

afford 3,3"-dimethoxy-3',4'-dimethyl-o-terphenyl (1d) as colorless oil. Yield: 0.4 g, 79%;
1H NMR (CDCl3) δ: 2.35 (s, 6H), 3.62 (s, 6H), 6.67 (dd, J1 = 2.58 Hz, J2 = 1.59 Hz, 2H),
7.74 (m, 4H), 7.13 (t, J = 7.77 Hz, 2H), 7.23 (s, 2H); 13C NMR (CDCl3) δ: 19.64, 50.31,
112.63, 115.31, 122.50, 129.02, 131.93, 136.18, 138.10, 143.08, 159.25.
Synthesis of 4,4"-dimethoxy-3',4'-dimethyl-o-terphenyl (1e)
Br
O
Br
(i) n-BuLi/THF/-78 oC/2h
Br
(ii) trimethylborate/-78 oC/12h
Na2CO3 (20% in H2O)
toluene, ethanol
Pd(PPh3)4
O
O
According to Method B, n-butyllithium (2.5M in hexane, 4.8 mL, 12 mmol) was added
o
to a solution of p-bromoanisole (1.74 g, 9.3 mmol) in THF (25 mL) at -78 C under an
argon atmosphere. After 2 h, trimethylborate (1.56 mL, 14 mmol) was added and the
resulting mixture was allowed to warm to room temperature during a 12h period. 1,2-
Dibromo-4,5-dimethylbenzene (0.82 g, 3.1 mmol), anhydrous toluene (25 mL), dry
ethanol (25 mL), aqueous Na2CO3 (5 g dissolved in 20 mL H2O), and Pd(PPh3)4 (50 mg)
were added. The reaction mixture was refluxed for 16 h. Standard work up afforded a
crude product which was purified by column chromatography on silica gel using 2%
ethyl acetate in hexanes as the eluent to afford 4,4"-dimethoxy-3',4'-dimethyl-o-terphenyl
o
1
(1e) as white solid. Yield: 0.9 g, 91%; mp 78-79 C; H NMR (CDCl3) δ: 2.37 (s, 6H),
3.81 (s, 6H), 6.79 (dt, J1 = 8.74 Hz, J2 = 2.25 Hz, 4H), 7.10 (dt, J1 = 8.74 Hz, J2 = 2.25
Hz, 4H), 7.21 (s, 2H); 13C NMR (CDCl3) δ: 19.58, 55.35, 113.52, 131.07, 132.09, 134.27,
135.66, 137.72, 158.27.
S6

Synthesis of 2,2-Bis(3,4-dimethoxyphenyl)propane (1f)
O
HS
O
O
O
O
O
O
O
OH
+
H2SO4-H2O
50-60 oC/ 12 h
According to a literature procedure,S4 1,2-dimethoxybenzene (9.5 mL), acetone (2.0 mL),
and mercaptoacetic acid (0.4 mL) were added to a solution prepared from conc. H2SO4 (d
1.84, 8.0 mL) and water (8.0 mL), and the resulting mixture was kept overnight at 50-60
oC. An standard aqueous workup and recrystallization from methanol afforded 2,2-
bis(3,4-dimethoxyphenyl)propane (1f) as colorless crystalline solid. Yield: 3.1 g, mp 91-
92 oC (lit.S4 mp 92 oC); 1H NMR (CDCl3) δ: 1.65 (s, 6H), 3.77 (s, 6H), 3.86 (s, 6H), 6.69
(d, J = 2 Hz, 2H), 6.76-6.84 (m, 4H); 13C NMR (CDCl3) δ: 31.2, 42.4, 55.8, 55.9, 110.4,
110.8, 118.5, 143.5, 147.0, 148.4.
Synthesis of 9,9-Bis(3,4-dimethoxyphenyl)fluorene (1g)
O
O
HS
O
O
OH
O
O
O
O
+
H2SO4-H2O
50-60 oC/ 12 h
Following a literature procedureS4 similar to the one described above for (1f), 1,2-
dimethoxybenzene (10 mL), fluorenone (1.8 g, 10 mmol), and mercaptoacetic acid (0.4
mL) were added to a solution prepared from conc. H2SO4 (d 1.84, 8.0 mL) and water
o
(8.0 mL), and the resulting mixture was kept overnight at 80 C. A standard aqueous
workup
and
recrystallization
from
methanol
afforded
9,9-bis(3,4-
dimethoxyphenyl)fluorene (1f) as a colorless crystalline solid. Yield: 4.1 g, 94%; mp
o
1
216-218 C; H NMR (CDCl3) δ: 3.69 (s, 6H), 3.81 (s, 6H), 6.69 (s, 4H), 6.77 (s, 2H),
S7

7.24-7.29 (m, 2H), 7.33-7.42 (m, 4H), 7.76 (d, J = 7 Hz, 2H) 13C NMR (CDCl3) δ: 55.91,
55.96, 64.8, 110.7, 112.0, 120.3, 120.4, 126.0, 127.6, 127.7, 138.4, 140.0, 147.9, 148.5,
151.6.
Synthesis of 3,4,3',4',3",4"-hexamethyl-o-terphenyl (1k)
Br
Br
(i) n-BuLi/THF/-78 oC/2h
Br
(ii) trimethylborate/-78 oC/12h
Na2CO3 (20% in H2O)
toluene, ethanol
Pd(PPh3)4
According to Method B, n-butyllithium (2.5M in hexane, 8 mL, 20 mmol) was added to
o
a solution of 4-bromo-o-xylene (2.78 g, 15 mmol) in 30 mL THF at -78 C under argon
atmosphere. After 2 h, trimethylborate (2.5 mL, 22.5 mmol) was added and the resulting
mixture was allowed to warm to room temperature during a 12h period. 1,2-Dibromo-
4,5-dimethylbenzene (1.32 g, 5 mmol), anhydrous toluene (30 mL), dry ethanol (30 mL),
aqueous Na2CO3 (7.5 g dissolved in 30 mL H2O), and Pd(PPh3)4 (40 mg) were added.
The reaction mixture was refluxed for 16 h. Standard work up afforded a crude product
which was purified by column chromatography on silica gel using hexanes as the eluent
to afford 3,4,3',4',3",4"-hexamethyl-o-terphenyl (1k) as a colorless oil. Yield: 0.50 g, 32
%; 1H NMR (CDCl3) δ: 2.20 (s, 6H), 2.23 (s, 6H), 2.35 (s, 6H), 6.81 (dd, J1 = 7.94 Hz, J2
13
= 1.90 Hz, 2H), 6.94 (d, J = 7.94 Hz, 2H), 7.02 (d, J = 1.90 Hz, 2H), 7.20 (s, 2H); C
NMR (CDCl3) δ: 19.58, 19.61, 19.67, 127.61, 129.15, 131.10, 132.17, 134.45, 135.57,
136.03, 138.16, 139.38.
S8

Synthesis of Hexakis(4-isoalkylphenyl)benzenes (1l-1n). The hexaarylbenzenes 1l-1n
were obtained according to a published procedureS2 from our laboratory according to the
Scheme shown below:
Scheme . Synthesis of various soluble hexakis(4-isoalkylphenyl)
benzenes (1l-1n)
O
O
O
O
O
a
b
O
I
O
O
O
c
(l) R = methyl, (m) R = ethyl, (n) R = hexyl
OH
R
R
R
R
OH
R
HO
R
d
R
R
OH
HO
R
R
R
1l-n
R
OH
a Benzene/DBU/H2O/ (PPh3)PdCl2/CuI/ Me3SiCCH, reflux. bCo2(CO)8/Dioxane/reflux.
c THF/RMgBr or RMgCl. d H+/H2 50 psi/ 10% Pd-C.
General Procedure for the Oxidative Cyclodehydrogenation with Acid and DDQ.
A solution of o-terphenyl 1a (0.1 mmol) in dichloromethane (10 mL) containing protic
o
acid (10% v/v) or Lewis acid (~10 equiv.) at ~0 C was treated with DDQ (1 equivalent
per C-C bond formation, i.e. 0.1 mmol), and the solution immediately took on a dark-
green coloration. [Note that the solution colors varied depending on the Scholl precursors
1
used (see Chart 1).] The progress of the reaction was monitored by TLC and H NMR
spectroscopy. After completion of the reaction, it was quenched with a saturated aqueous
S9

solution of NaHCO3 (20 mL). The dichloromethane layer was separated and washed with
water and brine solution and dried over anhydrous MgSO4 and filtered. Removal of the
solvent in vacuo afforded the crude product which by 1H/13C NMR analysis was shown to
be 2,3,10,11-tetramethoxytriphenylene (2a). Various Scholl precursors were subjected to
similar reaction conditions and the characterization data for the oxidative
cyclodehydrogenation products are summarized below:
o
1
2,3,10,11-Tetramethoxytriphenylene (2a). Yield: quantitative; mp 215-216 C; H
NMR (CDCl3) δ: 4.11 (s, 12H), 7.59 (q, 2H), 7.71 (s, 2H), 7.94 (s, 2H), 8.46 (q, 2H); 13C
NMR (CDCl3) δ: 56.08, 56.17, 104.11, 104.58, 122.99, 123.54, 123.94, 126.16, 128.93,
148.84, 149.39.
6,7-Dimethyl-2,3,10,11-tetramethoxytriphenylene (2b). White crystals, quantitative
o
yield; mp 282-283 C; 1H NMR (CDCl3) δ: 2.51 (s, 6H), 4.09 (s, 6H), 4.11 (s, 6H), 7.68
13
(s, 2H), 7.88 (s, 2H), 8.14 (s, 2H); C NMR (CDCl3) δ: 20.47, 56.14, 104.24, 104.46,
123.43, 123.54, 123.61, 127.15, 135.11, 148.79, 149.02.
6,7-Dimethyl-1,3,9,11-tetramethoxytriphenylene (2c). White solid, yield: 50%; mp
o
1
193-194 C; H NMR (CDCl3) δ: 2.49 (s, 6H), 3.97 (s, 6H), 4.01 (s, 6H), 6.68 (s, 2H),
7.51 (s, 2H), 8.16 (s, 2H); 13C NMR (CDCl3) δ: 20.49, 55.78, 56.00, 96.96, 98.09,
112.94, 124.25, 128.74, 132.34, 136.41, 158.82, 158.91. Note that the triphenylene 2c
undergoes decomposition under the reaction conditions and thus the pure 2c was isolated
by column chromatography on silica gel using 5% ethyl acetate in hexanes as eluent.
o
1
3,10-Dimethoxy-6,7-dimethyltriphenylene (2d). Yield: 100%, mp 208-211 C; H
NMR (CDCl3) δ: 2.52 (s, 6H), 4.02 (s, 6H), 7.21 (dd, J1 = 8.91 Hz, J2 = 2.58 Hz, 2H),
S10

7.99 (d, J = 2.58 Hz, 2H), 8.28 (s, 2H), 8.44 (d, J = 8.91 Hz, 2H); 20.53, 55.72, 105.76,
115.53, 123.93, 124.15, 124.51, 128.23, 130.30, 136.38, 158.34.
o
1
2,11-Dimethoxy-6,7-dimethyltriphenylene (2e). Yield: 60%; mp 214-215 C; H NMR
(CDCl3) δ: 2.49 (s, 6H), 4.02 (s, 6H), 7.25 (dd, J1 = 8.83 Hz, J2 = 2.56 Hz, 2H), 7.94 (d, J
= 2.56 Hz, 2H), 8.26 (s, 2H), 8.53 (d, J = 8.83 Hz, 2H); 13C NMR (CDCl3) δ: 20.48,
55.71, 106.32, 115.66, 123.54, 124.44, 124.95, 127.22, 130.79, 135.41, 158.56.
2,3,6,7-Tetramethoxy-9,9-dimethylfluorene (2f). White solid, yield: 100%; mp 178-
o
180 C; 1H NMR (CDCl3) δ: 1.65 (s, 6H), 3.77 (s, 6H), 3.86 (s, 6H), 6.69 (d, 2H, J = 2
Hz), 6.76-6.84 (m, 4H); 13C NMR (CDCl3) δ: 27.4, 46.7, 56.2, 56.3, 102.5, 106.1, 131.8,
146.1, 148.2, 148.7.
2,3,6,7-Tetramethoxy9,9-spirobifluorene (2g). White solid, yield: 100%; mp 242-244
oC; 1H NMR (CDCl3) δ: 3.61 (s, 6H), 4.03 (s, 6H), 6.18 (s, 2H), 6.75 (d, J = 7.6 Hz, 2H),
7.14 (t, J = 7 Hz, 2H), 7.26 (d, J = 5 Hz, 2H), 7.38 (t, J = 7.5 Hz, 2H), 7.85 (d, J = 7.6 Hz,
2H) 13C NMR (CDCl3) δ: 56.2, 56.3, 65.9, 102.3, 107.0, 120.0, 124.2, 127.8, 128.0,
134.7, 141.0, 141.7, 148.6, 149.1, 149.3.
6,7-Dihydro-2,3,9,10-tetramethoxydibenzo[1,c]cycloheptadiene (2h). White solid,
1
yield: 100%; mp 152-153 °C (litS5 mp 158-159 °C); H NMR (CDCl3) δ: 2.11-2.20 (m,
2H), 2.43 (t, J = 7 Hz, 4H), 3.92 (s, 12H), 6.77 (s, 2H), 6.89 (s, 2H); 13C NMR (CDCl3) δ:
31.2, 34.0, 56.1, 56.3, 111.7, 112.0, 132.2, 133.1, 147.6, 147.9.
4,4’,5,5’-Tetramethoxy-2,2’-dimethylbiphenyl (2i). White solid, yield: 100%; mp 113-
114 oC; 1H NMR (CDCl3) δ: 2.02 (s, 6H), 3.83 (s, 6H), 3.91 (s, 6H), 6.65 (s, 2H), 6.77 (s,
13
2H); C NMR (CDCl3) δ: 19.48, 56.04, 56.16, 112.91, 113.10, 128.36, 133.52, 146.66,
147.89.
S11

2,2’,5,5’-Tetramethoxy-4,4’-dimethylbiphenyl (2j). White solid, yield: 100%; mp 129-
130 oC; 1H NMR (CDCl3) δ: 2.29 (s, 6H), 3.75 (s, 6H), 3.81 (s, 6H), 6.79 (s, 2H), 6.83 (s,
13
2H); C NMR (CDCl3) δ: 16.60, 56.17, 56.82, 114.04, 115.08, 125.73, 126.71, 150.87,
151.87.
2,3,6,7,10,11-hexamethyltriphenylene (2k). Pale yellow crystals, quantitative yield, mp
303-306 oC; 1H NMR (CDCl3) δ: 2.51 (s, 18H), 8.33 (s, 6H); 13C NMR (CDCl3) δ: 20.50,
123.75, 127.80, 135.56.
Alkyl substituted hexa-peri-hexabenzocoronenes (2l-2o).
HBC 2l. Yellow/orange solid, Yield: qunatitative; mp >300 ºC; 1H NMR (CDCl3) δ: 1.73
(d, 36H), 3.58 (m, 6H), 8.9 (s, 12H); 13C NMR (CDCl3) δ: 24.97, 35.46, 120.04, 120.33,
124.15, 130.52, 146.56.
1
HBC 2m. Yellow/orange solid, Yield: quantitatve; mp >300 ºC; H NMR (CDCl3) δ:
1.11 (s, 18H), 1.69 (s, 18H), 2.07 (s, 12H), 3.29 (s, 6H), 9.03 (s, 12H); 13C NMR (CDCl3)
δ: 12.12, 22.36, 31.25, 44.36, 120.11, 120.13, 124.89, 131.09, 146.78.
HBC 2n. Yellow/orange solid, Yield: quantitatve; mp 110-112 ºC; 1H NMR (CDCl3) δ:
0.84 (t, 18H), 1.06 (d, 18H), 1.33 (m, 60H), 2.38 (m, 6H), 6.59 (s, 12H), 6.67 (d, 12H);
13C NMR (CDCl3) δ: 14.32, 22.95, 28.33, 29.80, 32.02, 32.12, 39.24, 41.31, 120.70,
120.77, 124.94, 130.55, 146.26.
o
1
HBC 2o. Yellow/orange solid, Yield: quantitatve; mp >320 ºC (litS5 mp >300 C) ; H
NMR (CDCl3) δ: 1.83 (s, 54H), 9.32 (s, 12H); 13C NMR (CDCl3) δ: 32.25, 35.95, 119.13,
120.71, 124.22, 130.72, 149.22.
S12

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C.; Schulz, E.; Lemaire, M. Chem. Rev. 2002, 102, 1359.
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49, 4869.
S3. Sun, D.; Lindeman, S. V.; Rathore, R.; Kochi, J. K. J. Chem. Soc., Perkin Trans. 2,
2001, 1585.
S4. Apel, S.; Nitsche, S.; Beketov, K.; Seichter, W.; Seidel, J.; Weber, E. J. Chem.
Soc., Perkin Trans. 2 2001, 1212.
S5. Ronlan, A.; Parker, V. D. J. Org. Chem. 1974, 39, 1014.
S6. Compare: Herwig, P. T.; Enkelmann, V.; Schmelz, O.; Muellen, K. Chem. Eur. J.
2000, 6, 1834.
S13

1H NMR spectrum of 3,3’,4,4’-tetramethoxy-o-terphenyl (1a).
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 3,3’,4,4’-tetramethoxy-o-terphenyl (1a).
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 2,3,10,11-tetramethoxytriphenylene (2a).
O
O
O
O
PPM 8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
S14

13C NMR spectrum of 2,3,10,11-tetramethoxytriphenylene (2a).
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 3',4'-dimethyl-3,4,3",4"-tetramethoxyl-o-terphenyl (1b)
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 3',4'-dimethyl-3,4,3",4"-tetramethoxyl-o-terphenyl (1b)
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S15

1H NMR spectrum of 6,7-dimethyl-2,3,10,11-tetramethoxytriphenylene (2b).
O
O
O
O
PPM 8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 6,7-dimethyl-2,3,10,11-tetramethoxytriphenylene (2b).
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 3',4'-dimethyl-3,5,3",5"-tetramethoxy-o-terphenyl (1c)
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
S16

13C NMR spectrum of 3',4'-dimethyl-3,5,3",5"-tetramethoxy-o-terphenyl (1c)
O
O
O
O
PPM
140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 6,7-dimethyl-1,3,9,11-tetramethoxytriphenylene (2c)
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 6,7-dimethyl-1,3,9,11-tetramethoxytriphenylene (2c)
O
O
O
O
PPM
140.0
120.0
100.0
80.0
S17
60.0
40.0
20.0

1H NMR spectrum of 3,3"-dimethoxy-3',4'-dimethyl-o-terphenyl (1d)
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
20.0
1.0
13C NMR spectrum of 3,3"-dimethoxy-3',4'-dimethyl-o-terphenyl (1d)
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
1H NMR spectrum of 3,10-dimethoxy-6,7-dimethyltriphenylene (2d)
O
O
PPM 8.0
7.0
6.0
5.0
4.0
3.0
2.0
S18

13C NMR spectrum of 3,10-dimethoxy-6,7-dimethyltriphenylene (2d)
O
O
PPM
130.0
110.0
90.0
70.0
50.0
30.0
10.0
1H NMR spectrum of 4,4"-dimethoxy-3',4'-dimethyl-o-terphenyl (1e)
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 4,4"-dimethoxy-3',4'-dimethyl-o-terphenyl (1e)
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S19

1H NMR spectrum of 2,11-dimethoxy-6,7-dimethyltriphenylene (2e)
O
O
PPM 8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 2,11-dimethoxy-6,7-dimethyltriphenylene (2e)
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 2,2-Bis(3,4-dimethoxyphenyl)propane (1f)
H3CO
H3CO
OCH3
OCH3
PPM7.0
6.0
5.0
4.0
3.0
2.0
1.0
S20

13C NMR spectrum of 2,2-Bis(3,4-dimethoxyphenyl)propane (1f)
H3CO
H3CO
OCH3
OCH3
PPM 140.0 120.0 100.0 80.0 60.0 40.0 20.0
1H NMR spectrum of 2,3,6,7-tetramethoxy-9,9-dimethylfluorene (2f)
OCH3
H3CO
H3CO
OCH3
PPM7.0
6.0
5.0
4.0
3.0
2.0
13C NMR spectrum of 2,3,6,7-tetramethoxy-9,9-dimethylfluorene (2f)
H3CO
H3CO
OCH3
OCH3
PPM 140.0 120.0 100.0 80.0 60.0 40.0 20.0
S21

1H NMR spectrum of 9,9-bis(3,4-dimethoxyphenyl)fluorene (1g)
M7.8
7.6
7.4
7.2
7.0
6.8
6.6
OCH3
OCH3
H3CO
H3CO
PPM
7.0
6.0
5.0
4.0
3.0
2.0
13C NMR spectrum of 9,9-bis(3,4-dimethoxyphenyl)fluorene (1g)
OCH3
OCH3
H3CO
H3CO
PP1M60.0 140.0 120.0 100.0 80.0
60.0
40.0
1H NMR spectrum of 2,3,6,7-tetramethoxyspirobifluorene (2g)
OCH3
H3CO
OCH3
H3CO
7.6
7.2
6.8
6.4
6.0
PPM8.0
7.0
6.0
5.0
4.0
3.0
S22

13C NMR spectrum of 2,3,6,7-tetramethoxyspirobifluorene (2g)
OCH3
OCH3
H3CO
H3CO
PPM
140.0
130.0
120.0
120.0
PPM 140.0
100.0
80.0
60.0
40.0
1H NMR spectrum of 1,3-bis(3,4-dimethoxyphenyl)propane (1h)
H3CO
H3CO
OCH3
OCH3
CDCl3
PPM 7.0
6.0
5.0
4.0
3.0
2.0
S23

13C NMR spectrum of 1,3-bis(3,4-dimethoxyphenyl)propane (1h)
H3CO
H3CO
OCH3
OCH3
PPM 140.0 120.0 100.0 80.0 60.0 40.0
1H NMR spectrum of 6,7-Dihydro-2,3,9,10-tetramethoxydibenzo-[1,c]cyclohepta-
diene (2h)
OMe
OMe
OMe
OMe
13C NMR spectrum of 6,7-Dihydro-2,3,9,10-tetramethoxydibenzo-[1,c]cyclohepta-
diene (2h)
OMe
OMe
OMe
OMe
PPM 140.0 120.0 100.0 80.0 60.0 40.0 20.0
S24

1H NMR spectrum of 3,4-dimethoxytoluene (1i)
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 3,4-dimethoxytoluene (1i)
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 4,4’,5,5’-Tetramethoxy-2,2’-dimethylbiphenyl (2i)
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 4,4’,5,5’-Tetramethoxy-2,2’-dimethylbiphenyl (2i)
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S25

1H NMR spectrum of 2,5-dimethoxytoluene (1j)
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 2,5-dimethoxytoluene (1j)
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
1H NMR spectrum of 2,2’,5,5’-Tetramethoxy-4,4’-dimethylbiphenyl (2j)
O
O
O
O
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of 2,2’,5,5’-Tetramethoxy-4,4’-dimethylbiphenyl (2j)
O
O
O
O
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S26

1H NMR spectrum of (1k)
PPM
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of (1k)
PPM
130.0
110.0
90.0
70.0
50.0
30.0
10.0
1H NMR spectrum of (2k)
PPM 8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of (2k)
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S27

1H NMR spectrum of HBC 2l
CDCl3
H2O
2l
CH2Cl2
13C NMR spectrum of HBC 2l
2l
S28

1H NMR spectrum of HBC 2m
2m
CDCl3
PPM
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of HBC 2m
2m
PPM 140.0
120.0
100.0
80.0
60.0
40.0
20.0
S29

1H NMR spectrum of HBC 2n
CDCl3
2n
PPM
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
13C NMR spectrum of HBC 2n
2n
S30