One-pot synthesis of multifunctionalized m-terphenyls

Article abstract of DOI:10.1016/j.tet.2013.09.036

A facile one-step synthetic protocol toward multifunctionalized m-terphenyls 5 and sulfonyl m-terphenyls 6 is developed from substituted chalcones 1 and allyl sulfone 2 in good yields via a [3C+3C] annulation. The NaH-mediated annulation features transition metal catalyst-free condition. Chalcones 1 with the functional groups tolerance are easily prepared via Claisen-Schmidt condensation of substituted benzaldehydes 3 with acetophenone 4 in a qualitative yield under an aqueous alkaline methanolic solution.

Full text of DOI:10.1016/j.tet.2013.09.036

Tetrahedron 69 (2013) 9616e9624
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
One-pot synthesis of multifunctionalized m-terphenyls
*
Meng-Yang Chang , Chieh-Kai Chan, Shin-Ying Lin, Ming-Hao Wu
Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 17 July 2013
Received in revised form 9 September 2013
Accepted 12 September 2013
Available online 18 September 2013
A facile one-step synthetic protocol toward multifunctionalized m-terphenyls 5 and sulfonyl m-ter-
phenyls 6 is developed from substituted chalcones 1 and allyl sulfone 2 in good yields via a [3Cþ3C]
annulation. The NaH-mediated annulation features transition metal catalyst-free condition. Chalcones 1
with the functional groups tolerance are easily prepared via ClaiseneSchmidt condensation of
substituted benzaldehydes 3 with acetophenone 4 in a qualitative yield under an aqueous alkaline
methanolic solution.
Keywords:
Terphenyls
Chalcones
Ó 2013 Elsevier Ltd. All rights reserved.
Allyl sulfones
OH
OH
1. Introduction
Functionalized phenyls are attractive scaffolds for synthetic
material sciences and drug discovery.1 To achieve these diversified
frameworks bearing different substituted groups, various kinds of
approaches have been established in the past decades.2 Some
functional profiles clearly indicate that polyaryl phenyl is a privi-
leged core for synthetic design.3 Among those methods, transition
metal mediated reactions have been proven to be one of the most
popular tools to construct the skeleton, especially SuzukieMiyaura
cross-coupling4 or Reppe cyclotrimerization.5 Efficient synthesis of
terphenyls is an important issue for organic chemists.6,7 Some m-
terphenyls are found in natural products, such as dictyoterphenyl
A,3j trifucol,8a macranthol,8b dunnialol,8c and mulberrofuran R
(Fig. 1).8d
HO
HO
OH
OH
OH
OH
OH
O
HO
H2N
OH
OH
OMe
dictyoterphenyl A
HO
OH
macranthol
trifucol
HO
OH
OH
OH
OH
HO
O
OH
OH
We previously reported the one-pot method for synthesizing
various carbon-skeletons with different aryl substituents based on
chalcones 1, such as monocyclic oxetanes and cyclohexanes, tri-
cyclic benzo[g]indazoles, and tetracyclic azahomoisotwistanes.9 To
explore the synthetic applications of substituted chalcones 1,
a transition metal-free route is employed to create the skeleton
of m-terphenyls 5 and 6 via a one-pot NaH-mediated tandem an-
nulation of chalcones 1 and allyl sulfone 2. Substituted chalcones 1
are easily prepared via ClaiseneSchmidt condensation of substi
tuted aldehydes 3 (R2 group) with methyl ketones 4 (R1 group)
(Scheme 1).
OH
dunnialol
mulberrofuran R
Me
Fig. 1. Structural frameworks of natural m-terphenyls.
H
O
Tol
3
S
O
R2
O
NaOH
MeOH
R2
S
R1
5
2
O
O
R2
R1
+
+
Tol
NaH, THF
1
O
O
4
R1
Me
R2
Scheme 1. One-pot route of m-terphenyls 5 and 6.
R1
6
* Corresponding author. Tel.: þ886
7 3121101x2220; e-mail addresses: my-
chang@kmu.edu.tw, mychang624@yahoo.com.tw (M.-Y. Chang).
0040-4020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.09.036

M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
9617
2. Results and discussion
deprotonation of allyl sulfone 2 with NaH. Under thermodynamic
conditions, both possible intermediates B1 and B2 should be gen-
erated from the 1,2- or 1,4-addition of intermediate A with chalcone
1a. After the removal of toluenesulfonic sodium salt (TolSO3Na),
intermediate C1, with the (E,E)-conjugated configuration, should be
afforded. Because TolSO3Na could be isolated by the extraction
process (from the aqueous layer), the reaction pathway from in-
termediate B1 to C1 was proposed. Next, the formation of m-ter-
To initiate the synthetic work, several chalcones 1 were pre-
pared in nearly quantitative yields according to our recent litera-
ture methods from the NaOH-mediated ClaiseneSchmidt
condensation of substituted methyl ketones 4 with aldehydes 3
under the methanolic refluxing solution.9 Next, synthesis of allyl
sulfone 2 was achieved from nucleophilic substitution of allyl
bromide with TolSO2Na in quantitative good yields. In an attempt to
develop a practical protocol of m-terphenyl with the structure of
1,3-disubstituted benzene, NaH-mediated one-pot [3Cþ3C] route
of the starting chalcone 1b (R1¼3-MeOPh; R2¼2-naphthalene) with
allyl sulfone 2 in refluxing THF provided m-terphenyl 5b (52%) and
sulfonyl m-terphenyl 6b (30%) in a ratio of 6:4. This is a short and
efficient route to achieve the structural skeleton of m-terphenyl. For
the regioselective introduction of a sulfonyl group on the m-ter-
phenyl skeleton, only one isomer 6b with specific site-selectivity
was isolated.
To change the bases with different equivalents in various sol-
vents from 25 ꢀC to refluxing temperature, we found that different
product ratios of m-terphenyl 5b and sulfonyl m-terphenyl 6b were
obtained between 6:4 and 5:5 with the lower total yields via one-
pot tandem reaction of model chalcone 1b with allyl sulfone 2 (see
Table 2). By adjusting the equivalents of NaH, reaction time, tem-
perature, and concentration (for entries 1e6), the isolated total
yield of m-terphenyl 5b and 6b was noticeably enhanced (see entry
3). After screening the base-mediated reaction conditions (entries
7e11), we found that NaH provided higher yields than other bases
(DBU, Et3N, DMAP, MeONa, LiHMDS). Furthermore, when the base
and solvent were replaced with Et3N/CH2Cl2 or MeONa/MeOH, the
isolated total yield of m-terphenyl 5b and 6b was decreased to 22%
or 31% (for entry 8, the starting material 1b was isolated in 65%
yield; for entry 10, unknown mixture was isolated in 46% yield as
the major product). According to the experimental results, we
envisioned that NaH (4 equiv) is an optimal base for elevating the
total yields of m-terphenyl 5b and 6b (82%) under boiling THF
conditions for 3 h (entry 3).10
phenyl 5a was observed via the 1,6-6p-electrocyclic disrotatory
ring closure followed by the sequential aromatization (oxidative
dehydrogenation process) of the resulting intermediate of cyclo-
hexadiene. At another stage, the proton exchange provided the
equilibrium process between intermediate B2 and C2. The corre-
sponding carbanion of intermediate C2 was delocalized to establish
intermediate D with cyclohexene ring. By the similar pathway
above, after dehydration and oxidative dehydrogenation, (an aro-
matization process), the formation of m-terphenyl 6a with sulfonyl
group was provided. From the above mentioned reaction mecha-
nism, we believe that air (molecular oxygen) plays an important
oxidant role to activate the aromatization step during the one-pot
direct transformation.12
3. Conclusion
In summary, we have successfully presented a novel and one-
pot cascade [C3þC3] methodology for synthesizing a series of m-
terphenyls 5aev and sulfonyl m-terphenyls 6aev via two important
steps: (1) 1,2- addition or 1,4-addition of chalcones 1aev with the
a-carbanion intermediate A of allyl sulfone 2 and (2) removal of
TolSO3Na/1,6-electrocyclization/aromatization of possible in-
termediates (for skeleton 5) or proton exchange/six-membered
ring formation/dehydration/aromatization of several possible in-
termediates (for skeleton 6). The structural skeletons of key prod-
ucts were confirmed by X-ray crystal analysis. The one-pot
transition metal-free synthetic approach begins with simple
starting materials and reagents, and provides a potential protocol
for the synthetic research and biological activities of m-terphenyls.
Further investigation regarding one-pot cascade synthesis of mul-
tifunctionalized arenes will be conducted and published in due
course.
With the result in hand, one-pot preparation of substituted m-
terphenyl 5 and 6 was further examined. Changing the R1 and R2
substituent of chalcones 3, major 1,3-disubstituted benzenes 5aev
and minor 1,3-disubstituted benzenes 6aev with sulfonyl group
were isolated with good total yields in different ratios by one-pot
domino methodology; they are summarized in Table 1. The for-
mation of skeletons 5 and 6 was confirmed through spectral anal-
ysis, including 1H and 13C NMR and HRMS spectra. For example, the
4. Experimental section
4.1. General
1H NMR spectra of compound 6u exhibited three singles at
d
8.32,
All other reagents and solvents were obtained from commercial
sources and used without further purification. Reactions were
routinely carried out under an atmosphere of dry air with magnetic
stirring. Products in organic solvents were dried with anhydrous
MgSO4 before concentration in vacuo. Melting points were de-
termined with a SMP3 melting apparatus. 1H and 13C NMR spectra
were recorded on a Varian INOVA-400 spectrometer operating at
7.56 and 7.32 for core benzene ring protons. Three CH protons
appeared as one doublet of H-1 (J¼8.4 Hz), one doublet of H-3
(J¼2.4 Hz), and one doublets of doublets of H-2 (J¼2.4 and 8.4 Hz).
The structure of compound 6u was confirmed by HRMS, which
showed a peak at m/z 371.1145 [Mþþ1]. The structural frameworks
of compounds 5f, 6i, and 6s were determined by single-crystal X-
ray crystallography, as shown in Figs. 2e4.11 Compared with the
isolated yields of products 5aev and 6aev, it was found that dif-
ferent kinds of substituents (e.g., electron-withdrawing oxygen-
containing groups, electron-donating fluoro-containing groups,
heterocyclic 2-thiophene group, aliphatic tert-butyl group) did not
obviously interfere with the product yields and ratios distribution
of skeletons 5 and 6. Quaterphenyls 5j and 6j were also prepared
from the one-pot domino reaction of chalcone 1j with sulfone 2 via
a (C3þC3) route.
200/400 and at 100 MHz, respectively. Chemical shifts (d) are re-
ported in parts per million (ppm) and the coupling constants (J) are
given in Hertz. High resolution mass spectra (HRMS) were mea-
sured with a mass spectrometer Finnigan/Thermo Quest MAT 95XL.
X-ray crystal structures were obtained with an Enraf-Nonius FR-
590 diffractometer (CAD4, Kappa CCD). Elemental analyses were
carried out with Heraeus Vario III-NCSH, Heraeus CHNeOS-Rapid
Analyzer or Elementar Vario EL III.
As shown in Scheme 2, a plausible explanation for the one-pot
synthesis of compounds 5a and 6a via the reaction of 1a and 2
4.2. A representative synthetic procedure of compounds 5aev
and 6aev is as follows
should be that intermediate
A of sodium a-carbanion was
first generated via NaH-mediated deprotonation of allyl sulfone
2 in refluxing THF. Initially, intermediate A was formed by
Sodium hydride (NaH, 60% in oil, 80 mg, 2.0 mmol) was added to
a solution of allyl sulfone 2 (98 mg, 0.5 mmol) in THF (8 mL). A

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M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
Table 1
Synthesis of multisubstituted m-terphenyls 5 and 6a
a
For the best one-pot reaction conditions: substituted chalcones 1aev (0.5 mmol), allyl sulfone 2 (0.5 mmol), NaH (60%, 80 mg, 2.0 mmol), THF (15 mL), reflux, 3 h.

M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
9619
Table 2
Reactions of compounds 1b and 2a
Entry
Base (equiv), solvent (mL), temp (ꢀC), time (h)
Yield (%) 5b/6b
1
2
3
4
5
6
7
8
NaH (4), THF (15), 25, 3
26/18b
36/25b
52/30c
43/30c
48/27c
50/28c
40/36b
12/10b
28/27b
14/17c,d
30/27b
NaH (4), THF (15), reflux, 1
NaH (4), THF (15), reflux, 3
NaH (4), THF (30), reflux, 3
NaH (10), THF (15), reflux, 3
NaH (4), THF (15), reflux, 10
DBU (4), THF (15), reflux, 3
Et3N (4), CH2Cl2 (15), reflux, 10
DMAP (4), THF (15), reflux, 10
MeONa (4), MeOH (15), reflux, 3
LiHMDS (1.0 M, 4), THF (15), reflux, 6
9
10
11
a
The reactions were run on a 0.5 mmol scale with chalcone 1b and allyl sulfone 2.
The starting material 1b (for entry 1, 40%; entry 2, 25%; entry 7, 8%; entry 8, 65%;
b
entry 9, 30%; entry 11, 20%) was recovered.
c
No starting material 1b was recovered.
Unknown mixture was isolated (for entry 9, 46%).
Fig. 4. X-ray structure of compound 6s.
d
O
O
O
2
Tol Tol
Tol
S
S
S
A
O
O
O
NaH
THF
+
O
O
O
Ph
Ph
Ph
Ph
1,2-addition
Ph
Ph
1a
1,4-addition
O
O
O
O
S
S
Tol Tol
O
H
O
Ph
Ph
Ph
Ph
B1
removal of
TolSO3Na
B2
Fig. 2. X-ray structure of compound 5f.
proton
exchange
O
O
S
electrocyclization
then
Tol
O
Ph
Ph
Ph
Ph
Ph
Ph
aromatization
5a
(E,E)-C1
H
C2
O
S
O
O
Tol
dehydration
S
Tol
O
O
Ph
then
Ph
Ph
Ph
aromatization
6a
D
Scheme 2. A possible mechanism to compounds 5a and 6a.
for C18H15 231.1174, found 231.1180; 1H NMR (400 MHz, CDCl3):
Fig. 3. X-ray structure of compound 6i.
d
7.82 (t, J¼2.0 Hz, 1H), 6.67e6.64 (m, 4H), 7.60e7.58 (m, 3H),
7.54e7.45 (m, 4H), 7.38 (dt, J¼2.0, 6.4 Hz, 2H); 13C NMR (100 MHz,
solution of chalcones 1 (0.5 mmol) in the THF (7 mL) was added to
the reaction mixture at rt. The reaction mixture was stirred at reflux
for 3 h. The reaction mixture was cooled to rt. Water (1 mL) was
added to the reaction mixture at 0 ꢀC. The solvent was concentrated
under reduced pressure. The residue was diluted with water
(10 mL) and the mixture was extracted with EtOAc (3ꢁ20 mL). The
combined organic layers were washed with brine, dried, filtered,
and evaporated to afford crude product. Purification on silica gel
(hexanes/EtOAc¼50/1e10/1) afforded compounds 5aev and 6aev.
CDCl3):
d
141.78 (2ꢁ), 141.18, 129.17 (2ꢁ), 128.79 (4ꢁ), 127.39 (2ꢁ),
127.26 (4ꢁ), 126.16, 126.11 (2ꢁ); Anal. Calcd for C18H14: C, 93.87; H,
6.13. Found: C, 93.67; H, 6.02.
4.2.2. Compound (5b). Yield¼52% (81 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C23H19O 311.1436, found 311.1441; 1H NMR
(400 MHz, CDCl3):
d
8.16 (d, J¼0.8 Hz, 1H), 8.01e7.92 (m, 4H), 7.85
(dd, J¼2.0, 8.4 Hz, 1H), 7.76 (dt, J¼1.6, 7.6 Hz, 1H), 7.66 (dt, J¼1.6,
7.6 Hz, 1H), 7.61 (d, J¼7.6 Hz, 1H), 7.59e7.52 (m, 2H), 7.45 (t,
J¼8.0 Hz, 1H), 7.35e7.32 (m, 1H), 7.29e7.28 (m, 1H), 7.49 (ddd,
J¼0.8, 2.4, 8.4 Hz, 1H), 3.93 (s, 3H); 13C NMR (100 MHz, CDCl3):
4.2.1. Compound (5a). Yield¼50% (58 mg); mp¼86e88 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
d
159.97, 142.69, 141.74, 141.61, 138.40, 133.65, 132.66, 129.80,

9620
M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
129.23, 128.45, 128.18, 127.62, 126.49, 126.38, 126.30, 126.21, 125.97,
125.89, 125.57, 119.78, 113.07, 112.75, 55.28.
6.02 (s, 2H), 3.94 (s, 6H), 3.91 (s, 3H); 13C NMR (100 MHz, CDCl3):
d
153.48 (2ꢁ), 148.16, 147.22, 141.95, 141.50, 137.17, 135.45, 129.99,
129.12, 128.76, 125.90, 125.77 (2ꢁ), 120.75, 108.61, 107.76, 104.57,
101.19, 60.95, 56.22 (2ꢁ).
4.2.3. Compound (5c). Yield¼50% (69 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C20H19O 275.1436, found 275.1435; 1H NMR
(400 MHz, CDCl3):
d
7.82 (t, J¼2.0 Hz,1H), 7.61e7.57 (m, 2H), 7.58 (d,
4.2.9. Compound (5i). Yield¼56% (90 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C21H21O3 321.1491, found 321.1496; 1H NMR
J¼8.0 Hz, 2H), 7.52 (t, J¼7.6 Hz, 1H), 7.40 (t, J¼7.6 Hz, 1H), 7.29 (d,
J¼8.0 Hz, 2H), 7.28e7.25 (m, 1H), 7.21 (t, J¼2.4 Hz, 1H), 6.95 (ddd,
J¼0.8, 2.4, 8.4 Hz, 1H), 3.90 (s, 3H), 2.44 (s, 3H); 13C NMR (100 MHz,
(400 MHz, CDCl3):
d
7.76 (t, J¼1.6 Hz, 1H), 7.67e7.65 (m, 2H),
7.60e7.47 (m, 5H), 7.41e7.37 (m, 1H), 6.84 (s, 2H), 3.95 (s, 6H), 3.92
CDCl3):
d
159.94, 142.79, 141.66, 141.60, 138.24, 137.19, 129.76,
(s, 3H); 13C NMR (100 MHz, CDCl3):
d
153.47 (2ꢁ), 141.94, 141.82,
129.51 (2ꢁ), 129.09, 127.07 (2ꢁ), 126.07, 125.97, 125.86, 119.75,
141.12, 137.73, 137.18, 129.12, 128.80 (2ꢁ), 127.45, 127.26 (2ꢁ),
126.17, 126.07 (2ꢁ), 104.46 (2ꢁ), 60.94, 56.21 (2ꢁ).
112.98, 112.76, 55.29, 21.09.
4.2.4. Compound (5d). Yield¼48% (70 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C19H14FO2 293.0978, found 293.0982; 1H
4.2.10. Compound (5j). Yield¼54% (107 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C27H25O3 397.1804, found 397.1812; 1H NMR
NMR (400 MHz, CDCl3):
d
7.73 (t, J¼2.4 Hz, 1H), 7.55e7.47 (m, 3H),
(400 MHz, CDCl3):
d
7.83 (t, J¼1.6 Hz, 1H), 7.77e7.63 (m, 7H),
7.44e7.42 (m, 2H), 7.37e7.34 (m, 1H), 7.14 (s, 1H), 7.12 (dd, J¼1.6,
8.4 Hz, 1H), 7.11e7.06 (m, 1H), 6.92 (dd, J¼1.6, 8.4 Hz, 1H), 6.02 (s,
7.59e7.47 (m, 4H), 7.41e7.37 (m, 1H), 6.87 (s, 2H), 3.96 (s, 6H), 3.94
(s, 3H); 13C NMR (100 MHz, CDCl3):
d
153.48 (2ꢁ), 142.02, 141.28,
2H); 13C NMR (100 MHz, CDCl3):
d
163.17 (d, J¼244.1 Hz), 148.17,
140.57, 140.33, 139.96, 137.75, 137.16, 129.18, 128.80 (2ꢁ), 127.59
(2ꢁ), 127.52 (2ꢁ), 127.38, 127.00 (2ꢁ), 126.15, 126.04, 125.92, 104.57
(2ꢁ), 60.93, 56.20 (2ꢁ).
147.25, 143.40 (d, J¼7.6 Hz), 141.58, 140.43 (d, J¼2.3 Hz), 135.23,
130.21 (d, J¼8.4 Hz), 129.24, 126.36, 125.73, 125.67, 122.81 (d,
J¼3.0 Hz),120.72, 114.14 (d, J¼21.3 Hz), 114.07 (d, J¼21.9 Hz),108.60,
107.69, 101.17.
4.2.11. Compound (5k). Yield¼50% (78 mg); mp¼135e136 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C23H19O 311.1436, found 311.1435; 1H NMR (400 MHz, CDCl3):
4.2.5. Compound (5e). Yield¼54% (78 mg); mp¼89e90 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C20H17O2 289.1229, found 289.1232; 1H NMR (400 MHz, CDCl3):
d
8.13e8.12 (m, 1H), 7.97e7.89 (m, 4H), 7.83 (dd, J¼1.6, 8.4 Hz, 1H),
7.70e7.50 (m, 7H), 7.04 (d, J¼8.4 Hz, 2H), 3.89 (s, 3H); 13C NMR
d
7.76e7.75 (m, 1H), 7.57 (d, J¼8.0 Hz, 2H), 7.56e7.54 (m, 1H),
(100 MHz, CDCl3): d 159.28, 141.61, 141.46, 138.58, 133.69, 133.66,
7.52e7.48 (m, 2H), 7.30 (dd, J¼0.8, 8.4 Hz, 2H), 7.16 (s, 1H), 7.15 (dd,
J¼2.0, 8.8 Hz, 1H), 6.93 (dd, J¼0.8, 8.0 Hz, 1H), 6.02 (s, 2H), 2.44 (s,
132.66, 129.22, 128.43, 128.27 (2ꢁ), 128.18, 127.64, 126.30, 125.95
(2ꢁ), 125.88, 125.79 (2ꢁ), 125.63, 114.25 (2ꢁ), 55.33; Anal. Calcd for
3H); 13C NMR (100 MHz, CDCl3):
d
148.10, 147.12, 141.65, 141.39,
C23H18O: C, 89.00; H, 5.85. Found: C, 89.31; H, 6.01.
138.23, 137.16, 135.59, 129.49 (2ꢁ), 129.08, 127.04 (2ꢁ), 125.64,
125.59, 125.54, 120.70, 108.56, 107.74, 101.12, 21.08; Anal. Calcd for
4.2.12. Compound (5l). Yield¼40% (51 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C16H12FS 255.0644, found 255.0646; 1H NMR
C
20H16O2: C, 83.31; H, 5.59. Found: C, 83.52; H, 5.80.
(400 MHz, CDCl3):
d
7.79 (t, J¼1.6 Hz,1H), 7.62 (dt, J¼1.6, 6.8 Hz,1H),
4.2.6. Compound (5f). Yield¼60% (91 mg); mp¼165e166 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C20H17O3 305.1178, found 305.1182; 1H NMR (400 MHz, CDCl3):
7.50e7.31 (m, 7H), 7.11 (dd, J¼3.6, 5.2 Hz,1H), 7.10e7.05 (m,1H); 13
C
NMR (100 MHz, CDCl3):
d
163.19 (d, J¼244.8 Hz), 144.03, 143.16 (d,
J¼7.6 Hz), 135.06, 130.28 (d, J¼9.1 Hz), 129.43, 128.07, 126.23,
125.44,125.12,125.12,124.76,123.45,122.84 (d, J¼3.0 Hz),114.31 (d,
J¼21.2 Hz), 114.11 (d, J¼21.9 Hz).
d
7.71e7.70 (m,1H), 7.59 (d, J¼8.8 Hz, 2H), 7.53e7.46 (m, 3H), 7.14 (s,
1H), 7.13 (dd, J¼2.0, 8.8 Hz, 1H), 7.01 (d, J¼9.2 Hz, 2H), 6.91 (dd,
J¼0.8, 8.0 Hz, 1H), 6.02 (s, 2H), 3.87 (s, 3H); 13C NMR (100 MHz,
CDCl3):
d
159.24, 148.11, 147.12, 141.41, 141.33, 135.62, 133.65, 129.10,
4.2.13. Compound (5m). Yield¼42% (53 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C17H15S 251.0895, found 251.0902; 1H NMR
128.21 (2ꢁ), 125.42, 125.37, 125.25, 120.70, 114.22 (2ꢁ), 108.56,
107.74, 101.14, 55.32; Anal. Calcd for C20H16O3: C, 78.93; H, 5.30.
Found: C, 79.12; H, 5.45. Single-crystal X-ray diagram: crystal of
compound 5f was grown by slow diffusion of EtOAc into a solution
of compound 5f in CH2Cl2 to yield colorless prisms. The compound
crystallizes in the monoclinic crystal system, space group P 1 21/c 1,
(400 MHz, CDCl3):
d
7.87 (dt, J¼0.4, 1.6 Hz, 1H), 7.63 (ddd, J¼1.2, 1.6,
7.6 Hz, 1H), 7.59 (d, J¼8.0 Hz, 2H), 7.56e7.53 (m, 1H), 7.49 (dt, J¼0.4,
7.6 Hz, 1H), 7.42 (dd, J¼0.4, 3.6 Hz, 1H), 7.35e7.31 (m, 3H), 7.15 (dd,
J¼3.6, 5.2 Hz, 1H), 2.46 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 144.37,
141.85, 137.96, 137.28, 134.80, 129.50 (2ꢁ), 129.22, 127.98, 127.01
(2ꢁ), 126.14, 124.86, 124.64, 124.60, 123.24, 21.80.
3
ꢀ
ꢀ
ꢀ
ꢀ
a¼15.2923(13) A, b¼7.2462(6) A, c¼13.8147(11) A, V¼1468.1(2) A ,
Z¼4, dcalcd¼1.377 g/cm3, F(000)¼640, 2
q
range 1.39e26.43ꢀ, R in-
dices (all data) R1¼0.0516, wR2¼0.0966.
4.2.14. Compound (5n). Yield¼50% (67 mg); mp¼110e111 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C17H15OS 267.0844, found 267.0841; 1H NMR (400 MHz, CDCl3):
4.2.7. Compound (5g). Yield¼62% (100 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C23H17O2 325.1229, found 325.1236; 1H NMR
d
7.80 (t, J¼1.6 Hz,1H), 7.58 (d, J¼8.8 Hz, 2H), 7.58e7.56 (m,1H), 7.48
(400 MHz, CDCl3):
d
8.10 (d, J¼1.2 Hz, 1H), 7.96e7.87 (m, 4H), 7.80
(dt, J¼1.6, 8.0 Hz, 1H), 7.44 (t, J¼7.6 Hz, 1H), 7.38 (dd, J¼1.2, 3.6 Hz,
1H), 7.31 (dd, J¼1.2, 5.2 Hz, 1H), 7.11 (dd, J¼3.6, 5.2 Hz, 1H), 7.02 (d,
(dd, J¼2.0, 8.4 Hz, 1H), 7.70e7.67 (m, 1H), 7.56e7.48 (m, 4H), 7.18 (s,
1H), 7.17 (dd, J¼2.4, 8.8 Hz, 1H), 6.94 (dd, J¼0.8, 8.8 Hz, 1H), 6.03 (s,
J¼8.8 Hz, 2H), 3.87 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 159.32,
2H); 13C NMR (100 MHz, CDCl3):
d
148.16, 147.21, 141.65, 141.58,
144.41, 141.52, 134.82, 133.38, 129.24, 128.21 (2ꢁ), 127.99, 125.92,
138.46, 135.54, 133.67, 132.69,129.24,128.46, 128.20, 127.64, 126.33,
126.11, 126.05, 125.98, 125.92, 125.90, 125.59, 120.78, 108.62, 107.78,
101.18.
124.86, 124.43, 124.31, 123.23, 114.24 (2ꢁ), 55.34; Anal. Calcd for
C
17H14OS: C, 76.66; H, 5.30. Found: C, 76.85; H, 5.13.
4.2.15. Compound (5o). Yield¼48% (69 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C20H15S 287.0895, found 287.0899; 1H NMR
4.2.8. Compound (5h). Yield¼60% (109 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C22H21O5 365.1389, found 365.1392; 1H NMR
(400 MHz, CDCl3):
d
8.10 (d, J¼1.2 Hz, 1H), 7.98e7.89 (m, 4H), 7.80
(400 MHz, CDCl3):
d
7.67 (br s, 1H), 7.52e7.46 (m, 3H), 7.12 (s, 1H),
(dd, J¼1.6, 8.4 Hz, 1H), 7.65 (J¼8.0 Hz, 1H), 7.65 (d, J¼7.6 Hz, 1H),
7.56e7.49 (m, 3H), 7.43 (dd, J¼0.8, 3.6 Hz, 1H), 7.34 (dd, J¼1.2,
7.11 (dd, J¼2.0, 8.4 Hz, 1H), 6.91 (dd, J¼0.8, 8.4 Hz, 1H), 6.81 (s, 2H),

M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
9621
5.2 Hz, 1H), 7.14 (dd, J¼3.6, 5.2 Hz, 1H); 13C NMR (100 MHz, CDCl3):
128.28 (2ꢁ), 124.02, 123.95, 123.72, 114.13 (2ꢁ), 55.34, 34.78,
31.40 (3ꢁ).
d
144.30, 141.56, 138.19, 134.99, 133.63, 132.72, 129.38, 128.49,
128.21, 128.05, 127.65, 126.59, 126.36, 126.05, 125.92, 125.51, 125.09,
124.99 (2ꢁ), 123.38.
4.2.23. Compound (6a). Yield¼36% (69 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C25H21O2S 385.1262, found 385.1263; 1H NMR
4.2.16. Compound (5p). Yield¼62% (101 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C19H19O3S 327.1055, found 327.1056; 1H NMR
(400 MHz, CDCl3):
d
8.47 (d, J¼8.4 Hz, 1H), 7.77 (dd, J¼2.0, 8.4 Hz,
1H), 7.62e7.59 (m, 2H), 7.47e7.31 (m, 5H), 7.25e7.21 (m, 2H), 7.16 (d,
J¼8.0 Hz, 2H), 7.07e7.04 (m, 2H), 7.01 (d, J¼8.0 Hz, 2H), 2.34 (s, 3H);
(400 MHz, CDCl3):
d
7.77 (d, J¼1.2 Hz, 1H), 7.60 (dt, J¼2.0, 6.8 Hz,
1H), 7.48e7.42 (m, 2H), 7.38 (dd, J¼0.8, 3.6 Hz, 1H), 7.32 (dd, J¼1.2,
5.2 Hz,1H), 7.11 (dd, J¼3.6, 5.2 Hz,1H), 6.81 (s, 2H), 3.95 (s, 6H), 3.92
13C NMR (100 MHz, CDCl3):
d 145.50, 143.32, 142.58, 138.86, 138.56,
138.22, 138.09, 131.20,130.00 (2ꢁ), 129.21, 128.98 (2ꢁ), 128.93 (2ꢁ),
(s, 3H); 13C NMR (100 MHz, CDCl3):
d
153.46 (2ꢁ), 144.15, 142.14,
128.53, 127.77 (2ꢁ), 127.63, 127.30 (2ꢁ), 127.24 (2ꢁ), 125.92, 21.47.
137.79,136.90,134.86,129.24,128.02,136.30,125.02,124.95,124.78,
123.38, 104.55 (2ꢁ), 60.93, 56.22 (2ꢁ).
4.2.24. Compound (6b). Yield¼30% (70 mg); mp¼151e152 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C30H25O3S 465.1524, found 465.1533; 1H NMR (400 MHz,
4.2.17. Compound (5q). Yield¼54% (94 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C23H22FO2 349.1604, found 349.1612; 1H NMR
CDCl3):
d
8.53 (d, J¼8.4 Hz, 1H), 8.08 (d, J¼1.2 Hz, 1H), 7.93e7.84 (m,
(400 MHz, CDCl3):
d
7.55e7.43 (m, 4H), 7.35e7.29 (m, 2H), 7.21 (dt,
4H), 7.74 (dd, J¼1.6, 8.4 Hz, 1H), 7.59 (d, J¼2.0 Hz, 1H), 7.54e7.51 (m,
2H), 7.23 (d, J¼8.0 Hz, 2H), 7.19 (t, J¼3.6 Hz, 1H), 7.04 (d, J¼8.4 Hz,
2H), 6.91 (dd, J¼2.4, 7.6 Hz, 1H), 6.75 (dd, J¼2.4, 7.6 Hz, 1H), 6.51 (t,
J¼2.4 Hz, 1H), 3.71 (s, 3H), 2.35 (s, 3H); 13C NMR (100 MHz, CDCl3):
J¼1.2, 7.6 Hz,1H), 7.16 (ddd, J¼1.2, 8.4,10.8 Hz,1H), 7.02 (d, J¼8.4 Hz,
1H), 6.88 (d, J¼8.4 Hz, 1H), 5.98e5.89 (m, 1H), 4.96 (dq, J¼1.6,
10.4 Hz, 1H), 4.82 (dq, J¼1.6, 17.2 Hz, 1H), 3.92 (s, 3H), 3.89 (s, 3H),
3.42 (dt, J¼1.6, 6.0 Hz, 2H); 13C NMR (100 MHz, CDCl3):
d
159.80 (d,
d 158.49, 145.30, 143.27, 142.34, 139.27, 138.62, 138.01, 135.99,
J¼246.4 Hz), 152.02, 147.38, 141.58, 137.64, 135.58, 135.36, 131.61,
130.78 (d, J¼3.7 Hz), 130.06, 128.97, 128.89, 128.73, 127.93, 127.39
(d, J¼3.1 Hz), 125.41, 124.30 (d, J¼3.0 Hz), 116.08 (d, J¼22.7 Hz),
114.94, 110.24, 60.67, 55.71, 21.83.
133.40, 133.04, 131.04, 129.11, 128.87 (2ꢁ), 128.75, 128.27 (2ꢁ),
127.81 (2ꢁ), 127.59, 126.59, 126.58, 126.53, 126.11, 124.88, 122.63,
114.83, 113.99, 54.93, 21.37; Anal. Calcd for C30H24O3S: C, 77.56; H,
5.21. Found: C, 77.92; H, 4.87.
4.2.18. Compound (5r). Yield¼43% (71 mg); mp¼140e142 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C20H16F3O 329.1153, found 329.1160; 1H NMR (400 MHz, CDCl3):
4.2.25. Compound (6c). Yield¼36% (77 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C27H25O3S 429.1524, found 429.1530; 1H NMR
(400 MHz, CDCl3):
d
8.45 (d, J¼8.4 Hz,1H), 7.76 (dd, J¼2.0, 8.4 Hz,1H),
d
7.76e7.70 (m, 5H), 7.61e7.57 (m, 3H), 7.55e7.52 (m, 2H), 7.02 (d,
7.51 (d, J¼8.4 Hz, 2H), 7.43 (d, J¼2.0 Hz,1H), 7.27e7.25 (m, 2H), 7.19 (d,
J¼8.4 Hz, 2H), 7.15 (t, J¼8.0 Hz, 1H), 7.02 (d, J¼8.0 Hz, 2H), 6.87 (ddd,
J¼0.8, 2.4, 8.4 Hz, 1H), 6.69 (dt, J¼0.8, 7.6 Hz, 1H), 6.46 (t, J¼2.0 Hz,
1H), 3.69 (s, 3H), 2.39 (s, 3H), 2.34 (s, 3H); 13C NMR (100 MHz, CDCl3):
J¼8.8 Hz, 2H), 3.87 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 159.41,
144.78, 141.66 (2ꢁ), 140.29, 133.32, 129.37, 128.25 (2ꢁ), 127.52 (2ꢁ),
126.59 (2ꢁ), 125.77, 125.72 (q, J¼3.8 Hz), 125.60, 114.32 (2ꢁ), 114.27,
55.37; Anal. Calcd for C20H15F3O: C, 73.16; H, 4.60. Found: C, 73.32;
H, 4.35.
d
158.49,145.40,143.23,142.26,139.39,138.61,138.29,138.14,135.91,
130.62, 129.71 (2ꢁ), 129.06, 128.87 (2ꢁ), 128.25, 127.83 (2ꢁ), 127.11
(2ꢁ), 125.66, 122.65, 114.81, 114.01, 54.96, 21.41, 21.12.
4.2.19. Compound (5s). Yield¼40% (70 mg); mp¼84e86 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C23H16F3 349.1204, found 349.1200; 1H NMR (400 MHz, CDCl3):
4.2.26. Compound (6d). Yield¼40% (89 mg); mp¼170e171 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C26H20FO4S 447.1066, found 447.1068; 1H NMR (400 MHz,
d
8.11 (s, 1H), 7.98e7.89 (m, 4H), 7.82e7.74 (m, 6H), 7.63e7.51 (m,
4H); 13C NMR (100 MHz, CDCl3):
d
144.68, 141.97, 140.43, 138.11
CDCl3):
d
8.44 (d, J¼8.4 Hz, 1H), 7.72 (dd, J¼2.0, 8.4 Hz, 1H),
(2ꢁ), 133.65, 132.75, 129.50, 128.58, 128.21, 127.67, 127.55 (4ꢁ),
127.26, 126.45, 126.43, 126.26, 126.14, 125.98, 125.76 (q, J¼3.8 Hz),
125.48; Anal. Calcd for C23H15F3: C, 79.30; H, 4.34. Found: C, 79.62;
H, 4.26.
7.43e7.36 (m, 3H), 7.30e7.27 (m, 1H), 7.26 (d, J¼8.4 Hz, 2H),
7.11e7.06 (m, 1H), 7.08 (d, J¼8.0 Hz, 2H), 6.68 (d, J¼8.0 Hz, 1H), 6.51
(dd, J¼1.6, 8.0 Hz, 1H), 6.42 (d, J¼1.6 Hz, 1H), 5.97 (s, 2H), 2.35 (s,
3H); 13C NMR (100 MHz, CDCl3):
d
163.10 (d, J¼245.6 Hz), 147.21,
146.69, 144.09 (d, J¼3.1 Hz), 143.56, 141.07, 141.00, 139.55, 137.97,
131.51, 131.26, 130.53 (d, J¼8.3 Hz), 129.23 (2ꢁ), 127.79 (2ꢁ), 125.91,
123.76, 122.94, 122.92, 115.35 (d, J¼21.2 Hz), 114.19 (d, J¼22.0 Hz),
110.46,107.20, 101.01, 21.44; Anal. Calcd for C26H19FO4S: C, 69.94; H,
4.29. Found: C, 70.18; H, 4.02.
4.2.20. Compound (5t). Yield¼40% (51 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C16H18NO2 256.1338, found 256.1339; 1H NMR
(400 MHz, CDCl3):
d
8.30 (d, J¼9.2 Hz, 2H), 7.74 (d, J¼8.8 Hz, 2H),
7.62 (br s, 1H), 7.51e7.46 (m, 1H), 7.44e7.43 (m, 2H), 1.39 (s, 9H); 13
NMR (100 MHz, CDCl3): 152.18, 148.30, 138.60, 128.89, 127.91
C
d
(2ꢁ), 126.01, 125.51, 124.62, 124.42, 124.04 (2ꢁ), 34.88, 31.34 (3ꢁ).
4.2.27. Compound (6e). Yield¼32% (71 mg); mp¼161ee162 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C27H23O4S 443.1317, found 443.1320; 1H NMR (400 MHz,
4.2.21. Compound (5u). Yield¼43% (46 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C14H17S 217.1051, found 217.1055; 1H NMR
CDCl3):
d
8.42 (d, J¼8.4 Hz, 1H), 7.73 (dd, J¼2.0, 8.4 Hz, 1H), 7.50 (d,
(400 MHz, CDCl3):
d
7.64 (dd, J¼1.2, 2.4 Hz, 1H), 7.45e7.43 (m, 1H),
J¼8.4 Hz, 2H), 7.40 (d, J¼2.0 Hz, 1H), 7.28e7.24 (m, 4H), 7.07 (d,
J¼8.0 Hz, 2H), 6.68 (d, J¼8.0 Hz, 1H), 6.53 (dd, J¼1.6, 8.0 Hz, 1H),
6.43 (d, J¼2.0 Hz,1H), 5.97 (s, 2H), 2.39 (s, 3H), 2.36 (s, 3H); 13C NMR
7.35e7.30 (m, 3H), 7.28 (dd, J¼1.2, 5.2 Hz,1H), 7.11 (dd, J¼3.6, 5.2 Hz,
1H),1.37 (s, 9H); 13C NMR (100 MHz, CDCl3):
d
151.77,145.05,134.10,
128.58, 127.89, 124.64, 124.56, 123.32, 123.14, 122.96, 34.73, 31.31
(100 MHz, CDCl3): d 147.10, 146.63, 145.42, 143.40, 141.95, 138.59,
(3ꢁ).
138.57, 138.23, 135.88, 131.87, 130.98, 129.70 (2ꢁ), 129.13, 128.85
(2ꢁ), 127.77 (2ꢁ), 127.08 (2ꢁ), 125.63, 123.79, 110.54, 107.16, 100.98,
21.44, 21.10; Anal. Calcd for C27H22O4S: C, 73.28; H, 5.01. Found: C,
73.60; H, 5.38.
4.2.22. Compound (5v). Yield¼50% (60 mg); colorless oil; HRMS
(ESI, Mþþ1) calcd for C17H21O 241.1592, found 241.1596; 1H NMR
(400 MHz, CDCl3):
d
7.57e7.56 (m, 1H), 7.53 (d, J¼8.8 Hz, 2H),
7.37e7.34 (m, 3H), 6.99 (d, J¼8.4 Hz, 2H), 3.86 (s, 3H), 1.38 (s, 9H);
4.2.28. Compound (6f). Yield¼34% (78 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C27H23O5S 459.1266, found 459.1262; 1H NMR
13C NMR (100 MHz, CDCl3):
d
159.03, 151.53, 134.44, 130.06, 128.40,

9622
M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
(400 MHz, CDCl3):
d
8.40 (d, J¼8.4 Hz, 1H), 7.70 (dd, J¼2.0, 8.4 Hz,
143.26, 142.44, 138.17, 138.11, 135.85, 132.47, 132.34, 131.16, 130.56,
129.18, 128.84, 128.73 (2ꢁ), 128.43 (2ꢁ), 128.00, 127.95, 127.68 (2ꢁ),
127.58, 126.64, 126.26, 126.06, 125.40, 114.45 (2ꢁ), 55.32, 21.32.
1H), 7.54 (d, J¼9.2 Hz, 2H), 7.36 (d, J¼2.0 Hz, 1H), 7.26 (d, J¼8.4 Hz,
2H), 7.07 (d, J¼8.0 Hz, 2H), 6.97 (d, J¼8.8 Hz, 2H), 6.68 (d, J¼8.0 Hz,
1H), 6.52 (dd, J¼1.6, 8.0 Hz, 1H), 6.42 (d, J¼1.6 Hz, 1H), 5.97 (s, 2H),
3.84 (s, 3H), 2.35 (s, 3H); 13C NMR (100 MHz, CDCl3):
d
160.13,
4.2.34. Compound (6l). Yield¼43% (88 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C23H18FO2S2 409.0732, found 409.0736; 1H
147.10, 146.63, 145.06, 143.38, 141.96, 138.29, 138.18, 131.92, 131.14,
130.65,129.18,128.85 (2ꢁ),128.40 (2ꢁ),127.77 (2ꢁ), 125.28,123.78,
114.42 (2ꢁ), 110.54, 107.16, 100.98, 55.33, 21.44.
NMR (400 MHz, CDCl3):
d
8.50 (d, J¼8.0 Hz, 1H), 7.75 (dd, J¼2.0,
8.4 Hz, 1H), 7.53 (d, J¼2.0 Hz, 1H), 7.45e7.36 (m, 2H), 7.31e7.25 (m,
4H), 7.21 (dd, J¼1.2, 3.6 Hz, 1H), 7.12e7.08 (m, 1H), 7.06 (d, J¼8.0 Hz,
2H), 7.02 (dd, J¼3.6, 5.2 Hz, 1H), 2.34 (s, 3H); 13C NMR (100 MHz,
4.2.29. Compound (6g). Yield¼26% (62 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C30H23O4S 479.1317, found 479.1321; 1H NMR
CDCl3):
d
163.15 (d, J¼245.6 Hz), 144.11, 143.56, 140.85 (d, J¼7.6 Hz),
(400 MHz, CDCl3):
d
8.49 (d, J¼8.0 Hz, 1H), 8.07 (d, J¼1.2 Hz, 1H),
140.17, 137.41, 137.36, 135.01, 132.52, 130.96, 130.60 (d, J¼8.3 Hz),
129.79, 129.02 (2ꢁ), 127.74 (2ꢁ), 127.11, 126.67, 126.58, 123.01 (d,
J¼3.0 Hz), 115.51 (d, J¼21.2 Hz), 114.28 (d, J¼21.8 Hz), 21.53.
7.93e7.85 (m, 4H), 7.72 (dd, J¼2.0, 8.4 Hz, 1H), 7.55e7.51 (m, 3H),
7.30 (d, J¼8.0 Hz, 2H), 7.09 (d, J¼8.0 Hz, 2H), 6.71 (d, J¼8.4 Hz, 1H),
6.58 (dd, J¼1.6, 8.4 Hz, 1H), 6.48 (d, J¼1.6 Hz, 1H), 5.99 (s, 2H), 2.37
(s, 3H); 13C NMR (100 MHz, CDCl3):
d
147.17, 146.68, 145.38, 143.47,
4.2.35. Compound (6m). Yield¼38% (77 mg); mp¼138e139 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C24H21O2S2 405.0983, found 405.0986; 1H NMR (400 MHz,
142.08, 138.95, 138.18, 136.04, 133.43, 133.08, 131.47, 129.24, 128.88
(2ꢁ), 128.77, 128.30, 127.80 (2ꢁ), 127.73, 127.63, 127.61 (2ꢁ), 126.55,
126.13, 124.92, 123.83, 110.56, 107.21, 101.01, 21.45.
CDCl3):
d
8.47 (d, J¼8.4 Hz, 1H), 7.75 (dd, J¼1.6, 8.0 Hz, 1H), 7.55 (d,
J¼1.6 Hz, 1H), 7.50 (d, J¼8.0 Hz, 2H), 7.29e7.25 (m, 5H), 7.21 (dd,
4.2.30. Compound (6h). Yield¼24% (62 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C29H27O7S 519.1478, found 519.1482; 1H NMR
J¼1.6, 8.0 Hz, 1H), 7.06 (d, J¼8.4 Hz, 2H), 7.02 (dd, J¼3.6, 5.2 Hz, 1H),
2.40 (s, 3H), 2.34 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 145.42,
(400 MHz, CDCl3):
d
8.41 (d, J¼8.4 Hz, 1H), 7.71 (dd, J¼2.0, 8.4 Hz,
143.39, 139.17, 138.73, 137.74, 137.64, 135.69, 134.75, 132.26, 130.78,
129.75 (2ꢁ), 129.68, 128.97 (2ꢁ), 127.70 (2ꢁ), 127.13 (2ꢁ), 126.91,
126.58, 126.30, 21.51, 21.14; Anal. Calcd for C24H20O2S2: C, 71.25; H,
4.98. Found: C, 71.52; H, 5.27.
1H), 7.34 (d, J¼2.0 Hz, 1H), 7.25 (d, J¼8.4 Hz, 2H), 7.07 (d, J¼8.0 Hz,
2H), 6.76 (s, 2H), 6.68 (d, J¼8.0 Hz, 1H), 6.52 (dd, J¼1.6, 8.0 Hz, 1H),
6.42 (d, J¼1.6 Hz, 1H), 5.97 (s, 2H), 3.90 (s, 6H), 3.88 (s, 3H), 2.35 (s,
3H); 13C NMR (100 MHz, CDCl3):
d
153.59 (2ꢁ), 147.16, 146.65,
145.56, 143.48, 141.95, 138.88, 138.10, 134.63, 131.68, 131.06, 129.87,
129.12, 128.86 (2ꢁ), 127.74 (2ꢁ), 125.86, 123.79, 110.51, 107.17,
104.59 (2ꢁ), 101.01, 60.88, 56.22 (2ꢁ), 21.43.
4.2.36. Compound (6n). Yield¼36% (76 mg); mp¼115e116 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C24H21O3S2 421.0932, found 421.0938; 1H NMR (400 MHz,
CDCl3):
d
8.45 (d, J¼8.4 Hz, 1H), 7.72 (dd, J¼2.0, 8.4 Hz, 1H), 7.54 (d,
4.2.31. Compound (6i). Yield¼23% (55 mg); mp¼202e204 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C28H27O5S 475.1579, found 475.1574; 1H NMR (400 MHz, CDCl3):
J¼8.8 Hz, 2H), 7.52 (d, J¼2.0 Hz, 1H), 7.29e7.27 (m, 1H), 7.26 (d,
J¼8.4 Hz, 2H), 7.58 (dd, J¼1.2, 3.6 Hz,1H), 7.05 (d, J¼8.0 Hz, 2H), 7.01
(dd, J¼3.6, 5.2 Hz, 1H), 6.97 (d, J¼8.4 Hz, 2H), 3.84 (s, 3H), 2.33 (s,
d
8.48 (d, J¼8.4 Hz, 1H), 7.78 (dd, J¼2.0, 8.4 Hz, 1H), 7.63e7.61 (m,
3H); 13C NMR (100 MHz, CDCl3):
d 160.20, 145.03, 143.36, 138.76,
2H), 7.48e7.38 (m, 4H), 7.20 (d, J¼8.4 Hz, 2H), 7.04 (d, J¼8.0 Hz, 2H),
137.77, 137.67, 134.74, 131.90, 130.90, 130.74, 129.69, 128.96 (2ꢁ),
128.43 (2ꢁ), 127.66 (2ꢁ), 126.87, 126.57, 125.91, 114.46 (2ꢁ), 55.34,
21.49; Anal. Calcd for C24H20O3S2: C, 68.54; H, 4.79. Found: C, 68.85;
H, 4.58.
6.20 (s, 2H), 3.91 (s, 3H), 3.69 (s, 6H), 2.33 (s, 3H); 13C NMR
(100 MHz, CDCl3):
d
152.04 (2ꢁ), 145.53, 143.18, 142.22, 138.85,
138.79, 138.03, 137.43, 133.18, 130.74, 129.00 (2ꢁ), 128.94, 128.81
(2ꢁ), 128.59, 127.88 (2ꢁ), 127.27 (2ꢁ), 125.91, 107.43 (2ꢁ), 60.90,
55.77 (2ꢁ), 21.35; Anal. Calcd for C28H26O5S: C, 70.86; H, 5.52.
Found: C, 70.96; H, 5.74. Single-crystal X-ray diagram: crystal of
compound 6i was grown by slow diffusion of EtOAc into a solution
of compound 6i in CH2Cl2 to yield colorless prisms. The compound
crystallizes in the triclinic crystal system, space group Pꢂ1,
4.2.37. Compound (6o). Yield¼40% (88 mg); mp¼169e170 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C27H21O2S2 441.0983, found 441.0982; 1H NMR (400 MHz,
CDCl3):
d
8.53 (d, J¼8.4 Hz, 1H), 8.07 (d, J¼2.0 Hz, 1H), 7.94e7.84 (m,
4H), 7.72 (dd, J¼1.6, 8.4 Hz, 1H), 7.69 (d, J¼2.0 Hz, 1H), 7.55e7.50 (m,
2H), 7.30 (dd, J¼0.8, 3.6 Hz, 1H), 7.28 (d, J¼8.4 Hz, 2H), 7.24 (dd,
J¼1.2, 5.2 Hz, 1H), 7.07 (d, J¼8.0 Hz, 2H), 7.04 (dd, J¼3.6, 5.2 Hz, 1H),
3
ꢀ
ꢀ
ꢀ
ꢀ
a¼9.918(3) A, b¼11.088(3) A, c¼11.599(3) A, V¼1166.7(5) A , Z¼2,
dcalcd¼1.351 g/cm3, F(000)¼500, 2
q
range 1.91e26.39ꢀ, R indices (all
data) R1¼0.0544, wR2¼0.1623.
2.35 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 145.44, 143.48, 139.60,
137.70, 137.62, 135.90, 134.93, 133.47, 133.17, 132.75, 130.92, 129.80,
129.03 (2ꢁ), 128.87, 128.37, 127.76 (2ꢁ), 127.69, 127.01, 126.82,
126.73 (2ꢁ), 126.67 (2ꢁ), 124.95, 21.54; Anal. Calcd for C27H20O2S2:
C, 73.61; H, 4.58. Found: C, 73.75; H, 4.67.
4.2.32. Compound (6j). Yield¼20% (55 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C34H31O5S 551.1892, found 551.1899; 1H NMR
(400 MHz, CDCl3):
d
8.47 (d, J¼8.4 Hz, 1H), 7.75 (dd, J¼2.0, 8.4 Hz,
1H), 7.65e7.62 (m, 2H), 7.52e7.41 (m, 6H), 7.19 (d, J¼8.4 Hz, 2H),
7.13 (d, J¼8.4 Hz, 2H), 6.99 (d, J¼8.0 Hz, 2H), 6.79 (s, 2H), 3.92 (s,
3H), 3.91 (s, 3H), 3.89 (s, 3H), 2.34 (s, 3H); 13C NMR (100 MHz,
4.2.38. Compound (6p). Yield¼30% (72 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C25H25O5S2 481.1144, found 481.1145; 1H NMR
CDCl3):
d
153.67 (2ꢁ), 153.02, 145.67, 143.42, 142.20, 140.68, 140.60,
(400 MHz, CDCl3):
d
8.47 (d, J¼8.4 Hz, 1H), 7.73 (dd, J¼2.0, 8.4 Hz,
138.79, 138.72, 137.18, 134.69, 130.93, 130.51 (2ꢁ), 129.22, 128.90
(2ꢁ), 127.83 (2ꢁ), 127.57, 127.05 (2ꢁ), 125.96 (2ꢁ), 125.94 (2ꢁ),
105.85, 104.67 (2ꢁ), 60.95, 56.29 (2ꢁ), 21.53.
1H), 7.50 (d, J¼2.0 Hz, 1H), 7.29 (dd, J¼1.6, 5.2 Hz, 1H), 7.25 (d,
J¼8.0 Hz, 2H), 7.21 (dd, J¼0.8, 3.6 Hz,1H), 7.05 (d, J¼8.0 Hz, 2H), 7.03
(dd, J¼3.6, 5.2 Hz, 1H), 6.76 (s, 2H), 3.91 (s, 6H), 3.88 (s, 3H), 2.34 (s,
3H); 13C NMR (100 MHz, CDCl3):
d
153.65 (2ꢁ), 145.58, 143.46,
4.2.33. Compound (6k). Yield¼32% (74 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C30H25O3S 465.1524, found 465.1532; 1H NMR
139.49, 137.57, 135.51, 134.75, 134.44, 132.35, 130.86, 129.65, 128.98
(2ꢁ), 127.67 (2ꢁ), 127.00, 126.63, 126.54, 104.66 (2ꢁ), 60.92, 56.27
(2ꢁ), 21.50.
(400 MHz, CDCl3):
d
8.47 (d, J¼8.1 Hz, 1H), 7.87 (d, J¼7.6 Hz, 1H),
7.78e7.73 (m, 2H), 7.61e7.47 (m, 6H), 7.30e7.27 (m, 2H), 7.06 (d,
J¼8.4 Hz, 2H), 6.97 (d, J¼8.8 Hz, 2H), 6.77 (d, J¼8.4 Hz, 2H), 3.84 (s,
4.2.39. Compound (6q). Yield¼33% (83 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C30H28FO4S 503.1692, found 503.1695; 1H
3H), 2.23 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 160.13, 145.09,

M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
9623
NMR (400 MHz, CDCl3):
d
8.47 (d, J¼8.4 Hz, 1H), 7.75 (dt, J¼1.6,
(400 MHz, CDCl3):
d
8.28 (d, J¼8.4 Hz, 1H), 7.53 (dd, J¼2.0, 8.4 Hz,
8.4 Hz, 1H), 7.40e7.29 (m, 3H), 7.24e7.05 (m, 6H), 6.75 (d, J¼8.4 Hz,
1H), 6.32 (d, J¼8.4 Hz, 1H), 5.69e5.59 (m, 1H), 4.80 (dq, J¼1.6,
10.0 Hz, 1H), 4.58 (dq, J¼1.6, 17.2 Hz, 1H), 3.92 (s, 3H), 3.80 (s, 3H),
2.90e2.84 (m, 1H), 2.37 (s, 3H), 2.16 (ddt, J¼1.2, 10.0, 17.2 Hz, 1H);
1H), 7.17 (br s, 1H), 7.16 (d, J¼8.0 Hz, 2H), 7.01 (d, J¼8.0 Hz, 2H), 6.93
(d, J¼8.4 Hz, 2H), 6.75 (d, J¼8.8 Hz, 2H), 3.85 (s, 3H), 2.32 (s, 3H), 1.31
(s, 9H); 13C NMR (100 MHz, CDCl3):
d 159.10, 156.43, 143.06, 141.52,
138.35, 137.21, 131.21 (2ꢁ), 131.09, 129.98, 128.77 (2ꢁ), 128.43,
13C NMR (100 MHz, CDCl3):
d
159.74 (d, J¼247.8 Hz), 152.53, 146.80,
127.67 (2ꢁ), 124.32, 112.56 (2ꢁ), 55.28, 34.98, 30.97 (3ꢁ), 21.41.
143.63, 140.30, 139.88, 138.96, 137.79, 137.01, 133.78 (d, J¼3.0 Hz),
132.72, 130.58 (d, J¼3.0 Hz), 130.15 (d, J¼7.6 Hz), 130.08, 129.07
(2ꢁ), 128.70, 128.36, 128.31, 128.08 (2ꢁ), 126.87, 124.55 (d,
J¼3.8 Hz), 116.32 (d, J¼22.7 Hz), 114.88, 109.34, 60.53, 55.75, 32.50,
21.55.
Acknowledgements
The authors would like to thank the National Science Council of
the Republic of China for its financial support (NSC 102-2113-M-
037-005-MY2).
4.2.40. Compound (6r). Yield¼35% (84 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C27H22F3O3S 483.1242, found 483.1250; 1H
Supplementary data
NMR (400 MHz, CDCl3):
d
8.48 (d, J¼8.4 Hz, 1H), 7.75 (dd, J¼2.0,
8.4 Hz, 1H), 7.70 (s, 4H), 7.41 (d, J¼2.0 Hz, 1H), 7.18 (d, J¼8.4 Hz, 2H),
Scanned photocopies of 1H and 13C NMR spectral data were
supported. Supplementary data related to this article can be found
at http://dx.doi.org/10.1016/j.tet.2013.09.036.
7.03 (d, J¼8.8 Hz, 2H), 6.97 (d, J¼8.8 Hz, 2H), 6.78 (d, J¼8.8 Hz, 2H),
3.86 (s, 3H), 2.34 (s, 3H); 13C NMR (100 MHz, CDCl3):
d 159.43,
143.93, 143.50 (2ꢁ), 142.71, 142.50, 139.89, 137.92, 131.72, 131.21
(4ꢁ), 130.23, 129.43, 128.94 (2ꢁ), 127.81 (2ꢁ), 127.68 (2ꢁ), 125.98,
125.92 (q, J¼3.8 Hz), 112.79 (2ꢁ), 55.36, 21.51.
References and notes
1. (a) Liu, J.-K. Chem. Rev. 2006, 106, 2209; (b) Mullen, K.; Wegner, G. Electronic
Materials: the Oligomer Approach; Wiley-VCH: Weinhein, Germany, 1988; (c)
Cook, T. R.; Zheng, Y. R.; Stang, P. J. Chem. Rev. 2013, 113, 734.
4.2.41. Compound (6s). Yield¼38% (95 mg); mp¼216e218 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C30H22F3O2S 503.1293, found 503.1289; 1H NMR (400 MHz,
2. (a) Ohkanda, J.; Lockman, J. W.; Kothare, M. A.; Qian, Y.; Blaskovich, M. A.; Sebti,
S. M.; Hamilton, A. D. J. Med. Chem. 2002, 45, 177; (b) Roberti, M.; Pizzirani, D.;
Recanatini, M.; Simoni, D.; Grimaudo, S.; Di Cristina, A.; Abbadessa, V.; Gebbia,
N.; Tolomeo, M. J. Med. Chem. 2006, 49, 3012; (c) Lin, J. M.; Gowda, A. S. P.;
Sharma, A. K.; Amin, S. Bioorg. Med. Chem. 2012, 20, 3202; (d) Guo, H.; Hu, H.;
Liu, S.; Liu, X.; Zhou, Y.; Che, Y. J. Nat. Prod. 2007, 70, 1519; (e) Zhang, C.; On-
deyka, J. G.; Herath, K. B.; Guan, Z.; Collado, J.; Pelaez, F.; Leavitt, P. S.; Gurnett,
A.; Nare, B.; Liberator, P.; Singh, S. B. J. Nat. Prod. 2006, 69, 710; (f) Simoni, D.;
Giannini, G.; Roberti, M.; Rondanin, R.; Baruchello, R.; Rossi, M.; Grisolia, G.;
Invidiata, F. P.; Aiello, S.; Marino, S.; Cavallini, S.; Siniscalchi, A.; Gebbia, N.;
Crosta, L.; Grimaudo, S.; Abbadessa, V.; Di Cristina, A.; Tolomeo, M. J. Med. Chem.
2005, 48, 4293; (g) Bugarcic, T.; Novakova, O.; Halamikova, A.; Zerzankova, L.;
Vrana, O.; Kasparkova, J.; Habtemariam, A.; Parsons, S.; Sadler, P. J.; Brabec, V. J.
Med. Chem. 2008, 51, 5310; (h) Patrick, D. A.; Ismail, M. A.; Arafa, R. K.; Wenzler,
T.; Zhu, X.; Pandharkar, T.; Jones, S. K.; Werbovetz, K. A.; Brun, R.; Boykin, D. W.;
Tidwell, R. R. J. Med. Chem. 2013, 56, 5473; (i) Bakunov, S. A.; Bakunova, S. M.;
Wenzler, T.; Ghebru, M.; Werbovetz, K. A.; Brun, R.; Tidwell, R. R. J. Med. Chem.
2010, 53, 254.
3. (a) Perato, S.; Voisin-Chiret, A. S.; Santos, J. S. O.; Legay, R.; Oulyadi, H.; Rault, S.
Tetrahedron 2012, 68, 1910; (b) Guillen, E.; Hierrezuelo, J.; Martinez-Mallorquin,
R.; Lopez-Romero, J. M.; Rico, R. Tetrahedron 2011, 67, 2555; (c) De Giorgi, M.;
Voisin-Chiret, A. S.; Santos, J. S. O.; Corbo, F.; Franchini, C.; Rault, S. Tetrahedron
2011, 67, 6145; (d) Zhang, X.; Xie, W.; Chen, W. Tetrahedron 2010, 66, 1188; (e)
Voisin-Chiret, A. S.; Muraglia, M.; Burzicki, G.; Perato, S.; Corbo, F.; Santos, J. S.
O.; Franchini, C.; Rault, S. Tetrahedron 2010, 66, 8000; (f) King, B. T.; Kroulik, J.;
Robertson, C. R.; Rempala, P.; Hilton, C. L.; Korinek, J. D.; Gortari, L. M. J. Org.
Chem. 2007, 72, 2279; (g) Goto, H.; Furusho, Y.; Miwa, K.; Yashima, E. J. Am.
Chem. Soc. 2009, 131, 4710; (h) Ormsby, J. L.; Black, T. D.; Hilton, C. L.; Bharat;
King, B. T. Tetrahedron 2008, 64, 11370; (i) Mitchell, P. S. R.; Sengul, I. F.; Kan-
demir, H.; Nugent, S. J.; Chen, R.; Bowyer, P. K.; Kumar, N.; Black, D. S. Tetra-
hedron 2012, 68, 8163; (j) Kikuchi, H.; Matsuo, Y.; Katou, Y.; Kubohara, Y.;
Oshima, Y. Tetrahedron 2012, 68, 8884; (k) Dohi, T.; Kamitanaka, T.; Watanabe,
S.; Hu, Y.; Washimi, N.; Kita, Y. Chem.dEur. J. 2012, 18, 13614.
CDCl3):
d
8.55 (d, J¼8.4 Hz, 1H), 7.88 (d, J¼8.0 Hz, 1H), 7.82 (dd,
J¼2.0, 8.4 Hz, 1H), 7.75 (d, J¼8.0 Hz, 1H), 7.72 (s, 4H), 7.61 (d,
J¼8.0 Hz, 1H), 7.56e7.48 (m, 3H), 7.29e7.26 (m, 2H), 7.05 (d,
J¼8.4 Hz, 2H), 6.78 (d, J¼8.0 Hz, 2H), 2.23 (s, 3H); 13C NMR
(100 MHz, CDCl3):
d 143.97, 143.55, 142.77, 142.43, 139.94, 137.79,
135.37, 132.56, 132.34, 131.40, 129.34, 128.91, 128.82 (2ꢁ), 128.05,
127.96, 127.84, 127.77 (4ꢁ), 127.70 (2ꢁ), 127.64, 126.81, 126.45,
126.30, 126.22, 125.95 (q, J¼3.8 Hz), 21.35; Anal. Calcd for
C
30H21F3O2S: C, 71.70; H, 4.21. Found: C, 71.91; H, 4.38. Single-
crystal X-ray diagram: crystal of compound 6s was grown
by slow diffusion of EtOAc into a solution of compound 6s in
CH2Cl2 to yield colorless prisms. The compound crystallizes in the
ꢀ
monoclinic crystal system, space group P 1 21/c 1, a¼5.8615(4) A,
3
ꢀ
ꢀ
ꢀ
b¼30.118(2) A, c¼13.3762(10) A, V¼2338.5(3) A , Z¼4,
dcalcd¼1.427 g/cm3, F(000)¼1040, 2
q
range 1.68e26.62ꢀ, R indices
(all data) R1¼0.0662, wR2¼0.1001.
4.2.42. Compound (6t). Yield¼30% (61 mg); mp¼197e199 ꢀC
(recrystallized from hexanes and EtOAc); HRMS (ESI, Mþþ1) calcd
for C23H24NO4S 410.1426, found 410.1430; 1H NMR (400 MHz,
CDCl3):
d
8.27 (d, J¼8.4 Hz, 1H), 8.08 (d, J¼8.8 Hz, 2H), 7.62 (dd,
J¼2.0, 8.4 Hz, 1H), 7.20 (d, J¼8.4 Hz, 2H), 7.19 (d, J¼8.8 Hz, 2H), 7.14
(d, J¼2.0 Hz, 1H), 7.06 (d, J¼8.4 Hz, 2H), 2.36 (s, 3H), 1.33 (s, 9H); 13
C
NMR (100 MHz, CDCl3):
d 157.01, 147.27, 145.61, 143.98, 139.28,
138.16, 136.90, 131.05 (2ꢁ), 129.20 (2ꢁ), 128.95, 128.90, 127.64 (2ꢁ),
4. (a) Hassan, J.; Sevignon, M.; Gozzi, C.; Schulz, E.; Lemaire, M. Chem. Rev. 2002,
102, 1359; (b) Schroter, S.; Stock, C.; Bach, T. Tetrahedron 2005, 61, 2245; (c)
Schnurch, M.; Flasik, R.; Khan, A. F.; Spina, M.; Mihovilovic, M. D.; Stanetty, P.
Eur. J. Org. Chem. 2006, 3283; (d) Wang, R.; Manabe, K. Synthesis 2009, 1405; (e)
Chang, M.-Y.; Lee, T.-W.; Lin, S.-Y. Tetrahedron 2013, 69, 228.
125.74, 122.27 (2ꢁ), 35.18, 30.98 (3ꢁ), 21.51; Anal. Calcd for
C
23H23NO4S: C, 67.46; H, 5.66; N, 3.42. Found: C, 67.56; H, 5.39; N,
3.65.
5. (a) Varela, J. A.; Saa, C. Chem. Rev. 2003, 103, 3787; (b) Grotjahn, D. B. Transition
Metal Alkyne Complexes: Transition Metal-catalyzed Cyclotrimerization. In
Comprehensive Organometallic Chemistry II; Abel, E. W., Stone, F. G. A.,
Wilkinson, G., Hegedus, L. S., Eds.; Pergamon: Oxford, UK, 1995; Vol. 12, p 741;
(c) Hilt, G.; Vogler, T.; Hess, W.; Galbiati, F. Chem. Commun. 2005, 1474; (d) Xu,
L.; Yu, R.; Wang, Y.; Chen, J.; Yang, Z. J. Org. Chem. 2013, 78, 5744; (e) Ozelov, O.
V.; Patrick, B. O.; Ladipo, F. T. J. Am. Chem. Soc. 2000, 122, 6423; (f) Cicero, D.;
Lembo, A.; Leoni, A.; Tagliatesta, P. New J. Chem. 2009, 33, 2162; (g) Cadierno, V.;
Garcia-Garrido, S. E.; Gimeno, J. J. Am. Chem. Soc. 2006, 128, 15094; (h) Sugihara,
T.; Wakabayashi, A.; Nagai, Y.; Takao, H.; Imagawa, H.; Nishizawa, M. Chem.
Commun. 2002, 576; (i) Bu, X.; Zhang, Z.; Zhou, X. Organometallics 2010, 29,
3530; (j) Liu, Y.; Yan, X.; Yang, N.; Xi, C. Catal. Commun. 2011, 12, 489.
6. For the one-pot synthesis of m-terphenyls, see: (a) Raghukumar, V.; Murugan,
P.; Ramakrishnan, V. T. Synth. Commun. 2001, 31, 3497; (b) Rashidzadeh, B.;
Jafarpour, F.; Saednya, A. Arkivoc 2008, xvii, 167; (c) Diallo, A.; Zhao, Y.-L.; Wang,
H.; Li, S.-S.; Ren, C.-Q.; Liu, Q. Org. Lett. 2012, 14, 5776 and references cited
herein.
4.2.43. Compound (6u). Yield¼40% (74 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C21H23O2S2 371.1140, found 371.1145; 1H NMR
(400 MHz, CDCl3):
d
8.32 (d, J¼8.4 Hz, 1H), 7.56 (dd, J¼2.4, 8.4 Hz,
1H), 7.32 (d, J¼2.4 Hz, 1H), 7.27e7.25 (m, 1H), 7.24 (d, J¼8.4 Hz, 2H),
7.15 (dd, J¼1.2, 5.2 Hz, 1H), 7.04 (d, J¼8.4 Hz, 2H), 7.00 (dd, J¼3.6,
5.2 Hz, 1H), 2.33 (s, 3H), 1.32 (s, 9H); 13C NMR (100 MHz, CDCl3):
d
156.45, 143.24, 138.26, 138.04, 137.79, 133.89, 131.13, 130.61,
128.96, 128.93 (2ꢁ), 127.70 (2ꢁ), 126.65, 126.53, 125.29, 35.04,
30.97 (3ꢁ), 21.50.
4.2.44. Compound (6v). Yield¼33% (65 mg); colorless gum; HRMS
(ESI, Mþþ1) calcd for C24H27O3S 395.1681, found 395.1686; 1H NMR

9624
M.-Y. Chang et al. / Tetrahedron 69 (2013) 9616e9624
7. For the applications with the sulfonyl m-terphenyls, see: (a) Sasabe, H.; Seino,
Y.; Kimura, M.; Kido, J. Chem. Mater. 2012, 24, 1404; (b) Wright, R. S.; Vinod, T. K.
Tetrahedron Lett. 2003, 44, 7129; (c) Udayakumar, B. S.; Schuster, G. B. J. Org.
Chem. 1992, 57, 348.
Y.-L.; Hsu, R.-T. Tetrahedron 2012, 68, 7941; (d) Chang, M.-Y.; Wu, M.-H.; Tai, H.-
Y. Org. Lett. 2012, 14, 3936.
10. (a) Chang, M.-Y.; Wu, M.-H.; Chen, Y.-L. Org. Lett. 2013, 15, 2822; (b) Chang, M.-
Y.; Chan, C.-K.; Wu, M.-H. Tetrahedron 2013, 69, 7916.
8. For the isolation of m-terphenyl natural products, see: (a) Glombitza, K. W.;
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11. CCDC 965640 (5f), 947193 (6i) and 965641 (6s) contains the supplementary
crystallographic data for this paper. This data can be obtained free of charge via
www.ccdc.cam.ac.uk/conts/retrieving.html (or from the CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: þ44-1223-336033; e-mail: deposit@ccdc.cam.ac.
uk).
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