Palladium(II)-catalyzed direct alkenylation and arylation of arenes: Removable 2-pyridylsulfinyl group assisted C-H bond activation

Article abstract of DOI:10.1021/jo200666z

Palladium-catalyzed C-H activation reactions directed by a removable 2-pyridylsulfinyl group were developed. Aromatic olefination products were formed in good yields on treatment of 2-(phenylsulfinyl)pyridines with alkenes in the presence of a Pd catalyst

Full text of DOI:10.1021/jo200666z

ARTICLE
pubs.acs.org/joc
Palladium(II)-Catalyzed Direct Alkenylation and Arylation of Arenes:
Removable 2-Pyridylsulfinyl Group Assisted CꢀH Bond Activation
Ming Yu, Zunjun Liang, Yongyong Wang, and Yuhong Zhang*
Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
S Supporting Information
b
ABSTRACT:
Palladium-catalyzed CꢀH activation reactions directed by a removable 2-pyridylsulfinyl group were developed. Aromatic
olefination products were formed in good yields on treatment of 2-(phenylsulfinyl)pyridines with alkenes in the presence of a
Pd catalyst. The reaction tolerates a wide range of substituted alkenes, including various acrylates and styrenes. The controlled
experiments indicated that the 2-pyridyl moiety, rather than the sulfinyl, played the role of ligand. The final reductive desulfonylation
affords the stilbenes, sulfides, and disulfides with different reductive conditions, respectively. More importantly, this transformation
could also be applied in arylation through dual CꢀH activation.
’ INTRODUCTION
and arylation of arenes by the use of a 2-pyridylsulfinyl group as
directing group. The (arylsulfinyl)pyridine compounds can be
prepared very conveniently by thiophenols and 2-bromopyridine
(see Supporting Information),6 and the 2-pyridylsulfinyl group
could be removed easily after the CꢀH bond functionalization
under reductive conditions or afford diverse reduction products.
The sequential alkenylation and arylation were achieved by
suitable control of the reaction conditions.
Transition-metal-catalyzed CꢀH functionalization has
emerged as a valuable and atom-economical alternative to tradi-
tional metal-catalyzed cross-couplings in the construction of
CꢀC and CꢀX (X = O, N, halogens) bonds.1 Of particular
interest is the palladium-catalyzed chelation-directed sp2 CꢀH
activation, which provides valuable products in a highly efficient
way.2 To date, diverse directing groups, including pyridine,2aꢀc
imidazoline,2d pyrazole,2e oxazoline,2f,g amide,2h,i oxime ether,2j
ketones,2k hydroxyl,2l,m and carboxylic acids,2n,o have been deve-
loped to assist aromatic CꢀH bond activation. However, in some
cases, the practicality might be restricted when the directing
groups cannot easily be removed from the products. Therefore,
significant effort has been directed toward the discovery of
efficient and removable directing groups. In a pioneering study,
Gevorgyan and co-workers discovered that pyridyldiisopropylsilyl
(PyDipSi) could be used successfully as the directing group for
the transformation of CꢀH bonds to CꢀO and CꢀX (X = Cl,
Br, and I) bonds via the sp2 CꢀH bond activation and then be
removed easily from the products.3 Arrayas and Carretero made
an advance in the directed C2-alkenylation of indoles by the use
of removable pyridylsulfonyl (PyS(O2)) as the directing group.4
More recently, pyridylsulfonyl-directed olefination and acetox-
ylation were reported by the Carretero group and the Manche~no
group, respectively.5 Herein, we report the Pd-catalyzed alkenylation
’ RESULTS AND DISCUSSION
Alkenylation is an important transformation in organic syn-
thesis,7 and direct CꢀH bond olefination has received much
attention in the past several years.8,9 Although many efficient
directing groups have been developed in the direct CꢀH
alkenylation reactions, the difficulty removing such directing
groups from the products remains a great challenge. Inspired
by the use of the chiral sulfinyl group as chiral ligand in asym-
metric synthesis, which can be easily cleaved after promoting
asymmetric transformation,10 we envisioned that the removable
sulfides could be installed in arenes as the directing groups and
then removed after the CꢀH bond functionalization under
suitable reaction conditions. For this end, we designed different
Received: March 30, 2011
Published: May 05, 2011
r
2011 American Chemical Society
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Table 1. Optimization of Reaction Conditionsa
Figure 1. Directing group screening.
sulfur-containing directing groups to investigate their possibility
in assisted CꢀH activation (Figure 1). We prepared 2-
(phenylsulfonyl)pyridine (I) and examined the reactivity in the
alkenylation reaction with methyl acrylate in the presence of
Pd(OAc)2 (10 mol %), AgOAc (2.5 equiv), and BQ (0.5 equiv)
in DMF (1 mL) at 130 °C for 12 h. Unfortunately, it failed to
provide the desired alkenylation product. To our delight, the use
of (phenylsulfinyl)pyridine (II) as substrate delivered the desired
ortho-alkenylation product 3a (Table 1) in 78% yield, while
2-(phenylthio)pyridine (III) afforded the ortho-alkenylation
product in 41% yield. Methylsulfinylbenzene (IV) was inactive.
The above results indicate that the use of (phenylsulfinyl)-
pyridine (II) is a useful strategy to achieve the CꢀH activation.
We optimized the reaction conditions by the use of 2-
(phenylsulfinyl)pyridine and methyl acrylate as model sub-
strates, and the selected results are listed in Table 1. First, a set
of palladium catalysts were tested. The results indicated that
Pd(OAc)2 was superior to other palladium sources, such as
Pd(PPh3)4, Pd(dba)2, PdCl2, PdCl2(PPh3)2, andPdCl2(CH3CN)2,
to give the desired alkenylation product 3a with 81% yield in the
presence of AgOAc (2.5 equiv) in CH3CN (1 mL) at 80 °C
(entries 1ꢀ6). We also evaluated RuCl3 as the catalyst under the
reaction conditions, but there was no reaction in this system. It
was found that the oxidants played a crucial role in the reaction.
The best result was obtained by the use of AgOAc. A comparable
reaction efficiency was presented by Ag2CO3, while other Ag(I)
salts showed poor reactivity (entries 7ꢀ10). It should be noted
that Cu(OAc)2 can also afford the desire product with 44% yield
(entry 11). No reaction took place without catalysts or oxidants
in this system. Then, the effect of solvents was examined. We
found that the alkenylation reaction of 2-(phenylsulfinyl)-
pyridine can be carried out smoothly in CH3CN, DCE, DME,
DMF, and THF, and CH3CN showed the best efficiency while
other solvents such as DMSO, toluene, and 1,4-dioxane were
inferior (entries 12ꢀ18). At last, the temperature effect was
tested, and heat was found to favor the reaction (entries 19ꢀ22).
When we performed the reaction of 1a with 2a in the presence of
10 mol % of Pd(OAc)2 and 1 equiv of AgOAc in CH3CN at
70 °C, 46% of the target product 3a was obtained (entry 8). The
yield of 3a was profoundly increased to 81% at 80 °C under these
reaction conditions, but it was helpless when the reaction
temperature was increased to 100 or 130 °C.
entry
catalyst
oxidant
solvent temp (°C) yield (%)
1
2
Pd(PPh3)4
Pd(dba)2
AgOAc
AgOAc
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
CH3CN
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
80
70
80
100
130
62
56
18
23
75
81
68
NR
NR
35
46
67
70
75
72
trace
32
44
46
81
75
77
3
Pd(CH3CN)2Cl2 AgOAc
4
Pd(PPh3)2Cl2
PdCl2
AgOAc
AgOAc
AgOAc
Ag2CO3
Ag2O
5
6
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
Pd(OAc)2
7
8
9
AgF
10
11
12
13
14
15
16
17
18
19
20
21
22
AgNO3
Cu(OAc)2 CH3CN
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
AgOAc
DCE
DME
DMF
THF
DMSO
dioxane
toluene
CH3CN
CH3CN
CH3CN
CH3CN
a Reaction conditions: 2-(phenylsulfinyl)pyridine 1a (60.9 mg, 0.3
mmol), methyl acrylate 2a (51.6 mg, 0.6 mmol), catalyst (0.03 mmol),
solvent (1 mL), air, 12 h.
pathway, and the surviving CꢀBr bond could be further trans-
formed to different useful functional groups (entry 12). In
addition, this useful coupling reaction could be applied to various
phenylsulfinyl substrates, and the electronic properties of the
substituents influenced the reactivity of the reaction. For exam-
ple, the reaction was carried out smoothly with electron-releasing
substituents such as methyl and methoxyl to give good yields
(entries 13ꢀ16), but higher temperature was required for the
electron-withdrawing substituents in moderate yield (entry 17).
When the arenes bearing stronger electron-withdrawing groups,
such as 2-(4-nitrophenylsulfinyl)pyridine, cannot afford the desire
alkenylation product, 2,20-sulfinyldipyridine is also the inert substrate.
The structure of this alkenylation product was further confirmed by
the X-ray crystallography of 3f (see Supporting Information).
Importantly, the (2-pyridyl)sulfinyl group could be easily
removed by the treatment of the corresponding alkenylated
product with n-BuLi, as shown in Scheme 1.11 Furthermore,
the alkenylated sulfoxide could be converted into the corre-
sponding sulfide 4a in 83% yield by the use of Zn dust as the
reductant.4,5 In the presence of sodium amalgam, disulfide 4g
resulted in good yield.
The scope of the alkenylation reaction was investigated as
summarized in Table 2. A variety of acrylates coupled cleanly
with 2-(phenylsulfinyl)pyridine to give the corresponding alke-
nylation products in moderate to good yields with excellent E-
stereoselectivity (entries 1ꢀ3). In the case of acrylonitrile, a higher
yield was obtained but with a mixture of Z and E stereoisomers
(entry 4). The more challenging styrene and its derivatives
also reacted with 2-(phenylsulfinyl)pyridine efficiently (entries
5ꢀ12). The styrenes bearing both electron-donating and elec-
tron-withdrawing groups in the phenyl ring afforded the desired
product smoothly. It should be noted that the presence of
bromide in the phenyl ring of styrenes did not alter the reaction
We noted that the 2-(arylsulfinyl)pyridines bearing electron-
withdrawing groups in the aryl ring are less active under the
reaction conditions. Thus, an electrophilic metalation mechanism
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ARTICLE
Table 2. Alkenylation of 2-(Phenylsulfinyl)pyridines with Alkenesa
a Reaction conditions: 2-(phenylsulfinyl)pyridines 1 (0.3 mmol), alkenes 2 (0.6 mmol), Pd(OAc)2 (6.7 mg, 0.03 mmol), and AgOAc (125 mg, 0.75 mmol) in
CH3CN(1mL) underairat80°C for 12 h. b DCE/DMF (2 mL/0.2 mL) under air at 130 °C for 12 h. c The reaction temperature was 130 °C under air for 24 h.
isfavored, asshown in Scheme 2.12 Initially, the electronicattackof
Pd(II) into 2-(phenylsulfinyl)pyridine forms the intermediate I,
which inserts into olefins to afford the intermediate II. The
subsequent β-hydro elimination results in the product and librates
Pd(0) as well as acetic acid. The Pd(II) is regenerated from the
oxidation of Pd(0) by silver(I) compounds.
reaction of 2-(phenylsulfinyl)pyridines 1a with arenes (Figure 2).
After optimization of the reaction conditions, it was found that
the arylation reaction13 could proceed successfully in the pre-
sence of Pd(OAc)2 (10 mol %), Ag2CO3 (2 equiv), and BQ (0.5
equiv) at 130 °C for 16 h. Both electron-rich (5a,5b) and
electron-deficient arenes (5cꢀ5e) took part in the arylation
reaction. However, the electron-deficient arenes were more
reactive to give the higher yields. The regioisomeric products
In order to investigate the versatility of the 2-pyridyl sulfoxide
directing group in CꢀH activation, we explored the arylation
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Scheme 1. Removing the Directing Group
Figure 2. Arylation reaction of 2-(phenylsulfinyl)pyridines 1 with
arenes. Conditions: 1 (0.3 mmol), Pd(OAc)2 (6.7 mg, 0.03 mmol),
BQ (16.2 mg, 0.15 mol), and Ag2CO3 (165.6 mg, 0.6 mmol) in arenes
(0.5 mL) under air at 130 °C for 16 h.
Scheme 2. Possible Mechanism of the Alkenylation
directing group can be easily removed or converted to another
useful synthetic moiety. Importantly, the sequential alkenylation
and arylation of arenes was achieved by suitable control of
reaction conditions.
’ EXPERIMENTAL SECTION
Typical Experimental Procedure for Preparation of Start-
ing Material: A 100 mL flask was charged with 2-bromopyridines
(30.0 mmol), thiophenols (35.0 mmol), DMF (25.00 mL), and K2CO3
(5.52 g, 40.0 mmol). The mixture was stirred at 110 °C for 20 h. The
mixture was filtered through a pad of Celite, and the waste cake was
washed with DMF (10 mL). The crude sulfide solution was transferred
to another 100 mL flask. The subsequent oxidation was carried out by
addition of glacial HOAc (2.00 mL) and heated to 80 °C. H2O2 solution
(30 wt %, 3.47 g, 40.0 mol) was added slowly and stirred for 2 h at 80 °C.
After the reaction, 20 mL of water was added into the reaction solution.
The pH of the mixture was controlled to 9 by the use of 20% (w/v)
NaOH solution, and the resulting slurry was cooled to <5 °C. The
mixture was stirred below 5 °C for 1.5 h and filtered through a pad of
Celite. The wet cake was washed with water (3 ꢁ 20 mL) and was
redissolved in ethyl acetate (50 mL). The resulting solution was dried
with anhydrous magnesium sulfate. The solvent was evaporated under
reduced pressure to provide 2-benzenesulfonyl pyridines.
were obtained when toluene was used (5b). 2-(p-Methoxylphe-
nylsulfinyl)pyridine and 2-(p-methylphenylsulfinyl)pyridine
reacted smoothly with 1,2,4,5-tetrafluorobenzene to give the
arylated product in acceptable yields (5f and 5g).
2-(Phenylsulfinyl)pyridine5a 1a: White solid, mp 48 °C
1
(uncorrected); H NMR (400 MHz, CDCl3, TMS) δ 8.54 (d, J =
Notably, the arylation reaction occurred smoothly under the
reaction conditions when the alkenylated products were used as
substrates. Thus, the sequential alkenylation and arylation could
be achieved by the treatment of compound 1a under the alkenylation
conditions first, and afterwords undergoing the arylation reaction
under the arylation conditions (Scheme 3).
4.0 Hz, 1H), 8.04 (d, J = 8.0 Hz, 1H), 7.86 (td, J1 = 8.0 Hz, J2 = 1.6 Hz,
1H), 7.82ꢀ7.80 (m, 2H), 7.47ꢀ7.43 (m, 3H), 7.30ꢀ7.27 (m, 1H); 13C
NMR (100 MHz, CDCl3) δ 166.1, 150.0, 144.3, 138.4, 131.4, 129.4,
125.1, 124.9, 118.7.
2-(o-Tolylsulfinyl)pyridine5a 1b: White solid, mp 103ꢀ105 °C
(uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.49 (d, J = 4.0 Hz,
1H), 8.03 (d, J = 4.0 Hz, 1H), 7.86 (td, J1 = 8.0 Hz, J2 = 1.6 Hz, 1H),
7.79ꢀ7.77 (m, 1H), 7.32ꢀ7.25 (m, 3H), 7.21ꢀ7.19 (m, 1H), 2.66 (s,
3H); 13C NMR (100 MHz, CDCl3) δ 166.3, 149.5, 142.9, 137.9, 137.4,
130.9, 130.8, 126.8, 124.4, 118.9, 19.3.
’ CONCLUSION
In summary, we have successfully developed an efficient
palladium(II)-catalyzed methods for alkenylation and arylation
of arenes by the use of 2-pyridyl sulfoxide as directing group. The
2-(p-Tolylsulfinyl)pyridine5a 1c: White solid, mp 66ꢀ67 °C
(uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.53 (d, J = 4.0
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Scheme 3. Sequential Alkenylation and Arylation
Hz, 1H), 8.05 (d, J = 8.0 Hz, 1H), 7.86 (t, J = 8.0 Hz, 1H), 7.66 (d, J = 8.0
Hz, 1H), 7.82ꢀ7.80 (m, 2H), 7.30ꢀ7.24 (m, 3H), 2.34 (s, 3H); 13C
NMR (100 MHz, CDCl3) δ 166.3, 150.0, 141.9, 141.2, 138.3, 130.1,
125.3, 124.3, 118.7, 21.6.
CDCl3) δ 166.2, 165.4, 149.8, 143.7, 140.0, 137.9, 134.3, 131.3, 130.6,
126.9, 125.3, 124.5, 121.6, 119.0, 64.6, 30.7, 19.1, 13.7; HRMS (EI) calcd
for C18H19NO3S (Mþ) 329.1086, found 329.1083.
(E)-3-(2-(Pyridin-2-ylsulfinyl)phenyl)acrylonitrile 3d: White
solid, mp 88ꢀ90 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS)
δ 8.49 (d, J = 4.0 Hz, 1H), 8.33 (d, J = 16.4 Hz, 1H), 8.06 (d, J = 8.0 Hz,
1H), 7.96ꢀ7.90 (m, 2H), 7.59 ꢀ7.54 (m, 2H), 7.51ꢀ7.47 (m, 1H),
7.33ꢀ7.30 (m, 1H), 5.95 (d, J = 16.4 Hz, 1H); 13C NMR (100 MHz,
CDCl3) δ 165.3, 149.7, 146.2, 143.6, 138.3, 133.1, 131.5, 131.4, 126.3,
125.2, 124.7, 118.6, 117.6, 99.5; HRMS (EI) calcd for C14H10N2OS
(Mþ) 254.0514, found 254.0513.
2-(3-Methoxyphenylsulfinyl)pyridine5a 1d: Colorless liquid;
1H NMR (400 MHz, CDCl3, TMS) δ 8.54 (d, J = 4.8 Hz, 1H), 8.07 (d,
J = 7.2 Hz, 1H), 7.89 (td, J1 = 8.0 Hz, J2 = 1.6 Hz, 1H), 7.39ꢀ7.29 (m,
4H), 6.96ꢀ6.93 (m, 1H), 3.81 (s, 3H); 13C NMR (100 MHz, CDCl3) δ
165.5, 160.0, 149.6, 145.1, 138.0, 130.0, 124.7, 118.3, 117.4, 117.0,
108.9, 55.4.
2-(4-Methoxyphenylsulfinyl)pyridine5a 1e: White solid, mp
77ꢀ78 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.54
(d, J = 4.8 Hz, 1H), 8.07 (d, J = 8.0 Hz, 1H), 7.89 (td, J1 = 7.6 Hz, J2 = 2.0
Hz, 1H), 7.70ꢀ7.67 (m, 2H), 7.31ꢀ7.28 (m, 1H), 6.96ꢀ6.94 (m, 2H),
3.80 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 165.9, 162.0, 149.7, 138.0,
135.1, 127.2, 124.4, 118.5, 114.6, 55.6.
(E)-2-(2-Styrylphenylsulfinyl)pyridine5a 3e: White solid, mp
99ꢀ100 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.48
(s, 1H), 8.01 (d, J = 8.4 Hz, 1H), 7.93 (d, J = 16.4 Hz, 1H), 7.90 (d, J = 7.6
Hz, 1H), 7.84 (t, J = 8.0 Hz, 1H), 7.69 (d, J = 7.6 Hz, 1H), 7.57 (d, J = 7.6
Hz, 2H), 7.44ꢀ7.37 (m, 4H), 7.30 (t, J = 6.8 Hz, 1H), 7.26ꢀ7.24 (m,
1H), 7.05 (d, J = 16.0 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 165.9,
149.5, 141.8, 137.8, 137.1, 136.8, 132.1, 131.2, 128.6, 128.3, 128.1, 126.9,
125.9, 125.1, 124.5, 123.9, 119.1; HRMS (EI) calcd for C19H15NOS
(Mþ) 305.0874, found 305.0874.
2-(4-Chlorophenylsulfinyl)pyridine5a 1f: White solid, mp
76ꢀ78 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.53
(d, J = 4.0 Hz, 1H), 8.01 (d, J = 4.0 Hz, 1H), 7.85 (td, J1 = 8.0 Hz, J2 = 1.6
Hz, 1H), 8.72 (d, J = 8.0 Hz, 2H), 8.39 (d, J = 8.0 Hz, 2H), 7.31ꢀ7.27
(m, 1H); 13C NMR (100 MHz, CDCl3) δ 165.3, 149.7, 142.4, 138.1,
137.3, 129.7, 126.1, 124.7, 118.2.
(E)-4-(2-(Pyridin-2-ylsulfinyl)styryl)phenyl acetate5a 3f:
1
White solid, mp 137ꢀ138 °C (uncorrected); H NMR (400 MHz,
Typical Experimental Procedure for the Alkenylation of
2-Pyridyl Sulfoxides: A mixture of 2-(phenylsulfinyl)pyridines (0.3
mmol), alkenes (0.6 mmol), Pd (OAc)2 (6.7 mg, 10 mol %), and AgOAc
(125.3 mg, 0.75 mmol) in acetonitrile (2 mL) was stirred at 80 °C
for 12 h. Afterward, the reaction mixture was allowed to cool to room
temperature and filtered through a pad of Celite. The solvent was
evaporated under reduced pressure, and the residue was subjected to
flash column chromatography (silica gel, ethyl acetate/petroleum ether =
1:3ꢀ5, v/v) to obtain the desired products.
CDCl3, TMS) δ 8.47 (d, J = 4.4 Hz, 1H), 8.00 (d, J = 7.6 Hz, 1H),
7.91ꢀ7.87 (m, 2H), 7.82 (td, J1 = 8.0 Hz, J2 = 1.2 Hz, 1H), 7.67 (dd, J1 =
8.0 Hz, J2 = 1.2 Hz, 1H), 7.57 (d, J = 8.0 Hz, 2H), 7.43ꢀ7.39 (m, 2H),
7.34ꢀ7.31 (m, 1H), 7.25ꢀ7.22 (m, 2H), 7.02 (d, J = 15.6 Hz, 1H), 2.29
(s, 3H); 13C NMR (100 MHz, CDCl3) δ 169.3, 165.9, 150.4, 149.5,
141.8, 137.9, 136.9, 134.6, 131.2, 130.9, 128.3, 127.8, 125.8, 125.0, 124.5,
124.1, 121.8, 119.1, 21.0; HRMS (EI) calcd for C21H17NO3S (Mþ)
363.0929, found 363.0922.
(E)-2-(2-(4-Methoxystyryl)phenylsulfinyl)pyridine5a 3g:
Orange oil; 1H NMR (400 MHz, CDCl3, TMS) δ 8.47 (d, J = 4.0 Hz,
1H), 8.00 (d, J = 8.0 Hz, 1H), 7.86 (d, J = 8.0 Hz, 1H), 8.86ꢀ7.77 (m,
2H), 7.66 (d, J = 7.6 Hz, 1H), 7.50 (d, J = 9.2 Hz, 2 H), 7.43ꢀ7.35 (m,
2H), 7.26 (m, 1H), 7.00 (d, J = 16.4 Hz, 1H), 6.92 (d, J = 8.8 Hz, 2H),
3.83 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 165.9, 159.7, 149.5, 141.4,
137.8, 137.4, 131.6, 131.2, 129.6, 128.2, 127.8, 125.6, 125.0, 124.4, 121.6,
119.1, 114.1, 55.2; HRMS (EI) calcd for C20H17NO2S (Mþ) 335.0980,
found 335.0996.
(E)-Methyl 3-(2-(Pyridin-2-ylsulfinyl)phenyl)acrylate5a 3a:
1
White solid, mp 76 °C (uncorrected); H NMR (400 MHz, CDCl3,
TMS) δ 8.51ꢀ8.47 (m, 2H), 8.05 (d, J = 8.0 Hz, 1H), 7.91ꢀ7.85 (m,
2H), 7.63 (d, J = 8.0 Hz, 1H), 7.49ꢀ7.45 (m, 2H), 7.28ꢀ7.25 (m, 1H),
6.44 (d, J = 15.6 Hz, 1H), 3.84 (s, 3H); 13C NMR (100 MHz, CDCl3) δ
166.5, 165.4, 149.7, 143.8, 139.7, 137.9, 134.2, 131.3, 130.6, 126.9, 125.3,
124.4, 121.1, 118.9, 51.7; HRMS (EI) calcd for C15H13NO3S (Mþ)
287.0616, found 287.0614.
(E)-Ethyl 3-(2-(Pyridin-2-ylsulfinyl)phenyl)acrylate 3b: Yel-
low oil; 1H NMR (400 MHz, CDCl3, TMS) δ 8.50ꢀ8.46 (m, 2H), 8.05
(d, J = 8.0 Hz, 1H), 7.91ꢀ7.87 (m, 2H), 7.63 (d, J2 = 2.0 Hz, 1H),
7.49ꢀ7.45 (m, 2H), 7.28 (m, 1H), 6.43 (d, J = 16.0 Hz, 1 H), 4.28 (m,
2H), 1.35 (m, 3H); 13C NMR (100 MHz, CDCl3) δ 166.5, 165.7, 150.1,
144.1, 139.9, 138.2, 134.6, 131.7, 130.9, 127.2, 125.7, 124.8, 122.0, 119.3,
61.0, 14.5; HRMS (EI) calcd for C16H15NO3S (Mþ) 301.0773, found
301.0763.
(E)-2-(2-(3-Fluorostyryl)phenylsulfinyl)pyridine 3h: Yellow
solid, mp 78ꢀ80 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS)
δ 8.47 (d, J = 4.0 Hz, 1H), 8.02 (d, J = 8.0 Hz, 1H), 7.94 (d, J = 16.0 Hz,
1H), 7.89 (dd, J1 = 8.0 Hz, J2 = 1.2 Hz, 1H), 7.83 (td, J1 = 8.0 Hz, J2 =
1.6 Hz, 1H), 7.68ꢀ7.66 (m, 1H), 7.46ꢀ7.39 (m, 2H), 7.34ꢀ7.31 (m,
2H), 7.28ꢀ7.23 (m, 2H), 7.00 (d, J = 16.0 Hz, 1H), 7.03ꢀ6.96 (m, 1H);
13C NMR (100 MHz, CDCl3) δ 165.8, 163.1 (d, J = 244.8 Hz, CꢀF),
149.5, 142.0, 139.1 (d, J = 7.3 Hz, 1C), 137.9, 137.4, 136.6, 131.3, 130.7
(d, J = 2.8 Hz, 1C), 130.0(d, J = 8.5 Hz, 1C), 128.6, 125.9, 125.3, 124.5,
122.7 (d, J = 2.6, Hz 1C), 119.0, 114.8 (d, J = 23.1 Hz, 1C), 113.2 (d, J =
20.8 Hz, 1C); HRMS (EI) calcd for C19H14FNOS (Mþ) 323.0780,
found 323.0782.
(E)-Butyl 3-(2-(Pyridin-2-ylsulfinyl)phenyl)acrylate5a 3c:
Yellow oil; 1H NMR (400 MHz, CDCl3, TMS) δ 8.51ꢀ8.47 (m,
2H), 8.05 (d, J = 8.0 Hz, 1H), 7.91ꢀ7.85 (m, 2H), 7.64 (dd, J1 = 8.0
Hz, J2 = 1.6 Hz, 1H), 7.51ꢀ7.43 (m, 2H), 7.29ꢀ7.25 (m, 1H), 6.43 (d,
J = 15.6 Hz, 1H), 4.24 (t, J = 6.8 Hz, 2H), 1.75ꢀ1.68 (m, 2H),
1.51ꢀ1.42(m, 2H), 0.97 (t, J = 7.2 Hz, 3H); 13C NMR (100 MHz,
(E)-2-(2-(4-Fluorostyryl)phenylsulfinyl)pyridine 3i: Yellow
solid, mp 75ꢀ76 °C (uncorrected); 1H NMR (400 MHz, CDCl3,
4991
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The Journal of Organic Chemistry
ARTICLE
TMS) δ 8.47 (d, J = 2.4 Hz, 1H), 8.02 (d, J = 7.6 Hz, 1H), 7.89ꢀ7.81 (m,
3H), 7.67ꢀ7.65 (m, 1H), 7.55ꢀ7.52 (m, 2H), 7.45ꢀ7.37 (m, 2H),
7.26ꢀ7.23 (m, 1H), 7.07 (t, J = 8.0 Hz, 2H), 7.01 (d, J = 16.0 Hz, 1H);
13C NMR (100 MHz, CDCl3) δ 165.9, 162.4 (d, J = 247.0 Hz, CꢀF),
149.5, 141.9, 137.9, 137.0, 133.1 (d, J = 3.0 Hz, 2C), 131.3, 130.8, 128.5
(d, J = 8.4 Hz, 2C), 128.3, 125.8, 125.1, 124.5, 123.8, 119.1, 115.6 (d, J =
22.1 Hz, 2C); HRMS (EI) calcd for C19H14FNOS (Mþ) 323.0780,
found 323.0782.
(400 MHz, CDCl3, TMS) δ 8.48 (d, J = 3.2 Hz, 1H), 8.44 (d, J = 16.0 Hz,
1H), 8.07 (d, J = 7.6 Hz, 1H), 7.88 (t, J = 7.6 Hz, 1H), 7.75 (d, J = 8.8 Hz,
1H), 7.28ꢀ7.25 (m, 1H), 7.10 (d, J = 1.6 Hz, 1H), 6.99 (dd, J1 = 8.8 Hz,
J2 = 2.0 Hz, 1H), 6.42 (d, J = 16.0 Hz, 1H), 3.84 (s, 3H), 3.83 (s, 3H);
13C NMR (100 MHz, CDCl3) δ 166.5, 165.7, 161.9, 149.8, 139.8, 137.9,
136.2, 135.2, 128.0, 124.3, 121.6, 119.1, 116.6, 111.9, 55.5, 51.8; HRMS
(EI) calcd for C16H15NO4S (Mþ) 317.0722, found 317.0737.
(E)-Methyl 3-(5-Chloro-2-(pyridin-2-ylsulfinyl)phenyl)-
1
(E)-2-(2-(Perfluorostyryl)phenylsulfinyl)pyridine 3j: White
acrylate 3q: White solid, mp 128ꢀ129 °C (uncorrected); H NMR
1
solid, mp 158ꢀ159 °C (uncorrected); H NMR (400 MHz, CDCl3,
(400 MHz, CDCl3, TMS) δ 7.47 (d, J = 3.2 Hz, 1H), 8.41 (d, J = 16.0 Hz,
1H), 8.04 (d, J = 8 Hz, 1H), 7.89 (td, J1 = 7.6 Hz, J2 = 1.6 Hz, 1H), 7.84
(d, J = 8.4 Hz, 1H), 7.61 (d, J = 1.6 Hz, 1H), 7.44 (dd, J1 = 8.4 Hz, J2 = 2.0
Hz, 1H), 7.31ꢀ7.28 (m, 1H), 6.45 (d, J = 16.0 Hz, 1H), 3.85 (s, 3H);
13C NMR (100 MHz, CDCl3) δ 166.2, 165.2, 149.8, 142.3, 138.7, 138.1,
137.7, 135.7, 130.6, 126.8, 126.7, 124.6, 122.3, 118.9, 51.9; HRMS (EI)
calcd for C15H12ClNO3S (Mþ) 321.0226, found 321.0233.
TMS) δ 8.49 (s, 1H), 8.29 (d, J = 16.4 Hz, 1H), 8.07 (d, J = 7.6 Hz, 1H),
7.90ꢀ7.86 (m, 2H), 7.71ꢀ7.69 (m, 1 H), 7.51ꢀ7.45 (m, 2H),
7.30ꢀ7.27 (m, 1H), 6.99 (d, J = 16.4, 1H); 13C NMR (100 MHz,
CDCl3) δ 165.6, 149.7, 142.7, 138.0, 136.3, 132.6 (d, CꢀC6F5), 131.5,
129.5, 126.1, 125.3, 124.6, 119.0, 116.2; HRMS (EI) calcd for
C19H10F5NOS (Mþ) 395.0403, found 395.0407.
(E)-2-(2-(3-Nitrostyryl)phenylsulfinyl)pyridine 3k: Yellow
The Reaction of Removing or Transforming Pyridylsulfi-
nyl Group: Reduction of (E)-2-(2-(4-Fluorostyryl)phenylsul-
finyl)pyridine 3i to (E)-1-Fluoro-4-styrylbenzene14 4i: To a
solution of (E)-2-(2-(4-fluorostyryl)phenylsulfinyl)pyridine 3i (97 mg,
0.3 mmol) in dry THF (2.5 mL) was added a 2.5 M solution of BuLi in
hexane (0.48 mL, 1.2 mmol) at ꢀ78 °C under nitrogen atmosphere. The
mixture was stirred at ꢀ78 °C for 10 min before a saturated aqueous
solution of NH4Cl was added. The two phases were separated, and the
aqueous phase was extracted with EtOAc (2 ꢁ 5 mL). The combined
organic phase was dried (MgSO4) and concentrated under reduced
pressure. The residue was purified by flash chromatography using
petroleum ether as elute to afford (E)-1-fluoro-4-styrylbenzene 4i with
63% yield: 1H NMR (400 MHz, CDCl3, TMS) δ 7.53ꢀ7.48 (m, 4H),
7.39 (t, J = 1.2 Hz, 2H), 7.29 (t, J = 6.8 Hz, 1H), 7.12ꢀ7.02 (m, 4H); 1H
NMR (100 MHz, CDCl3) δ 162.5 (J = 245.9 Hz, 1C), 137.1, 133.5 (J =
2.8 Hz, 1C), 128.7, 128.5, 128.0 (J = 8.2 Hz, 2C), 127.6, 127.5, 126.4,
115.7 (J = 22.3 Hz, 1C).
1
solid, mp 125ꢀ127 °C (uncorrected); H NMR (400 MHz, CDCl3,
TMS) δ 8.50 (d, J = 4.0 Hz, 1H), 8.39 (s, 1H), 8.15 (dd, J1 = 8.0 Hz, J2 =
1.6 Hz, 1H), 8.11ꢀ8.06 (m, 2H), 7.94ꢀ7.86 (m, 3H), 7.72ꢀ7.70 (m,
1H), 7.57 (t, J = 8.0 Hz, 1H), 7.50ꢀ7.43 (m, 2H), 7.30ꢀ7.27 (m, 1H),
7.00 (d, J = 16 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ 165.8, 149.5,
148.6, 142.3, 138.7, 138.1, 135.9, 132.4, 131.3, 129.6, 129.3, 129.0, 127.1,
126.0, 125.1, 124.6, 122.4, 121.6, 119.1; HRMS (EI) calcd for
C19H14N2O3S (Mþ) 350.0725, found 350.0717.
(E)-2-(2-(4-Bromostyryl)phenylsulfinyl)pyridine5a 3l: Yellow
1
solid, mp 135ꢀ137 °C (uncorrected); H NMR (400 MHz, CDCl3,
TMS) δ 8.46 (d, J = 4.4 Hz, 1H), 8.01 (d, J = 7.6 Hz, 1H), 7.93 (d, J = 16.0
Hz, 1H), 7.89 (dd, J1 = 7.6 Hz, J2 = 1.6 Hz, 1H), 7.84 (td, J1 = 8.0 Hz, J2 =
2.0 Hz, 1H), 7.67 (d, J = 8.0 Hz, 1H), 7.50 (d, J = 8.4 Hz, 2H), 7.45ꢀ7.39
(m, 4H), 7.27ꢀ7.22 (m, 1H), 6.97 (d, J = 16.0 Hz, 1H); 13C NMR (100
MHz, CDCl3) δ 165.9, 149.5, 142.0, 137.9, 136.8, 135.8, 131.8, 131.3,
130.7, 128.5, 128.4, 125.9, 125.2, 124.7, 124.5, 122.0, 119.1; HRMS (EI)
calcd for C19H14BrNOS (Mþ) 382.9979, found 382.9979.
Reduction of (E)-Methyl 3-(2-(Pyridin-2-ylsulfinyl)phenyl)-
acrylate 3a to (E)-Methyl 3-(2-(Pyridin-2-ylthio)phenyl)-
acrylate 4a: A suspension of (E)-methyl 3-(2-(pyridin-2-ylsulfinyl)-
phenyl)acrylate 3a (86.0 mg, 0.3 mmol) and Zn dust (960.0 mg,
15 mmol) in a 1:1 mixture of THF/saturated aqueous NH4Cl (2 mL)
was stirred at room temperature overnight. The mixture was diluted with
EtOAc (5 mL) and filtered through a pad of Celite. The filtrate was
concentrated under reduced pressure. The residue was purified by flash
chromatography (hexane/EtOAc 3:1) to give (E)-methyl 3-(2-(pyridin-
2-ylthio)phenyl)acrylate 4a as a colorless oil in 83% yield: 1H NMR (400
MHz, CDCl3, TMS) δ 8.35 (d, J = 4.4 Hz, 1H), 8.19 (d, J = 16.0 Hz, 1H),
7.70 (d, J = 7.6 Hz, 1H), 7.63 (d, J = 7.6 Hz, 1H), 7.45ꢀ7.36 (m, 3H),
6.97ꢀ6.93 (m, 1H), 6.74 (d, J = 8.0 Hz, 1H), 6.35 (d, J = 16.0 Hz, 1H),
3.70 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 166.9, 160.3, 149.7, 142.3,
138.5, 137.1, 136.8, 131.6, 130.8, 130.0, 127.5, 121.3, 120.4, 120.0, 51.7;
HRMS calcd for C15H13NO2S (Mþ) 271.0677, found 271.0673.
Reduction of (E)-2-(2-(4-Methoxystyryl)phenylsulfinyl)-
pyridine 3g to 2,20-Bis(2-(4-methoxystyryl)phenyl)disulfide
4g: A suspension of (E)-2-(2-(4-methoxystyryl)phenylsulfinyl)pyridine
3g (100.5 mg, 0.3 mmol) and 30% (w/w) NaꢀHg (230.0 g, 10 mmol) in
a MeOH (2 mL) was stirred at room temperature for 20 min. The
mixture was diluted with EtOAc (5 mL) and filtered through a pad
of Celite. The filtrate was concentrated under reduced pressure. The
residue was purified by flash chromatography (petroleum ether/EtOAc
50:1) to give 2,20-bis(2-(4-methoxystyryl)phenyl)disulfide 4g as a white
solid in 71% yield: 1H NMR (400 MHz, CDCl3, TMS) δ 7.59 (dd, J1 =
7.6, J2 = 1.2 Hz, 2H), 7.54 (dd, J1 = 7.6 Hz, J2 = 1.2 Hz, 2H), 7.41 (d, J =
16.0 Hz, 2H), 7.37 (dd, J1 = 6.8 Hz, J2 = 2.0 Hz, 4H), 7.22 (td, J1 = 7.6
Hz, J2 = 0.8 Hz, 2H), 7.14 (td, J1 = 8.0 Hz, J2 = 1.2 Hz, 2H), 6.92 (d, J =
(E)-Methyl 3-(3-methyl-2-(pyridin-2-ylsulfinyl)phenyl)-
acrylate5a 3m: Colorless liquid; 1H NMR (400 MHz, CDCl3, TMS)
δ 8.55 (d, J = 15.2 Hz, 1H), 8.45 (d, J = 4.0 Hz, 1H), 8.18 (d, J = 8.4 Hz,
1H), 7.88 (td, J1 = 8.0 Hz, J2 = 1.6 Hz, 1H), 7.39ꢀ7.35 (m, 2H),
7.27ꢀ7.24 (m, 2H), 6.12 (d, J = 16.0 Hz, 1H), 3.78 (s, 3H), 2.64 (s, 3H);
13C NMR (100 MHz, CDCl3) δ 166.8, 164.9, 150.1, 141.4, 140.9, 140.3,
137.4, 137.2, 133.3, 132.1, 126.5, 124.2, 121.5, 120.9, 52.0, 20.2; HRMS
(EI) calcd for C16H15NO3S (Mþ) 301.0773, found 301.0786.
(E)-Butyl 3-(5-Methyl-2-(pyridin-2-ylsulfinyl)phenyl)-
acrylate 3n: Colorless liquid; 1H NMR (400 MHz, CDCl3, TMS) δ
8.42ꢀ8.38 (m, 1H), 8.41 (d, J = 16.0 Hz, 1H), 8.00 (d, J = 8.0 Hz, 1H),
7.81 (td, J1 = 8.0 Hz, J2 = 1.6 Hz, 1H), 7.70 (d, J = 8.0 Hz, 1H), 7.40 (s,
1H), 7.25ꢀ7.19 (m, 1H), 6.37 (d, J = 16.0 Hz, 1H), 4.18 (t, J = 6.8, 2H),
2.32 (s, 3H), 1.68ꢀ1.62 (m, 2H), 1.44ꢀ1.38 (m, 2H), 0.92 (t, J = 7.2 Hz,
3H); 13C NMR (100 MHz, CDCl3) δ 166.6, 165.9, 150.0, 142.2, 141.0,
140.0, 138.2, 134.5, 131.8, 127.8, 126.0, 124.7, 121.3, 119.3, 64.8, 30.9,
21.6, 19.4, 13.9; HRMS (EI) calcd for C19H21NO3S (Mþ) 343.1242,
found 343.1246.
(E)-Methyl 3-(4-Methoxy-2-(pyridin-2-ylsulfinyl)phenyl)-
1
acrylate 3o: White solid, mp 100ꢀ102 °C (uncorrected); H NMR
(400 MHz, CDCl3, TMS) δ 8.48 (d, J = 4 Hz, 1H), 8.41 (d, J = 15.6 Hz,
1H), 8.00 (d, J = 7.6 Hz, 1H), 7.89 (td, J1 = 7.6 Hz, J2 = 1.2 Hz, 1H), 7.61
(d, J = 8.8 Hz, 1H), 7.43 (d, J = 2.4 Hz, 1H), 7.30ꢀ7.26 (m, 1H), 6.96
(dd, J1 = 8.8 Hz, J2 = 2.4 Hz, 1H), 6.35 (d, J = 16.0 Hz, 1H), 3.84 (s, 3H),
3.82 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 166.9, 165.3, 161.7, 149.8,
145.5, 139.4, 137.9, 128.3, 126.3, 124.6, 118.9, 118.4, 118.3, 108.5, 55.7,
51.9; HRMS (EI) calcd for C16H15NO4S (Mþ) 317.0722, found
317.0723.
16.0 Hz, 1H), 6.87 (dd, J1 = 6.4 Hz, J2 = 2.0 Hz, 2H), 3.83 (s, 6H); 13
NMR (100 MHz, CDCl3) δ 159.4, 138.9, 134.8, 132.0, 130.5, 130.0,
C
(E)-Methyl 3-(5-Methoxy-2-(pyridin-2-ylsulfinyl)phenyl)-
acrylate 3p: White solid, mp 142ꢀ143 °C (uncorrected); H NMR
1
4992
dx.doi.org/10.1021/jo200666z |J. Org. Chem. 2011, 76, 4987–4994

The Journal of Organic Chemistry
ARTICLE
128.4, 128.0, 127.6, 125.6, 123.6, 114.0, 55.2. HRMS calcd for
C30H26O2S2 (Mþ) 482.1374, found 482.1376.
reaction mixture was allowed to cool to room temperature and filtered
through a pad of Celite. The solvent was evaporated under reduced
pressure, and the residue was subjected to flash column chromatography
(silica gel, ethyl acetate/petroleum ether = 1:3 v/v) to obtain the desired
products: white solid, mp 179ꢀ180 °C (uncorrected); 1H NMR (400
MHz, CDCl3, TMS) δ 8.58 (d, J = 15.6 Hz, 1H), 8.43 (d, J = 4.4 Hz, 1H),
7.87 (d, J = 7.2 Hz, 1H), 7.80 (td, J1 = 8.0 Hz, J2 = 1.6 Hz, 1H), 8.68 (d,
J = 7.2 Hz, 1H), 7.61 (t, J = 7.6 Hz, 1H), 7.33 (d, J = 7.2 Hz, 1H),
7.26ꢀ7.23 (m, 1H), 7.17ꢀ7.13 (m, 1H), 6.19 (d, J = 16.0 Hz, 1H), 3.79
(s, 3H); 13C NMR (100 MHz, CDCl3) δ 166.2, 163.7, 149.9, 141.1,
139.9, 137.7, 137.1, 133.8, 132.1, 129.7, 129.6, 124.2, 122.3, 119.9, 106.2
(m, 1C), 51.8; HRMS (EI) calcd for C21H13F4NO3S (Mþ) 435.0552,
found 435.0563.
Typical Experimental Procedure for the Arylation of 2-
Pyridyl Sulfoxides: A mixture of 2-(phenylsulfinyl)pyridines 1
(0.3 mmol), Pd(OAc)2 (6.7 mg, 10 mol %), BQ (16.2 mg, 0.15 mol),
Ag2CO3 (165.6 mg, 0.6 mmol), and 0.5 mL of arenes was stirred at
130 °C for 16 h. Afterward, the reaction mixture was allowed to cool to
room temperature and filtered through a pad of Celite. The solvent was
evaporated under reduced pressure, and the residue was subjected to flash
column chromatography (silica gel, ethyl acetate/petroleum ether =
1:3ꢀ5, v/v) to obtain the desired products.
2-(Biphenyl-2-ylsulfinyl)pyridine 5a: Yellow solid, mp 109ꢀ
110 °C (uncorrected); 1H NMR (400 MHz, CDCl3, TMS) δ 8.51 (d, J =
4.8 Hz, 1H), 7.87ꢀ7.80 (m, 3H), 7.63ꢀ7.60 (m, 2H), 7.52ꢀ7.38 (m,
6H), 7.27ꢀ7.26 (m, 1H); 13C NMR (100 MHz, CDCl3) δ 165.6, 149.8,
143.0, 142.6, 138.2, 137.6, 131.2, 130.5, 130.4, 128.6, 128.1, 128.0, 126.4,
124.3, 120.1; HRMS (EI) calcd for C17H13NOS (Mþ) 279.0718, found
279.0720.
’ ASSOCIATED CONTENT
S
Supporting Information. General experimental proce-
b
dures and spectroscopic data (1H NMR, 13C NMR, HRMS, and
MS) for the corresponding products. This material is available
free of charge via the Internet at http://pubs.acs.org.
2-(20,30,40,50,60-Pentafluorobiphenyl-2-ylsulfinyl)pyridine
5c: White solid, mp 100ꢀ102 °C (uncorrected); 1H NMR (400 MHz,
CDCl3, TMS) δ 8.35 (d, J = 4.4, 1H), 8.07 (d, J = 7.6 Hz, 1H), 7.86 (d,
J = 7.6 Hz, 1H), 7.82 (t, J = 8.4 Hz, 1H), 7.63 (t, J = 7.6 Hz, 1H), 7.56 (t,
J = 7.6 Hz, 1H), 7.30 (d, J = 7.6 Hz, 1H), 7.27ꢀ7.23 (m, 1H); 13C NMR
(100 MHz, CDCl3) δ 165.2, 149.5, 144.5, 138.1, 131.6, 131.4, 130.6,
125.2, 124.8, 124.6, 118.4; HRMS (EI) calcd for C17H8F5NOS (Mþ)
369.0247, found 369.0240.
’ AUTHOR INFORMATION
Corresponding Author
*E-mail: yhzhang@zju.edu.cn.
2-(20,30,50,60-Tetrafluorobiphenyl-2-ylsulfinyl)pyridine 5d:
1
’ ACKNOWLEDGMENT
White solid, mp 141ꢀ142 °C (uncorrected); H NMR (400 MHz,
CDCl3, TMS) δ 8.36 (d, J = 4.0 Hz, 1H), 8.06 (dd, J1 = 7.6 Hz, J2 = 1.2
Hz, 1H), 7.84ꢀ7.79 (m, 2H), 7.61 (td, J1 = 8.0 Hz, J2 = 1.2 Hz, 1H), 755
(td, J1 = 7.6 Hz, J2 = 2.0 Hz, 1H), 7.32 (d, J = 8.0 Hz, 1H), 7.25ꢀ7.16 (m,
2H); 13C NMR (100 MHz, CDCl3) δ 165.1, 149.6, 144.3, 137.9, 131.3,
131.2, 130.4, 126.2, 124.7, 124.6, 118.6, 106.2 (m, 1C); HRMS (EI)
calcd for C17H9F4NOS (Mþ) 351.0341, found 351.0350.
Funding from National Basic Research Program of China
(No. 2011CB936003) and NSFC (No. 20872126, No. 2107216)
is highly acknowledged.
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Gevorgyan, V. Angew. Chem., Int. Ed. 2010, 49, 8729. (c) Huang, C.;
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1
solid, mp 115ꢀ117 °C (uncorrected); H NMR (400 MHz, CDCl3,
TMS) δ 8.50 (d, J = 4.0 Hz, 1H), 8.00 (d, J = 8.0 Hz, 1H), 7.88 (d, J1 =
7.6 Hz, J2 = 2.0 Hz, 1H), 7.80ꢀ7.76 (m, 1H), 7.74 (d, J = 2.0 Hz, 1H),
7.55ꢀ7.49 (m, 4H), 7.80ꢀ7.76 (m, 2H); 13C NMR (100 MHz,
CDCl3) δ 165.6, 149.7, 143.2, 140.2, 138.1, 137.9, 132.5, 132.2,
131.4, 130.3, 130.0, 129.9, 129.4, 128.9, 126.6, 124.5, 119.7; HRMS
(EI) calcd for C17H11Cl2NOS (Mþ) 346.9938, found 346.9934.
2-(20,30,50,60-Tetrafluoro-5-methoxybiphenyl-2-ylsulfinyl)-
1
pyridine 5f: White solid, mp 159ꢀ160 °C (uncorrected); H NMR
(400 MHz, CDCl3, TMS) δ 8.40 (d, J = 4.0 Hz, 1H), 7.91 (d, J = 9.2 Hz,
1H), 7.82ꢀ7.80 (m, 1H), 7.24 (m, 1H), 7.18 (t, J = 8.4 Hz, 1H), 7.10
(dd, J1 = 8.8 Hz, J2 = 2.8 Hz, 1H), 6.83 (d, J = 2.8 Hz, 1H), 3.84 (s, 3H);
13C NMR (100 MHz, CDCl3) δ165.4, 161.6, 149.6, 137.8, 135.2, 128.1,
127.1, 124.5, 118.6, 116.9, 115.9, 106.2 (m, 1C), 55.6; HRMS (EI) calcd
for C18H11F4NO2S (Mþ) 381.0477, found 381.0471.
2-(20,30,50,60-Tetrafluoro-5-methylbiphenyl-2-ylsulfinyl)-
pyridine 5g: White solid, mp 145ꢀ147 °C (uncorrected); 1H NMR
(400 MHz, CDCl3, TMS) δ 8.37 (d, J = 4.0 Hz, 1H), 7.92 (d, J = 8.0 Hz,
1H), 7.84ꢀ7.77 (m, 2H), 7.41 (d, J1 = 8.0 Hz, J2 = 0.8 Hz, 1H),
7.25ꢀ7.13 (m, 3H), 2.40 (m, 3H); 13C NMR (100 MHz, CDCl3) δ
165.3, 149.6, 142.0, 141.1, 137.9, 132.0, 131.3, 126.2, 124.9, 124.6, 118.6,
106.1, 21.2; HRMS (EI) calcd for C18H11F4NOS (Mþ) 365.0497, found
365.0508.
Experimental Procedure for (20,30,50,60-Tetrafluoro-
2-(pyridin-2-ylsulfinyl)biphenyl-3-yl)acrylate 6a: A mixture
of (E)-methyl 3-(2-(pyridin-2-ylsulfinyl)phenyl)acrylate 3a (86 mg,
0.3 mmol), Pd (OAc)2 (6.7 mg, 10 mol %), BQ (16.2 mg, 0.15 mol),
Ag2CO3 (165.6 mg, 0.6 mmol), and 0.25 mL of 2,3,5,6-tetrafluoroben-
zene and 0.5 mL of DCE was stirred at 130 °C for 16 h. Afterward, the
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R. G.; Carretero, J. C. Chem.—Eur. J. 2010, 16, 9676.
4993
dx.doi.org/10.1021/jo200666z |J. Org. Chem. 2011, 76, 4987–4994

The Journal of Organic Chemistry
ARTICLE
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