Cyclization of 2-Biphenylthiols to Dibenzothiophenes under PdCl2/DMSO Catalysis

Article abstract of DOI:10.1021/acs.orglett.8b02347

A palladium-catalyzed synthesis of dibenzothiophenes from 2-biphenylthiols is described. This highly efficient reaction employs a simple PdCl₂/DMSO catalytic system, in which PdCl₂ is the sole metal catalyst and DMSO functions as an oxidant and solvent. This transformation has broad substrate scope and operational simplicity and proceeds in high yield. The synthetic utility was demonstrated by the facile synthesis of helical dinapthothiophene 3 and an eminent organic semiconductor DBTDT 4. Importantly, highly strained trithiasumanene 5, a buckybowl of considerable synthetic challenge, was observed under this catalytic system.

Full text of DOI:10.1021/acs.orglett.8b02347

Letter
pubs.acs.org/OrgLett
Cite This: Org. Lett. XXXX, XXX, XXX−XXX
Cyclization of 2‑Biphenylthiols to Dibenzothiophenes under PdCl2/
DMSO Catalysis
Tao Zhang, Guigang Deng, Hanjie Li, Bingxin Liu, Qitao Tan,* and Bin Xu*
Department of Chemistry, Innovative Drug Research Center, Shanghai University, Shanghai, 200444, China
S
* Supporting Information
ABSTRACT: A palladium-catalyzed synthesis of dibenzothiophenes from 2-
biphenylthiols is described. This highly efficient reaction employs a simple PdCl2/
DMSO catalytic system, in which PdCl2 is the sole metal catalyst and DMSO
functions as an oxidant and solvent. This transformation has broad substrate scope
and operational simplicity and proceeds in high yield. The synthetic utility was
demonstrated by the facile synthesis of helical dinapthothiophene 3 and an eminent organic semiconductor DBTDT 4.
Importantly, highly strained trithiasumanene 5, a buckybowl of considerable synthetic challenge, was observed under this
catalytic system.
ibenzo-fused thiophenes are privileged scaffolds with
Several straightforward methods for the synthesis of
dibenzothiophenes have been reported,1,9 which generally
require multistep procedures from halogenated or metalated
compounds. Recently, Jiang and Shimizu independently
reported an elegant synthesis of dibenzothiophenes by the
reaction of diaryliodonium salts with S8 or AcSK.10 Sakai et al.
reported the preparation of dibenzothiophene derivatives using
2-biphenylyl disulfides in the presence of molecular iodine or a
palladium catalyst.11 Over the past decade, several transition-
metal-catalyzed reactions have been developed for the
synthesis of dibenzothiophenes through different C−H
functionalization strategies (Figure 2a).12
D
numerous applications in pharmaceuticals and organic
electronics.1 For example, compound BMS-251873 was
reported to be a selective topoisomerase I active agent that
showed curative antitumor activity against prostate carcinoma
xenografts (Figure 1).2 11-Arylbenzo[b]naphtho[2,3-d]-
Dibenzothiophenes constitute a family of 9-heterofluorenes
that include carbazoles, dibenzofurans, dibenzosiloles, and
dibenzophospholes. Transition-metal-catalyzed intramolecular
cyclization of the corresponding “X−H” containing 2-biphenyl
precursors via C−H functionalization and C−X bond
formation is an ideal protocol to produce 9-heterofluorenes
(Figure 2b). For example, Buchwald and Gaunt reported the
synthesis of carbazoles from the corresponding 2-amino-
biphenyl derivatives through palladium-catalyzed C−H
functionalization/C−N bond formation.13 Liu and Yoshikai
developed the palladium-catalyzed synthesis of dibenzofurans
from 2-arylphenols.14 An elegant rhodium-catalyzed synthesis
of silafluorene derivatives was reported by Takai from
biphenylhydrosilanes via cleavage of the Si−H and C−H
bonds.15,16 Dibenzophosphole oxides were also obtained from
secondary hydrophosphine oxides with a biphenyl group by
dehydrogenation in the presence of a catalytic amount of
palladium(II) acetate.17 However, synthesis of dibenzothio-
phenes from 2-biphenylthiols through transition-metal-cata-
lyzed intramolecular cyclization has scarcely been reported
probably due to the known poisoning effect of phenylthiols on
transition metals.18
Figure 1. Representative benzo-fused thiophenes as pharmaceuticals
or organic functional materials.
thiophene was reported to be a selective PTPase inhibitor
that functions as an oral antidiabetic agent.3 Notably, the use of
ladder-type small molecule 2,7-dioctyl[1]benzothieno[3,2-b]-
[1]benzothiophene (C8-BTBT) as an organic semiconductor
has yielded thin-film transistors with average carrier mobilities
as high as 16.4 cm2 V−1 s−1.4 Dibenzo[d,d′]thieno[3,2-b;4,5-
b′]dithiophene (DBTDT) is an eminent p-type semiconductor
in organic plastics.5 Employing the disc-shaped dithioperylene
in the organic field-effect transistors (OFETs) produced carrier
mobilities as high as 2.13 cm2 V−1 s−1 and an on/off ratios up
to 106 for single-crystalline nanoribbons by a solution process.6
Trithiasumanene, possessing a bowl-shaped geometry with
three embedded benzo-fused thiophene rings,7 is useful for
molecular recognition.8
Received: July 25, 2018
© XXXX American Chemical Society
A
DOI: 10.1021/acs.orglett.8b02347
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
semiconductor DBTDT 4, and the preparation of highly
strained buckybowl trithiasumanene 5.
The reaction conditions were optimized based on the model
transformation of 4′-methyl-2-biphenylthiol 1a (Table 1).
Initial attempts employing PdCl2 as the catalyst and copper
acetate as the oxidant in acetic acid at 120 °C afforded the
desired product 2a in 57% yield (entry 1). The use of n-butyric
acid as the solvent led to higher yields (entries 2−3). When the
reaction was carried out at 140 °C, an 80% yield was obtained.
No apparent product was observed in the absence of an
oxidant when the reaction was performed in the neat acid
(entry 5). The reaction in DMSO afforded the product in a
comparable yield to the acid (entry 6). Interestingly, an
external oxidant was found to be unnecessary for the reaction
carried out in DMSO, which gave an excellent yield (entry 7).
Surprisingly, palladium acetate only gave a trace amount of the
product (entry 8). Pd(PPh3)4 afforded the desired product,
albeit in a much lower yield (entry 9). Copper acetate was not
an effective catalyst for this transformation (entry 10). Other
solvents did not give the product in the absence of an oxidant,
which indicates that DMSO plays a role as an oxidant (entries
11−14). No product was obtained in the absence of a metal
catalyst (entry 15). Lowering the temperature or performing
the reaction under an air or oxygen atmosphere decreased the
yields (entries 16−18).
Figure 2. Synthesis of dibenzothiophenes.
With the optimized conditions in hand, the substrate scope
was next investigated. As shown in Scheme 1, various
dibenzothiophenes were prepared in good to excellent yields.
The 2-biphenylthiols with functional groups on the 4′ position,
regardless of their electronic properties, gave the cyclized
products in excellent yields (2a−2h). Interestingly, a C−Br
bond remained intact under the conditions (2d). The methyl
group on the 2′ position of the 2-biphenylthiol did not affect
the cyclization (2i). Notably, substrate 1j with a methyl group
We herein report an efficient synthesis of dibenzothiophenes
via C−H functionalization and C−S bond formation from
readily available 2-biphenylthiols under simple PdCl2/DMSO
catalysis (Figure 2c). The notable features of the reaction are
as follows: (1) no need for additives, such as ligands, external
oxidants, or bases; (2) DMSO as the solvent and oxidant; (3)
broad substrate scope; (4) multifold cyclization also possible.
The utilities of this method have been demonstrated by a facile
synthesis of helical dinapthothiophene 3, p-type organic
a
Table 1. Optimization of the Conditions
b
entry
catalyst
oxidant (equiv)
solvent
temp [°C]
yield [%]
1
2
3
4
5
6
7
8
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
PdCl2
Pd(OAc)2
Pd(PPh3)4
Cu(OAc)2
PdCl2
PdCl2
PdCl2
PdCl2
−
Cu(OAc)2 (1.5)
Cu(OAc)2 (1.5)
Cu(OAc)2 (2.0)
Cu(OAc)2 (2.0)
AcOH
120
120
120
140
140
140
140
140
140
140
140
140
140
140
140
120
140
140
57
65
71
80
<5
80
85
<5
32
<5
<5
<5
<5
<5
<5
70
65
52
n-PrCO2H
n-PrCO2H
n-PrCO2H
n-PrCO2H
DMSO
DMSO
DMSO
DMSO
DMSO
toluene
DMF
NMP
AcOH
DMSO
DMSO
DMSO
DMSO
−
Cu(OAc)2 (2.0)
−
−
−
−
−
−
−
−
−
−
−
−
9
10
11
12
13
14
15
16
PdCl2
PdCl2
PdCl2
c
17
18
d
a
b
c
Reaction conditions: 1a (0.3 mmol), cat. (0.015 mmol) in DMSO (2.0 mL), 140 °C, under a N2 atmosphere, 12 h. Isolated yield. O2
d
atmosphere. Air atmosphere.
B
DOI: 10.1021/acs.orglett.8b02347
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Organic Letters
Letter
a b
,
Scheme 1. Substrate Scope of the Reaction
Scheme 2. Application in the Synthesis of Helical
Dinaphthothiophene 3 and DBTDT 4
Trithiasumane 5, a sulfur-doped buckybowl, was pioneer-
ingly synthesized through a seven-step procedure employing a
flash vacuum pyrolysis as the key step (FVP, 1000 °C and
0.005 Torr, total yield <5%).7c Recently, Shao and our group
reported the practical synthesis of trithiasumanene 5 and its
derivatives via nonpyrolytic conditions (Scheme 3a).7a,b The
Scheme 3. Attempt for the Synthesis of Trithiasumanene 5
via Direct “Stitching” Strategy
a
Reaction conditions: 1 (0.3 mmol), PdCl2 (0.015 mmol) in DMSO
b
(2.0 mL), 140 °C, under a N2 atmosphere, 12 h. Isolated yields.
c
PdCl2 (0.03 mmol, 10 mol %).
on the 3′ position gave the less hindered product 2j,
exclusively. The sterically hindered thiol 1k bearing a methyl
group on the 3-position afforded the product in good yield.
Symmetrical and unsymmetrical disubstituted dibenzothio-
phenes (2k−2o) were also prepared in excellent yield.
Compound 2m is a particularly valuable building block for
many thiophene-based organic materials or polymers,19 which
is generally prepared from 2b through oxidation, bromination,
and reduction.19b The structure of 2o was confirmed by X-ray
crystallographic analysis. This compound adopted a herring-
bone stacking in the solid state (see the Supporting
Information for details). To demonstrate the generality of
this transformation, a pyridine-fused thiophene 2p was
synthesized with equal efficiency. However, the cyclization of
2-phenylethanethiol or 2-phenoxybenzenethiol did not give the
desired 2,3-dihydrobenzo[b]thiophene or phenoxathiine.
The utility of this reaction has been further demonstrated in
the synthesis of two challenging targets that include the
dinapthothiophene 3 and DBTDT 4 (Scheme 2). Compound
3 is a helical compound with a large torsion angle (25.9°),
which arises from strong repulsion between the two twisted
naphthyl groups.20 It has been previously prepared in variable
yields of 20−50% via Newman−Kwart thermal rearrangement
of the thiocarbamoyl precursor at 285 °C.21 Under our
conditions, this helical compound could be obtained in 83%
yield. DBTDTs are eminent p-type organic semiconductors for
high-performance OFETs,5 which were first prepared by Szperl
80 years ago.22 The pristine DBTDT 4 was prepared in 41%
yield by this method via a twofold cyclization.
nonpyrolytic methods involve the initial formation of six-
membered 1,2-dithiin rings followed by copper-mediated
desulfurization leading to the desired trithiasumanenes. This
“ring contraction” strategy is energetically favored in
comparison to the direct “stitching” of substituted tripheny-
lenes. For example, the synthesis of sumanene from 1,5,9-
trimethylsumanene through a “stitching” strategy under FVP
C
DOI: 10.1021/acs.orglett.8b02347
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
conditions failed, indicating the difficulties of the direct
“stitching” method for the synthesis of highly strained
sumanene derivatives.23 We hypothesized that PdCl2/DMSO
catalysis might be useful for the synthesis of 5 due to the six-
membered palladacycle intermediates that were formed.
Triphenylene-1,5,9-trithiol 9 was prepared from 8, which was
previously prepared on a decagram scale by us.24 To our
delight, trithiasumanene 5 was unambiguously observed (2%
The disulfide 11 can be transformed to the desired product at
120 °C under the PdCl2/DMSO catalysis. These experiments
support that disulfides might be intermediates.
In summary, we have developed an efficient synthesis of
dibenzothiophenes from 2-biphenylthiols under simple PdCl2/
DMSO catalysis. The procedure employs a simple catalytic
system, in which PdCl2 is the sole metal catalyst required, and
no additives such as ligands, oxidants, and bases are needed.
DMSO is believed to play vital roles as an oxidant, ligand, and
solvent. This direct high-yielding and atom-economical
procedure shows broad substrate scope as demonstrated by
the efficient synthesis of helical dinapthothiophene 3 and an
eminent organic semiconductor DBTDT 4. Remarkably,
trithiasumanene 5, a highly strained buckybowl, was also
observed in a threefold cyclization of the rigid precursor 9
under the PdCl2/DMSO catalysis. This result suggests that the
synthesis of highly curved aromatics such as sumanene
derivatives by a suitable transition-metal-catalyzed “stitching”
strategy is feasible. Further studies toward improvement of the
synthetic efficiency of trithiasumanen 5, and the application of
this reaction to the synthesis of other planar or curved
aromatics, are currently underway in our laboratories.
1
yield by H NMR) under the present PdCl2/DMSO catalysis,
along with 1025 (5% yield) (Scheme 3b). Albeit in low yield,
the observation of 5 is remarkable, which represents the first
“stitching” synthesis of a curved sumanene derivative from a
triphenylene precursor.26 The low yield is mainly attributable
to the instability of 5 in the PdCl2/DMSO conditions,
probably driven by the relief of strain in the curved skeleton.27
An authentic sample of 5 gave a complicated mixture under the
PdCl2/DMSO catalysis (Figure S1).
Our current mechanistic proposal for this palladium-
catalyzed cyclization is outlined in Scheme 4. First, ligand
Scheme 4. Proposed Mechanism and Control Reactions
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.or-
glett.8b02347.
Details of experimental procedures and compound
1
characterization data, H, 13C, and 19F NMR spectra of
synthesized compounds (PDF)
Accession Codes
CCDC 1854874 and 1855043 contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by
emailing data_request@ccdc.cam.ac.uk, or by contacting The
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
AUTHOR INFORMATION
Corresponding Authors
■
*E-mail: qttan@shu.edu.cn.
*E-mail: xubin@shu.edu.cn.
ORCID
Qitao Tan: 0000-0002-6220-651X
Bin Xu: 0000-0002-9251-6930
Notes
The authors declare no competing financial interest.
exchange between PdCl2 and ArSH gives a complex A, in
which DMSO might act as ligands.28 Cyclization of A via C−H
functionalization affords the palladacycle B, reductive elimi-
nation of which affords the product and generates the Pd(0)/
DMSO complex C.28 It has been reported that DMSO can
oxidize aromatic thiols to diaryl disulfides.29 Therefore, we
hypothesize that the 2-biphenylthiol is oxidized to the disulfide
D by DMSO. Oxidative addition of disulfides with a Pd(0)
complex is a known process.30 Therefore, D reacts with C to
give A by insertion of the palladium(0) to the weak S−S bond.
Control reactions confirmed that the 2-biphenylthiol 1a can be
oxidized to disulfide 11 in excellent yields by DMSO in the
presence or absence of PdCl2 at lower temperature (100 °C).
ACKNOWLEDGMENTS
■
We thank the National Natural Science Foundation of China
(Nos. 21672140 and 21672136) for financial support. The
authors thank Prof. Hongmei Deng (Laboratory for Micro-
structures, SHU) for NMR spectroscopic measurements.
REFERENCES
■
(1) For selected reviews, see: (a) Cinar, M. E.; Ozturk, T. Chem. Rev.
2015, 115, 3036. (b) Takimiya, K.; Osaka, I.; Mori, T.; Nakano, M.
Acc. Chem. Res. 2014, 47, 1493. (c) Jiang, W.; Li, Y.; Wang, Z. Chem.
Soc. Rev. 2013, 42, 6113. (d) Takimiya, K.; Shinamura, S.; Osaka, I.;
D
DOI: 10.1021/acs.orglett.8b02347
Org. Lett. XXXX, XXX, XXX−XXX

Organic Letters
Letter
Miyazaki, E. Adv. Mater. 2011, 23, 4347. (e) Mishra, A.; Ma, C.;
(18) Antonchick et al. reported the transformation of 1b to 2b to
support their proposed mechanism using stoichiometric amounts of
AgOAc as the oxidant and PdCl2 as the catalyst in AcOH, but no
further studies were found on this transformation; see ref 12f.
(19) (a) Li, W.; Hendriks, K. H.; Furlan, A.; Roelofs, W. S. C.;
Wienk, M. M.; Janssen, R. A. J. J. Am. Chem. Soc. 2013, 135, 18942.
(b) Kawabata, K.; Takeguchi, M.; Goto, H. Macromolecules 2013, 46,
2078.
̈
Bauerle, P. Chem. Rev. 2009, 109, 1141. (f) Hale, K. J.; Manaviazar, S.
Chapter 3: Thiophenes, hydrothiophenes, benzothiophenes and
related compounds. Second Supplements to the 2nd Edition of Rodd’s
Chemistry of Carbon Compounds; Sainsbury, M., Ed.; Elsevier:
Amsterdam, 1997; Vol. IV A, pp 337−456.
(2) Balasubramanian, B. N.; St. Laurent, D. R.; Saulnier, M. G.;
Long, B. H.; Bachand, C.; Beaulieu, F.; Clarke, W.; Deshpande, M.;
Eummer, J.; Fairchild, C. R.; Frennesson, D. B.; Kramer, R.; Lee, F.
Y.; Mahler, M.; Martel, A.; Naidu, B. N.; Rose, W. C.; Russell, J.;
Ruediger, E.; Solomon, C.; Stoffan, K. M.; Wong, H.; Zimmermann,
K.; Vyas, D. M. J. Med. Chem. 2004, 47, 1609.
(3) Wrobel, J.; Sredy, J.; Moxham, C.; Dietrich, A.; Li, Z.; Sawicki,
D. R.; Seestaller, L.; Wu, L.; Katz, A.; Sullivan, D.; Tio, C.; Zhang, Z.
J. Med. Chem. 1999, 42, 3199.
(4) Minemawari, H.; Yamada, T.; Matsui, H.; Tsutsumi, J.; Haas, S.;
Chiba, R.; Kumai, R.; Hasegawa, T. Nature 2011, 475, 364.
(5) (a) Miyata, Y.; Yoshikawa, E.; Minari, T.; Tsukagoshi, K.;
Yamaguchi, S. J. Mater. Chem. 2012, 22, 7715. (b) Gao, J. H.; Li, R. J.;
Li, L. Q.; Meng, Q.; Jiang, H.; Li, H. X.; Hu, W. P. Adv. Mater. 2007,
19, 3008.
(20) Fabbri, D.; Dore, A.; Gladiali, S.; De Lucchi, O.; Valle, G.
Gazz.Chim. Ital. 1996, 126, 11.
(21) (a) Treskow, M.; Neudorfl, J.; Giernoth, R. Eur. J. Org. Chem.
̈
2009, 2009, 3693. (b) Cho, Y.; Kina, A.; Shimada, T.; Hayashi, T. J.
Org. Chem. 2004, 69, 3811. (c) Fabbri, D. J. Org. Chem. 1993, 58,
1748. (d) Newman, M. S.; Hetzel, F. W. Org. Synth. 1971, 51, 139.
(e) Kwart, H.; Evans, E. R. J. Org. Chem. 1966, 31, 410.
(22) Szperl, L. Rocz. Chem. 1938, 18, 804.
(23) For a synthetic attempt: (a) Mehta, G.; Shahk, S. R.;
Ravikumarc, K. J. Chem. Soc., Chem. Commun. 1993, 1006. For
successful synthesis of sumanene and triazasumanene: (b) Sakurai,
H.; Daiko, T.; Hirao, T. Science 2003, 301, 1878. (c) Tan, Q.;
Higashibayashi, S.; Karanjit, S.; Sakurai, H. Nat. Commun. 2012, 3,
891.
(24) Tan, Q.; Chen, H.; Xia, H.; Liu, B.; Xu, B. Chem. Commun.
2016, 52, 537.
(25) Klemm, L. H.; Hall, E.; Cousins, L.; Klopfenstein, C. E. J.
Heterocycl. Chem. 1989, 26, 345.
(6) Jiang, W.; Zhou, Y.; Geng, H.; Jiang, S.; Yan, S.; Hu, W.; Wang,
Z.; Shuai, Z.; Pei, J. J. Am. Chem. Soc. 2011, 133, 1.
(7) (a) Tan, Q.; Zhou, D.; Zhang, T.; Liu, B.; Xu, B. Chem. Commun.
2017, 53, 10279. (b) Li, X.; Zhu, Y.; Shao, J.; Wang, B.; Zhang, S.;
Shao, Y.; Jin, X.; Yao, X.; Fang, R.; Shao, X. Angew. Chem., Int. Ed.
2014, 53, 535. (c) Imamura, K.; Takimiya, K.; Aso, Y.; Otsubo, T.
Chem. Commun. 1999, 1859.
(8) Liu, Y.; Xia, D.; Li, B.; Zhang, Q.; Sakurai, T.; Tan, Y.; Seki, S.;
Xie, S.; Zheng, L. Angew. Chem., Int. Ed. 2016, 55, 13047.
(9) (a) Beletskaya, I. P.; Ananikov, V. P. Chem. Rev. 2011, 111, 1596.
(b) Jepsen, T. H.; Larsen, M.; Jørgensen, M.; Solanko, K. A.; Bond, A.
D.; Kadziola, A.; Nielsen, M. B. Eur. J. Org. Chem. 2011, 2011, 53.
(c) Kienle, M.; Unsinn, A.; Knochel, P. Angew. Chem., Int. Ed. 2010,
49, 4751. (d) Kondo, T.; Mitsudo, T. Chem. Rev. 2000, 100, 3205.
(10) (a) Wang, M.; Wei, J.; Fan, Q.; Jiang, X. Chem. Commun. 2017,
53, 2918. (b) Wang, M.; Chen, S.; Jiang, X. Org. Lett. 2017, 19, 4916.
(c) Wang, M.; Fan, Q.; Jiang, X. Org. Lett. 2016, 18, 5756.
(d) Shimizu, M.; Ogawa, M.; Tamagawa, T.; Shigitani, R.; Nakatani,
M.; Nakano, Y. Eur. J. Org. Chem. 2016, 2016, 2785.
(26) For recent reviews on the synthesis of curved aromatic
́
molecules, see: (a) Majewski, M. A.; Stępien, M. Angew. Chem., Int.
Ed. DOI: 10.1002/anie.201807004. (b) Hiroto, S. Bull. Chem. Soc.
Jpn. 2018, 91, 829. (c) Saito, M.; Shinokubo, H.; Sakurai, H. Mater.
Chem. Front. 2018, 2, 635.
(27) For special reactivity caused by bowl-shaped geometry, see:
(a) Scott, L. T. Chem. Soc. Rev. 2015, 44, 6464. (b) Li, X.; Zhu, Y.;
Shao, J.; Chen, L.; Shao, S.; Wang, B.; Zhang, S.; Shao, Y.; Zhang, H.;
Shao, X. Angew. Chem., Int. Ed. 2015, 54, 267. (c) Tashiro, S.;
Yamada, M.; Shionoya, M. Angew. Chem., Int. Ed. 2015, 54, 5351.
(28) For selected examples, see: (a) Diao, T.; White, P.; Guzei, I.;
Stahl, S. S. Inorg. Chem. 2012, 51, 11898. (b) Zierkiewicz, W.;
Privalov, T. Organometallics 2005, 24, 6019. (c) Chen, M. S.; White,
M. C. J. Am. Chem. Soc. 2004, 126, 1346. (d) van Benthem, R. A. T.
M.; Hiemstra, H.; van Leeuwen, P. W. N. M.; Geus, J. W.; Speckamp,
W. N. Angew. Chem., Int. Ed. Engl. 1995, 34, 457. (e) Price, J. H.;
Williamson, A. N.; Schramm, R. F.; Wayland, B. B. Inorg. Chem. 1972,
11, 1280.
(11) (a) Nishino, K.; Ogiwara, Y.; Sakai, N. Chemistry
DOI: 10.1002/chem.201802475. (b) Nishino, K.; Ogiwara, Y.;
Sakai, N. Eur. J. Org. Chem. 2017, 2017, 5892.
(12) (a) Tobisu, M.; Masuya, Y.; Baba, K.; Chatani, N. Chem. Sci.
2016, 7, 2587. (b) Huang, Q.; Fu, S.; Ke, S.; Xiao, H.; Zhang, X.; Lin,
S. Eur. J. Org. Chem. 2015, 2015, 6602. (c) Saravanan, P.; Anbarasan,
P. Org. Lett. 2014, 16, 848. (d) Che, R.; Wu, Z.; Li, Z.; Xiang, H.;
Zhou, X. Chem. - Eur. J. 2014, 20, 7258. (e) Wesch, T.; Berthelot-
(29) (a) Wallace, T. J. J. Am. Chem. Soc. 1964, 86, 2018.
(b) Yiannios, C. N.; Karabinos, J. V. J. Org. Chem. 1963, 28, 3246.
(30) (a) Kim, Y.; Choi, K.; Lee, S. G.; Zheng, Z. N.; Lee, S. W. Bull.
Korean Chem. Soc. 2014, 35, 1205. (b) Inamoto, K.; Arai, Y.; Hiroya,
K.; Doi, T. Chem. Commun. 2008, 5529. (c) Kawamoto, T.; Suzuki,
S.; Konno, T. J. Organomet. Chem. 2007, 692, 257. (d) Ananikov, V.
P.; Kabeshov, M. A.; Beletskaya, I. P.; Khrustalev, V. N.; Antipin, M.
Y. Organometallics 2005, 24, 1275. (e) Kuniyasu, H.; Ogawa, A.;
Miyazaki, S.; Ryu, I.; Kambe, N.; Sonoda, N. J. Am. Chem. Soc. 1991,
113, 9796.
́
Brehier, A.; Leroux, F. R.; Colobert, F. Org. Lett. 2013, 15, 2490.
(f) Samanta, R.; Antonchick, A. P. Angew. Chem., Int. Ed. 2011, 50,
5217. (g) Chen, S.; Wang, M.; Jiang, X. Chin. J. Chem. 2018, 36,
DOI: 10.1002/cjoc.201800242.
(13) (a) Jordan-Hore, J. A.; Johansson, C. C. C.; Gulias, M.; Beck, E.
M.; Gaunt, M. J. J. Am. Chem. Soc. 2008, 130, 16184. (b) Tsang, W.
C.; Zheng, N.; Buchwald, S. L. J. Am. Chem. Soc. 2005, 127, 14560.
(14) (a) Xiao, B.; Gong, T.; Liu, Z.; Liu, J.; Luo, D.; Xu, J.; Liu, L. J.
Am. Chem. Soc. 2011, 133, 9250. (b) Wei, Y.; Yoshikai, N. Org. Lett.
2011, 13, 5504.
(15) Ureshino, T.; Yoshida, T.; Kuninobu, Y.; Takai, K. J. Am. Chem.
Soc. 2010, 132, 14324.
(16) (a) Zhou, D.; Gao, Y.; Liu, B.; Tan, Q.; Xu, B. Org. Lett. 2017,
19, 4628. (b) Murai, M.; Okada, R.; Asako, S.; Takai, K. Chem. - Eur.
J. 2017, 23, 10861. (c) Murai, M.; Okada, R.; Nishiyama, A.; Takai, K.
Org. Lett. 2016, 18, 4380. (d) Murai, M.; Matsumoto, K.; Okada, R.;
Takai, K. Org. Lett. 2014, 16, 6492. (e) Kuninobu, Y.; Yamauchi, K.;
Tamura, N.; Seiki, T.; Takai, K. Angew. Chem., Int. Ed. 2013, 52, 1520.
(17) Kuninobu, Y.; Yoshida, T.; Takai, K. J. Org. Chem. 2011, 76,
7370.
E
DOI: 10.1021/acs.orglett.8b02347
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