Synthesis of dibenzophosphole oxides via palladium-catalyzed intramolecular direct arylation reactions of ortho-halodiarylphosphine oxides

Article abstract of DOI:10.1002/adsc.201301081

A palladium-catalyzed intramolecular direct arylation reaction was developed and two efficient one-pot sequential direct arylation/Suzuki-Miyaura coupling and intra/intermolecular direct arylation reations were also realized. The method provides a simple and straightforward procedure for the synthesis and further functionalization of dibenzophosphole oxides from easily accessible ortho-halodiarylphosphine oxides in good to excellent yields.

Full text of DOI:10.1002/adsc.201301081

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DOI: 10.1002/adsc.201301081
Synthesis of Dibenzophosphole Oxides via Palladium-Catalyzed
Intramolecular Direct Arylation Reactions of ortho-Halodiaryl-
phosphine Oxides
Yuming Cui,a,* Lingzi Fu,a Jian Cao,a Yuan Deng,a and Jianxiong Jianga
a
Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal
University, Wenyi Road 222, Hangzhou 310012, Peopleꢀs Republic of China
Fax : (+86)-571-2886-8715; phone: (+86)-571-2886-5135; e-mail: ym_cui@hznu.edu.cn
Received: December 3, 2013; Published online: && &&, 0000
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201301081.
Abstract:
A
palladium-catalyzed intramolecular
have been synthesized via intramolecular direct aryla-
tion.[3b,9] To the best of our knowledge, the synthesis
of dibenzophospholes via direct arylation of ortho-
halodiarylphosphines has never been reported and
the difficulty may be due to the instability and unde-
sired coordination of the metal with the phosphine,
although the dibenzophospholes are valuable building
blocks for tailoring organic p-conjugated materials
and their photophysics and redox properties can be
efficiently tuned through the diverse and reversible
phosphorus chemistry.[10]
direct arylation reaction was developed and two ef-
ficient one-pot sequential direct arylation/Suzuki–
Miyaura coupling and intra/intermolecular direct ar-
ylation reations were also realized. The method
provides a simple and straightforward procedure
for the synthesis and further functionalization of di-
benzophosphole oxides from easily accessible
ortho-halodiarylphosphine oxides in good to excel-
lent yields.
Keywords: catalysis; C H activation; direct aryla-
tion; heterofluorenes; palladium
The previously used methods[11] to synthesize diben-
zophospholes often required the synthesis of function-
alized biaryl subunits and/or suffered from the
modest functional group tolerance, particularly in the
many cases using aryllithium reagents. On the other
hand, the frequently used procedure through meta-
À
In the field of organic materials, heterofluorenes have thesis reaction between 2,2’-dilithiated biaryls and
attracted considerable attention due to a growing in- RPCl2 is suitable for the synthesis of the symmetrical
terest as components of optical and electronic devices. dibenzophosphole oxides, only being restricted by the
The particular interaction between the heteroatoms availability of the dihalobiaryls. To overcome the
(nitrogen,[1,2] silicon,[1,3] boron,[4,5] sulfur,[6] germani- issues mentioned above and increase the steric effect
um,[7] etc.) and the p-conjugated polyphenylene-like between the two phenyl groups, we attempted a palla-
framework in the oligomers and polymers determines dium-catalyzed intramolecular direct arylation as
their electronic nature which will play the key role in a new synthetic route to symmetrical and unsymmet-
the performance of the final materials. To achieve the rical dibenzophosphole oxides from the easily accessi-
desired function such as electroluminescence and high ble substrates (Scheme 1). These oxides can be easily
charge mobility, the properties of p-conjugated oligo- reduced to phosphines by treatment with HSiCl3 and
mers and polymers need to be tailored at the molecu- further functionalization (sulfuration, borylation,
lar level. However, the facile synthesis of differently methylation, metalation, etc.) can be carried out fol-
substituted heterofluorenes is still a challenge for lowing established procedures.[12]
chemists, limiting the application of heterofluorenes.
Considering the significant potential of palladium
In recent years, direct arylation reactions that allow in tandem catalysis, we sought to investigate the pos-
À
À
direct C C formation by C H activation have sibility of a one-pot sequential coupling protocol for
emerged as a powerful tool for the construction of the synthesis of functionalized dibenzophosphole
aryl-aryl bonds and thus have many advantages over oxides. Fagnou reported the tandem Heck/direct ary-
the more commonly employed cross-coupling reac- lation and Heck/direct arylation/hydrogenation reac-
tions.[8] A few of heterofluorenes including carbazoles, tions and the key factor influencing reaction success
dibenzofurans, dibenzothiophenes, and silafluorenes was the use of bromochloro substrates to ensure good
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Table 1. Optimization of the reaction conditions.[a]
Entry
x
y
Base
Solvent
Yield [%][b]
1
2
3
4
5
6
7
8
3
3
3
3
3
3
3
3
3
1
3
3
3
1
6
6
6
6
6
6
6
6
6
2
–
–
–
–
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
Cs2CO3
NEt3
KOAc
K2CO3
K2CO3
K2CO3
KOAc
K2CO3
K2CO3
DMF
dioxane
THF
88
86
55
94
98
83
20
94
82
93
93
88
81
92
toluene
DMAc
DMAc
DMAc
DMAc
DMAc
DMAc
DMAc
DMAc
DMAc
DMAc
9[c]
10
11
12
13[d]
14
Scheme 1. Syntheis of dibenzophosphole oxides.
site-selectivity.[13] In fact, it will be a tough task to use
dihalo-substituted substrates in the tandem reactions
in spite of their being prepared readily compared with
those bearing the different reactive groups. Herein,
we present a new synthetic method for the synthesis
of dibenzophosphole oxides using the intramolecular
direct arylation as the key transformation. Based on
the good compatibility of palladium catalysts, the pal-
ladium-catalyzed sequential direct arylation/Suzuki–
[a]
Unless otherwise specified, the reaction was carried out
using 1a (1.0 mmol), base (1.5 mmol), Pd(OAc)2
(x mol%), and PCy3·HBF4 (y mol%) in solvent (3 mL) at
1208C for 12 h under N2.
Isolated yields.
At 908C.
ACHTUNGTRENNUNG
[b]
[c]
[d]
Pd2ACHTUNTRGNEUNG(dba)3 was used.
Miyaura coupling and intra-/intermolecular direct ary- under the reaction conditions could behave as the
lation reactions were also realized.
active catalyst.[14]
Initial reaction optimization was performed with
With the optimized conditions in hand, we then in-
OPPh
To our delight, reactions in DMF at 1208C using a and the results are summarized in Table 1. We fo-
Pd(OAc)2/PCy3·HBF4 catalyst system and K2CO3 as cused on Pd(OAc)2/PCy3·HBF4 as the catalyst system
2ACHTUNGTRENNUNG(o-C6H4Br) 1a as a model substrate (Table 1). vestigated the scope of the direct arylation reactions
A
ACHTUNGTRENNUNG
the base lead to the desired dibenzophosphole oxide because it gave very good yields of the products and
product 2a in 88% yield (entry 1). Next, we investi- is air stable and inexpensive. As shown in Table 2, the
gated the effects of different solvents, bases, and tem- substrates with electron-rich and poor functional
perature on the reaction outcome. Among the select- groups can be tolerated to give the desired products
ed solvents, DMAc was superior to other solvents in good to excellent yields. For electron-donating
such as dioxane, toluene, and THF, providing the groups, methyl- and methoxy-substituted products 2b
product 2a in almost quantitative yield (entries 2 to and 2c were obtained in 85% and 96% yields, respec-
5). With DMAc as the solvent, a survey of different tively (entries 2 and 3). In addition, various electron-
bases including Cs2CO3, NEt3, and KOAc revealed withdrawing groups are suitable for these transforma-
that no improvement was observed, suggesting that tions. We were pleased to find that the chloro-substi-
K2CO3 is the best choice for this transformation (en- tuted substrate could be successfully employed to give
tries 6 to 8). Attempts to lower the reaction tempera- 2d in 94% yield without any problem (entry 4). In the
ture from 1208C to 908C led to inferior results, pro- cases of 2c and 2d, the methoxy and chloro groups
ducing 2a in only 82% yield (entry 9). Interestingly, could be used to extend the p-conjugated systems of
no significant drop of the yield (93%) was observed dibenzophosphole oxides, applying the previously re-
when using a catalyst loading as low as 1 mol% ported coupling methods.[3b,15] Fluorodibenzophos-
(entry 9). It should be noted that the reaction can be
ACHTUNGTRENpNGNU hole oxide 2e was also formed in excellent yield, up
performed in the absence of phosphine ligand and to 97% (entry 5). Furthermore, two kinds of ester-
similar results were obtained (entries 10 and 14), and nitrile-substituted products 2f and 2g were first
reaching 92% yield. For these cases, the palladium synthesized in very good yields under our conditions
colloids or nanoparticles generated from PdACHTUNTRGNEU(GN OAc)2 which cannot be prepared directly using the most
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Synthesis of Dibenzophosphole Oxides
Table 2. Syntheis of dibenzophosphole oxides 2.[a]
Entry
Boronic acid
Product
Yield
[%]
Scheme 2. Synthesis of 2i by double direct arylation.
1
2
3
1a
1b
1c
2a 98
diarylphosphine oxide 1i. Such a result constitutes
one of the rare examples in the direct arylation of
chloroarenes in very high yields.[16] Through a rational
design of the substrate structure, this method could
be applied to the synthesis of polycyclic dibenzo-
phosphole oxides in the tandem reaction. Polycyclic
phosphole oxide 2i was prepared in 82% yield via
double direct arylation reactions and the use of two
distinct arylation couplings endowed a high degree of
modularity to this strategy (Scheme 2). The structure
of new compound 2i was determined by X-ray analy-
sis, which confirmed that regioselective direct aryla-
tion procceeded preferentially at the most sterically
accessible site to afford 2i (Figure 1).[17]
Encouraged by the facile synthesis of functionalized
dibenzophosphole oxides through a second intramo-
lecular biaryl coupling reacion, we then investigated
the viability of one-pot sequential coupling reactions
using arylboronic acids and heteroarenes as the
second coupling partners respectively. In 2004, Xiao
reported the Suzuki coupling reactions of 1a with a va-
riety of arylboronic acids for the synthesis of biaryl-
phosphine oxides.[18] When 2,5’-dibromo-substituted
substrate 1k was used, it is very important to control
the reaction conditions to suppress the undesired cou-
pling at 2-position with boronic acids (Table 3). It was
not surprising to find that 2j was only isolated in 49%
2b 85
2c 96
4
5
6
1d
1e
1f
1g
2d 94
2e 97
2f 90
2g 83
7
8
1h
1i
2h 94
2a 97
9
[a]
Unless otherwise specified, the reaction was carried out
using 1 (1.0 mmol), K2CO3 (1.5 mmol), Pd(OAc)2 (3 mol%),
AHCTUNGTRENNUNG
and PCy3·HBF4 (6 mol%) in DMAc (3 mL) at 1208C for
12 h under N2.
common organolithium method due to their sensitivi-
ties to electrophilic attack (entries 6 and 7). On
changing the phenyl to an isopropyl group on the
phosphorus atom, the reaction proceeded smoothly to
produce the corresponding product 2h in 94% yield
(entry 5).
Taking into account of the wide generality of the
direct arylation coupling method as for ortho-bromo-
diarylphosphine oxides, we turned our attention to
the more challenging chloro-substituted substrates. As
demonstrated by entry 9, the desired product 2a was
formed in high yield up to 97% from ortho-chloro- Figure 1. ORTEP representation of 2i.
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Table 3. Synthesis of 3-(het)aryldibenzophosphole oxides
2.[a]
acid, which has been proved to promote direct aryla-
tion for a concerted metalation-deprotonation mecha-
nism.[19] In addition, it was observed that slow addi-
tion of arylboronic acids is another critical factor to
achieve satisfactory results. Finally, an efficient one-
pot sequential tandem approach was successfully de-
veloped using arylboronic acids with different elec-
tronic properties. For example, the outcomes of the
tandem coupling reaction were greatly improved to
afford the desired product 2j in 87% yield under our
optimized conditions when phenylboronic acid was
used as a coupling partner (entry 1). Analogously, 1k
also reacts smoothly with 4-methyl- and 4-methoxy-
carbonylphenylboronic acids and the corresponding
products 2k and 2l were prepared in 82% and 81%
yields, respectively (entries 2 and 3). Furthermore, we
successfully synthesized a new family of thiophene-
containing extended p-conjugated dibenzophosphole
oxides through the sequential intra-/intermolecular
direct arylation in a one-pot manner. This method is
compatible with 2-methylthiophene (entry 4), 2-ace-
tylthiophene (entry 5), benzothiophene (entry 6), and
2-phenylthiophene (entry 7) producing the corre-
sponding products in good yields ranging from 75%
to 86%.
In conclusion, we have developed a new method
for the synthesis of dibenzophosphole oxides by palla-
dium-catalyzed direct arylation reactions from the
readily available ortho-halodiarylphosphine oxides. In
addition, the utilities of this method were demonstrat-
ed by the facile access to extended p-conjugated sys-
tems of dibenzophosphole oxides combined with the
second direct arylation or Suzuki–Miyaura coupling
reacions in a tandem process. This strategy features
simplicity, atom-economics, high yields, and good
functional group compatibility, providing an efficient
and versatile entrance to a variety of dibenzophosp-
hole oxides applicable in materials. Studies on further
applications of the reported method are currently un-
derway.
Entry 3 or 4
Product
Yield [%]
1
2
3
4
5
6
3a
3b
3c
4a
4b
4c
2j 87; 49[b]
2k 82
2l 81
2m 86
2n 83
2o 75
7
4d
2p 85
[a]
Reaction conditions: For Suzuki coupling, 3 (1.1 mmol) in
DMAc (2 mL) was added dropwise to a solution of 1k
Experimental Section
(1.0 mmol), K2CO3
( 2.5 mmol), PivOH (30 mol%),
Pd(OAc)2 (3 mol%), and PCy3·HBF4 (6 mol%) in DMAc
ACHTUNGTRENNUNG
Representative Procedure for the Synthesis of
Dibenzophosphole Oxide 2g
(2 mL) at 1008C within 2 h and then stirred for 12 h
under N2 after addition. For direct heteroarylation, 4
(2 mmol), 1k (1.0 mmol), K2CO3 ( 2.5 mmol), PivOH
(30 mol%), PdACHTNUTRGNEUNG(OAc)2 (3 mol%), and PCy3·HBF4
(6 mol%) in DMAc (2 mL) were stirred at 1008C for
20 h under N2.
To a mixture of crushed K2CO3 (207 mg, 1.5 mmol), 3-
bromo-4-(diphenylphosphinoyl)-benzonitrile (1g) (382 mg,
1.0 mmol), PdACHTUNGTRNEG(UN OAc)2 (6.7 mg, 3 mol%), and PCy3·HBF4
(22 mg, 6 mol%) in a 10-mL Schlenk tube equipped with
a magnetic stir bar under a nitrogen atmosphere were added
3 mL of N,N-dimethylacetamide (DMAc). The contents of
the Schlenk tube were stirred at 1208C for 12 h. The reac-
tion mixture was cooled to room temperature and quenched
with water and then extracted with DCM. The extract was
washed with brine and dried over Na2SO4. The solvent was
[b]
3a was mixed with the other reagents.
yield under our standard conditions. To address the
issue of competitive arylation resulting from the intra-
and intermolecular coupling, the reaction was carried
out in the presence of catalytic amounts of pivalic then evaporated under vacuum and the residue was purified
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Synthesis of Dibenzophosphole Oxides
by using an SiO2 column with ethyl acetate as eluent to
afford the final product 2g; yield: 250 mg, 83%; white solid;
mp 269–2718C. 1H NMR (400 MHz, CDCl3): d=8.07 (s,
1H), 7.75–7.88 (m, 3H), 7.59–7.70 (m, 4H), 7.40–7.56 (m,
4H); 13C NMR (100 MHz, CDCl3): d=142.5 (d, J=
10.9 Hz), 139.8 (d, J=20.5 Hz), 138.1 (d, J=91.6 Hz), 134.0
(d, J=2.1 Hz), 132.8 (d, J=1.4 Hz), 132.7 (d, J=14.1 Hz),
132.5 (d, J=105.0 Hz), 131.0 (d, J=11.0 Hz), 130.8 (d, J=
11.3 Hz), 130.4, 130.4 (d, J=18.5 Hz), 129.3 (d, J=
104.0 Hz), 129.0 (d, J=12.8 Hz), 124.5 (d, J=9.9 Hz), 121.7
(d, J=10.0 Hz), 117.9, 117.0 (d, J=2.3 Hz); 31P NMR
(CDCl3): d=33.4; IR (film): n=2229, 1442, 1400, 1203,
1109, 839, 775, 752, 731, 692, 617, 601 cmÀ1; HR-MS: m/z=
302.0729, calcd. for C19H13NOP (M+H)+: 302.0729.
Shirasaka, S. Akiyama, K. Tamao, J. Am. Chem. Soc.
2002, 124, 8816.
[6] a) C. Wang, H. Dong, W. Hu, Y. Liu, D. Zhu, Chem.
Rev. 2012, 112, 2208; b) X.-F. Li, Z.-G. Chi, B.-J. Xu,
H.-Y. Li, X.-Q. Zhang, W. Zhou, Y. Zhang, S.-W. Liu,
J.-R. Xu, J. Fluoresc. 2011, 21, 1969; c) H. Li, A. S. Bat-
sanov, K. C. Moss, H. L. Vaughan, F. B. Dias, K. T.
Kamtekar, M. R. Bryce, A. P. Monkman, Chem.
Commun. 2010, 46, 4812.
[7] a) S. Alem, S. C. Tse, Y. Tao, M. Leclerc, Macromole-
cules 2010, 43, 2328; b) R. West, Pure Appl. Chem.
2008, 80, 563; c) Y. Liu, D. Ballweg, T. Muller, I. A.
Guzei, R. W. Clark, R. West, J. Am. Chem. Soc. 2002,
124, 12174.
[8] For reviews, see: a) J. J. Mousseau, A. B. Charette, Acc.
Chem. Res. 2013, 46, 412; b) C. S. Yeung, V. M. Dong,
Chem. Rev. 2011, 111, 1215; c) J. Le Bras, J. Muzart,
Chem. Rev. 2011, 111, 1170; d) S. H. Cho, J. Y. Kim, J.
Kwak, S. Chang, Chem. Soc. Rev. 2011, 40, 5068; e) C.
Sun, B. Li, Z. Shi, Chem. Rev. 2011, 111, 1293; f) P. B.
Arockiam, C. Bruneau, P. H. Dixneuf, Chem. Rev.
2012, 112, 5879; g) T.-S. Mei, L. Kou, S. Ma, K. M.
Engle, J.-Q. Yu, Synthesis 2012, 44, 1778.
[9] a) T. Wesch, A. Berthelot-Brꢂhier, F. R. Leroux, F. Co-
lobert, Org. Lett. 2013, 15, 2490; b) R. Samanta, A. P.
Antonchick, Angew. Chem. 2011, 123, 5323; Angew.
Chem. Int. Ed. 2011, 50, 5217; c) D. Alberico, M. E.
Scott, M. Lautens, Chem. Rev. 2007, 107, 174.
Crystallographic Data for 2i[17]
A single crystal of 2i was obtained, grown by slow vapor dif-
fusion of n-hexane into a solution of 2i in THF at room tem-
perature. mp 210–2128C.
Supporting Information
Experimental procedures, characherization and spectroscop-
ic data are available in the Supporting Information.
Acknowledgements
[10] a) Y. Ren, T. Baumgartner, Dalton Trans. 2012, 41,
˝
7792; b) P.-A. Bouit, A. Escande, R. Szucs, D. Szie-
We are grateful to the National Natural Science Foundation
of China (Project No. 21102029) for financial support.
berth, C. Lescop, L. Nyulꢄszi, R. Rꢂau, J. Am. Chem.
Soc. 2012, 134, 6524; c) Y. Ren, W. H. Kan, V. Thanga-
durai, T. Baumgartner, Angew. Chem. 2012, 124, 4031;
Angew. Chem. Int. Ed. 2012, 51, 3964.
[11] a) H. Tsuji, S. Komatsu, Y. Kanda, T. Umehara, T.
Saeki, K. Tamao, Chem. Lett. 2006, 35, 758; b) Y.
Matano, H. Imahori, Org. Biomol. Chem. 2009, 7,
1258; c) Y. Matano, A. Saito, T. Fukushima, Y. Toku-
dome, F. Suzuki, D. Sakamaki, H. Kaji, A. Ito, K.
Tanaka, H. Imahori, Angew. Chem. 2011, 123, 8166;
Angew. Chem. Int. Ed. 2011, 50, 8016; d) Y. Ren, T.
Baumgartner, J. Am. Chem. Soc. 2011, 133, 1328. For
other methods, see: e) A. Bruch, A. Fukazawa, E. Ya-
maguchi, S. Yamaguchi, A. Studer, Angew. Chem. 2011,
123, 12300; Angew. Chem. Int. Ed. 2011, 50, 12094;
f) Y. Kuninobu, T. Yoshida, K. Takai, J. Org. Chem.
2011, 76, 7370; g) Y. Sawada, S. Furumi, A. Takai, M.
Takeuchi, K. Noguchi, K. Tanaka, J. Am. Chem. Soc.
2012, 134, 4080; h) K. Baba, M. Tobisu, N. Chatani,
Angew. Chem. Int. Ed. 2013, 52, 11892.
References
[1] S. Beauprꢂ, P.-L. T. Boudreault, M. Leclerc, Adv.
Mater. 2010, 22, E6.
[2] a) N. Blouin, M. Leclerc, Acc. Chem. Res. 2008, 41,
1110; b) A. Michaud, D. Gendron, S. Wakim, E. Blair,
R. Neagu-Plesu, M. Belletete, G. Durocher, Y. Tao, M.
Leclerc, J. Am. Chem. Soc. 2008, 130, 732.
[3] a) K. Geramita, Y. Tao, R. A. Segalman, T. D. Tilley, J.
Org. Chem. 2010, 75, 1871; b) M. Shimizu, K. Mochida,
T. Hiyama, Angew. Chem. 2008, 120, 9906; Angew.
Chem. Int. Ed. 2008, 47, 9760; c) G. Lu, H. Usta, C.
Risko, L. Wang, A. Facchetti, M. A. Ratner, T. J.
Marks, J. Am. Chem. Soc. 2008, 130, 7670; d) H. Usta,
G. Lu, A. Facchetti, T. J. Marks, J. Am. Chem. Soc.
2006, 128, 9034; e) K. L. Chan, M. J. McKiernan, C. R.
Towns, A. B. Holmes, J. Am. Chem. Soc. 2005, 127,
7662.
[4] a) S. Yamaguchi, A. Wakamiya, Pure Appl. Chem.
2006, 78, 1413; b) A. Wakamiya, K. Mishima, K.
Ekawa, S. Yamaguchi, Chem. Commun. 2008, 579.
[5] a) Y. Tokoro, A. Nagai, K. Tanaka, Y. Chujo, Macro-
mol. Rapid Commun. 2012, 33, 550; b) A. Iida, S. Ya-
maguchi, J. Am. Chem. Soc. 2011, 133, 6952; c) F.
Jꢃkle, Chem. Rev. 2010, 110, 3985; d) C. Ribero, P. Bro-
gueira, G. Lvareda, C. N. Carvalho, A. Amaral, L.
Santos, J. Morgado, U. Scherf, V. D. B. Bonifꢄcio, Bio-
sens. Bioelectron. 2010, 26, 1662; e) S. Yamaguchi, T.
[12] T. Baumgartner, T. Neumann, B. Wirges, Angew.
Chem. 2004, 116, 6323; Angew. Chem. Int. Ed. 2004, 43,
6197.
[13] J.-P. Leclerc, M. Andrꢂ, K. Fagnou, J. Org. Chem. 2006,
71, 1711.
[14] J. G. de Vries, Dalton Trans. 2006, 421.
[15] For examples of nickel-catalyzed cross-coupling reac-
tions of aryl methyl ether, see: a) J. W. Dankwardt,
Angew. Chem. 2004, 116, 2482; Angew. Chem. Int. Ed.
2004, 43, 2428; b) L.-G. Xie, Z.-X. Wang, Chem. Eur. J.
2011, 17, 4972. For a review of palladium-catalyzed
cross-coupling reactions of aryl chlorides, see: c) A. F.
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
5
ÞÞ
These are not the final page numbers!

COMMUNICATIONS
Yuming Cui et al.
Littke, G. C. Fu, Angew. Chem. 2002, 114, 4350;
Angew. Chem. Int. Ed. 2002, 41, 4176.
graphic Data Centre via www.ccdc.cam.ac.uk/data_re-
quest/cif.
[16] L.-C. Campeau, M. Parisien, A. Jean, K. Fagnou, J.
[18] C. Baillie, J. Xiao, Tethrahedron 2004, 60, 4159.
[19] a) M. Lafrance, K. Fagnou, J. Am. Chem. Soc. 2006,
128, 16496; b) D. J. Schipper, K. Fagnou, Chem. Mater.
2011, 23, 1594.
Am. Chem. Soc. 2006, 128, 581.
[17] CCDC 970868 (2i) contains the supplementary crystal-
lographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallo-
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COMMUNICATIONS
Synthesis of Dibenzophosphole Oxides via Palladium-
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Catalyzed Intramolecular Direct Arylation Reactions of
ortho-HalodiarylACHTUNGTRENNUNGphosphine Oxides
Adv. Synth. Catal. 2014, 356, 1 – 7
Yuming Cui,* Lingzi Fu, Jian Cao, Yuan Deng,
Jianxiong Jiang
Adv. Synth. Catal. 0000, 000, 0 – 0
ꢁ 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
7
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These are not the final page numbers!