One-step highly selective borylation/Suzuki cross-coupling of two distinct aryl bromides in pure water

Article abstract of DOI:10.1039/c8nj02184h

A Na₂PdCl₄-catalysed B₂(OH)₄-mediated direct cross-coupling of two distinct aryl bromides in pure water is described. This one-step borylation/Suzuki method exhibits an outstanding cross-coupling selectivity and no tendency to produce homocoupling products, therefore leading to biaryls and heterobiaryls in moderate to good yields. Moreover, the reaction has high regio-selectivity and can be scaled-up. Using such a simple, economical and practical protocol, the unsymmetrical diarylation of 3,5-dibromopryidine is achieved.

Full text of DOI:10.1039/c8nj02184h

NJC
View Article Online
View Journal
LETTER
One-step highly selective borylation/Suzuki
cross-coupling of two distinct aryl bromides
Cite this:DOI: 10.1039/c8nj02184h
in pure water†
Received 4th May 2018,
Accepted 17th September 2018
Shan Dong Xu,a Fang Zhou Sun,b Wei Hang Deng,b Han Haob and
a
Xin Hong Duan
*
DOI: 10.1039/c8nj02184h
rsc.li/njc
A Na2PdCl4-catalysed B2(OH)4-mediated direct cross-coupling of partner for producing the cross-coupling products. In most
two distinct aryl bromides in pure water is described. This one-step cases, it also suffers from long reaction time, harsh conditions
borylation/Suzuki method exhibits an outstanding cross-coupling as well as a narrow scope of the substrates. As such, there is a
selectivity and no tendency to produce homocoupling products, continued need to develop simpler, more efficient and selective
therefore leading to biaryls and heterobiaryls in moderate to good cross-coupling methods for the construction of biaryls.
yields. Moreover, the reaction has high regio-selectivity and can be
We envisaged that an ideal strategy for biaryl synthesis could
scaled-up. Using such a simple, economical and practical protocol, be an optimal combination of the direct procedure and MBSC
the unsymmetrical diarylation of 3,5-dibromopryidine is achieved.
reaction, i.e. the one-step borylation/Suzuki cross-coupling
(OBSC) of two different aryl halides. Obviously this method
that integrates the C–X borylation and the Suzuki coupling into
one step faces a considerably more difficult synthetic challenge,
because of the inevitable homo-coupling originating from non-
selective and often incomplete borylation. To the best of our
knowledge, there have been no reports on such an OBSC reaction.
Water as a solvent can offer unique reactivity and selectivity
that cannot be attained in organic solvents;18 it was therefore
anticipated that the use of pure water as a solvent might lead
to an effective OBSC reaction with high reactivity and cross-
selectivity even when two aryl bromides are employed as the
substrates, albeit different halides with a significant difference
in reactivity (e.g., ArI/ArBr or ArBr/ArCl) are normally used for
biaryl cross-couplings. Here, we first report the Na2PdCl4-catalysed
B2(OH)4-mediated OBSC of two different aryl bromides in pure
water (Scheme 1). Moreover, the application of this protocol for
the regioselective C2-arylation of 2,5-dibromopyidine and the
unsymmetrical diarylation of 3,5-dibromopyidine is described.
By selecting equimolar amounts of PhBr and 4-BrPhCOCH3
as model substrates, we began to investigate this OBSC reaction
with a slight excess of B2(OH)4 or B2pin2, using 1–2 mol% Pd
catalyst in the presence of several bases, i.e. Na2CO3, K3PO4,
NaOAc or NaOH (Table 1). It was found that the reaction did
not occur in pure water at 100 1C unless NaOH was used to
obtain the product 1a in an 87% yield (Table 1; entries 1 and 2).
In this case sodium dodecyl sulfate (SDS) as an additive improved
the yield (99% yield, Table 1, entry 3). The use of PCy3HBF419 in a
4:1 ratio with Na2PdCl4 accelerated the reaction (Table 1, entry 4),
even in the presence of only 1 mol% Pd catalyst (Table 1, entry 5).
Under the conditions of entry 4, the absence of B2(OH)4 resulted
Biaryls are ubiquitous in natural products, pharmaceuticals
and organic materials, and are often used as ligands in transi-
tion metal catalysis.1 Although to date Pd- or Ni-catalysed cross-
couplings of arylmetallic reagents (ArM; M = B, Sn, Si, Zn, Mg,
Mn, Bi, In, etc.) with aryl halides are some of the most effective
methods to form biaryls,2–9 the need to preform each arylme-
tallic reagent can be limiting. For example, due to the synthetic
challenges and environmental concerns in the preparation
and purification of arylboron reagents,2a,c,10 the Suzuki cross-
coupling is somewhat inefficient.11 In this regard, one-pot multi-
step borylation/Suzuki cross-coupling (MBSC) strategies have
been recently developed for avoiding the isolation of arylboron
intermediates.12–14 To achieve reactivity and cross-selectivity, for
example, the C–X12 or C–H13 MBSCs require expensive ligands
and/or boron sources as well as organic solvents for the boryl-
ation reaction, and/or double loading of specific catalysts in the
Suzuki step; the Sandmeyer-type14 MBSC is a more complex
process involving three consecutive steps of diazotization, boryl-
ation and Suzuki coupling in organic co-solvents. On the other
hand, although the Pd, Ni or Co-catalysed direct cross-coupling
of two aryl halides provides more straightforward access to
biaryls,15–17 this procedure not only needs to combine with
reductive agents, but also requires large excess of one coupling
a College of Science, Beijing Forestry University, Beijing 100083, China.
E-mail: xinhong116@163.com
b College of Materials Science and Technology, Beijing Forestry University,
Beijing 100083, China
† Electronic supplementary information (ESI) available: Experimental details and
characterization of the biaryl products. See DOI: 10.1039/c8nj02184h
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018
New J. Chem.

View Article Online
Letter
NJC
water. However, EtOH as the solvent led to almost no product of
1a apart from large amounts of homo-coupling products
(Table 1; entry 13); a DMF/H2O (1 : 1, v/v) solvent could not
make the reaction happen (Table 1; entry 14). These results
show that pure water as a solvent favours the reactivity and
cross-coupling selectivity.
With the above optimized conditions in hand, we next
investigated the substrate scope and selectivity of the OBSC
reaction (Table 2). The best results were obtained when an
electron-deficient aryl bromide reacted with an electron-rich one;
on the contrary, the combination appears to be less favourable
when each aryl partner contains an electron-donating group (for
example, 1e). These results reveal that the more electron-rich an
aryl bromide is, the more easily it is borylated; the more electron-
deficient the other aryl bromide is, the better it works with
the boronic acid intermediate.2a,21 As a result, this method
uniquely favours the cross-coupling pathway, and indeed
the homo-coupling was observed in no case. Ortho-substitution
was well tolerated in this study, yielding the mono- or di-ortho-
substituted product (1f, 1g or 1h). Moreover, the mono-arylation
Scheme 1 A one-step method for the borylation/Suzuki cross-coupling
of two distinct aryl bromides in pure water.
Table 1 Optimization of the reaction conditionsa
Entry
Pd Cat./ligand
B source
Additive
Yieldb (%)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Na2PdCl4
Na2PdCl4
Na2PdCl4
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
0c
87
99
100d
96e
0
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Pd/C
PdCl2/PCy3HBF4
Pd(OAc)2/PCy3HBF4
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Na2PdCl4/PCy3HBF4
Table 2 Scope for the cross-coupling of two aryl bromidesa,b
B2(pin)2
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
B2(OH)4
0
0
12
8
0g
f
0i
h
5j
0k
a
Reaction conditions: PhBr (1 mmol), 4-BrPhCOCH3 (1 mmol), boron
source (1.2 mmol), NaOH (2.5 mmol), SDS (10 mol%), Pd catalyst
(2 mol%), PCy3HBF4 (8 mol%). Pd catalyst and PCy3HBF4 in 2.5 ml
water were preheated at 60 1C for 0.5 h before addition of substrates
and another 2.5 ml portion of water. The reaction mixture was refluxed
b
c
at 100 1C for 12 h. GC yield. 2.5 mmol of Na2CO3, K3PO4 or NaOAc
d
e
was used as base. Refluxing for 4 h. 1 mol% Na2PdCl4 and 4 mol%
f
g
h
PCy3HBF4. 2 mmol of PhBr as substrate. Yield of Ph–Ph. 2 mmol of
4-BrPhCOCH3 as substrate. Yield of CH3COPh–PhCOCH3. EtOH as
solvent at reflux for 12 h. DMF : H2O in 1 : 1 (v/v) as solvent at 100 1C
i
j
k
for 12 h.
in no reaction (Table 1; entry 6), demonstrating that the C–Br
borylation to intermediate boronic acid is the key to realizing the
OBSC reaction. The attempts to replace B2(OH)4 by B2pin2,20
another active borylating agent in aqueous solution failed
(Table 1; entry 7), indicating that B2(OH)4 plays an irreplaceable
role. Several other catalysts i.e. Pd/C, PdCl2 and Pd(OAc)2 were
also investigated and found to have no catalyst activity (Table 1;
entries 8–10). It is particularly noteworthy that, despite the
homo-coupling being inevitable in the direct cross-coupling of
aryl halides,15–17 no such product (neither Ph–Ph nor CH3COPh–
PhCOCH3) was observed in this Na2PdCl4–B2(OH)4–H2O system
(for further details see ESI†) even in the presence of PhBr (or
a
Reaction conditions: two bromides (1 mmol each), B2(OH)4 (1.2 mmol),
Na2PdCl4 (1 mol%), PCy3HBF4 (4 mol%), NaOH (2.5 mmol) and SDS
(10 mol%). Na2PdCl4 and PCy3HBF4 in 2.5 ml water were preheated at
4-BrPhCOCH3) alone as a substrate (Table 1; entries 11 or 12). 60 1C for 0.5 h before addition of substrates and 2.5 ml water and
b
c
heated at 100 1C for 12 h. Isolated yields. 2-BrPhCN and 4-BrPhCH3
(20 mmol each), B2(OH)4 (22 mmol), Na2PdCl4 (2 mol%), Pcy3HBF4
(8 mol%), NaOH (50 mmol) and SDS (10 mol%) in 80 ml water were
To investigate the contribution of pure water as a solvent to the
reactivity and the complete cross-selectivity, the reaction was
conducted in conventional solvents as compared to that in pure heated at 100 1C for 12 h.
New J. Chem.
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018

View Article Online
NJC
Letter
of 1,4-dibromobenzene led to 84% yield of 1i, providing a
handle for further functionalization. In addition, this protocol
proved to be suitable for scale-up. For example, the synthesis of
a known intermediate of Santan17a (1g) could be easily per-
formed on a 20 mmol scale, the yield was almost identical to
that obtained on a 1 mmol scale.
Although an array of cross-couplings has been developed to
access heterobiaryls in water,22 novel methods in an economical
and practical manner from accessible heteroaryl halides remain
an important and challenging goal. As such, our investigation
continued with the OBSC of heteroaryl bromides. As shown in
Table 3, a variety of heteroaryl substrates reacted smoothly under
the present conditions. For example, 2-bromobenzofuran under-
went the OBSC to give 2k in a 53% yield. Furthermore, N- and
S-containing heterocycles such as an indole, pyridines, quino-
lines and thiophenes all afforded the desired products (2a–j) in
good yields, even in the presence of base-sensitive functional
groups like –CHO, –COMe, and –COOEt.
Scheme 2 The C2 arylation of 2,5-dibromopyidine. Reaction conditions:
Na2PdCl4 (2 mol%) and PCy3HBF4 (8 mol%) in 2.5 ml water were preheated
at 60 1C for 0.5 h. Then, 2,5-dibromopyridine, 4-bromotoluene or 3-bromo-
thiophene (1 mmol each), B2(OH)4 (1.2 mmol), NaOH (2.5 mmol), SDS
(10 mol%) and 2.5 ml water were added and heated at 100 1C.
This OBSC reaction exhibited high regio-selectivity. As shown
in Scheme 2, the mono-arylation of 2,5-dibromopyridine was
found to occur selectively at the C2 position. In comparison,
Scheme 3 The unsymmetrical diarylation of 3,5-dibromopyidine in a
one-pot manner. Reaction conditions: (1) Na2PdCl4 (2 mol%) and PCy3HBF4
(8 mol%) in 2.5 ml water were preheated at 60 1C for 0.5 h. Then,
3,5-dibromopyridine, 2-bromotoluene (1 mmol each), B2(OH)4 (1.2 mmol),
NaOH (2.5 mmol), SDS (10 mol%) and 2.5 ml water were added and heated
for 12 h at 100 1C; (2) 3-bromothiophene (1 mmol), B2(OH)4 (1.2 mmol),
NaOH (2.5 mmol) were added and heated for 12 h at 100 1C.
Table 3 The cross-couplings for heterobiarylsa,b
although 3-bromothiophene as a coupling partner is more reac-
tive than 4-bromotoluene, its coupling yield of 3a was lower than
that of 3b due to the easier formation of the diarylated product.
Given that the unsymmetrical diarylation of symmetrical
dihalo aryls in a one-pot manner has remained poorly addressed
to date,23 especially uncovered in water, we preferred to use this
OBSC method to iteratively diarylate 3,5-dibromopyridine in
pure water, based on which it was successfully mono-arylated
to give the product 2e in a 77% yield. As described in Scheme 3,
such a reaction was achieved by performing two sequential
OBSCs in a one-pot manner, which led to isolation of the
dicoupled product 4a in a 54% overall yield.
In summary, we have developed the direct cross-coupling of
two different aryl bromides by Na2PdCl4 catalysis mediated by
B2(OH)4. Compared with reported Pd-catalysed biaryl cross-
couplings, the advantages of this method include (1) the use
of pure water as the solvent leading to a greener protocol;
(2) being a simpler and more practical one-step procedure which
has broad substrate scope and functional group compatibility
(including electron-donating and moderate electron-deficient
groups); (3) having complete cross-coupling selectivity which is
achieved without an excess of either substrate; and (4) favouring
the use of an inexpensive and atom-economical boron source
a
Reaction conditions: two bromides (1 mmol each), B2(OH)4 (1.2 mmol), and overcoming the use of an expensive and synthetically
Na2PdCl4 (2 mol%), PCy3HBF4 (8 mol%), NaOH (2.5 mmol) and SDS
(10 mol%). Na2PdCl4 and PCy3HBF4 in 2.5 ml water were preheated at
60 1C for 0.5 h before addition of substrates and 2.5 ml water and heated at
challenging ligand. These features will render it a useful tool
to facilitate and simplify a variety of biaryl systems and more
100 1C for 12 h. Isolated yields. The reaction was performed for 10 h. complex natural products.
b
c
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018
New J. Chem.

View Article Online
Letter
NJC
A. Eichhorn, P. G. Steel, Z. Lin and T. B. Marder, Angew.
Chem., Int. Ed., 2015, 54, 11843–11847.
Conflicts of interest
There are no conflicts to declare.
´
11 L. J. Goossen, N. Rodrıguez, B. Melzer, C. Linder, G. Deng
and L. M. Levy, J. Am. Chem. Soc., 2007, 129, 4824–4833.
12 (a) O. Baudoin, M. Cesario, D. Guenard and F. Gueritte,
J. Org. Chem., 2002, 67, 1199–1207; (b) K. L. Billingsley,
T. E. Barder and S. L. Buchwald, Angew. Chem., Int. Ed.,
2007, 46, 5359–5363; (c) B. M. Rosen, C. Huang and
V. Percec, Org. Lett., 2008, 10, 2597–2600; (d) D. A. Wilson,
C. J. Wilson, B. M. Rosen and V. Percec, Org. Lett., 2008, 10,
4879–4882; (e) G. A. Molander, S. L. J. Trice and S. D. Dreher,
J. Am. Chem. Soc., 2010, 132, 17701–17703; ( f ) G. A.
Molander, S. L. J. Trice and S. M. Kennedy, J. Org. Chem.,
2012, 77, 8678–8688; (g) L. Wang, X. Cui, J. Li, Y. Wu, Z. Zhu
and Y. Wu, Eur. J. Org. Chem., 2012, 595–603; (h) B. O. A.
Tasch, D. Antovic, E. Merkul and T. J. J. Mu¨ller, Eur. J. Org.
Chem., 2013, 4564–4569; (i) V. Pandarus, G. Gingras,
Notes and references
1 (a) J. Hassan, M. Sevignon, C. Gozzi, E. Schulz and
M. Lemaire, Chem. Rev., 2002, 102, 1359–1470; (b) Metal-
Catalyzed Cross-coupling Reactions, ed. A. de Meijere and
F. Diederich, Wiley-VCH, Weinheim, 2004; (c) I. Cepanec,
Synthesis of Biaryls, Elsevier, Amsterdam, 1st edn, 2004;
(d) G. Bringmann, A. J. Price Mortimer, P. A. Keller,
M. J. Gresser, J. Garner and M. Breuning, Angew. Chem.,
Int. Ed., 2005, 44, 5384–5427; (e) J. Corbet and G. Mignani,
Chem. Rev., 2006, 106, 2651–2710; ( f ) J. Magano and
J. R. Dunetz, Chem. Rev., 2011, 111, 2177–2250.
2 (a) N. Miyaura and A. Suzuki, Chem. Rev., 1995, 95,
2457–2483; (b) A. F. Littke and G. C. Fu, Angew. Chem., Int.
Ed., 2002, 41, 4176–4211; (c) T. Ishiyama and N. Miyaura,
J. Organomet. Chem., 2003, 680, 3–11; (d) T. Ishiyama and
N. Miyaura, Chem. Rec., 2004, 3, 271–280; (e) R. Jana,
T. P. Pathak and M. S. Sigman, Chem. Rev., 2011, 111,
1417–1492; ( f ) C. C. C. J. Seechurn, M. O. Kitching,
T. J. Colacot and V. Snieckus, Angew. Chem., Int. Ed., 2012,
51, 5062–5085.
3 (a) J. K. Stille, Angew. Chem., Int. Ed., 1986, 25, 508–524;
(b) P. Espinet and A. M. Echavarren, Angew. Chem., Int. Ed.,
2004, 43, 4704–4734.
4 (a) S. E. Denmark and C. S. Regens, Acc. Chem. Res., 2008,
41, 1486–1499; (b) Y. Nakao and T. Hiyama, Chem. Soc. Rev.,
2011, 40, 4893–4901.
5 (a) P. Knochel and R. D. Singer, Chem. Rev., 1993, 93,
2117–2188; (b) V. B. Phapale and D. J. Cardenas, Chem.
Soc. Rev., 2009, 38, 1598–1607.
´
F. Beland, R. Ciriminna and M. Pagliaro, Beilstein J. Org.
Chem., 2014, 10, 897–901; ( j) G. A. Molander, S. L. J. Trice
and B. Tschaen, Tetrahedron, 2015, 71, 5758–5764;
(k) A. Hooper, A. Zambon and C. J. Springer, Org. Biomol.
Chem., 2016, 14, 963–969.
13 (a) A. D. Finke and J. S. Moore, Org. Lett., 2008, 10,
´
4851–4854; (b) V. J. Olsson and K. J. Szabo, Org. Lett.,
ˇ
´ˇ ´
2008, 10, 3129–3131; (c) M. Klecka, R. Pohl, B. Klepetarova
and M. Hocek, Org. Biomol. Chem., 2009, 7, 866–868;
(d) P. Harrisson, J. Morris, T. B. Marder and P. G. Steel,
Org. Lett., 2009, 11, 3586–3589; (e) P. Harrisson, J. Morris,
P. G. Steel and T. B. Marder, Synlett, 2009, 147–150;
( f ) T. E. Hurst, T. K. Macklin, M. Becker, E. Hartmann,
W. Ku¨gel, J.-C. Parisienne-La Salle, A. S. Batsanov, T. B.
Marder and V. Snieckus, Chem. – Eur. J., 2010, 16, 8155–8161.
14 W. Erb, M. Albini, J. Rouden and J. Blanchet, J. Org. Chem.,
2014, 79, 10568–10580.
´
15 (a) C. Amatore, E. Carr, A. Jutand, H. Tanaka, Q. Ren and
S. Torii, Chem. – Eur. J., 1996, 2, 957–966; (b) J. Hassan,
C. Hathroubi, C. Gozzi and M. Lemaire, Tetrahedron Lett.,
2000, 41, 8791–8794; (c) J. Hassan, C. Hathroubi, C. Gozzi
and M. Lemaire, Tetrahedron, 2001, 57, 7845–7855;
(d) G. Satyanarayana and M. E. Maier, Eur. J. Org. Chem.,
2008, 5543–5552; (e) L. Wang and W. Lu, Org. Lett., 2009, 11,
1079–1082.
16 (a) G. Meyer, Y. Rollin and J. Perichon, J. Organomet. Chem.,
1987, 333, 263–267; (b) C. Gosmini, S. Lasry, J.-Y. Nedelec
and J. Perichon, Tetrahedron, 1998, 54, 1289–1298;
(c) C. Gosmini, J.-Y. Nedelec and J. Perichon, Tetrahedron
Lett., 2000, 41, 201–203; (d) C. Gosmini, J.-Y. Nedelec and
J. Perichon, Tetrahedron Lett., 2000, 41, 5039–5042.
6 (a) R. Martin and A. Fu¨rstner, Angew. Chem., Int. Ed., 2004,
43, 3955–3957; (b) C. E. I. Knappke and A. J. V. Wangelin,
Chem. Soc. Rev., 2011, 40, 4948–4962.
7 (a) E. Riguet, M. Alami and G. Cahiez, J. Organomet. Chem.,
2001, 624, 376–379; (b) A. Leleu, Y. Fort and R. Schneider,
Adv. Synth. Catal., 2006, 348, 1086–1092.
8 (a) M. L. N. Rao and A. Kumar, Tetrahedron Lett., 2014, 55,
5764–5770; (b) M. L. N. Rao and R. J. Dhanorkar, Tetrahe-
dron, 2015, 71, 338–349.
9 M. A. Pena, J. P. Sestelo and L. A. Sarandeses, J. Org. Chem.,
2007, 72, 1271–1275.
10 (a) I. A. I. Mkhalid, J. H. Barnard, T. B. Marder, J. M. Murphy
and J. F. Hartwig, Chem. Rev., 2010, 110, 890–931;
(b) J. F. Hartwig, Chem. Soc. Rev., 2011, 40, 1992–2002;
(c) E. Yamamoto, K. Izumi, Y. Horita and H. Ito, J. Am. 17 (a) M. Amatore and C. Gosmini, Angew. Chem., Int. Ed., 2008,
Chem. Soc., 2012, 134, 19997–20000; (d) J. F. Hartwig, Acc.
Chem. Res., 2012, 45, 864–873; (e) G. A. Molander,
47, 2089–2092; (b) S. Gu
¨lak, O. Stepanek, J. Malberg,
B. R. Rad, M. Kotora, R. Wolf and A. J. V. Wangelin, Chem.
Sci., 2013, 4, 776–784.
´
´
L. N. Cavalcanti and C. Garcıa-Garcıa, J. Org. Chem., 2013,
´
´
78, 6427–6439; ( f ) A. Ros, R. Fernandez and J. M. Lassaletta, 18 (a) A. Lubineau and J. Auge, Top. Curr. Chem., 1999, 206,
Chem. Soc. Rev., 2014, 43, 3229–3243; (g) S. K. Bose,
K. Fucke, L. Liu, P. G. Steel and T. B. Marder, Angew. Chem.,
Int. Ed., 2014, 53, 1799–1803; (h) S. K. Bose, A. Deißenberger,
1–39; (b) C.-J. Li, Chem. Rev., 2005, 105, 3095–3165;
(c) C.-J. Li and L. Chen, Chem. Soc. Rev., 2006, 35, 68–82;
(d) A. Chanda and V. V. Fokin, Chem. Rev., 2009, 109,
New J. Chem.
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018

View Article Online
NJC
725–748; (e) R. N. Butler and A. G. Coyne, Chem. Rev., 2010,
Letter
´
G. Herve, G. Sartori, G. Enderlin and C. Len, New J. Chem.,
2013, 37, 1989–1995; (c) X. Tan, Z. J. Zhou, J. X. Zhang and
X. H. Duan, Eur. J. Org. Chem., 2014, 5153–5157; (d) P. Qiu,
J. Y. Zhao, X. Shi and X. H. Duan, New J. Chem.,
2016, 40, 6568–6572; (e) Z. Li, C. Gelbaum, Z. S. Campbell,
P. C. Gould, J. S. Fisk, B. Holden, A. Jaganathan, G. T.
Whiteker, P. Polleta and C. L. Liotta, New J. Chem., 2017, 41,
15420–15432.
110, 6302–6337.
19 M. R. Netherton and G. C. Fu, Org. Lett., 2001, 3, 4295–4298.
20 C. L. Peck, J. A. Calderone and W. L. Santos, Synthesis, 2015,
2242–2248.
21 (a) D. Zim, A. L. Monteiro and J. Dupont, Tetrahedron Lett., 2000,
´
´
41, 8199–8202; (b) O. Baudoin, D. Guenard and F. Gueritte, J. Org.
Chem., 2000, 65, 9268–9271; (c) C. R. LeBlond, A. T. Andrews,
Y. Sun and J. R. Sowa, Jr., Org. Lett., 2001, 3, 1555–1557.
23 (a) F. Beaumard, P. Dauban and R. H. Dodd, Org. Lett., 2009,
11, 1801–1804; (b) S. Ishikawa and K. Manabe, Angew.
Chem., Int. Ed., 2010, 49, 772–775.
22 (a) K. W. Anderson and S. L. Buchwald, Angew. Chem.,
Int. Ed., 2005, 44, 6173–6177; (b) S. Gallagher-Duval,
This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018
New J. Chem.