Catalyst-free suzuki-type coupling of allylic bromides with arylboronic acids

Article abstract of DOI:10.1002/ejoc.201101527

The coupling of arylboronic acids with electron-rich allylic bromides is accomplished in the absence of any transition-metal catalyst through conventional heating. The reaction is completely regioselective, affording only the α-coupled product, and can be carried out under mild aerobic conditions in an organic solvent; the presence of a base is required. Copyright

Full text of DOI:10.1002/ejoc.201101527

SHORT COMMUNICATION
DOI: 10.1002/ejoc.201101527
Catalyst-Free Suzuki-Type Coupling of Allylic Bromides with Arylboronic
Acids
Alberto Scrivanti,*[a] Valentina Beghetto,[a] Matteo Bertoldini,[a] and Ugo Matteoli[a]
Keywords: C–C coupling / Allylation / Boron / Cross-coupling
The coupling of arylboronic acids with electron-rich allylic
bromides is accomplished in the absence of any transition-
metal catalyst through conventional heating. The reaction is
completely regioselective, affording only the α-coupled prod-
uct, and can be carried out under mild aerobic conditions in
an organic solvent; the presence of a base is required.
absence of any transition-metal catalyst. Delighted by this
discovery, we decided to thoroughly investigate this cou-
pling reaction and its potential applications.
Introduction
There is great interest in developing practical and simple
approaches to the synthesis of allylated arenes owing to
their importance as natural products[1] and owing to the
variety of chemical transformations that are feasible on aryl
and allyl moieties.[2]
In the last two decades, Suzuki–Miyaura coupling
emerged as a versatile and efficient tool for the formation
of carbon–carbon bonds.[3] Exploiting the Suzuki reaction,
the synthesis of allylated arenes can be carried out accord-
Scheme 2. Coupling of cinnamyl bromide with phenylboronic acid.
ing to two different approaches (Scheme 1): either an allyl- Results and Discussion
boronic acid is coupled with an aryl halide [Equation (1)][4]
In the initial investigations, commercial arylboronic acids
or an arylboronic acid is coupled with an allylic halide
[Equation (2)];[5] both reactions require a transition-metal
catalyst, usually a palladium complex. In Equation (2), the
allylic halide may be replaced by an allylic alcohol or one
of its derivatives.[6]
(Aldrich) were employed as received, but soon we observed
that samples belonging to different production lots may dis-
play significant differences in reactivity. Inspection of the
1H NMR spectra of the less reactive arylboronic acids re-
vealed that they invariably contained high amounts of the
corresponding anhydrides (boroxines, see Scheme 3).[8]
Scheme 3. The arylboronic acid/triarylboroxine equilibrium.
Scheme 1. Synthesis of allylated arenes through a Suzuki–Miyaura
reaction.
1
In fact, reactivity studies supported by H NMR investi-
gations (see below) allowed us to establish that the actual
reacting species is the acid, whereas the cyclic anhydride is
by far less reactive. This finding is not surprising, as in the
literature there are several examples of reactions in which a
boronic acid and the corresponding boroxine display dif-
ferent reactivities.[8b,9]
To address the reproducibility difficulties due to the dif-
ferent arylboronic acid/boroxine molar ratios in different
lots of the commercial reagents, the arylboronic acids were
recrystallized from hot water and suction dried in air as
described by Ellman.[9a] This procedure affords “wet” bor-
During studies focused on employing Pd(OAc)2 as the
catalyst[7] in the coupling of (E)-cinnamyl bromide with
phenylboronic acid (Scheme 2), we serendipitously ob-
served that the reaction takes place at 90 °C even in the
[a] Dipartimento di Scienze Molecolari e Nanosistemi,
Università Cà Foscari di Venezia,
Calle Larga S. Marta 2137-30123 Venezia, Italy
Fax: +39-0412348967
E-mail: scrivanti@unive.it
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201101527.
264
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2012, 264–268

Catalyst-Free Suzuki-Type Coupling
onic acids, the water content of which was determined by (Table 1, Entry 13), but no improvement is observed when
1H NMR spectroscopy[9a,10] before use (see the Supporting an excess amount of boronic acid is used (Table 1, En-
Information).
try 14).
The influence of substituents on the allyl moiety is re-
The data relevant to the coupling of (E)-cinnamyl brom-
ide with a variety of arylboronic acids under different con- ported in Table 2. According to the overall reactivity order
ditions are reported in Table 1.
found (prenyl bromide ≈ cinnamyl bromide ϾϾ crotyl
bromide Ͼ allyl bromide), it appears that the presence of
electron-donating groups on the allyl moiety is required to
observe good reaction rates. The data in Table 2 confirm
that the reaction is totally regioselective giving only the α-
coupled isomer. The small amounts of γ-isomer (≈4%)
formed when crotyl bromide is coupled with the different
boronic acids are to be ascribed to a small amount of 3-
bromobut-1-ene (≈4%) present in the reagent. The crotyl
bromide E/Z isomer ratio (85:15) did not change in the re-
action products.
Table 1. Coupling of cinnamyl bromide with arylboronic acids.
Entry[a]
Aryl
H2O [mol][b] Solvent
Base
Conv. [%][c]
1
2
3
4
5
6
7
8
C6H5
(C6H5BO)3
C6H5
4-MeC6H4
4-MeOC6H4
4-MeC(O)C6H4
C6H5
0
0
toluene K2CO3 57
[d]
toluene K2CO3 20
3.0
2.3
1.4
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
toluene K2CO3 84 (70)[e]
toluene K2CO3 80 (62)[e]
toluene K2CO3 82 (72)[e]
Table 2. Coupling of allyl bromides with arylboronic acids.
toluene K2CO3
toluene
toluene K3PO4
0
0
76
–
[f]
C6H5
C6H5
C6H5
C6H5
9
toluene Na2CO3 25
[g]
10
11
12
13
14
toluene K2CO3
93
DMF[h] K2CO3 25
C6H5
dioxane K2CO3
6
[i]
C6H5
C6H5
toluene K2CO3 98[l]
toluene K2CO3 84
[m]
[a] Reaction conditions: cinnamyl bromide (2.0 mmol), arylboronic
acid (2.0 mol), base (2.0 mmol), solvent (10 mL). [b] Residual water
in boronic acids (mol of water/mol of acid) as determined by 1H
NMR spectroscopy. [c] Cinnamyl bromide conversion as deter-
mined by GLC (internal standard: n-nonane). [d] Triphenylborox-
ine. [e] In parentheses: isolated yield. [f] K3PO4·H2O. [g] Base:
4.0 mmol. [h] DMF: dimethylformamide. [i] Cinnamyl bromide:
4.0 mmol. [l] Cinnamyl bromide conversion calculated by dividing
the actual conversion by the theoretical conversion based on the
limiting reagent available (phenylboronic acid). [m] Phenylboronic
acid: 4.0 mmol.
[a] Reaction conditions: allyl bromide (2.0 mmol), arylboronic acid
(2.0 mmol), K2CO3 (2.0 mmol), toluene (10 mL). [b] Allylic brom-
ide conversion as determined by GLC (internal standard: n-
nonane). [c] Containing 3.0 mol of water per mol of acid as deter-
mined by 1H NMR spectroscopy. [d] In parentheses: isolated yield.
[e] Containing 2.3 mol of water per mol of acid as determined by
1H NMR spectroscopy. [f] Containing 1.4 mol of water per mol of
The crucial role played by the acid–boroxine equilibrium
becomes evident by comparing Table 1, Entries 1 and 2,
whereas Entry 3 highlights the beneficial effect of extra
water on the reaction. The reaction is totally regio- and
stereoselective, forming only the linear (E)-α-coupled prod-
uct; it is also worth noting that no inert atmosphere is re-
1
acid as determined by H NMR spectroscopy.
Finally, it should be noted that exploratory experiments
quired. Phenylboronic acid, 4-methylphenylboronic acid, show that the reaction also proceeds with the use of allylic
and 4-methoxyphenylboronic acid display approximately chlorides, albeit in lower yields: for instance under the reac-
the same reactivities (Table 1, Entries 3–5). No reaction was tion conditions of Table 1, the coupling of cinnamyl chlor-
observed with 4-acetylphenylboronic acid, indicating that ide with phenylboronic acid gave (E)-1,3-diphenylprop-1-
the presence of electron-withdrawing substituents drasti- ene in 40% yield.
cally hampers the reactivity of the arylboronic acid
Only three examples of “catalyst-free” Suzuki-type reac-
(Table 1, Entry 6). The presence of a base is mandatory tions are known. In 2003, Leadbeater[11] first reported that
(Table 1, Entry 7). The best results were obtained by using the coupling of arylboronic acids with aryl halides could be
K2CO3; K3PO4 is slightly less efficient, whereas with accomplished in water at 150 °C under microwave irradia-
Na2CO3 the reaction is significantly slower (Table 1, En- tion. In 2005, Kabalka[12] showed that the alkenylation of
try 3 vs. Entries 8 and 9). The reaction rate can be improved allylic alcohols could be carried out by using alkenylboron
by using an excess amount of base (Table 1, Entry 10). The dihalides in the absence of any transition-metal catalyst. In
coupling is much faster in toluene than in oxygenated sol- 2006, Yan[13] developed a catalyst- and base-free Suzuki
vents such as dimethylformamide or dioxane (Table 1, En- coupling of sodium tetraphenylborate with hypervalent iod-
try 3 vs. Entries 11 and 12). The coupling can be pushed anes, which proceeds under microwave irradiation to afford
to completion by using an excess amount of allyl bromide biaryls. Noteworthy is that Leadbeater’s original claim was
Eur. J. Org. Chem. 2012, 264–268
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
265

A. Scrivanti, V. Beghetto, M. Bertoldini, U. Matteoli
SHORT COMMUNICATION
later reassessed owing to the detection of trace amounts of Table 3. Coupling of allyl bromides with phenylboronic acid cata-
palladium in Na2CO3 used as the base in the reaction;[14]
lyzed by Pd(OAc)2.
eventually, an “ultra-low metal-catalyzed Suzuki coupling
protocol” was developed.[14,15]
We took greatest care to exclude the possibility that the
observed reaction results from the accidental presence of
minute amounts of catalytically active transition metals. Be-
cause the allylic substrates were purified by distillation (allyl
bromide, crotyl bromide, and prenyl bromide) or sublima-
tion (cinnamyl bromide) and the boronic acids were recrys-
tallized as above described, the inorganic base was consid-
ered to be the only possible source of transition-metal con-
taminants. The routinely employed K2CO3 (Aldrich, ACS
reagent Ͼ99%) was analyzed by inductively coupled
plasma–mass spectrometry (ICP-MS) to determine the con-
tent of the metals (Pd,[3b] Ni,[3b,16] Pt,[3b] Cu,[17] Ru,[18] and
Rh[6b,19]), which alone or in combination are known to be
active in the Suzuki reaction. According to ICP-MS analy-
[a] Reaction conditions: allyl bromide (2.0 mmol), phenylboronic
sis, the Pd, Ni, Cu, Pt, and Ru content in the reaction mix-
acid (2.0 mmol) containing 3.0 mol of water per mol of acid as
determined by H NMR, K2CO3 (2.0 mmol), toluene (10 mL), re-
1
ture was calculated to be 1.2, 4.1, Ͻ0.03, 2.7, 3.0, and
0.22 ppb, respectively (see the Supporting Information). Ac- action time: 3 h. [b] Allyl bromide conversion as determined by
cording to the literature data,[3b,6b,16–19] these concentra-
tions appear to be too low to promote the reaction; in par-
GLC (internal standard: n-nonane). [c] By GLC. [d] About 8% of
the product derived from the homocoupling of prenyl bromide was
also formed. [e] About 4% of the product derived from the homo-
ticular, it is worth to note that the Pd level (1.2 ppb) is
coupling of prenyl bromide was also formed. [f] In parentheses: iso-
about 50 times lower than that used in the “ultra-low metal-
catalyzed Suzuki coupling protocol” developed by Lead-
beater, which also requires microwave irradiation. It should
lated yield. [g] E/Z isomer ratio: 85:15. [h] E/Z isomer ratio: 81:19.
[i] E/Z isomer ratio: 80:20.
also be noted that identical results were obtained by em- ity is that the reaction occurs through the formation of an
ploying high-purity K2CO3 (Aldrich, 99.995% trace metal adduct between the boronic acid and the allyl bromide, fol-
basis).
lowed by migration of the aryl from the boron to the α-
Positive evidence supporting the fact that no palladium carbon of the allyl (see Scheme 4) in a concerted fashion.
species are involved in our reaction emerges by comparing
the results in Tables 1 and 2 with those of analogous experi-
ments (see Table 3) carried out by employing “homeo-
pathic” amounts[20] of Pd(OAc)2 as the catalyst [0.002–
0.0001 mol-% of Pd(OAc)2/substrate/catalyst ratio
=
50000:1–1000000:1]. This comparison appears meaningful
when considering that Pd(OAc)2 is widely employed as a
precursor of “ligand-free” palladium catalysts[7] and that if
some palladium was accidentally involved in the reaction,
it would be in a “ligand-free” form.
Scheme 4. Suggested reaction mechanism.
Data in Table 3 (for succinctness, only the experiments
with phenylboronic acid are reported) reveal that the use of
Pd(OAc)2 (even in very low loadings) brings about two ef-
fects: (i) The reaction rate is enhanced (in particular with
less activated substrates). (ii) The reaction is no longer com-
pletely regioselective, giving in all cases a mixture of α- and
γ-coupled products. This latter finding is rationalized by
taking into account that a general issue in allylic arylations
is the control of the regioselectivity,[21] which can be
achieved only by employing suitably designed ligands.
In light of all these considerations, the complete regiose-
lectivity observed in the developed catalyst-free coupling
appears to be a distinguishing feature ruling out the acci-
dental presence of palladium in the reaction mixture.
As far as the reaction mechanism is concerned, a radical
pathway seems unlikely, because the coupling can be suc-
Conclusions
In conclusion, we have developed a catalyst-free Suzuki-
type coupling that proceeds under conventional thermal
conditions to provide stereodefined allylated arenes. Besides
the general chemical interest, the absence of a catalyst may
be particularly advantageous for the synthesis of biolo-
gically active compounds, as they will result free from heavy
metal contaminants. Studies are in progress to expand the
scope of the reaction to allylic chlorides and other sub-
strates, to clarify the reaction mechanism, and to establish
the role of the base.
Experimental Section
Preparation of (E)-1,3-Diphenylprop-1-ene (Table 1, Entry 3) as a
cessfully carried out under aerobic conditions. One possibil- Representative Procedure: Cinnamyl bromide (394 mg, 2.0 mmol),
266
www.eurjoc.org
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2012, 264–268

Catalyst-Free Suzuki-Type Coupling
Nolan, Org. Lett. 2005, 7, 1829–1832; g) C. Nájera, J. Gil-
Moltó, S. Karlström, Adv. Synth. Catal. 2004, 346, 1798–1811;
h) L. Botella, C. Nájera, J. Organomet. Chem. 2002, 663, 46–
57; i) D. A. Alonso, C. Nájera, M. C. Pacheco, J. Org. Chem.
2002, 67, 5588–5594; j) J. Cortés, M. Moreno-Mañas, R. Pleix-
ats, Eur. J. Org. Chem. 2000, 239–243.
phenylboronic acid [C6H5B(OH)2·3H2O; 352 mg, 2.0 mmol],
K2CO3 (277 mg, 2.0 mmol), and toluene (10 mL) were added into
a 25-mL round-bottomed flask equipped with a magnetic stirring
bar and reflux condenser. The reaction mixture was heated whilst
stirring at 90 °C for 3 h, and after cooling to room temperature,
was then evaporated to dryness. The crude product was purified by
column chromatography (silica gel; diethyl ether/n-hexane, 1:9) to
afford the title compound (270 mg, 70% yield) as a white solid. 1H
NMR (300 MHz, CDCl3, 25 °C, TMS): δ = 7.45–7.31 (m, 5 H),
6.18–6.05 (m, 1 H), 5.26–5.10 (m, 2 H), 3.52 (d, J = 6.6 Hz, 2 H)
ppm. The characterization data agree with the literature.[22] 13C
NMR (75 MHz, CDCl3, 25 °C, TMS): δ = 139.9, 137.4, 128.5,
128.3, 126.0, 115.7, 40.2 ppm. MS (EI): m/z = 118 [M]+, 103, 91,
77.
[6]
Allylic alcohols: a) Y. Kayaki, T. Koda, T. Ikariya, Eur. J. Org.
Chem. 2004, 4989–4993; b) M. L. Kantam, K. B. S. Kumar, B.
Sreedhar, J. Org. Chem. 2008, 73, 320–322; c) H. Tsukamoto,
T. Uchiyama, T. Suzuki, Y. Kondo, Org. Biomol. Chem. 2008,
6, 3005–3013; d) G. W. Kabalka, G. Dong, B. Venkataiah, Org.
Lett. 2003, 5, 893–895; allylic alcohol derivatives: e) Y. Makida,
H. Ohmiya, M. Sawamura, Chem. Asian J. 2011, 6, 410–414;
f) D. Li, T. Tanaka, H. Ohmiya, M. Sawamura, Org. Lett. 2010,
12, 3344–3347; g) H. Ohmiya, N. Yokokawa, M. Sawamura,
Org. Lett. 2010, 12, 2438–2440; h) F. C. Pigge, Synthesis 2010,
1745–1762; i) H. Ohmiya, Y. Makida, D. Li, M. Tanabe, M.
Sawamura, J. Am. Chem. Soc. 2010, 132, 879–889; j) T. Nishi-
kata, B. H. Lipshutz, J. Am. Chem. Soc. 2009, 131, 12103–
12105; k) H. Ohmiya, Y. Makida, T. Tanaka, M. Sawamura, J.
Am. Chem. Soc. 2008, 130, 17276–17277; l) T. Mino, K. Kaji-
wara, Y. Shirae, M. Sakamoto, T. Fujita, Synlett 2008, 2711–
2715; m) G. W. Kabalka, M. Al-Masum, Org. Lett. 2006, 8,
11–13; n) D. Bouyssi, V. Gerusz, G. Balme, Eur. J. Org. Chem.
2002, 2445–2448; o) K.-G. Chung, Y. Miyake, S. Uemura, J.
Chem. Soc. Perkin Trans. 1 2000, 15–18; p) H. Chen, M.-Z.
Deng, J. Organomet. Chem. 2000, 603, 189–193.
Supporting Information (see footnote on the first page of this arti-
cle): General methods, complete experimental details, and charac-
terization data for all compounds.
Acknowledgments
We thank Dr. W. Cairns (CNR-IDPA of Venice) for support in
ICP-MS analyses.
[7]
a) N. A. Bumagin, V. V. Bykov, I. P. Beletskaya, Bull. Acad. Sci.
USSR, Div. Chem. Sci. (Engl. Transl.) 1989, 38, 2206; b) T. I.
Wallow, B. M. Novak, J. Org. Chem. 1994, 59, 5034–5037; c)
M. T. Reetz, E. Westermann, Angew. Chem. 2000, 112, 170;
Angew. Chem. Int. Ed. 2000, 39, 165–168; d) R. B. Bedford,
M. E. Blake, C. P. Butts, D. Holder, Chem. Commun. 2003,
466–467.
a) D. G. Hall in Boronic Acids (Ed.: D. G. Hall), Wiley-VCH,
Weinheim, 2005, pp. 1–99; b) Y. Tokunaga, H. Ueno, Y. Shimo-
mura, T. Seo, Heterocycles 2002, 57, 787–790; c) A. L. Korich,
P. M. Iovine, Dalton Trans. 2010, 39, 1423–1431.
Selected references on the different reactivity of arylboronic
acids and boroxines: a) M. Storgaard, J. A. Ellman, Org. Synth.
2009, 86, 360–371; b) A. Antoft-Finch, T. Blackburn, V.
Snieckus, J. Am. Chem. Soc. 2009, 131, 17750–17752; c) L. J.
Gooßen, J. Paetzold, Adv. Synth. Catal. 2004, 346, 1665–1668;
d) T. Nishikata, Y. Yamamoto, N. Miyaura, Angew. Chem.
2003, 115, 2874; Angew. Chem. Int. Ed. 2003, 42, 2768–2770.
T. M. B. Islam, K. Yoshino, H. Nomura, T. Mizuno, A. Sasane,
Anal. Sci. 2002, 18, 363–366.
a) N. E. Leadbeater, M. Marco, Angew. Chem. 2003, 115, 1445;
Angew. Chem. Int. Ed. 2003, 42, 1407–1409; b) N. E. Lead-
beater, M. Marco, J. Org. Chem. 2003, 68, 5660–5667.
a) G. W. Kabalka, M.-L. Yao, S. Borella, Z. Wu, Chem. Com-
mun. 2005, 2492–2494; b) G. W. Kabalka, M.-L. Yao, S. Bor-
ella, Z. Wu, J.-H. Ju, T. Quick, J. Org. Chem. 2008, 73, 2668–
2673 and references cited therein.
J. Yan, M. Zhu, Z. Zhou, Eur. J. Org. Chem. 2006, 2060–2062.
R. K. Arvela, N. E. Leadbeater, M. S. Sangi, A. Williams, P.
Granados, R. D. Singer, J. Org. Chem. 2005, 70, 161–168.
R. K. Arvela, N. E. Leadbeater, T. L. Mack, C. M. Kormos,
Tetrahedron Lett. 2006, 47, 217–220.
Recent selected references: a) T. Tu, H. Mao, C. Herbert, M.
Xua, K. H. Dötz, Chem. Commun. 2010, 46, 7796–7798; b) J.-
i. Kuroda, K. Inamoto, K. Hiroya, T. Doi, Eur. J. Org. Chem.
2009, 2251–2261; c) Y. Zhou, Z. Xi, W. Chen, D. Wang, Orga-
nometallics 2008, 27, 5911–5920.
Selected references: a) J.-H. Li, D.-P. Wang, Eur. J. Org. Chem.
2006, 2063–2066; b) J. Mao, J. Guo, F. Fang, S.-J. Ji, Tetrahe-
dron 2008, 64, 3905–3911; c) M. B. Thathagar, J. Beckers, G.
Rothenberg, Adv. Synth. Catal. 2003, 345, 979–985; the Suzuki
reaction can be catalyzed by a combination of Pd and Cu: d)
J. Z. Deng, D. V. Paone, A. T. Ginnetti, H. Kurihara, S. D.
[1] Selected recent papers: a) M. Iwasaki, H. Yorimitsu, K. Osh-
ima, Bull. Chem. Soc. Jpn. 2009, 82, 249–253; b) F. Bakkali, S.
Averbeck, D. Averbeck, M. Idaomar, Food Chem. Toxicol.
2008, 46, 446–475; c) A. Demotie, I. J. S. Fairlamb, F.-J. Lu,
N. J. Shaw, P. A. Spencer, J. Southgate, Bioorg. Med. Chem.
Lett. 2004, 14, 2883–2887; d) B. M. Trost, O. R. Thiel, H.-C.
Tsui, J. Am. Chem. Soc. 2002, 124, 11616–11617.
[2] a) A. Scarso, M. Colladon, P. Sgarbossa, C. Santo, R. A. Mich-
elin, G. Strukul, Organometallics 2010, 29, 1487–1497; b) M. A.
Brown, M. A. Kerr, Tetrahedron Lett. 2001, 42, 983–985; c) A.
Fürstner, O. R. Thiel, G. Blanda, Org. Lett. 2000, 2, 3731–
3734.
[3] a) A. Suzuki, Angew. Chem. Int. Ed. 2011, 50, 6722–6737; b)
N. Miyaura in Metal-Catalyzed Cross-Coupling Reactions
(Eds.: A. de Meijere, F. Diederich), 2nd ed., Wiley-VCH,
Weinheim, 2004, pp. 41–123; c) C. Torborg, M. Beller, Adv.
Synth. Catal. 2009, 351, 3027–3043; d) C. G. Fu, Acc. Chem.
Res. 2008, 41, 1555–1564; e) H. Doucet, Eur. J. Org. Chem.
2008, 2013–2030; f) F. Alonso, I. P. Beletskaya, M. Yus, Tetra-
hedron 2008, 64, 3047–3101; g) Y. Fall, H. Doucet, M. Santelli,
Appl. Organomet. Chem. 2008, 22, 503–509; h) R. Martin, S. L.
Buchwald, Acc. Chem. Res. 2008, 41, 1461–1473; i) L. Yin, J.
Liebscher, Chem. Rev. 2007, 107, 133–173; j) G. A. Molander,
N. Ellis, Acc. Chem. Res. 2007, 40, 275–286; k) J.-P. Corbet, G.
Mignani, Chem. Rev. 2006, 106, 2651–2710; l) F. Bellina, A.
Carpita, R. Rossi, Synthesis 2004, 2419–2440.
[4] Selected references: a) D. C. Gerbino, S. D. Mandolesi, H.-G.
Schmalz, J. C. Podestá, Eur. J. Org. Chem. 2009, 3964–3972; b)
E. Alacid, C. Nájera, J. Org. Chem. 2009, 74, 2321–2327; c) S.
Sebelius, V. J. Olsson, O. A. Wallner, K. J. Szabó, J. Am. Chem.
Soc. 2006, 128, 8150–8151; d) Y. Yamamoto, S. Takada, N.
Miyaura, Chem. Lett. 2006, 35, 704–705; e) Y. Yamamoto, S.
Takada, N. Miyaura, Chem. Lett. 2006, 35, 1368–1369; f) S.
Kotha, M. Behera, V. R. Shah, Synlett 2005, 1877–1880; g) A.
Fürstner, G. Seidel, Synlett 1998, 161–162.
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[5] Recent references: a) J. F. Civicos, D. A. Alonso, C. Nájera,
Adv. Synth. Catal. 2011, 353, 1683–1687; b) R. Ghosh, N. N.
Adarsh, A. Sarkar, J. Org. Chem. 2010, 75, 5320–5322; c) B.
Crociani, S. Antonaroli, M. Burattini, P. Paoli, P. Rossi, Dalton
Trans. 2010, 39, 3665–3672; d) E. Alacid, C. Nájera, J. Or-
ganomet. Chem. 2009, 694, 1658–1665; e) G. W. Kabalka, E.
Dadush, M. Al-Masum, Tetrahedron Lett. 2006, 47, 7459–
7461; f) R. Singh, M. S. Viciu, N. Kramareva, O. Navarro, S. P.
[17]
Eur. J. Org. Chem. 2012, 264–268
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
267

A. Scrivanti, V. Beghetto, M. Bertoldini, U. Matteoli
SHORT COMMUNICATION
Dreher, S. A. Weissman, S. R. Stauffer, C. S. Burgey, Org. Lett.
2009, 11, 345–347.
Commun. 2004, 1559–1563; c) N. T. S. Phan, M. Van Der Sluys,
C. W. Jones, Adv. Synth. Catal. 2006, 348, 609–679.
[18] Selected references: a) M. Kawatsura, K. Kamesaki, M. Yama-
moto, S. Hayase, T. Itoh, Chem. Lett. 2010, 39, 1050–1051; b)
Y. Na, S. Park, S. B. Han, H. Han, S. Ko, S. Chang, J. Am.
Chem. Soc. 2004, 126, 250–258.
[19] Selected references: a) J.-Y. Yii, R. Kuwano, Angew. Chem.
2009, 121, 7353; Angew. Chem. Int. Ed. 2009, 48, 7217–7220;
b) S. W. Youn, Eur. J. Org. Chem. 2009, 2597–2605.
[20] Selected references: a) I. P. Beletskaya, A. V. Cheprakov, Chem.
Rev. 2000, 100, 3009–3066; b) M. T. Reetz, J. G. de Vries, Chem.
[21]
U. Kazmaier, M. Pohlman in Metal-Catalyzed Cross-Coupling
Reactions (Eds.: A. de Meijere, F. Diederich), 2nd ed., Wiley-
VCH, Weinheim, 2004, pp. 531–583.
[22] M. L. N. Rao, D. Banerjee, S. Giri, J. Organomet. Chem. 2010,
695, 1518–1525.
Received: October 19, 2011
Published Online: November 24, 2011
268
www.eurjoc.org
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2012, 264–268