High efficiency of cavity-based triaryl-phosphines in nickel-catalysed Kumada-Tamao-Corriu cross-coupling

Article abstract of DOI:10.1039/c0cc05805j

Combining diaryl-calixarenyl phosphines with [Ni(cod)₂] resulted in highly active Kumada-Tamao-Corriu cross-coupling catalysts. With one of the ligands, TOFs up to 439000 mol(ArBr) mol(Ni)^-1 h^-1 were observed in the reaction of 1-bromonaphthalene with PhMgBr. The systems were also found to be active at room temperature with aryl chlorides.

Full text of DOI:10.1039/c0cc05805j

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COMMUNICATION
High efficiency of cavity-based triaryl-phosphines in nickel-catalysed
Kumada–Tamao–Corriu cross-couplingw
´
Laure Monnereau, David Semeril* and Dominique Matt*
Received 27th December 2010, Accepted 11th April 2011
DOI: 10.1039/c0cc05805j
Combining diaryl-calixarenyl phosphines with [Ni(cod)2]
resulted in highly active Kumada–Tamao–Corriu cross-coupling
catalysts. With one of the ligands, TOFs up to 439000 mol(ArBr)
mol(Ni)À1 hÀ1 were observed in the reaction of 1-bromonaphthalene
with PhMgBr. The systems were also found to be active at room
temperature with aryl chlorides.
favouring the formation of monoligand-M(0) species. It is
noteworthy that Pd(0)-monophosphine complexes have been
recognised as key intermediates in Suzuki–Miyaura cross-
coupling with arylbromides.22–28 A monophosphine pathway
has also been proposed by Liu for the Ni-catalyzed cross-
coupling between various ArX substrates and arylboronic
acids in the presence of a bulky monophosphine.29 It should
further be mentioned here that the capacity of phosphino-
substituted calix[4]arenes to bind in solution metal–arene units
in a supramolecular fashion was structurally proven (by NMR
and X-ray analysis) in the case of Ru(p-cymene) complexes,
arene binding involving interactions with two distal phenoxy
rings.30,31
Metallation-cross-coupling strategies dominate in the construc-
tion of numerous sophisticated molecules, including natural
products, organic materials, polymers, and building blocks for
supramolecular chemistry.1–8 One of the methodologies that
still plays a prominent role in aryl–aryl coupling is the Kumada–
Tamao–Corriu (KTC) reaction, that is the coupling of a Grignard
reagent (ArMgX) with an aryl halide.9–12 The continuous
interest for these reactions is mainly due to the fact that Grignards
are among the most easily prepared and least expensive
arylmetals. In this chemistry the efficacy of nickel catalysts is
well-documented,13 although palladium remains the most
frequently employed metal.14 Until recently, it was commonly
accepted that the best results arise from a combination of
nickel with diphosphines, especially if these display a large bite
angle, e.g. as with Ph2P(CH2)3PPh2, Ph2P(CH2)4PPh2, or
[Fe(C5H4PPh2)2]. Such diphosphines may assist the reductive
elimination step, as they force the organic fragments to be cis
and rather close to one another.15–17 Other authors have
shown that monodentate ligands with strong donor properties,
e.g., N-heterocyclic carbenes,18,19 or diaminophosphine oxide
derivatives,20 may also efficiently accelerate this reaction.
We have recently shown that a particular class of chemically
robust aryl-monophosphines, namely calix[4]arenes substituted
at their upper rim by a diarylphosphino group, promote the
palladium-catalysed cross-coupling between arylboronic acids
and aryl halides.21 One factor which may contribute to the
high reaction rates observed arises from the receptor properties
of the calixarenyl fragment, which is able to temporarily
entrap the phosphorus-bonded ‘‘M(p-arene)’’ unit, thereby
increasing the bulkiness of the ligand and consequently
Aiming to enlarge the scope of applications of calixarene-
based monophosphines, we have now investigated the perfor-
mance of the three receptors 1–3 in nickel-catalysed Kumada–
Tamao–Corriu (KTC) coupling. It is worth mentioning here
that bulky monophosphines able to promote the formation of
monoligand-M(0) intermediates (e.g. Buchwald ligands) are
now classically used in palladium-catalysed Kumada–Tamao–
Corriu cross-coupling, but surprisingly, to date, this ligand-
type has not been considered for nickel-catalysed, Grignard
mediated aryl–aryl couplings. While the more recent develop-
ments in the nickel-catalysed KTC couplings are focusing on
electron-rich ligands, the ligands of this study are triaryl-
phosphines, which makes them particularly easy to handle.
We began our investigations by studying the reaction of
PhMgBr with 4-bromoanisole in the presence of a mixture of
[Ni(cod)2] and two equiv. of phosphine 1.32 The 1 h-test
reactions were carried out in dioxane (Table 1). Using a
catalyst loading of 0.002% and operating at 100 1C gave the
expected coupling product in 50.6% yield, a result which
corresponds to a TOF of 25 300 mol(ArBr) mol(Ni)À1 hÀ1
Laboratoire de Chimie Inorganique et Catalyse, Institut de Chimie
´
UMR 7177 CNRS, Universite de Strasbourg, 67008, Strasbourg
Cedex, France. E-mail: dsemeril@unistra.fr, dmatt@unistra.fr;
Fax: +33 368851637; Tel: +33 368851719
w Electronic supplementary information (ESI) available: Experimental
details for the synthesis of 6 and catalytic runs. See DOI: 10.1039/
c0cc05805j
c
6626 Chem. Commun., 2011, 47, 6626–6628
This journal is The Royal Society of Chemistry 2011

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Table 1 Kumada–Tamao–Corriu cross-coupling of 4-bromoanisole
with phenyl boronic acid—the search for optimal conditionsa
Table 2 Kumada–Tamao–Corriu cross-coupling of aryl bromides
using a ArBr/Ni ratio of 10 000a
Conversion (%)
1
2
3
Entry
1
ArBr
Entry Precatalyst
ArBr/[Ni] T/1C Conv. (%) TOFb
1
2
3
4
5
6
7
[Ni]/1 (2 equiv.)
50 000
50 000
50 000
100 000
100 000
100 50.6
80 41.4
60 19.9
100 31.3
25 300
20 700
9950
31 300
8300
86.4
89.4
88.4
[Ni]/1 (2 equiv.)
[Ni]/1 (2 equiv.)
[Ni]/1 (2 equiv.)
[Ni]/PPh3 (2 equiv.)
[Ni]/P(o-tol)3 (2 equiv.) 100 000
[Ni]/4 (1 equiv.) 100 000
100
8.3
2
3
52.3
85.3
54.5
88.9
59.3
86.8
100 14.4
100 26.2
14 400
26 200
a
Conditions: [Ni(cod)2], 4-bromoanisole, PhMgBr (2 equiv./ArBr),
dioxane (1.50 mL), decane (0.05 mL), 1 h. Conversions by GC;
calibrations based on decane. mol(ArBr) mol(Ni)À1 hÀ1
.
b
4
95.5
96.9
98.2
(Table 1, entry 1). Operating at lower temperatures led to
significantly lower activities (Table 1, entries 2 and 3). A
temperature of 100 1C was therefore applied to all the following
runs. When reducing the catalyst loading by a factor of two the
conversion still reached 31% after 1 h (TOF = 31 300 mol(ArBr)
5
6
80.8
58.1
96.3
71.7
49.3
44.4
mol(Ni)À1
h
À1). In comparison, under similar conditions,
PPh3 and the bulky P(o-tolyl)3 ligand led to significantly lower
conversions, 8.3% and 14.4%, respectively (TOFs = 8300 and
14 400 mol(ArBr) mol(Ni)À1 À1). The remarkable efficiency
h
7
76.2
82.7
85.7
90.0
73.6
87.7
of ligand 1 was further confirmed by a comparison with
calixarenyl-diphosphine 4 (1 equiv.), a chelating ligand which
was previously shown to be highly efficient in other C–C bond
forming reactions as a result of its large bite angle.33
8
a
Conditions: [Ni(cod)2] (5 Â 10À5 mmol, 1 Â 10À2 mol%), phosphine
(2 equiv./Ni), ArBr (0.5 mmol), PhMgBr (1 mmol), dioxane (1.50 mL),
decane (0.05 mL), 100 1C, 1 h. Conversions by GC; calibrations based
on decane.
and applying a catalyst loading of 1% led straightforwardly
(1–3 h; 100 1C) to conversions close to 100% for all substrates,
except for 2-chlorotoluene (24.6% after 1 h), which is more
encumbered than the other chloroarenes. As expected, better
activities were observed for the electron-deficient 4-nitro-
chlorobenzene (Table 3, entry 9) than for the electron-rich
substrates 4-chloroanisole and chlorotoluene (Table 3, entries
1–6). Reducing the catalyst concentration by a factor 100 still
led to high conversions (Table 3). Similar trends and activities
were observed with the other two ligands. The reactions with
aryl chlorides could also be performed in moderate-to-good
conversions at 25 1C (Table 4). Replacing the triarylphosphine
ligand 1 with the more basic ligand 6 accelerated these reactions
by ca. 30% (Table 4). The moderate increase of reaction rate
observed with 6 is in line with the studies by Liu et al. who
suggested (a) that a monophosphine mechanism is favoured in
the case of bulky phosphines and (b) that oxidative addition of
ArX (X = Cl, Br) to nickel(0) is only weakly influenced by the
basicity of the phosphine used.31 Finally, we found that using
PPh3 resulted in a catalytic system which turned out to be
4 times less active than 1 at room temperature.
Ligand 4 led to a ca. 20% lower TOF than that obtained
with 1 (Table 1, entry 7). Note that some homocoupling
product (Ph–Ph) also formed, but in none of the above runs
did the ratio Ph–Ph : Ar–Ph exceed 9% (see ESIw).
As a next step, we assessed the efficiency of ligands 1–3 in
reactions with various aryl bromides using catalyst loadings of
0.01% (Table 2). For each non-encumbered aryl bromide, at
least one of the three phosphines led to conversions superior to
85%. With sterically hindered substrates, the conversions,
although lower, remained satisfactory (44.4–71.7%; Table 2,
entries 2 and 6). Interestingly, 1-bromonaphthalene (naphtBr)
gave the fastest reactions, full conversion being observed for
this substrate under the above conditions whatever the phosphine
employed (Table 2, entry 4). Remarkably, when the experi-
ments carried out with naphtBr were repeated with a Ni/ArBr
ratio of 1 : 106, the conversions still reached 40% after 1 h
(TOF = 386 000 (1), 439 000 (2) and 426 000 (3) mol(naphtBr)
mol(Ni)À1
Buchwald-type triarylphosphine 534 led in this case to an
activity of 253 000 mol(naphtBr) mol(Ni)À1 hÀ1
h
À1, see Table S3, ESIw). In comparison, the
Overall, the above results show that ligands 1–3 display
activities in KTC cross-coupling catalysis that are unusually high
for a triarylphosphine ligand. We tentatively propose the forma-
tion of a transient [Ni(p-ArX)(calix-phosphine)] intermediate35
having the coordinated ArX entrapped in a supramolecular
.
High conversions were also obtained with the more challenging
aryl chlorides (Table 3). Thus, for example, using phosphine 1
c
This journal is The Royal Society of Chemistry 2011
Chem. Commun., 2011, 47, 6626–6628 6627

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Table 3 Kumada–Tamao–Corriu cross-coupling of arylchlorides
catalyzed by [Ni(cod)2]/1a
exceptionally robust. Further studies are aimed at the discovery
of other catalytic reactions exploiting the supramolecular
potential of calixarenyl-monophosphines.
[Ni(cod)2]
(mol%)
Reaction
time/h
Conversion
(%)
This work was supported by the French ANR (Program
MATCALCAT) and University Louis Pasteur (grant to LM).
Entry
ArCl
1
2
1
3
98.5
37.4
0.01
16
Notes and references
3
4
1
3
99.6
42.2
1 W. A. Herrmann, in Homogeneous Catalysis with
Organometallic Compounds, ed. B. Cornils and W. A. Herrmann,
Wiley-VCH, Weinheim, 2002, 2nd edn, p. 91.
0.01
16
2 Metal-Catalyzed Cross-Coupling Reactions, ed. A. de Meijere and
F. Diederich, Wiley-VCH, Weinheim, 2004.
3 A. Zapf and M. Beller, Chem. Commun., 2005, 431.
4 J.-P. Corbet and G. Mignani, Chem. Rev., 2006, 106, 2651.
5 R. Martin and S. L. Buchwald, Acc. Chem. Res., 2008, 41, 1461.
5
6
1
1
1
5
24.6
75.4
6 B. D. Sherry and A. Furstner, Acc. Chem. Res., 2008, 41, 1500.
¨
7
8
1
1
5
97.9
69.2
7 Y. Fu, Acc. Chem. Res., 2008, 41, 1555.
8 P. Styring and A. I. R. Parracho, Beilstein J. Org. Chem., 2009, 5,
29.
0.01
9 R. J. P. Corriu and J. P. Masse, J. Chem. Soc., Chem. Commun.,
1972, 144.
10 K. Tamao, K. Sumitani and M. Kumada, J. Am. Chem. Soc., 1972,
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11 M. Kumada, Pure Appl. Chem., 1980, 52, 669.
12 K. Tamao, J. Organomet. Chem., 2002, 653, 23.
13 Modern Organonickel Chemistry, ed. Y. Tamaru, Wiley-VCH,
Weinheim, 2005.
14 C. Barnard, Platinum Met. Rev., 2008, 52, 38.
15 K. G. Moloy and J. E. Marcone, J. Am. Chem. Soc., 1998, 120,
8527.
9
1
1
5
99.2
60.3
10
0.01
a
Conditions: [Ni(cod)2], monophosphine
1 (2 equiv./Ni), ArCl
(0.25 mmol), PhMgBr (0.5 mmol), dioxane (0.75 mL), decane
(0.025 mL), 100 1C. The conversions were determined by GC, the
calibrations being based on decane. At 100 1C, the nitro group did not
undergo nucleophilic attack.
16 P. W. N. M. van Leeuwen, P. C. J. Kamer, J. N. H. Reek and
P. Dierkes, Chem. Rev., 2000, 100, 2741.
17 J.-C. Hierso, R. Smaliy, R. Amardeil and P. Meunier, Chem. Soc.
Rev., 2007, 36, 1754.
Table 4 Kumada–Tamao–Corriu cross-coupling of aryl chlorides in
the presence of monophosphines 1 and 6 at 25 1Ca
18 V. P. W. Bohm, C. W. K. Gstottmayr, T. Weskamp and
Monophosphine
¨
W. A. Herrmann, Angew. Chem., Int. Ed., 2001, 40, 3387.
¨
1
6
Entry
1
ArCl
19 V. P. W. Bohm, T. Weskamp and C. W. K. Gstottmayr, Angew.
¨
Chem., Int. Ed., 2000, 39, 1602.
¨
20 L. Ackermann, R. Born, J. H. Spatz and D. Meyer, Angew. Chem.,
Int. Ed., 2005, 44, 7216.
´
21 L. Monnereau, D. Semeril, D. Matt and L. Toupet, Chem.–Eur. J.,
2010, 16, 9237.
22 J. Yin, M. P. Rainka, X.-X. Zhang and S. L. Buchwald, J. Am.
Chem. Soc., 2002, 124, 1162.
23 M. Miura, Angew. Chem., Int. Ed., 2004, 43, 2201.
24 T. E. Barder, S. D. Walker, J. R. Martinelli and S. L. Buchwald,
J. Am. Chem. Soc., 2005, 127, 4685.
25 F. Barrios-Landeros and J. F. Hartwig, J. Am. Chem. Soc., 2005,
127, 6944.
conv. (%) (6 h)
conv. (%) (6 h)
72.2
88.2
2
3
66.7
92.3
conv. (%) (24 h)
conv. (%) (24 h)
62.5
45.2
80.9
64.4
4
26 H. Ohta, M. Tokunaga, Y. Obora, T. Iwai, T. Iwasawa,
T. Fujihara and Y. Tsuji, Org. Lett., 2007, 9, 89.
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4043.
28 D. J. M. Snelders, G. van Koten and R. J. M. Klein Gebbink,
J. Am. Chem. Soc., 2009, 131, 11407.
a
Conditions: [Ni(cod)2] (7.5 Â 10À3 mmol, 3 mol%), monophosphine
(2 equiv./Ni), ArCl (0.25 mmol), PhMgBr (0.5 mmol), dioxane (0.75 mL),
decane (0.025 mL), 25 1C. Conversions determined by GC; calibra-
tions based on decane. At 25 1C, neither the cyano nor the nitro groups
were found to undergo nucleophilic attack.
29 Z. Li, S.-L. Zhang, Y. Fu, Q.-X. Guo and L. Liu, J. Am. Chem.
Soc., 2009, 131, 8815.
30 S. Sameni, C. Jeunesse, D. Matt and L. Toupet, Chem.–Eur. J.,
2009, 15, 10446.
31 S. Sameni, C. Jeunesse, D. Matt and R. Welter, Dalton Trans.,
2009, 7912.
32 Employing 1 equiv. of 1 led to comparable yields; the use of 2
equiv. of phosphine provided a higher catalyst stability. See ESIw.
´
33 L. Monnereau, D. Semeril, D. Matt, L. Toupet and A. J. Mota,
Adv. Synth. Catal., 2009, 351, 1383.
34 C. Baillie, W. Chen and J. Xiao, Tetrahedron Lett., 2001, 42, 9085.
35 It has been proposed that in Ni-catalysed KTC coupling, formation
of a metal–haloarene Z2-complex precedes the oxidative addition
step: see N. Yoshikai, H. Matsuda and E. Nakamura, J. Am. Chem.
Soc., 2008, 130, 15258–15259.
manner in the cavity. The resulting orientation of the P–M
bond in this complex, turned towards the calixarene axis
(and not outwards), should artificially increase the ligand bulk,
and incidentally favour the formation of a mono-ligand Ni(0)
intermediate.
In summary, we have reported the first examples of highly
efficient Kumada–Tamao–Corriu cross-coupling reactions
carried out by combining a nickel centre with a triaryl mono-
phosphine. The systems described are particularly easy to
handle as the reported calixarene-phosphines are chemically
c
6628 Chem. Commun., 2011, 47, 6626–6628
This journal is The Royal Society of Chemistry 2011