One-pot palladium-catalyzed cross-coupling reaction of aryl iodides with stannylarsanes and stannylstibanes

Article abstract of DOI:10.1021/ol0349357

(Formula presented) The reaction of Ph₃As and Ph₃Sb with Na metal in liquid ammonia gives Ph₂M^- ions (M = As, Sb) that react with n-Bu₃SnCl to afford n-Bu₃Sn-MPh ₂ (1). The ammonia was allowed to evaporate, and toluene was added. The Pd-catalyzed cross-coupling reactions of these stannanes with aryl iodides afford functionalized triaryl-arsanes and triaryl-stibanes in high yields in a one-pot procedure (80-99%). The use of the commercially available, air-stable, and inexpensive Ph₃M as the initial reagent and the one-pot process make this method a useful approach. This is the first report on the synthesis of 1 and the exploration of its chemistry.

Full text of DOI:10.1021/ol0349357

ORGANIC
LETTERS
2003
Vol. 5, No. 15
2731-2734
One-Pot Palladium-Catalyzed
Cross-Coupling Reaction of Aryl Iodides
with Stannylarsanes and
Stannylstibanes
Mariana Bonaterra, Sandra E. Mart´ın,* and Roberto A. Rossi*
INFIQC, Departamento de Qu´ımica Orga´nica, Facultad de Ciencias Qu´ımicas,
UniVersidad Nacional de Co´rdoba, Co´rdoba, 5000, Argentina
rossi@dqo.fcq.unc.edu.ar
Received May 28, 2003
ABSTRACT
The reaction of Ph3As and Ph3Sb with Na metal in liquid ammonia gives Ph2M- ions (M ) As, Sb) that react with n-Bu3SnCl to afford n-Bu3Sn-
MPh2 (1). The ammonia was allowed to evaporate, and toluene was added. The Pd-catalyzed cross-coupling reactions of these stannanes with
aryl iodides afford functionalized triaryl-arsanes and triaryl-stibanes in high yields in a one-pot procedure (80−99%). The use of the commercially
available, air-stable, and inexpensive Ph3M as the initial reagent and the one-pot process make this method a useful approach. This is the first
report on the synthesis of 1 and the exploration of its chemistry.
Transition metal-catalyzed reactions of aryl halides with
organoheteroatom compounds are widely used for the
synthesis of different heteroatom-containing compounds.1
Organotin compounds are extensively utilized as nucleophiles
in cross-coupling reactions with the formation of C-C, C-N,
C-P, C-S, and C-Sn bonds.2 The Pd-catalyzed coupling
of alkyl and aryl halides or triflates with organostannanes
(the Stille reaction) is a powerful tool in organic synthe-
sis.2a Although the scope of the Pd(0)-catalyzed cross-
coupling reactions of group-XV-derived organostannanes
such as aminostannanes3 and (trialkylstannyl)diphenylphos-
phanes4,5 have been studied, the use of organotin-arsanes and
organotin-stibanes to form C-As and C-Sb bonds has not
been reported. To extend the applications of this already
powerful methodology, we studied the Pd-catalyzed cross-
coupling reaction of stannanes derived from arsenic and
antimony [n-Bu3Sn-MPh2 (1), M ) As (1a), Sb (1b)] with
aryl iodides.
The chemistry of organoarsanes and organostibanes,
analogues of organophosphanes, has been extensively de-
veloped, and the uses of these compounds in organic
synthesis are of current interest.6 They are an important class
of compounds, both as intermediates in organic synthesis
and as ligands in transition metal-catalyzed reactions. Arsanes
have been reported to be more appropriate ligands than
(1) (a) Nishiyama, Y.; Tokunaga, K.; Sonoda, N. Org. Lett. 1999, 1,
1725-1727 and references therein. (b) Farina, V., Abel, E. W., Gordon,
F., Stone, A., Wilkinson, G., Eds.; ComprehensiVe Organometallic Chem-
istry II; Elsevier: Amsterdam, 1995; Vol. 12.
(2) (a) Farina, V.; Krishnamurthy, V.; Scott, W. J. The Stille Reaction.
In Organic Reactions; Paquette, L. A., Ed.; Wiley: New York, 1997; Vol.
50, p 1. (b) Farina, V., Abel, E. W., Gordon, F., Stone, A., Wilkinson, G.,
Eds.; ComprehensiVe Organometallic Chemistry II; Elsevier: Amsterdam,
1995, Vol. 12.
(3) (a) Guram, A. S.; Buchwald, S. L. J. Am. Chem. Soc. 1994, 116,
7901-7902. (b) Paul, F.; Patt, J.; Hartwing, J. F. J. Am. Chem. Soc. 1994,
116, 5969-5970.
(4) Tunney, S. E.; Stille, J. K. J. Org. Chem. 1987, 52, 748-753.
(5) Mart´ın, S. E.; Bonaterra, M.; Rossi, R. A. J. Organomet. Chem. 2002,
664, 223-227.
(6) Norman, N. C. Chemistry of Arsenic, Antimony and Bismuth;
Academic and Professional: London, 1998.
10.1021/ol0349357 CCC: $25.00 © 2003 American Chemical Society
Published on Web 07/03/2003

phosphanes in a number of transition metal-catalyzed organic
reactions.7 Synthetic applications of organostibane com-
pounds are of increasing importance.8 Such compounds have
been used as efficient reagents in palladium-catalyzed C-C
bond formation.9
antimony trihalides by allylic stannanes.18 Tertiary stibane
containing heterocyclic aromatic groups were obtained from
SbCl3 and the organolithium reagents from the heterocycles.19
We herein report the Pd-catalyzed cross-coupling reaction
of 1 using Ph3M as the initial reagent in a one-pot process
to obtain triaryl-functionalized arsanes and stibanes. This is
the first report on the synthesis of 1 and the exploration of
its chemistry.
Methods for preparation of tertiary arsanes and stibanes
involve the reaction of organolithium or organomagnesium
reagents with haloarsanes or halostibanes, reactions incom-
patible with many functional groups.10,11 Another method is
the reaction of aryl halides with R2MLi/Na (M ) As, Sb),
prepared in situ, generally in liquid ammonia.7a,12,13 Also,
triaryl-arsanes and triaryl-stibanes were obtained by the
photostimulated reactions of Ph2As- and Ph2Sb- ions with
aryl halides by an SRN1 mechanism in liquid ammonia, but
scrambling of products was observed.14 Shibasaki and co-
workers described the catalyzed arsination using Ni(0) and
Ph2AsH.7b A synthesis of arsane sulfonic acids from 4-fluoro-
benzenesulfonate with KAsPh2 was also described.15
The only straightforward method for functionalized arsanes
has been recently reported, a catalytic, solvent-free, Pd-
catalyzed aryl-aryl exchange reaction from phosphorus to
arsenic. This method yields only 51% of the triaryl-arsanes.16
A new approach has recently been established for the
preparation of Sb-chiral stibanes based on nucleophilic
displacement of phenylethyl moieties in bis-ethynylstibane
with Grignard and/or organolithium reagents.17 Allylic ar-
sanes and stibanes were obtained by allylation of arsenic and
We found an efficient strategy for the generation and
subsequent use of 1 according to the procedure previously
reported by us for the synthesis of tertiary phosphanes by
Pd-catalyzed reaction of aryl iodides with R3Sn-PPh2 in a
one-pot process.5 Reagent 1 was formed in almost quantita-
tive yield by the reaction of Ph2M- anion (generated from
Ph3M and Na metal in liquid ammonia) with n-Bu3SnCl. To
the best of our knowledge, this is the first report on the
formation of organostannanes with arsines and stibines.
A typical procedure20 involves the formation of Ph2M-
ions from Ph3M and Na metal in liquid ammonia (eq 1),
followed by addition of n-Bu3SnCl to obtain the n-Bu3Sn-
MPh2 (eq 2). The Pd-catalyzed cross-coupling reaction was
carried out with 1 and the aryl iodide in the presence of
(PPh3)2PdCl2 (eq 3). All the processes were done in a one-
pot reaction under nitrogen (Scheme 1).
Scheme 1
(7) (a) Namyslo, J. C.; Kaufmann, D. E. Synlett 1999, 114-116. (b)
Kojima, A.; Boden, C. D. J.; Shibasaki, M. Tetrahedron Lett. 1997, 38,
3459-3460. (c) Jeanneret, V.; Meerpoel, L.; Vogel, P. Tetrahedron Lett.
1997, 38, 543-546. (d) Rossi, R.; Bellina, F.; Carpita, A.; Mazzarella, F.
Tetrahedron 1996, 52, 4095-4110. (e) Johnson, C. R.; Braun, M. P. J.
Am. Chem. Soc. 1993, 115, 11014-11015. (f) Farina, V.; Krishnan, B. J.
Am. Chem. Soc. 1991, 113, 9585-9595. (g) Trost, B. M.; Edstrom, E. D.;
Carter-Petillo, M. B. J. Org. Chem. 1989, 54, 4489-4490.
(8) (a) Kang, S.-K.; Ryu, H.-C.; Lee, S.-W. J. Organomet. Chem. 2000,
610, 38-41. (b) Freedman, L. D.; Doak, G. O. J. Organomet. Chem. 1995,
496, 137-152. (c) Freedman, L. D.; Doak, G. O. J. Organomet. Chem.
1994, 477, 1-29. (d) Huang, Y.-Z. Acc. Chem. Res. 1992, 25, 182-187.
(9) (a) Moiseev, D. V.; Morugova, V. A.; Gushchin, A. V.; Dodonov,
V. A. Tetrahedron Lett. 2003, 44, 3155-3157. (b) Kakusawa, N.;
Yamaguchi, K.; Kurita, J.; Tsuchiya, T. Tetrahedron Lett. 2000, 41, 4143-
4146. (c) Kakusawa, N.; Tsuchiya, T.; Kurita, J. Tetrahedron Lett. 1998,
39, 9743-9746. (d) Cho, S. C.; Tanabe, K.; Itoh, O.; Uemura, S. J. Org.
Chem. 1995, 60, 274-275. (e) Cho, S. C.; Tanabe, K.; Uemura, S.
Tetrahedron Lett. 1994, 35, 1275-1278. (f) Barton, D. H. R.; Khamsi, J.;
Ozbalik, N.; Reibenspies, J. Tetrahedron 1990, 46, 3111-3122.
(10) As: (a) Fitzpatrick, M. G.; Hanton, L. R.; Henderson, W.; Kneebone,
P. E.; Levy, E. G.; McCaffrey, L. J.; McMorran, D. A. Inorg. Chim Acta
1998, 281, 101-110. (b) Ketelaere, R. F.; Delbeke, F. T.; Van der Kelen,
G. P. J. Organomet. Chem. 1971, 28, 217-223. (c) Bishop, J. J.; Davison,
A.; Katcher, M. L.; Lichtenberg, D. W.; Merrill, R. E.; Smart, J. C. J.
Organomet. Chem. 1971, 27, 241-249. (d) Heaney, H.; Heinekey, D. M.;
Mann, F. G.; Millar, I. T. J. Chem. Soc. 1958, 3838-3844.
We used n-Bu3SnCl to obtain the stannane because, as
discussed earlier in the phosphination reaction,5 under the
same conditions, the reaction of Me3Sn-PPh2 with 1-iodo-
naphthalene (2) in the presence of Pd catalyst affords the
product in lower yields. Otherwise, tributylstannane deriva-
tives are usually preferred because of their lower cost and
(11) Sb: (a) Sharma, P.; Jha, N. K. J. Organomet. Chem. 1996, 506,
19-23. (b) Yasuike, S.; Ohta, H.; Shiratori, S.; Kurita, J.; Tsuchiya, T. J.
Chem. Soc., Chem. Commun. 1993, 1817-1819.
(17) (a) Okajima, S.; Yasuike, S.; Kakusawa, N.; Osada, A.; Yamaguchi,
K.; Seki, H.; Kurita, J. J. Organomet. Chem. 2002, 656, 234-242. (b)
Kakusawa, N.; Ikeda, T.; Osada, A.; Kurita, J.; Tsuchiya, T. Synlett 2000,
1503-1505.
(12) As: (a) Aguiar, A. M.; Archibald, T. G. J. Org. Chem. 1967, 32,
2627-2628. (b) Ellermann, J.; Dorn, K. Chem. Ber. 1967, 100, 1230-
1234.
(18) Le Serre, S.; Guillemin, J.-C. J. Org. Chem. 1998, 63, 59-68.
(19) Sharma, J. V. P.; Cabrera, A.; AÄ lvarez, C.; Rosas, N.; Hernandez,
S.; Toscano, A. J. Organomet. Chem. 2001, 634, 5-11.
(13) Sb: (a) Yasuike, S.; Okajima, S.; Yamaguchi, K.; Seki, H.; Kurita,
J. Tetrahedron: Asymmetry 2000, 11, 4043-4047. (b) Shewchuk, E.; Wild,
S. B. J. Organomet. Chem. 1981, 210, 181-191. (c) Sato, S.; Matsumura,
Y.; Okawara, R. J. Organomet. Chem. 1972, 43, 333-337.
(20) Typical procedure involves the formation of Ph2M- ions from Ph3M
(1 mmol) and Na metal (2 mmol) in 300 mL of dry liquid ammonia, and
after addition of t-BuOH to neutralize the amide ions formed, n-Bu3SnCl
(1 mmol) was added. The ammonia was allowed to evaporate, and toluene
was added. The Pd-catalyzed cross-coupling reaction was carried out with
the solution of 1 in 25 mL of toluene and the aryl iodide (0.7 mmol) in the
presence of (PPh3)2PdCl2 (1.5 mol %) at 80 °C in a Schlenk tube. All
processes were done in a one-pot reaction under nitrogen.
(14) Rossi, R. A.; Pierini, A. B.; Pen˜e´n˜ory, A. B. Chem. ReV. 2003, 103,
71-167 and references cited therin.
(15) Wallow, T I.; Goodson, F. E.; Novak, B. M. Organometallics 1996,
15, 3708-3716.
(16) Kwong, F. Y.; Lai, C. W.; Chan, K. S. J. Am. Chem. Soc. 2001,
123, 8864-8865.
2732
Org. Lett., Vol. 5, No. 15, 2003

lower toxicity when compared with trimethylstannane
derivatives.2a
We selected 2 as the model substrate, and the results are
presented in Table 1. The reaction of 1a with 2 catalyzed
catalyzed by (PPh3)2PdCl2 affords naphthalen-1-yl-diphenyl-
stibane24 in moderate yields (entry 5, Table 1). The observa-
tion of an important ligand effect in the Stille reaction and,
in particular, the remarkable catalytic activity displayed by
a Pd catalyst employing phosphines as ancillary ligands25
promoted us to undertake the reaction with PPh3 as a ligand
for the catalyst. When this ligand was added to the reaction
(1:4 with respect to the catalyst, total Pd:L ) 1:6), the system
became more efficient and the yield of the product increased
(entry 6, Table 1). We have not done kinetic studies, so we
could not address the benefit of the excess PPh3 with respect
to either a faster rate of reaction or the catalyst stability.
When the reaction was carried out without n-Bu3SnCl, the
conversion of the substrate was only about 7%. When the
reaction was carried out without the Pd catalyst, only 10%
yield of the product was afforded (entries 7 and 8, Table 1).
Substituted aryl iodides afford triaryl-arsane and triaryl-
stibane compounds in very good yields, regardless of the
electronic nature of the substituent. Table 2 shows the results
Table 1. Reaction of 1 with 2 and (PPh3)2PdCl2 as the
Catalysta
1-naphthylMPh2
entry
reagent
catalyst
(% yield)b
1
2
3
4c
5
6
7
8
1a
(PPh3)2PdCl2
(PPh3)2PdCl2
85
10
9
68
62
80
7
Ph2As-
1a
1a
1b
1b
Ph2Sb-
1b
(PPh3)2PdCl2
(PPh3)2PdCl2
(PPh3)2PdCl2/Ph3P
(PPh3)2PdCl2
d
10
a Reaction conditions: Ph2M- anion was prepared in 300 mL of liquid
ammonia from Ph3M (1 mmol) and Na metal (2 mmol), and then n-Bu3SnCl
(1 mmol) was added. The coupling reaction was carried out with 2 (0.7
mmol) and (PPh3)2PdCl2 (1.5 mol %) in toluene at 80 °C for 24 h. b GC
yields. c Electrophile was 1-naphthyl-trifluoromethanesulfonate. d Reaction
was carried out with (PPh3)2PdCl2 and PPh3 as the ligand in a ratio 1:4;
total Pd:L ) 1:6.
Table 2. Syntheses of Functionalized Triaryl-arsanes and
Triaryl-stibanes from Iodoarenes and 1 with (PPh3)2PdCl2 as the
Catalysta
entry
1
substrate
product
% yieldb
by (PPh3)2PdCl2 afforded naphthalen-1-yl-diphenyl-arsane21
with total selectivity in 85% yield in 24 h (entry 1, Table
1). The system was shown to be reasonably effective, since
only 1.5 mol % of the Pd catalyst was used. No improved
yields could be observed at higher temperatures.
We also examined the activity of the (PPh3)4Pd catalyst.
The results were found to be similar to those with (PPh3)2-
PdCl2 as a catalyst.
It should be noticed that the reaction with only Ph2As-
ions, but without n-Bu3SnCl and under the same experimental
conditions described above for the Pd-catalyzed cross-
coupling reaction, affords only 10% yield of product. When
the reaction was carried out without the Pd catalyst, there
was almost no reaction (entries 2 and 3, Table 1).
1
2
3c
4
5d
6
7c
8d
1a
1a
1a
1b
1b
1b
1b
1b
4-MeOC6H4I
4-ClC6H4I
4-ClC6H4I
4-MeOC6H4I
4-MeOC6H4I
4-ClC6H4I
4-ClC6H4I
4-ClC6H4I
4-MeOC6H4AsPh2
4-ClC6H4AsPh2
4-ClC6H4AsPh2
4-MeOC6H4SbPh2
4-MeOC6H4SbPh2
4-ClC6H4SbPh2
4-ClC6H4SbPh2
4-ClC6H4SbPh2
98
50
90
63
99
72
57
98
a Reaction conditions: Ph2M- anion was prepared in 300 mL of liquid
ammonia from Ph3M (1 mmol) and Na metal (2 mmol), and then n-Bu3SnCl
(1 mmol) was added. The coupling reaction was carried out with the
iodoarene (0.7 mmol) and (PPh3)2PdCl2 (1.5 mol %) in toluene at 80 °C
for 24 h. b GC yields. c DMF at 100 °C for 24 h. d Reaction was carried
out with (PPh3)2PdCl2 and PPh3 as the ligand in a ratio 1:4; total Pd:L )
1:6.
The Pd-catalyzed cross-coupling reaction of organo-
stannanes with aryl triflates is a versatile method for selective
C-C bond formation.22 The reaction of 1-naphthyl trifluoro-
methanesulfonate under the same reaction conditions as
previously indicated, but adding to the reaction mixture 3
equiv of LiCl23 and PPh3 as ligand, affords naphthalen-1-
yl-diphenyl-arsane in 68% yield. Without addition of LiCl,
the reaction did not take place. No improved yields were
observed at higher temperatures or longer reaction times.
On the other hand, the Pd-catalyzed coupling reaction can
also be successfully performed with 1b to obtain the
corresponding triaryl-stibanes. The reaction of 1b and 2
of the reaction of 1 with aryl iodides in the presence of a
catalytic amounts of (PPh3)2PdCl2. Aryl bromides and
chlorides do not react by these coupling reactions, as in the
phosphination reaction.5
The reaction can successfully be carried out with 4-meth-
oxyiodobenzene. The (4-methoxyphenyl)diphenyl-arsane16
was formed in 98% yield (entry 1, Table 2). When 4-chloro-
iodobenzene was allowed to react under the same experi-
mental conditions, the (4-chlorophenyl)diphenyl-arsane26 was
obtained in moderate yields. To improve the product yield,
we carried out the reaction with DMF as the solvent and a
(21) (a) Alonso, R. A.; Rossi, R. A. J. Org. Chem. 1982, 47, 77-80. (b)
Yusupov, F. Y.; Manulkin, M. Z. Doklady Akad. Nauk S. S. S. R. 1954, 97,
267-268; Chem. Abstr. 1955, 49, 8843d.
(22) (a) Echavarren, A. M.; Stille, J. K. J. Am. Chem. Soc. 1987, 109,
5478-5486. (b) Fu, J. M.; Snieckus, V. Tetrahedron Lett. 1990, 31, 1665-
1668. (c) Ohe, T.; Miyuara, N.; Suzuki, A. Synlett 1990, 221-222.
(23) Halide source (e.g., LiCl) is essential for coupling to occur; see ref
21a.
(24) Woods, L. A.; Gilman, H. Proc. Iowa Acad. Sci. 1941, 48, 251-
254; Chem. Abstr. 1942, 36, 34924.
(25) (a) Farina, V.; Krishnan, B. J. Am. Chem. Soc. 1991, 113, 9585-
9595. (b) Farina, V.; Baker, S. R.; Benigni, D. A.; Hauck, S. I.; Sapino, C.
J. Org. Chem. 1990, 55, 5833-5847.
(26) Nesmeyanov, A. N.; Reutov, O. A.; Bundel, Y. G.; Beletskaya, I.
P. IzVest. Akad. Nauk S. S. S. R., Otdel. Khim. Nauk 1957, 929-941; Chem.
Abstr. 1958, 52, 4534e.
Org. Lett., Vol. 5, No. 15, 2003
2733

higher temperature (100 °C). Under these conditions, 90%
of the product was obtained (entries 2 and 3, Table 2).
aryl-Pd intermediate, which subsequently suffers reductive
elimination to afford the coupling product and regenerates
the Pd(0) catalyst.
4-Methoxyiodobenzene reacts with 1b to give (4-meth-
oxyphenyl)diphenyl-stibane20 in 63% yield. However, when
we carried out the reaction with PPh3 as the ligand, the
product was obtained in 99% yield (entries 4 and 5, Table
2). As previously discussed for the arsination reaction, when
4-chloroiodobenzene was allowed to react with 1b under the
same experimental conditions, (4-chlorophenyl)diphenyl-
stibane27 was obtained in moderate yield; the yield was not
improved when the reaction was conducted in DMF at a
higher temperature. The transformation of 4-chloroiodoben-
zene to the corresponding triaryl-stibane was successfully
carried out using PPh3 as the ligand (entries 6-8, Table 2).
The general reaction conditions for the Pd-catalyzed cross-
coupling reaction of different aryl iodides with 1b to obtain
triaryl-stibanes in good yields required PPh3 as an ancillary
ligand.
Although we did not examine the reaction mechanism in
detail, the most probable mechanism of this reaction is likely
to be similar to that described by Stille4 for the phosphination
with Me3Si-PPh2 catalyzed by Pd(0). The first step involves
the catalyst activation of the phosphine complex to give the
Pd(0) catalyst. Then, the oxidative addition of the aryl iodide
to the Pd catalyst generates an arylpalladium iodide species.
Next, transmetalation of this complex with 1 generates the
In summary, the first Pd-catalyzed cross-coupling reaction
of aryl iodides with 1 was successfully carried out to yield
functionalized triaryl-arsanes and triaryl-stibanes. We found
a very efficient one-pot reaction starting with the com-
mercially available, air-stable and inexpensive triphenyl-
arsane and triphenyl-stibane to synthesize 1a and 1b,
respectively. Once more, the specificity of the organotin
compounds on transition metal catalysis can be realized, and
of note is the fact that the reaction can be carried out in the
presence of different functional groups.
Further studies are in progress to extend the application
of this methodology to the synthesis of functionalized triaryl-
arsanes and triaryl-stibanes ligands.
Acknowledgment. This work was supported in part by
the Agencia Nacional de Promocio´n Cient´ıfica y Te´cnica
(FONCYT), Universidad Nacional de Co´rdoba (SECYT),
and the Consejo Nacional de Investigaciones Cient´ıficas y
Te´cnicas (CONICET), Argentina.
Supporting Information Available: Experimental pro-
cedures and spectroscopic data (1H NMR and 13C NMR) for
compounds mentioned herein. This material is available free
of charge via the Internet at http://pubs.acs.org.
(27) Yasuhiko, K.; Shinichi, Y.; Ichiro, H. Mem. Kyushu Inst. Technol.,
Eng. 1974, 4, 25-32; Chem. Abstr. 1974, 81, 78034f.
OL0349357
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