Strategies for the synthesis of bi- and triarylic materials starting from commercially available phenols

Article abstract of DOI:10.1016/j.jorganchem.2005.05.023

A series of arylstannanes have been synthesized, through an S_RN1 mechanism, in good to excellent yields (74%-99%) by the photostimulated reaction of trimethyl stannyl ion with substrates supporting different nucleofugal groups. The arylstannanes thus obtained were suitable intermediates for Stille cross-coupling reactions leading to asymmetric bi- and triaryl compounds in acceptable global yields. An attractive feature of this route is that simple commercially available benzenediols, chloro- and methoxy phenols might be useful starting substrates, leading the latter to higher global yields of products in fewer steps. The strategies proposed open a broad synthetic tool.

Full text of DOI:10.1016/j.jorganchem.2005.05.023

Journal of Organometallic Chemistry 690 (2005) 3865–3877
www.elsevier.com/locate/jorganchem
Strategies for the synthesis of bi- and triarylic materials starting
from commercially available phenols
,1
*
´
Alicia B. Chopa , Gustavo F. Silbestri, Marıa T. Lockhart
´ ´
INIQO, Departamento de Quımica, Universidad Nacional del Sur, Avda. Alem 1253, 8000 Bahıa Blanca, Argentina
Received 30 March 2005; received in revised form 11 May 2005; accepted 11 May 2005
Available online 29 June 2005
Abstract
A series of arylstannanes have been synthesized, through an SRN1 mechanism, in good to excellent yields (74–99%) by the photo-
stimulated reaction of trimethyl stannyl ion with substrates supporting different nucleofugal groups. The arylstannanes thus
obtained were suitable intermediates for Stille cross-coupling reactions leading to asymmetric bi- and triaryl compounds in accept-
able global yields. An attractive feature of this route is that simple commercially available benzenediols, chloro- and methoxy phe-
nols might be useful starting substrates, leading the latter to higher global yields of products in fewer steps. The strategies proposed
open a broad synthetic tool.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: SRN1; Stille reaction; Arylstannanes; Biphenyls; Terphenyls
1. Introduction
duced in place of a phenolic hydroxy group. Specifically,
phenols are converted into their diethyl aryl phosphate
esters (ArDEP) which on reaction with sodium
triorganostannides (Me3SnNa or Ph3SnNa) in liquid
ammonia afford aryltriorganostannanes by the SRN1
mechanism in good to excellent yields (50–100%). It
should be noted that, under similar conditions, sub-
strates containing two leaving groups (Cl and DEP) also
afford the related disubstitution product in high yield
[4d].
Because of their interesting properties, there is a
growing interest in the synthesis of valuable bi- and tri-
aryls. Herein we report the synthesis of some trimethyl-
stannyl derivatives and their potential appliance to the
construction of mixed bi- and triarylic materials. The or-
ganic synthetic strategy proposed is based on the succes-
sive selective substitution of suitable leaving groups with
trimethyltin anion followed by Pd-catalyzed cross-cou-
pling reactions. An attractive feature of this approach
is that simple commercially available derivatives such
as benzenediols, chloro- and methoxy phenols might
be useful starting substrates.
Pd-catalyzed cross-coupling reaction has become a
very important tool in organic synthesis [1]. Among oth-
ers, Pd-catalyzed cross-coupling of organotin com-
pounds with carbon electrophiles (the Stille reaction)
has been a versatile method for C–C bond formation
[2]. In connection with the synthetic importance of these
reactions, we are interested in searching new routes to
aryl- and vinylstannanes. Thus, application of SRN1
reactions [3] to the synthesis of aryl- [4] and vinylstann-
anes [5] is currently in progress in our laboratory. This
alternative route to the synthesis of organostannanes
avoids the use of Grignard reagents or organolithium
compounds. Recently [4c,4d,4e], we have demonstrated
that a triorganostannyl group (Me3Sn– and Ph3Sn–)
can, with interposition of one additional step, be intro-
*
Corresponding author. Tel.: +54 291 4595101; fax: +54 291
4595187.
E-mail address: abchopa@uns.edu.ar (A.B. Chopa).
Member of CIC.
1
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.05.023

3866
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
Table 1
Synthesis of arylstannanes by the photostimulated reaction of ArDEP
with 11
2. Results and discussion
We initiated our investigations employing 1,2-, 1,3-
and 1,4-benzenediols as starting materials. The introduc-
tion of the first trimethylstannyl group in the aromatic
moiety, i.e., the synthesis of the corresponding mono
trimethylstannyl derivatives from these substrates, was
carried out as is sketched in Scheme 1.
X
SnMe3
Me3SnNaa - NH3(liq)
hν - 4 h
OP
OP
Entry
Xb
OPc
Product and yield (%)d
We decided to use tetrahydropyranyl as protecting
group taking into account that the hydroxyl group
may be easily regenerated under mild conditions.
Desymmetrization of benzenediols was carried out with
one equivalent of DHP [6a] (step i) affording, in all
cases, the desired mono-ether in 30–40% yield, together
with starting material (10–30%) and the related di-ether
(20–30%). It should be mentioned that each component
of the obtained mixtures could be isolated, quantita-
tively, by column chromatography on silica gel. In the
second step (step ii) it was observed that meanwhile
the reaction of 5 and 6 with diethyl phosphite led to
the corresponding diethyl aryl phosphates 7 and 8 in
very good yields (85% and 88%, respectively), the reac-
tion of 4 with diethyl phosphite did not give the desired
product (probably because of steric factors) and a com-
plex mixture was obtained. Finally, the photostimulated
reaction of 7 and 8 with trimethylstannyl sodium (11)
(step iii) led, after 4 h, to trimethyl(3-tetrahydro-2H-2-
pyranyloxyphenyl)stannane (9, 84%) and trimethyl(4-
tetrahydro-2H-2-pyranyloxyphenyl)stannane (10, 82%),
respectively (Table 1, entries 1 and 2). Thus, the
mono-stannylated products 9 and 10 were both obtained
in 25% overall yield from 2 and 3. The low yields ob-
tained were essentially owed to the desymmetrization
reaction of benzenediols where substantial starting
material was lost.
1
2
3
4
5
6
7
a
DEP
DEP
Cl
3-OTHP
4-OTHP
2-OTHP
4-OTHP
4-OMe
9; 84
10; 82
16; 85
10; 85
21; 81e
24; 74
25; 90
Cl
DEP
DEP
DEP
2-OMe
3-OMe
Substrate/Me3 SnNa = 1:1.2.
DEP = OP(O)(OEt)2.
b
c
THP = tetrahydropyranyl.
Isolated yield of pure products.
Ref. [4d].
d
e
SnMe3
OTHP
Cl
Cl
i
ii
OH
12 (2-)
13 (4-)
OTHP
14
15
16
10
Scheme 2. Reagents and conditions (i) DHP, p-TsOH. (ii) Me3SnNa,
NH3(liq.), hm.
The subsequent photostimulated reaction of 14 and 15
with 11 in liquid ammonia rendered the trimethylstannyl
derivatives in excellent yields. Thus, trimethyl(2-tetrahy-
dro-2H-2-pyranyloxyphenyl)stannane (16) and its iso-
mer 10 were both obtained in 85% yield (Table 1,
entries 3 and 4). The overall yields of 16 and 10, from
12 and 13, were 77% and 78%, respectively; i.e., they
were three times higher compared with those obtained
from benzenediols. Since the low yields obtained from
benezenediols as starting materials were owed to the
desymmetrization reaction, we thought that this prob-
lem could be solved synthesizing the trimethylstannyl
derivatives from commercially available desymmetrized
dihydroxyphenols such as 2- (17), 3- (18) and 4-methoxy
phenol (19), as is sketched in Scheme 3. We have previ-
ously proved that the diethyl phosphate ester 20, derived
Taking into account that Cl is also a good nucleo-
fugal group in SRN1 reactions [4d], we considered of
interest to carry out the synthesis of the mono-trimeth-
ylstannyl derivatives from commercially available chlor-
ophenols. The route of synthesis is sketched in Scheme
2.
In order to compare the yields of these reactions, we
used again tetrahydropyranyl as protecting group. The
tetrahydropyranyl ethers 14 and 15 were obtained in
90% and 92% yield from 12 to 13, respectively [6b].
SnMe3
DEP
OH
OH
SnMe3
OH
DEP
i
ii
iii
OTHP
OTHP
OH
OTHP
OMe
OMe
OMe
4
5
6
1 (2-)
2 (3-)
3 (4-)
17 (2-)
18 (3-)
19 (4-)
22
23
20
9
10
24
25
21
7
8
Scheme 1. Reagents and conditions (i) DHP, AlCl3. (ii) HPO(OEt)3,
NEt3, CCl4 (iii) Me3SnNa, NH3(liq.), hm.
Scheme 3.

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3867
Table 2
Biphenyl substrates obtained by Pd-catalyzed cross-coupling reactions of arylstannanes with haloarenes
PO
FG
PO
FG
Pd Catalyst
Conditions
SnMe
X
+
3
Entry OP (No.)
X
I
FG
Pd Catalyst (mol%)a Conditions
Solvent
Product (No.)
Yield (%)b,c
50(5)
Temp (ꢁC) Time (h)
1
4-OTHP, 10
4-OMe PdCI2(PPh3)2(2)
DMF
80
3
THPO
OMe
26
2
10 Br
–
’’
’’
’’
’’
3
81
THPO
THPO
27
3
10
I
4-Me
’’
’’
24
35(26)
Me
28
4
5
10 Br 4-DEP ’’
’’
’’
’’
’’
3
70(18)
THPO
THPO
DEP
29
3-OTHP, 9 Br ’’
’’
48
4
DEP
30
6
7
9
’’
2-OTHP, 16 ’’
’’
’’
Pd(PPh3)4(5)
PdCI2 (PPh3)2(2)
Toluene 110
DMF 80
20
48
30
60(14)
5
OTHP
DEP
31
8
9
16 ’’
16
’’
Pd(PPh3)4(5)
Toluene 110
DMF 80
20
48
31
35(19)
25(14)
–
2-OMe PdCI2(PPh3)2(20)d
OTHP
MeO
32
10
11
4-OMe, 21 ’’
–
–
PdCI2(PPh3)2(2)
DMF
80
20
20
75
65
MeO
33
3-OMe, 25 ’’
Pd(PPh3)4(2)
Toluene 110
34
MeO
(continued on next page)

3868
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
Table 2 (continued)
Entry OP (No.)
X
FG
Pd Catalyst (mol%)a Conditions
Solvent Temp (ꢁC)
Product (No.)
Yield (%)b,c
Time (h)
12
13
25
2-OMe, 24
’’
’’
–
–
PdCI2(PPh3)2(2)
PdCI2(PPh3)2(2)
DMF
DMF
80
80
20
20
34
87
73
OMe
35
14
21
Br 4-DEP Pd(PPh3)4(2)
Toluene 110
48
73
MeO
DEP
36
a
b
c
With respect to arylstannane.
Isolated yield of pure products.
Yields in brackets refer to corresponding deprotected hydroxy compound obtained together with the cross-coupling product.
With addition of Cul (1.25 equiv.), CsF (13.8 equiv.) and BHT (a crystal).
d
from 19, reacted with 11 in liquid ammonia, yielding tri-
methyl(4-methoxyphenyl)stannane (21) in 81% yield [4d]
(Table 1, entry 5). In the same way, the photostimulated
reaction of 11 with O,O-diethyl O-2-methoxyphenyl
phosphate (22) and O,O-diethyl O-3-methoxyphenyl
phosphate (23), synthesized in 78% and 89% yield from
the corresponding phenols 17 and 18, led to the desired
trimethylstannyl derivatives 24 [7] and 25 [7] in 74% and
90% yield, respectively. Thus, 21, 24 and 25 were ob-
tained in very good overall yields (71%, 58% and 80%,
respectively) from economic commercially available
substrates.
from Tables 2 and 3, the choice of the appropriate cat-
alytic system is very important for the success of the
reaction.
First, we carried out the reactions between tetrahy-
dropyranyl ethers 9, 10 and 16 and aryl halides. The
results obtained are summarized in Table 2. The cou-
pling reaction of 10 with 4-iodoanisol in the presence
of Cl2Pd(PPh3)2 (2%) in DMF at 80 ꢁC for 3 h, led to
40-methoxybiphenyl-4-yl tetrahydro-2H-2-pyranyl ether
(26) in 50% yield together with the corresponding
deprotected hydroxy compound (5%) (entry 1). Under
a similar catalytic protocol, biphenyl-4-yl tetrahydro-
2H-2-pyranyl ether (27) and 40-methylbiphenyl-4-yl
tetrahydro-2H-2-pyranyl ether (28) were obtained from
10 by reaction with either bromobenzene or 4-iodotolu-
ene in 81% (3 h) and 35% (24 h) yield, respectively (en-
With the aim of determining the feasibility of the syn-
thetic strategy proposed, we carried out a series of Stille
cross-coupling reactions with the arylstannanes ob-
tained in order to synthesize a series of biaryls. As seen
Table 3
Different catalytic protocols for the synthesis of 36 from 21
p-DEP-C H Br
6
4
Pd Catalyst
MeO
SnMe
3
36
additive-conditions
21
Pd catalyst (mol%)a
Ratio 21:ArBr
Additive (mol%)a
Solvent and conditions
Yield 33 (%)b
PdCI2(PPh3)2 (2)
PdCI2(PPh3)2 (5)
Pd2(dba)3(2.8)AsPh3(23)
Pd(PPh3)4 (5)
1.1:1
1.3:1
1:1.2
1:1.2
1:1.2
None
DMF 80 ꢁC, 48 h
DMF r.t., 20 h
36c
40c
Cul(10)
Cul(57)
None
d
DMF 70 ꢁC, 21 h
Toluene 110 ꢁC, 48 h
Toluene 110 ꢁC, 48 h
ꢀ
60
73
Pd(PPh3)4 (2)
None
a
With respect to the minor reagent.
Isolated yield of pure products.
b
c
Together with homocoupling and ‘‘scrambling’’products.
Complex mixture.
d

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3869
tries 2 and 3). It should be emphasized that compound
28 was also obtained together with a significant amount
(26%) of the related deprotected hydroxy compound.
The cross-coupling reaction of 10 with O,O-diethyl
O-4-bromophenyl phosphate yielded the desired prod-
uct, i.e., O,O-diethyl O-40-tetrahydro-2H-2-pyranyl-
oxybiphenyl-4-yl phosphate (29) (70%) together with
the corresponding deprotected hydroxy compound in
18% yield (entry 4).
coupling position by ortho substituents usually has a neg-
ative effect on the yield. All the results obtained showed
that the partial deprotection of the hydroxy group took
place under the employed catalytic protocols.
We also carried out the cross-coupling reactions of
(2-) (24), (3-) (25) and (4-methoxyphenyl)trimethylstannane
(21) with different aryl halides. The best results obtained
are summarized in Table 2. In our initial experiments,
Cl2Pd(PPh3)2 (2%) in DMF at 80 ꢁC, proved to be an
efficient protocol for the cross-coupling reaction of 21,
24 and 25 with bromobenzene leading to biaryls 33–35
[9] in good yields (entries 10–13). Nevertheless, the same
catalytic protocol proved to be inefficient in the cross-
coupling reaction of 21 with O,O-diethyl O-4-bromophe-
nyl phosphate. Thus, this reaction yielded only 36% of
O,O-diethyl O-40-methoxybiphenyl-4-yl phosphate (36)
together with large amounts of undesired homocoupling
and ‘‘scrambling’’ products (CG/MS). When we carried
out the reaction under similar conditions but in the pres-
ence of Cu(I) [10], the yield of 36 was slightly increased
(40%). In order to minimize the ‘‘scrambling’’ product
we used Pd2(dba)3, CuI and AsPh3 in DMF [11] as cata-
lytic protocol. Unfortunately, under these conditions we
could not detect the presence of biaryl 36 and a complex
mixture was obtained. These coupling reactions worked
better in the presence of catalytic amounts of Pd(PPh3)4
(5% and 2%) in refluxing toluene (48 h). Under these con-
ditions, product 36 was obtained in 60% and 73% yields,
respectively. These results are summarized in Table 3.
It should be mentioned that compound 36 could also
be synthesized from compound 26 by deprotection of
the hydroxy group and generation of the phosphate es-
ter. The global yields of both synthetic procedures were
52% from 4-methoxyphenol (19) (three steps: 71% in the
two first and 73% in the last one) and 28% from 4-chlo-
On the other hand, the same catalytic protocol proved
to be inefficient in the reaction between compound 9 and
O,O-diethyl O-4-bromophenyl phosphate. An analogous
result was obtained in the reaction carried out with com-
pound 16. In both cases, the desired cross-coupling prod-
ucts were detected in very low yields (ca. 5%) (entries 5 and
7). These coupling reactions worked better in presence of a
catalytic amount of Pd(PPh3)4 (5%) in refluxing toluene.
Thus, compounds 9 and 16 reacted with O,O-diethyl O-
4-bromophenyl phosphate providing O,O-diethyl O-30-
tetrahydro-2H-2-pyranyloxybiphenyl-4-yl phosphate (30)
(20 h) and O,O-diethyl O-20-tetrahydro-2H-2-pyra-
nyloxybiphenyl-4-yl phosphate (31) (20 h) in 60% and
35% yield, respectively (entries 6 and 8). In both cases
the deprotected hydroxy compounds were also detected
(14% and 19%, respectively). Typical byproducts found
(CG/MS) in these reactions are the biaryls derived from
homocoupling of the stannane and Ar–Ph derived from
phenyl transfer from the ligand, which makes difficult
the purification of the desired compounds. The reaction
of 16 with 2-iodoanisol, in the presence of Cl2Pd(PPh3)2
(20%), CuI, CsF and in DMF (80 ꢁC, 48 h) [8], led to
the expected cross-coupling product 20-methoxybiphe-
nyl-2-yl tetrahydro-2H-2-pyranyl ether (32) in 25% yield
together with the corresponding deprotected compound
(14%) (entry 9). As it is known, steric hindrance of the
DEP
OTHP
OH
OTHP
OH
SnMe3
DEP
Br
MeO
I
Pd (0)
Pd (0)
OMe
SnMe3
Cl
OMe
21
10
13
19
OMe
OMe
36
26
Pd (0)
MeO
I
DEP
21
10
SnMe3
37
Scheme 4.

3870
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
rophenol (13) (five steps: 78% in the two first, 50% in the
third one and 72% in the two last steps) (Scheme 4).
Another route to compound 36 is also shown in Scheme
4. In order to propose different synthetic approaches, we
considered that it would be interesting to synthesize aryltin
compounds containing a DEP group, such as 37, to be
used as starting substrates in cross-coupling reactions.
In principle, either compounds 10 or 21 might be used
as starting materials for the synthesis of 37 by deprotec-
tion of the ether function and generation of DEP.
Unfortunately, under deprotection conditions [6],
compound 10 led only to phenyl tetrahydro-2H-2-pyra-
nyl ether due to aryl-tin bond cleavage (Eq. (1))
11/ClOPO(OEt)2 ratios as well as reaction times. Unfor-
tunately, under the conditions studied, the aryl-tin bond
is also partially cleaved and compound 37 was obtained
in low yield together with some amounts of anisol and
O,O-diethyl O-phenyl phosphate. In Eq. (2) are shown
the conditions which led to higher yields of 37. Although
it is possible to purify compound 37 by column chroma-
tography on silicagel, the low reaction yield prevented us
to consider the strategy proposed in Scheme 4 as a good
alternative. Similar reactions were carried out with iso-
mers 24 and 25, leading to analogous results. Neverthe-
less, the presence of O,O-diethyl O-phenyl phosphate in
the reaction mixtures indicates that, under the reaction
conditions studied, it is possible to cleave the methyl–
oxygen bond and to generate the corresponding phos-
phate ester. Based on this observation we carried out a
series of reactions with anisol and triphenyltin anion
(Ph3SnNa) in DMSO, in order to find the best reaction
conditions for the synthesis of diethyl aryl phosphates
from anisols in a ‘‘one-pot’’ reaction. We used Ph3SnNa
instead of 11 with the aim of recovering the tetraorgano-
tin formed. We found that the reaction of anisol,
Ph3SnNa and ClOPO(OEt)2 in 1/2/2.4 ratio in DMSO,
led to the desired phenyl diethyl phosphate ester in
quantitative yield (Eq. (3)).
OTHP
OTHP
AlCl .6 H O
3
2
ð1Þ
MeOH, r.t.
SnMe
3
10
On the other hand, the reaction using compound 21
as starting substrate implies the cleavage of an aryl
methyl ether. With this purpose, extremely harsh condi-
tions such as BBr3 or refluxing MeMgI [12] could not be
applied to compound 21 because they would also lead to
aryl-tin bond cleavage. Taking into account that aryl
methyl ethers are susceptible to attack by powerful
nucleophiles in dipolar aprotic solvents [12] we consid-
ered that it would be possible to cleave the methyl–oxy-
gen bond with trimethyl tin anion in DMSO.
Furthermore, the phenoxide ion thus obtained would
be trapped with diethyl chloro phosphate [ClO-
PO(OEt)2] yielding the aryl diethyl phosphate 37 in a
‘‘one-pot’’ reaction from compound 21. We employed
trimethyltin anion as nucleophile in order to minimize
probable secondary reactions between the nucleophile
and the aryl-tin bond of the substrate.
OMe
DEP
i, ii
Ph3SnNa
Ph3SnNa
+
+
Reagents and conditions i) DMSO, 110 ˚, 12 h. ii) ClPO(OEt)2,
r.t., 24 h
ð3Þ
It should be mentioned that both, the phosphate ester
and the triphenylmethylstannane generated in the reac-
tion were recovered, quantitatively, from the mixture
by column chromatography on silicagel. These reaction
conditions were used forward.
SnMe3
SnMe3
Me3SnNa (2 equiv.)
DMSO, 110 ˚C, 1.5 h
The biaryls resumed in Table 2 could be suitable
starting materials for the synthesis of triaryl com-
pounds. For instance, compounds supporting a DEP
group, such as 29–31 and 36, may be excellent starting
substrates to generate the corresponding trimethyltin
derivatives which, by posterior coupling reactions with
the appropriate aryl halide, would lead to the expected
triaryl material [13]. In Scheme 5 are shown two of such
reactions. The photostimulated reaction of 29 with 11
yielded the corresponding trimethyltin derivative 38
(99%). The subsequent coupling reaction of 38 with
O,O-diethyl O-4-bromophenyl phosphate led to the de-
sired triaryl compound 4-(diethoxyphosphinyl)oxy-400-
OMe
ONa
21
SnMe3
ClPO(OEt)2 (1.2 equiv.)
r.t., 24 h
+
+
OMe
12%
DEP
60%
DEP
37
28%
ð2Þ
tetrahydro-2H-2-pyranyloxy-[1,10;40,100]terphenyl
(39,
We carried out a series of reactions between 21 and
11 in DMSO. In an effort to improve the yield of 37,
the reaction conditions were varied with respect to 21/
40%). On the other hand, the photostimulated reaction
of 36 and 11 led to trimethyl(40-methoxybiphenyl-4-
yl)stannane (40) in 80% yield. The coupling reaction of

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3871
of triaryls. In order to prove the feasibility of our pro-
posal and to compare results, we carried out a series
of reactions with compounds 27 and 33 as starting mate-
rials as is sketched in Scheme 6.
OTHP
OTHP
OTHP
DEP
Br
Whereas compound 27 is an example of DHP as pro-
tecting group, compound 33 is an example of Me as pro-
tecting group. The deprotection and generation of the
diethyl aryl phosphate ester 42 implies two sequential
steps from 27, with a global yield of 82%. On the other
hand, 42 (90%) is obtained from 33 through the ‘‘one-
pot’’ reaction mentioned above (see Section 3). The pos-
terior photostimulated reaction of 42 with 11 yielded
compound 43 (80%) [4d]. Therefore, the global yield of
43 was 72% (two steps) and 64% (three steps) starting
from 33 and 27, respectively. The coupling reaction of
43 with 4-iodoanisol, 1-bromonaphthalene and 2,5-dib-
romopyridine yielded the corresponding triaryl com-
pounds, i.e., 4-methoxy-[1,10; 40, 100]terphenyl (44, 75%)
[14], 1-(biphenyl-4-yl)naphtalene (45, 70%), and 5-
(biphenyl-4-yl)-2-bromopyridine (46, 40%). As shown
in Scheme 6, these reactions illustrate the successive
selective replacement of two substituents supported by
an aryl substrate (compounds 13 and 19).
11
Pd (0)
40%
99%
DEP
SnMe3
29
38
DEP
39
OMe
OMe
OMe
NC
I
11
Pd (0)
78%
80%
DEP
SnMe3
36
40
CN
41
Similar reaction schemes could be carried out starting
from compounds 28, 32, 34 and 35. It should be men-
tioned that we have proved that compounds 34 and 35
yielded the corresponding phosphate esters 47 (85%)
and 48 (75%) [15] through a ‘‘one-pot’’ reaction, and that
the photostimulated reaction of both esters with 11 in li-
quid ammonia led to the trimethyltin derivatives 49 [16]
Scheme 5.
40 with 4-iodobenzonitrile gave 4-methoxy-400-cyano
[1,10;40,100]terphenyl (41, 78%).
Alternatively, biaryl compounds 27, 28 and 32–35
may also be suitable starting materials for the synthesis
OH
DEP
SnMe3
SnMe3
Cl
Cl
Br
Br
Pd (0)
75%
Pd (0)
81%
92%
88%
81%
90%
85%
82%
OMe
OMe
OMe
OTHP
OH
OTHP
19
21
10
15
13
20
OMe
DEP
OTHP
33
42
27
80%
Br
MeO
I
OMe
Pd (0)
70%
Pd (0)
75%
45
44
SnMe3
43
Br
N
Br
40%
Pd (0)
N
Br
46
Scheme 6.

3872
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
for 119Sn) using CDCl3 as solvent (except where it is
otherwise stated) and SiMe4 or SnMe4 as internal refer-
ence. Mass spectra were obtained by use of a GC/MS
HP 6890. Infrared spectra were recorded on a Nicolet–
Nexus FTIR. Most of the reagents and catalyst were
commercially available. Diethyl aryl phosphate esters
were prepared by the method of Kenner [19] and charac-
terized by IR [20] and NMR spectroscopy. All manipu-
lations were performed under nitrogen or argon. The
solvents used were dried and distilled in accordance with
standard procedures.
OMe
DEP
SnMe3
i, ii
iii
34 (3-)
35 (2-)
49
50
47
48
Reagents and conditions i) Ph3SnNa, DMSO. ii) ClPO(OEt)2.
iii) Me3SnNa, NH3(liq.), hν
Scheme 7.
3.2. Photostimulated reaction of O,O-diethyl O-3-
tetrahydro-2H-2-pyranyloxyphenyl phosphate (7) with
Me3SnNa (11) in liquid ammonia
and 50 [17] in good yields (75% and 78%, respectively).
The global yield of stannanes 49 and 50 starting from
34 and 35 were 64% and 58%, respectively (Scheme 7).
The present results show the utility of readily accessible
substances such benzenediols, chlorophenols and meth-
oxyphenols for preparing asymmetric bi- and triaryl
compounds. All the reactions involved – SRN1 and Pd
cross-coupling reactions – are regioselective, therefore it
would be possible to synthesize tailored bi- and triarylic
materials by choosing appropriately substituted aromatic
moieties. The strategies proposed open a broad synthetic
tool. The results obtained demonstrate that commercially
available desymmetrized dihydroxybenzenes 17–19 are
the best starting materials. They lead to higher global
yields of the expected products in a fewer number of steps.
We have also proved that it is possible to introduce a
trimethylstannyl group in an aryl moiety in place of a
methoxy group, with interposition of one additional
step. Thus, in a ‘‘one-pot’’ reaction a series of anisols
have been converted to the corresponding arylDEP es-
ters with high yields (75–90%). In a second step, the sub-
stitution reaction led to the corresponding stannylated
substrate in excellent yields. It should be emphasized
that an aryl-tin bond is highly reactive towards diverse
electrophiles [18]. Therefore, an arylmethyl ether should
be considered as a potential substrate for the introduc-
tion of diverse electrophiles in an aromatic moiety,
opening important synthetic routes to different reaction
schemes. Further work is in progress to study the scope
of this reaction.
The reactions were performed by following the same
procedure in all cases. Into a 250-mL two-necked round-
bottomed flask, equipped with a coldfinger condenser
charged with acetone-liquid nitrogen, a nitrogen inlet
and magnetic stirrer, were condensed 220 mL of so-
dium-dried ammonia. Me3SnCl (1.10 mmol) was dis-
solved and sodium metal (2.53 mg atom) was added
until the blue color persisted for at least 5 min. When
the blue color disappeared, 7 (1.00 mmol) was added
and the resulting solution was then irradiated with stir-
ring for 4 h. The reaction was quenched by adding
NH4Cl in excess, and the ammonia was allowed to evap-
orate. The residue was treated with water and then ex-
tracted with diethyl ether. Ether extracts were washed
with brine and dried over MgSO4. Removal of the sol-
vent left 0.286 g (0.841 mmol) of trimethyl(3-tetrahy-
dro-2H-2-pyranyloxyphenyl)stannane (9) (84% yield,
colorless oil). The product could be used for the cou-
pling reaction without further purification, although
the attempted purification by column chromatography
on silica gel was unsuccessful due to decomposition.
1H NMR (CDCl3): d 7.25–6.87 (m, 4H), 4.87 (m, 1H),
3.79 (m, 1H), 3.44 (m, 1H), 2.03–1.40 (m, 6H), 0.35
2
(s, JHSn = 55.3/53.0 Hz, 9H, SnMe3); 13C NMR: d
157.11 (Caryl), 143.99 (2JCSn = 39.2 Hz, CHaryl),
129.38 (1JCSn = no, Caryl), 129.29 (CHaryl), 124.33
(3JCSn = 29.7 Hz, CHaryl), 116.51 (2JCSn = 42.1 Hz,
CHaryl), 95.06 (CH), 63.29 (CH2), 31.10 (CH2), 25.87
(CH2), 20.14 (CH2), ꢀ9.17 (1JCSn = 356.9/338.2 Hz,
SnCH3); 119Sn NMR: d ꢀ28.82; MS (m/z, relative inten-
sity): 342 (1, M+), 327 (3, M+ ꢀ 15), 258 (11), 243 (100),
227 (2), 212 (16), 165 (8); HRMS (EI): m/z Calc. for
C14H22O2Sn (M+): 340.9261. Found: 340.9258.
3. Experimental
3.1. General methods
3.3. Trimethyl(4-tetrahydro-2H-2-
pyranyloxyphenyl)stannane (10)
Irradiation was conducted in a reactor made of
Pyrex, equipped with four 250 W UV lamps emitting
maximally at 350 nm (Philips Model HPT, water-refrig-
erated). NMR spectra were recorded on a Bruker ARX
The procedure described for compound 9 was
followed using O,O-diethyl O-4-tetrahydro-2H-2-pyra-
1
300 (300.1 MHz for H, 75.5 MHz for 13C, 111.9 MHz

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3873
nyloxyphenyl phosphate (8) (1.00 mmol) to give product
10 (0.280 g, 0.823 mmol, 82%) as a colorless oil. The
product was used for the coupling reaction without fur-
HRMS (EI): m/z Calc. for C20H26O2Sn (M+):
417.0234. Found: 417.0229.
1
3
ther purification. H NMR: d 7.23 (d, JHH = 8.6 Hz,
3.6. Trimethyl(40-methoxybiphenyl-4-yl)stannane (40)
3
3JHSn = 42.9 Hz, 2H), 6.89 (d, JHH = 8.6 Hz, 2H), 5.27
(m, 1H), 3.86 (m, 1H), 3.54 (m, 1H), 2.03–1.34 (m,
The procedure described for compound 9 was fol-
lowed using O,O-diethyl O-40-methoxybiphenyl-4-yl
phosphate (33) (1.00 mmol). Purification by column
chromatography on silica gel (eluent: hexane:EtOAc,
8:2) gave 0.279 g (0.80 mmol, 80%) of product 40 as a
2
6H), 0.09 (s, JHSn = 55.1/52.8 Hz, 9H, SnMe3); 13C
NMR: d 157.82 (Caryl), 137.26 (3JCSn = 40.5 Hz, CHaryl),
134.02 (1JCSn = no, Caryl), 116.87 (2JCSn = 48.7 Hz,
CHaryl), 96.51 (CH), 62.38 (CH2), 30.79 (CH2), 25.66
(CH2), 19.19 (CH2), ꢀ9.08 (1JCSn = 350.9/335.7 Hz,
SnCH3); 119Sn NMR: ꢀ30.43; MS (m/z, relative inten-
sity): 342 (1, M+), 327 (4, M+ ꢀ 15), 258 (7), 243
(100), 227 (5), 212 (12), 165 (5); HRMS (EI): m/z Calc.
for C14H22O2Sn (M+): 340.9261. Found: 340.9267.
1
white solid. M.p. 78–80 ꢁC; H NMR: d 7.54–6.81 (m,
8H), 3.72 (s, 3H), 0.23 (s, JHSn = 55.2/53.9 Hz, 9H,
2
SnCH3), 13C NMR: d 159.67 (Caryl), 141.32 (Caryl),
140.68
(1JCSn = 463.6/442.5 Hz,
Caryl),
136.69
(3JCSn = 36.4 Hz, CHaryl), 134.26 (Caryl), 128.59 (CHar-
yl), 126.84 (2JCSn = 45.7 Hz, CHaryl), 114.70 (CHaryl),
55.75 (CH3), ꢀ9.09 (1JCSn = 350.9/335.7 Hz, SnCH3);
119Sn NMR: d ꢀ27.10; MS (m/z, relative intensity):
348 (11, M+), 333 (100, M ꢀ 15), 303 (37), 286 (5), 258
(6); HRMS (EI): m/z Calc. for C16H20OSn (M+):
346.9332. Found: 346.9347.
3.4. Trimethyl(2-tetrahydro-2H-2-
pyranyloxyphenyl)stannane (16)
The procedure described for compound 9 was fol-
lowed using 2-chlorophenyl tetrahydro-2H -2-pyranyl
ether (14) (1.00 mmol) to give product 16 (0.290 g,
0.85 mmol, 85%) as a colorless oil. The product was
used for the coupling reaction without further purifica-
tion.1H NMR: d 7.54–7.25 (m, 4H), 5.51 (m, 1H), 3.93
(m, 1H), 3.66 (m, 1H), 2.12–1.58 (m, 6H), 0.35 (s,
2JHSn = 56.1/54.7Hz, 9H, SnMe3); 13C NMR: d 161.93
(Caryl), 136.69 (3JCSn = 26.4 Hz, CHaryl), 130.55 (CHar-
yl), 130.53 (1JCSn = no, Caryl), 122.00 (2JCSn = 45.8 Hz,
CHaryl), 112.86 (3JCSn = 22.3 Hz, CHaryl), 96.20 (CH),
62.02 (CH2), 30.76 (CH2), 25.64 (CH2), 19.02 (CH2),
ꢀ8.58 (1JCSn = 360.3/344.5 Hz, SnCH3); 119Sn NMR: d
ꢀ31.77; MS (m/z, relative intensity): 342 (1, M+), 327
(10, M+ ꢀ 15), 258 (4), 243 (100), 227 (4), 212 (17),
165 (4); HRMS (EI): m/z Calc. for C14H22O2Sn (M+):
340.9261. Found: 340.9256.
3.7. Cross-coupling reaction of trimethyl(3-methoxy-
phenyl)stannane (25) with PhBr catalyzed by
PdCl2(PPh3)2: General procedure A
A two-necked, 50 mL round-bottomed flask fitted
with a reflux condenser, nitrogen inlet, magnetic stirrer
and rubber septum, was charged with a mixture of
bromobenzene (1.20 mmol) and PdCl2(PPh3)2 (2 mol%)
suspended in dry DMF (20 mL). 25 (1.00 mmol) was
added dropwise via syringe and the mixture was stirred
at 80 ꢁC (oil bath) for 20 h (monitoring the disappear-
ance of the stannane by TLC). After the resulting black
precipitates were filtered through a silical gel pad, water
(50 mL) was added and then the solution was extracted
with ethyl ether (3 · 20 mL). The combined organic lay-
ers were dried over MgSO4 and concentrated under re-
duced pressure. The residue was purified by dry
column vacum chromatography (DCVC) [21] on silica
gel (hexane:EtOAc, 9:1–6:4) to give 0.160 g
(0.869 mmol, 87%) of 3-methoxybiphenyl (34) as a col-
orless oil. 1H NMR: d 7.50–7.43 (m, 2H), 7.34–7.26
(m, 2H), 7.25–7.17 (m, 2H), 7.10–6.99 (m, 2H); 6.77
(m, 1H), 3.71 (s, 3H); 13C NMR: d 160.51 (Caryl),
143.27 (Caryl), 141.63 (Caryl), 130.22 (CHaryl), 129.21
(CHaryl), 127.88 (CHaryl), 127.67 (CHaryl), 120.16 (CHaryl),
113.45 (CHaryl), 113.20 (CHaryl), 55.72 (CH3) [9].
3.5. Trimethyl(40-tetrahydro-2H-2-pyranyloxybiphenyl-
4-yl)stannane (38)
The procedure described for compound 9 was fol-
lowed using O,O-diethyl O-40-tetrahydro-2H-2-pyra-
nyloxybiphenyl-4-yl phosphate (29) (1.00 mmol).
Crystallization from cold Et2O gave 0.408 g (0.98 mmol,
1
98%) of product 38 as a white solid. M.p. 64–66 ꢁC; H
NMR: d 6.99–7.58 (m, 8H), 5.38 (m, 1H), 3.86 (m, 1H),
3.54 (m, 1H), 2.05–1.43 (m, 6H), 0.23 (s, JHSn = 54.9/
2
53.0 Hz, 9H, SnCH3); 13C NMR: 157.07 (Caryl), 141.22
(Caryl), 140.72, (1JCSn = no, Caryl), 136.65 (3JCSn
=
3.8. Cross-coupling reaction of 25 with PhBr catalyzed by
Pd(PPh3)4: General procedure B
36.9 Hz, CHaryl), 135.05 (Caryl), 128.50 (CHaryl), 126.87
(2JCSn = 46.9 Hz, CHaryl), 117.14 (CHaryl), 96.79 (CH),
62.48 (CH2), 30.80 (CH2), 25.66 (CH2), 19.21 (CH2),
ꢀ9.10 (1JCSn = 351.5/335.1 Hz, SnCH3); 119Sn NMR: d
ꢀ25.29; MS (m/z, relative intensity): 418 (1, M+); 403
(2, M+ ꢀ 15); 334 (8); 319 (100); 303 (1); 289 (32).
A two-necked, 50 mL round-bottomed flask fitted
with a reflux condenser, a nitrogen inlet, a magnetic stir-
rer and rubber septum, was charged with a mixture of

3874
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
bromobenzene (1.20 mmol) and Pd(PPh3)4 (2 mol%)
suspended in dry toluene (20 mL). 25 (1.00 mmol) was
added dropwise via syringe and the mixture was heated
to 110 ꢁC (oil bath) for 20 h. The reaction mixture was
diluted with dietyl ether and then was filtered through
a silical gel pad. The organic solution was dried over
MgSO4 and concentrated under reduced pressure. The
residue was purified by DCVC on silica gel (eluent: hex-
ane:EtOAc, 9:1–6:4) to give 0.118 g (0.65 mmol, 65%) of
34.
crude product was purified by DCVC (eluent: hex-
ane:EtOAc, 7:3) to give 29 (0.284 g, 0.70 mmol, 70%)
1
as a pale yellow liquid. H NMR: d 7.52–6.99 (m, 8H),
5.38 (m, 1H), 4.16 (m, 4H), 3.85 (m, 1H), 3.55 (m,
3
1H), 2.08–1.46 (m, 6H), 1.28 (dt, JHH = 7.0 Hz,
4JHP = 0.9 Hz, 6H); 13C NMR: d 157.05 (Caryl), 150.36
(2JCP = 7.0 Hz, Caryl), 138.22 (Caryl), 134.05 (Caryl),
128.35 (CHaryl), 128.35 (CHaryl), 120.57 (3JCP = 4.7 Hz,
CHaryl); 117.18 (CHaryl), 96.79 (CH), 64.99
(2JCP = 6.5 Hz, CH2), 62.45 (CH2), 30.75 (CH2), 25.61
(CH2), 19.16 (CH2); 16.50 (3JCP = 6.5 Hz, CH3); HRMS
(EI): m/z Calc. for C21H27O6P (M+): 406.4124. Found:
406.4126.
3.9. 40-Methoxybiphenyl-4-yl tetrahydro-2H-2-pyranyl
ether (26)
General procedure A was followed to prepare the title
compound by reaction of 10 (1.00 mmol) with 4-iodoan-
isol (1.20 mmol). The crude product was purified by col-
umn chromatography (eluent: hexane:EtOAc, 8:2) to
give 26 (0.142 g, 0.501 mmol, 50%) as a white solid.
3.12. O,O-Diethyl O-30-tetrahydro-2H-2-
pyranyloxybiphenyl-4-yl phosphate (30)
General procedure B with the adjustment of 5 mol%
of Pd(PPh3)4, was followed to prepare the title com-
pound by reaction of 9 (1.00 mmol) with O,O-diethyl
O-4-bromophenyl phosphate (1.20 mmol). The crude
product was purified by DCVC (eluent: hexane:EtOAc,
7:3) to give 30 (0.244 g, 0.60 mmol, 60%) as an orange
1
M.p. 91–93 ꢁC; H NMR: d 7.50–7.28 (m, 4H), 7.09–
6.81 (m, 4H), 5.37 (m, 1H), 3.87 (m, 1H), 3.76 (s, 3H),
3.60–3.46 (m, 1H), 2.04–1.46 (m, 6H); 13C NMR:
d 159.11 (Caryl), 156.56 (Caryl), 134.79 (Caryl), 134.75
(Caryl), 128.19 (CHaryl), 128.06 (CHaryl), 117.13 (CHaryl),
114.54 (CHaryl), 96.81 (CH), 62.47 (CH2), 55.74 (CH3),
30.79 (CH2), 25.64 (CH2), 19.21 (CH2); MS (m/z, rela-
tive intensity): 284 (1, M+), 200 (100, M+-84), 185 (53),
157 (31), 128 (15), 102 (4); HRMS (EI): m/z Calc. for
C18H20O3 (M+): 284.3536. Found: 284.3529.
1
oil. H NMR: d 7.52–6.74 (m, 8H), 5.33 (m, 1H), 4.15
(m, 4H), 3.82 (m, 1H), 3.54 (m, 1H), 1.97–1.44 (m,
3
4
6H), 1.28 (dt, JHH = 6.1 Hz, JHP = 0.9 Hz, 6H), 13C
NMR: d 158.54 (Caryl), 151.92 (2JCP = 7.0 Hz, Caryl),
128.78 (Caryl), 120.79 (Caryl), 133.06 (CHaryl), 130.27
(CHaryl), 113.46 (CHaryl), 122.22 (CHaryl), 122.16 (CHaryl),
109.20 (3JCP = 5.3 Hz, CHaryl), 96.95 (CH), 64.92
(2JCP = 5.9 Hz, CH2), 62.40 (CH2), 30.66 (CH2), 25.53
(CH2), 19.06 (CH2), 16.46 (3JCP = 6.4 Hz, CH3); HRMS
(EI): m/z Calc. for C21H27O6P (M+): 406.4124. Found:
406.4122.
3.10. 40-Methylbiphenyl-4-yl tetrahydro-2H-2-pyranyl
ether (28)
General procedure A was followed to prepare the title
compound by reaction of 10 (1.00 mmol) with 4-iodotol-
uene (1.20 mmol). The crude product was purified by
DCVC (eluent: hexane:EtOAc, 9:1) to give 28 (0.094 g,
3.13. O,O-Diethyl O-20-tetrahydro-2H-2-
pyranyloxybiphenyl-4-yl phosphate (31)
1
0.35 mmol, 35%) as a white solid. M.p. 89–90 ꢁC; H
NMR: d 7.85–7.31 (m, 8H), 5.70 (m, 1H), 4.18 (m,
1H), 3.86 (m,1H), 2.62 (s, 3H), 2.38–1.85 (m, 6H); 13C
NMR: d 160.99 (Caryl), 136.79 (Caryl), 135.01 (Caryl),
129.81 (CHaryl), 128.29 (CHaryl), 127.04 (CHaryl),
117.08 (CHaryl), 96.79 (CH), 62.46 (CH2), 30.77 (CH2),
25.63 (CH2), 21.46 (CH3), 19.19 (CH2); MS (m/z, rela-
tive intensity): 268 (1, M+), 184 (100, M+-84), 165 (4),
152 (4), 139 (2), 128 (3); HRMS (EI): m/z Calc. for
C18H20O2 (M+): 268.3542. Found: 268.3539.
General procedure B with the adjustment of 5 mol%
of Pd(PPh3)4, was followed to prepare 31 by reaction
of 16 (1.00 mmol) with O,O-diethyl O-4-bromophenyl
phosphate (1.20 mmol). The title compound could be
isolated by DCVC (eluent: hexane:EtOAc, 6:4), as an
orange liquid, contaminated by starting diethyl phos-
phate ester. (0.142 g, 0.35 mmol, 35%). 1H NMR: d
7.57–6.94 (m, 8H), 5.34 (m, 1H), 4.17 (m, 4H), 3.71
(m, 1H), 3.52 (m, 1H), 1.85–1.41 (m, 6H), 1.30 (dt,
4
3JHH = 6.5 Hz, JHP = 1.0 Hz, 6H); 13C NMR:
d
3.11. O,O-Diethyl O-40-tetrahydro-2H-2-
pyranyloxybiphenyl-4-yl phosphate (29)
154.24 (Caryl); 150.12 (2JCP = 7.0 Hz, Caryl), 135.90
(Caryl); 131.24 (CHaryl); 130.05 (Caryl); 129.06 (CHaryl);
122.32 (CHaryl); 122.20 (3JCP = 5.3 Hz, CHaryl), 120.38
(4JCP = 4.7 Hz, CHaryl), 116.24 (CHaryl); 97.13 (CH),
64.89 (2JCP = 5.9 Hz, CH2), 62.22 (CH2), 30.66 (CH2),
25.59 (CH2), 18.91 (CH2), 16.46 (3JCP = 6.55 Hz, CH3);
General procedure A was followed to prepare the title
compound by reaction of 10 (1.00 mmol) with O-O-
diethyl O-4-bromophenyl phosphate (1.20 mmol). The

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3875
4
HRMS (EI): m/z Calc. for C21H27O6P (M+): 406.4124.
Found: 406.4126.
3JHH = 7.0 Hz; JHP = 0.9 Hz, 6 H); 13C NMR:
d
157.19 (Caryl), 150.67 (2JCP = 7.0 Hz, Caryl), 140.29
(Caryl), 138.95 (Caryl), 138.10 (Caryl), 134.41 (Caryl),
128.58 (CHaryl), 128.35 (CHaryl), 127.67 (CHaryl),
127.53 (CHaryl), 120.68 (3JCP = 4.7 Hz, CHaryl), 117.25
(CHaryl), 96.87 (CH), 65.00 (2JCP = 6.5 Hz, CH2), 62.46
(CH2), 30.78 (CH2), 25.62 (CH2), 19.18 (CH2), 16.49
(3JCP = 7.0 Hz, CH3); HRMS (EI): m/z Calc. for
C27H31O6P (M+): 482.5101. Found: 482.5112.
3.14. 20-Methoxybiphenyl-2-yl tetrahydro-2H-2-pyranyl
ether (32)
General procedure A was followed with the adjust-
ment of 20 mol% of Cl2Pd(PPh3)2. In addition 1.25
equiv of CuI, 13.8 equiv of CsF and a crystal of 2,6-
di-tert-butyl-4-methylphenol was added to DMF solu-
tion of 2-iodoanisol (1.20 mmol) to prepare the title
compound from 16 (1.00 mmol). The crude product
was purified by preparative TLC (eluent: hexane:EtOAc,
8:2) to give 32 (0.071 g, 0.25 mmol, 25%) as a pale yel-
3.17. 4-Methoxy-400-cyano-[1,10;40,100]terphenyl (41)
General procedure A was followed to prepare the title
compound by reaction of 40 (1.00 mmol) with 4-
iodobenzonitrile (1.20 mmol). The crude product was
purified by DCVC (eluent: hexane:EtOAc, 7:3) to give
41 (0.222 g, 0.779 mmol, 78%) as a white solid. M.p.
212–214 ꢁC; 1H NMR (DMSO-d6): d 7.83–7.74 (m,
4H), 7.68–7.57 (m, 4H), 7.56–7.49 (m, 2H), 6.94–6.85
(m, 2H), 3.65 (s, 3H); 13C NMR: d 159.61 (Caryl),
144.52 (Caryl), 140.49 (Caryl), 136.74 (Caryl), 131.93
(Caryl), 133.21 (CHaryl), 128.42 (CHaryl), 128.14 (CHaryl),
127.65 (CHaryl), 127.14 (CHaryl), 119.23 (CN), 114.86
(CHaryl), 110.28 (Caryl), 55.59 (CH3); MS (m/z, relative
intensity): 285 (100, M+), 270 (30, M+ ꢀ 15), 242 (23),
214 (5), 190 (2), 163 (1), 142 (7), 115 (4), 94 (2), 63 (2);
HRMS (EI): m/z Calc. for C20H15NO (M+): 285.3441.
Found: 285.3439.
1
low liquid. H NMR: d 7.34–6.84 (m, 8 H), 5.29 (m,
1H), 3.69 (s, 3H), 3.76 (m, 1H), 3.46 (m, 1H), 1.64–
1.32 (m, 6H); 13C NMR: d 156.00 (Caryl), 154.11 (Caryl),
132.87 (CHaryl), 131.68 (CHaryl), 129.71 (CHaryl), 129.62
(CHaryl), 127.51 (Caryl), 126.61 (Caryl), 122.58 (CHaryl),
121.34 (CHaryl), 117.76 (CHaryl), 112.08 (CHaryl), 95.09
(CH), 63.30 (CH2), 56.61 (CH3), 30.07 (CH2),
25,86 (CH2), 20.13 (CH2); MS (m/z, relative intensity):
284 (1, M+), 200 (100, M+-84), 185 (23), 169 (36),
157 (18), 139 (23), 128 (38), 115 (15); HRMS (EI):
m/z Calc. for C18H20O3 (M+): 284.3534. Found:
284.3531.
3.15. O,O-Diethyl O-40-methoxybiphenyl-4-yl phosphate
(36)
3.18. 1-Biphenyl-4-yl)naphthalene (45)
General procedure B was followed to prepare the title
compound by reaction of 21 (1.00 mmol) with O,O-
diethyl O-4-bromophenyl phosphate (1.20 mmol). The
crude product was purified by DCVC (eluent: hex-
ane:EtOAc, 7:3) to give 36 (0.245 g, 0.73 mmol, 73%)
General procedure A with the adjustment of 5 mol%
of Cl2Pd(PPh3)2 was followed to prepare the title com-
pound by reaction of 43 (1.00 mmol) with 1-bromo-
naphthalene (1.20 mmol). The crude product was
purified by DCVC (eluent: hexane:EtOAc, 9:1) to give
45 (0.196 g, 0.703 mmol, 70%) as a white solid. M.p.
139–41 ꢁC; 1H NMR: d 7.95–7.13 (m); 13C NMR: d
141.28 (Caryl), 140.55 (Caryl), 140.29 (Caryl), 140.20
(Caryl), 134.30 (Caryl), 132.08 (Caryl), 130.89 (CHaryl),
129.24 (CHaryl), 128.71 (CHaryl), 128.11 (CHaryl), 127.76
(CHaryl), 127.54(CHaryl), 127.39(CHaryl), 127.34(CHaryl),
126.47 (CHaryl), 126.44 (CHaryl), 126.20 (CHaryl), 125.80
(CHaryl); MS (m/z, relative intensity): 280 (100, M+), 202
(20), 138 (7), 98 (2), 77 (3), 51 (2); HRMS (EI): m/z Calc.
for C22H16(M+): 280.3682. Found: 280.3687.
1
as a pale yellow liquid. H NMR: d 7.59–7.46 (m, 4H),
7.35–7.24 (m, 2H), 7.06–6.95 (m, 2H), 4.34–4.19 (m,
3
4
4H), 3.86 (s, 3H), 1.39 (dt, JHH = 7.0, JHP = 0.9, 6H);
13C NMR: d 159.61 (Caryl), 150.21 (2JCP = 7.0 Hz, Caryl),
138.16 (Caryl), 133.21 (Caryl), 128.39 (CHaryl), 128.27
(CHaryl), 120.59 (3JCP = 4.7 Hz, CHaryl), 114.67 (CHaryl),
64.97 (2JCP = 5.8 Hz, CH2), 55.72 (CH3), 16.48
(3JCP = 6.4 Hz, CH3); HRMS (EI): m/z Calc. for
C17H21O5P (M+): 336.3221. Found: 336.3219.
3.16. 4-Diethoxyphosphinyl)oxy-400-tetrahydro-2H-2-
pyranyloxy-[1,10;40,100]terphenyl (39)
General procedure A was followed to prepare the title
compound by reaction of 38 (1.00 mmol) with O,O-
diethyl O-4-bromophenyl phosphate (1.20 mmol). The
crude product was purified by DCVC (eluent: hex-
ane:EtOAc, 6:4) to give 39 (0.193 g, 0.401 mmol, 40%)
as a white solid. M.p. 109–110 ꢁC; H NMR: d 7.62–
7.02 (m, 12H), 5.41 (m, 1H), 4.27–4.11 (m, 4H), 3.88
(m, 1H), 3.58 (m, 1H), 2.06–1.46 (m, 6H), 1.31 (dt,
3.19. 5-Biphenyl-4-yl)-2-bromopyridine (46)
General procedure B was followed to prepare the title
compound by reaction of 43 (1.00 mmol) with 2,5-dib-
romopyridine (1.20 mmol). Crystallization from cold
Et2O gave 0.124 g (0.405 mmol, 40%) of compound 46
as a pale yellow solid. m.p. >300 ꢁC; 1H NMR
(DMSO-d6): d 9.09–8.99 (m, 1 H); 8.58–8.21 (m, 4 H);
1

3876
A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
8.93–8.11 (m, 4H); 7.79–7.59 (m, 3H); 13C NMR: d
154.77 (Caryl), 150.60 (CHaryl), 141.44 (Caryl), 140.13
(CHaryl), 139.74 (Caryl), 136.84 (Caryl), 129.38 (CHaryl),
128.18 (CHaryl), 127.46 (CHaryl), 127.43 (CHaryl),
127.03 (CHaryl), 122.31 (CHaryl), 119.48 (Caryl); HRMS
(EI): m/z Calc. for C17H12BrN (M+): 310.1935. Found:
310.1929.
(7), 213 (11), 183 (8), 165 (12), 135 (16), 109 (11), 8
(20), 65 (4); HRMS (EI): m/z Calc. for C13H23O4PSn
(M+): 392.8953. Found: 392.8949.
Acknowledgements
This work was partially supported by the Consejo
´
Nacional de Investigaciones Cientıficas y Tecnicas
(CONICET), the Comision de Investigaciones Cientıfi-
cas de la Provincia de Buenos Aires (CIC), the Fun-
´
3.20. Synthesis of O,O-Diethyl O-biphenyl-4-yl phosphate
(42) by demethylation of 34 with Ph3SnNa followed by
phosphorylation in a one-pot-type reaction
´
´
´
dacion Antorchas and the Universidad Nacional del
Sur, Bahıa Blanca, Argentina. CONICET is thanked
´
In a two-necked, 50 mL round-bottomed flask,
Ph3SnNa (2.00 mmol) was prepared in liquid ammonia
(20 mL) starting from Ph3SnCl (2.2 mmol) and Na
(5.57 mg atom). Then, dry DMSO (10 mL) was added
and the ammonia was allowed to evaporate. The cold-
finger condenser was replaced by a reflux condenser
and 35 (1.00 mmol) was added. The solution was stirred
at 110 ꢁC (oil bath) for 12 h. Diethyl chlorophosphate
(2.4 mmol) was added at room temperature and the
resulting solution was stirred for 24 h. The reaction
was quenched by addition of 10 mL of water and then
extracted with ethyl ether (3 · 20 mL). The ether frac-
tions were washed with brine, dried (MgSO4) and con-
centrated under reduced pressure to give a crude
orange–yellow liquid. The title product was purified by
DCVC on silica gel (hexane:ethyl acetate, 6:4) yielding
0.260 g (0.85 mmol, 85%) of 42 as a pale yellow liquid.
Spectroscopic characteristics are in agreement with
those of an authentic sample prepared by a known pro-
cedure [19]. Ph3SnMe eluted with hexane (0.764 g,
2.09 mmol).
for a research fellowship to G.F.S.
References
[1] F. Diederich, P.J. Stang, Metal-catalyzed Cross-coupling Reac-
tions, Wiley-VCH, New York, 1997.
[2] V. Farina, V. Krishnamurthy, W.J. Scott, L.A. Paquette Organic
Reactions, vol. 50, Wiley, New York, 1997.
´
[3] R.A. Rossi, A.B. Pierini, A.B. Pen˜en˜ory, Chem. Rev. 103 (2003)
71.
[4] (a) M.T. Lockhart, A.B. Chopa, R.A. Rossi, J. Organometal.
Chem. 582 (1999) 229;
(b) A.B. Chopa, M.T. Lockhart, G.F. Silbestri, Organometallics
20 (2001) 3358;
(c) A.B. Chopa, M.T. Lockhart, G.F. Silbestri, Organometallics
21 (2002) 5874;
(d) A.B. Chopa, M.T. Lockhart, V.B. Dorn, Organometallics 21
(2002) 1425;
(e) A.B. Chopa, M.T. Lockhart, G.F. Silbestri, Organometallics
19 (2000) 2249.
[5] A.B. Chopa, V.B. Dorn, M.A. Badajoz, M.T. Lockhart, J. Org.
Chem. 69 (2004) 3801.
[6] (a) V.V. Namboodiri, R.S. Varma, Tetrahedron Lett. 43 (2002)
1143;
(b) K. Mori, Tetrahedron 30 (1974) 3807.
[7] Structure confirmed by comparison with an authentic sample
prepared according with C. Eaborn, H.L. Hornfeld, D.R.M.
Walton, J. Organomet. Chem. 10 (1967) 529.
[8] Favorable conditions for o-substituted substrates: J.M. Saa, G.
Martorell, J. Org. Chem. 58 (1993) 1963.
3.21. O,O-Diethyl O-4-trimethylstannylphenyl phosphate
(37)
The synthesis of the title compound was carried out
according to a similar procedure starting from 21 using
Me3SnNa (11) instead Ph3SnNa as deprotecting reagent.
The mixture of 11 and 21 in DMSO was heated at
110 ꢁC for 90 min. The crude product was purified by
preparative TLC (eluent: hexane:EtOAc, 6:4) to yield
0.110 g (0.281 mmol, 28%) of 37 as a pale yellow liquid;
[9] Spectroscopic data are in agreement with those of an authentic
sample synthesized from commercially available biphenols,
according with R.A.W. Johnstone, M.E. Rose, Tetrahedron 35
(1979) 2169.
[10] G.D. Allred, L.S. Liebeskind, J. Am. Chem. Soc. 118 (1996)
2748.
[11] L.S. Liebeskind, S.W. Riesinger, J. Org. Chem. 58 (1993)
408.
3
1H NMR: d 7.44 (d, JHH = 8.4 Hz, 2H), 7.19 (d,
3JHH = 8.4 Hz, 2H), 4.21 (m, 4H), 1.35 (dt,
[12] P.J. Kocienski, Protecting Group, Georg Thieme Verlag Stuttgart,
New York, 1994.
4
2
3JHH = 7.1 Hz; JHP = 1.1 Hz, 6H), 0.28 (s, JHSn
=
[13] It should be noted that compounds 29, 30, 31 and 36 support also
an ether function (OTHP or OCH3) suitable to be transformed
into a DEP group leading to a biaryl containing two DEP groups
proper for the generation of a bis(trimethylstannyl) derivative
which would lead to a tetraaryl compound through a suitable
coupling reaction.
55.5/53.2 Hz, 9H, SnMe3); 13C NMR:
d 151.56
(2JCP = 7.0 Hz, Caryl),138.72 (CHaryl), 137.40 (2JCSn
=
=
40.0 Hz, CHaryl), 120.05 (3JCSn = 45.8 Hz, JCP
3
4.5 Hz,
C
aryl), 64.90 (2JCP = 5.9 Hz, CH2), 16.45
(3JCP = 7.0 Hz, CH3), ꢀ9.15 (1JCSn = 353.5/338.0 Hz,
SnCH3); MS (m/z, relative intensity): 394 (9, M+), 379
(100, M ꢀ 15), 349 (16), 321 (12), 293 (9), 275 (3), 243
[14] Physical and spectroscopic data are in agreement with those
reported by C.-H. Cho, I.-S. Kim, K. Park, Tetrahedron 60
(2004) 4589.

A.B. Chopa et al. / Journal of Organometallic Chemistry 690 (2005) 3865–3877
3877
[15] Spectroscopic data are in agreement with those of an authentic
samplesynthesizedfrom commercially availablebiphenols. See [19].
[16] Structure confirmed by comparison with an authentic sample
prepared according with H. Zimmer, M.A. Barcelon, W.R. Jones,
J. Organomet. Chem. 63 (1973) 133.
[18] (a) A.G. Davies, Organotin chemistry, VCH, Weinheim, 1997;
(b) T. Sato, Comprehensive Organometallic Chemistry II, vol. 8,
Pergamon, New York, 1995.
[19] G.W. Kenner, N.R. Williams, J. Chem. Soc. (1955)
522.
[20] IR spectra of the esters present characteristic absorption at 1030,
[17] Structure confirmed by comparison with an authentic sample
prepared according with A.B. Evnin, D. Seyferth, J. Am. Chem.
Soc. 89 (1967) 952.
1155–1164, 1183–1214 and 1265–1274 cmꢀ1
.
[21] D.S. Pedersen, C. Rosenbohn, Synthesis 16 (2001) 2431.