First reusable ligand-free palladium catalyzed C-P bond formation of aryl halides with trialkylphosphites in neat water

Article abstract of DOI:10.1039/c4ra07680j

A reusable ligand-free palladium catalyzed phosphonation of aryl iodides, bromides and chlorides with trialkylphosphites is described for the first time in neat water. The aryl phosphonates are obtained in good to excellent yields. The reaction can be also performed with Ni(II) with longer reaction time. The role of tetrabutylammonium bromide in this reaction as reducing agent for generation of Pd(0) at room temperature is also demonstrated. Pd(0)/TBAB was easily reused for three runs without decreasing the efficiency.

Full text of DOI:10.1039/c4ra07680j

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PAPER
First Reusable Ligand-Free Palladium Catalyzed C-P
Bond Formation of Aryl Halides With
Trialkylphosphites in Neat Water
Cite this: DOI:
0.1039/x0xx00000x
1
Nasser Iranpoor*, Habib Firouzabadi*, Khashayar Rajabi Moghadam and Somayeh
Motavalli
Received 00th January 2012,
Accepted 00th January 2012
A reusable ligandꢀfree palladium catalyzed phosphonation of aryl iodides, bromides and
chlorides with trialkylphosphites is described for the first time in neat water. The aryl phosphonates
are obtained in good to excellent yields. The reaction can be also performed with Ni(II) with longer
reaction time. The role of tetrabutylammonium bromide in this reaction as reducing agent for
generation of Pd(0) at room temperature is also demonstrated. Pd(0)/TBAB was easily reused in
three runs without decreasing the efficiency.
DOI: 10.1039/x0xx00000x
www.rsc.org/
Introduction
than dialkyl Hꢀphosphonates have been found considerable
synthetic applications in different organic transformations.
1
2
Transition
metalꢀcatalyzed
carbon–phosphorous
bond
The substitution of aryl halides with trialkylphosphites in the
formation plays a key role in the preparation of different types
of phosphorous compounds such as phosphonates,
phosphinates, phosphine oxides, phosphines, etc. Some of these
compounds have been found wide biological activites or
material science applications and some have been considered as
presence of stoichiometric amount of copper catalyst at 150ꢀ
13
1
75 °C,
the two step reaction of aniline with
14
trialkylphosphites, the reaction of triethylphosphite with 2ꢀ
haloanilides in the presence of NiX2 complexes that were
conducted under the atmosphere of dry argon (Schlenk
technique), doing reaction under microwave irradiation and
using electrolysis methods are some examples for the
1
versatile ligands in some catalytic reactions. In comparison
15
7
with the phosphorus compounds containing the more reactive
NꢀP, SꢀP or OꢀP linkages, organophosphonates are synthetically
more important due to the more resistant of their CꢀP linkage to
16
synthesis of aryl phosphonates. In addition, recently Dhokale et
al. reacted 2ꢀ(trimethylsilyl)phenyl trifluoromethanesulfonate
as an unusual aryl substrate instead of readily available aryl
halides with triethylphospite and cesium fluoride in acetonitrile
2
chemical hydrolysis, thermal decomposition and photolysis.
Most of the methods for the synthesis of aryl phosphonates are
usually based on the use of hydrogen dialkylphosphonates as
the source of phosphorous compound. The first palladiumꢀ
catalyzed phosphonation of aryl iodides or bromides was
reported by Hirao et al. using this class of phosphorous
o
under inert atmosphere at 20 C to offer diethyl phenyl
17
phosphonate after 20h. The use of NiCl2 and PdCl with
2
various ligands as catalyst have also been reported for
preparation of aryl phosphonates from aryl halides and
3
a
compounds for CꢀP bond formatin. After this report, research
efforts have focused on this reaction and remarkable progress
have been achieved on the improvements of the classical Hirao
reaction conditions such as; applying different transition
o
18
trialkylphosphites but under high temperature at 140ꢀ195 C
,
14,15
7
inert atmosphere
or microwave irradiation.
The importance of green reactions in organic synthesis has
encouraged scientists to use water as environmentally friendly
reaction media. In this line, efforts have been focused on the
aryl CꢀP bond formation in aqueous solutions. Reports on the
1
a,3,4,5
6,3d,4c,3c,3n
metals
ligands and solvents
alongside with use of
7
,3h
techniques such as microwave irradiation.
After successful application of dialkyl Hꢀphosphonates as
phosphorous source in phosphonation of aryl halides, the use
CꢀP bond formation using aryl halides in neat water are rare in
3
19,1a
the literature.
Tang’s group reported the first example of the
of these phosphonating agents have been attended in CꢀP bond
conversion of aryl iodides and bromides to aryl phosphine
oxides using Hꢀdiphenylphosphine oxide in the presence of zinc
8
,5b
formation in the reaction with arylboronic acids,
terminal
sodium
9
3e,10
acetylenes,
diaryliodoniumsalts
and
19a
powder and NiCl ·6H O as the catalyst in water at 2011. On
2
2
1
1
benzenesulfinates.
the other work, the reaction of halogenated benzoic acids were
performed with Hꢀdiphenylphosphine oxide using Pd/C as the
In recent years, trialkylphosphites as convenient phosphorus
source with higher boiling pints and more chemical stability
This journal is © The Royal Society of Chemistry 2013
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catalyst in water under microwave irradiation by Bokhoven et pronounced effect and the reaction time was dramatically
1
9b
al.
reduced from 12 h to 1.5 h in PEG200 and the yield was found
Due to the importance of using water as the solvent for to be excellent (Table 1, entry 8). The effect of other solvents
synthesis of phosphonates, Wu et al, subsequently developed such as DMF, DMSO, diglyme, EtOH, THF, H O, and also
2
the crossꢀcoupling reaction of aryl halides by using diisopropyl solventꢀfree condition were then studied using
nꢀPr N as the
3
Hꢀphosphonate, and a palladacycle as catalyst in refluxing most suitable base (Table 1, entries 9ꢀ15). Among these
1
a
waterꢀisoꢀpropanol mixture at 2013. In general, dialkyl Hꢀ solvents, H O was found to be even more suitable than PEG
2
phosphonates are unstable in water and produce phosphorous and the reaction proceeded well in the shortest reaction time
acid and their corresponding alcohols. Regarding the (Table 1, entry 14). Et N was also examined as base in water,
3
reversibility of the decomposition reaction of diisopropyl Hꢀ however, the yield of the product was decreased and instead,
,
phosphonate, to avoid this side reaction, Wu s group added iso
ꢀ
the yield of biphenyl was increased (Table 1, entry 23). When
1
a
propanol to the reaction mixture. As far as we know, there are PdCl2 was replaced with NiCl , monitoring of the reaction
2
no reports in the literature for the synthesis of phosphonates showed the formation of the desired product in excellent yield
from aryl halides using trialkylphosphites in neat water.
with some increase in the reaction time (Table 1, entry 16). In
In continuation of our recent works on the palladium catalyzed the absence of base, the starting material remained unchanged
2
0
crossꢀcoupling reactions, herein we report the first reusable (Table 1, entry 22). After optimizing the solvent and the base,
ligandꢀfree palladium catalyzed phosphorylation reaction of the required amount of TBAB was also optimized. The results
aryl halides with trialkylphosphites in neat water.
of Table 1 show that decreasing the amount of TBAB from one
equivalent to 0.25 extends the reaction time from 1 to 4 h
(Table 1, entry 18). When TBAB was removed from the
reaction mixture, the reaction was not occurred (Table 1, entry
Results and discussion
Among the reported methods for phosphonation of aryl
halides, the use of more stable trialkylphosphites with higher
boiling points than their corresponding dialkyl Hꢀphophonates
seems to be a more practical method. In this work, for the first
time, we report an efficient method for phosphonation of aryl
iodides, and bromides as well as chlorides in the presence of
trialkylphosphites in refluxing neat water as a green medium
1
9).
Table 1. Effect of different reaction parameters on
phosphonation of iodobenzene.
b
Entry
Base
Solvent
Yield (%)
Time(h)
1
2
3
4
5
6
7
8
9
DBU
DABCO
Morpholine
PEG200
PEG200
PEG200
PEG200
PEG200
PEG200
PEG200
PEG200
DMF
DMSO
Diglyme
Ethanol
THF
90
84
70
57
35
50
66
90
70
62
90
85
45
98
76
90
96
95
0
12
12
24
24
24
24
24
1.5
24
24
24
24
2
1
2.5
5
1
4
24
1
1
24
2
(
Scheme 1).
Et N
3
O
KOAc
NaOH
X
P OR'
OR'
PdCl (4.4 mol%), TBAB
2
R
P(OR')3
R
+
o
nꢀPr N, H O, 100 C
K CO3
3
2
2
1
2
3
nꢀPr N
3
R= H, 4ꢀMe, 4ꢀOMe, 4ꢀNitro, 4ꢀCN, 4ꢀCF , 2ꢀMe, 1ꢀNaphtyl, 4ꢀBiphenyl,
3
nꢀPr N
3
4ꢀBr, 4ꢀCl, 4ꢀNitroꢀ2ꢀMethyl, 4ꢀHydroxy, 4ꢀAmino, Styryl
1
1
1
1
0
1
2
3
nꢀPr N
3
R'= Ethyl, Isopropyl
X= I, Br, Cl
nꢀPr N
3
nꢀPr N
3
nꢀPr N
Scheme 1
For optimization of the reaction conditions, we first
performed the phosphonation of iodobenzene with
triethylphosphite as a model reaction in the presence of
catalytic amounts of PdCl2 and the effects of different
parameters were studied. Several bases and solvents were
3
a
1
4
n-Pr N
H O
3
2
1
5
nꢀPr N
noꢀSolvent
3
c
1
1
1
6
7
8
nꢀPr N
H O
3
2
d
e
f
nꢀPr N
H O
3
2
nꢀPr N
H O
3
2
1
9
nꢀPr N
H O
3
2
g
h
i
screened
for
this
reaction.
Initially,
1,8ꢀ
2
2
0
1
nꢀPr N
H O
97
96
0
3
2
diazabicyclo[5.4.0]undecꢀ7ꢀene (DBU) was utilized as base and
the reaction was carried out in the presence of
nꢀPr N
H O
3
2
22
23
None
H O
2
tetrabuthylammonium bromide (TBAB) in PEG 200 the solvent
Et
3
N
H
2
O
65
o
a
at 100 C. The desired product was obtained in 90% yield after Reaction
conditions :
4ꢀiodobenzene
(0.5
mmol),
1
2h (Table 1, entry 1). Then DBU was replaced by bases such triethylphosphite (2.0 mmol), base: (1.0 mmol), TBAB: (0.5
b
as 1,4ꢀdiazabicyclo[2.2.2]octane (DABCO), morpholine, Et N, mmol), catalyst: (0.022 mmol), solvent (1.5mL). isolated yield.
and KOAc. However, no improvement in the performance of NiCl (0.022 mmol) as catalyst. TBAB: (1.0 mmol) TBAB:
the reaction was observed (Table 1, entries 2ꢀ5). Inorganic (0.25 mmol) . without TBAB. base: (3.0 mmol) base (2.0
bases such as NaOH and K CO were also found not to be mmol) whitout base.
3
c
d
e
2
f
g
h
i
2
3
suitable for this reaction in terms of reaction time and yield.
Having the optimized conditions; 0.5 mmol of aryl halide,
ꢀPr N, 0.022 mmol of
(
Table 1, entries 6, 7). Using ꢀPr N as an organic base has 2.0 mmol of P(OR) , 1.0 mmol of
n
n
3
3
3
2
| J. Name., 2012, 00, 1-3
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DOI: 10.1039/C4RA07680J
o
PdCl , and 0.5 mmol of TBAB in 1.5 ml of H O at 100 C Table 2. Phosphonation of aryl halides with trialkylphosphite
(
2
2
a
Table 1, entry 14), the phosphorylation reactions proceeded in the presence of PdCl and TBAB in water
2
efficiently for iodobenzene and iodobenzenes bearing either an
electronꢀwithdrawing or an electronꢀdonating group at the
paraꢀposition (Table 2, entries 3a, 3b, 3d, 3e, and 3f). The
methodology was further extended to the coupling of sterically
hindered aryl iodides such as 2ꢀiodotoluene, 1ꢀiodonaphthalene,
and 4ꢀnitroꢀ2ꢀiodotoluene (Table 2, entries 3g, 3h, and 3l). The
applicability of this system was developed to aryl bromides and
O
POR'
OR'
X
PdCl (4.4 mol%)
2
R
R
+
P(OR')3
o
nꢀPr N, H O, 100 C
3
2
=
=========================================================
O
POEt
OEt
O
POEt
OEt
O
P OEt
OEt
OMe
Me
X = I
b: 2.5h, 90%
X=Br
X = I
3c: 2h, 83%
X=Br
vinyl bromide.
ß
ꢀBromostyrene and 1ꢀbromonaphthalene
X = I
a: 1.5h, 99%
X=Br
a': 4h, 85%
3
3
reacted successfully to produce their corresponding
phosphonates (Table 2, entries 3a’, 3b’, 3c’, 3d’, 3e’, 3h’, 3i
and 3o). In order to investigate the chemoselectivity of the
reaction, 4ꢀchlorobromobenzene and 4ꢀbromoiodobenzene were
examined under the optimized conditions and the results
showed high selectivity as illustrated in Table 2, entries 3j and
3b': 5h, 78%
3c': 4h, 87%
3
ꢀ
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
O
POEt
OEt
O
POEt
OEt
O
POEt
OEt
NO2
CN
CF3
X = I
X = I
d: 1h, 85%
X=Br
3d': 2h, 89%
X=Cl
d": 5h, 90%
X = I
3f: 1.5h, 83%
3
e: 1h, 65%
3
3
k. We also tried to use this method for the coupling of
X=Br
3
e': 2h, 75%
triethylphosphite with chlorobenzene. Although the crossꢀ
coupling reaction proceeded efficiently for chlorobenzenes
bearing an electronꢀwithdrawing group at the paraꢀposition
X=Cl
3
e": 5.5h, 87%
3
ꢀ
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
O
POEt
OEt
O
POEt
OEt
O
P OEt
OEt
(
Table 2, entries 3d" and 3e"), the reaction did not proceed with
chlorobenzene, and chlorobenzenes bearing an electronꢀ
donating group even in a sealed tube. The reactions didn't
performed even in the presence of PPh3 as ligand with
X = I
h: 4h, 99%
X=Br
X = I
g: 5h, 67%
3
X = Br
3i: 4h, 99%
3
increasing the amounts of PdCl from 5 mol% to 10 mol% In
2
3
h': 6h, 88%
ꢀ
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
entries 3m, 3m’, 3n and 3n’, the effect of hydroxy and amino
groups in iodo and bromo dervaties of phenol and aniline were
studied. The reactions proceeded well and their corresponding
phosphonates were obtained in 79ꢀ90% yield.
O
P OEt
OEt
O
POEt
OEt
O
P OEt
OEt
Br
Cl
NO2
X = I
3j: 2h, 99%
X = Br
X = Cl
3l: 4h, 85%
Instead of triethylphosphite, we also examined this method for
the coupling of triisopropylphosphite with iodobenzene. The
reactions were occurred efficiently and the corresponding
products were obtained in high yields (Table 2, entries 3pꢀ3s).
The role of TBAB in this reaction is crucial. It is
noteworthy that the presence of TBAB not only makes the
catalytic system stable by preventing the formation of
3
k: 4h, 99%
ꢀ
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
O
POEt
OEt
O
P OEt
OEt
O
P OEt
OEt
OH
NH2
X = I
m: 3h, 86%
X=Br
3m': 5h, 90%
X = I
3n: 4h, 79%
X=Br
X = Br
3o: 5h, 79%
3
2
1
3n': 6h, 87%
palladium black but also acts both as reducing agent for the
generation of Pd(0) and also phase transfer catalyst for making
the reaction mixture homogeneous.
ꢀ
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
O
POPr
OPr
O
POPr
OPr
O
POPr
OPr
i
i
i
i
i
i
In order to gain insight about the reducing property of TBAB,
for the first time we probed the UV spectrum of the aqueous
solution of Pd(II) in the presence of TBAB, nꢀPr N and also
3
OMe
NO2
X = I
p: 6h, 95%
X = I
3q: 8h, 76%
X = I
3r: 4.5h, 93%
3
ꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀꢀ
triethylphosphite separately. The UV spectra of these solutions
are shown in Figure 1. The white color of the aqueous solution
of TBAB changed almost immediately to gray upon the
addition of Pd(II) at room temperature. The UV spectrum
showed the disappearance of the peak around 300 nm (blue
curve) after 5 minutes, which confirms that Pd(II) has been
reduced to the Pd(0) species. The formation of a peak at about
O
POPr
OPr
i
i
X = I
s: 12h, 88%
3
3
80 nm for Br , demonstrates the efficiency of the generation of
2
zeroꢀvalent palladium by TBAB through oxidation of bromide
ion to Br . In comparison, neither ꢀPr N, nor triethylphophite
n
2
3
reduced Pd(II) under similar condition (Fig. 1).
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the fourth run, loss of the activity of the catalytic system was
observed (Fig. 3).
Fig. 1.UV spectra of PdCl in neat water with TBAB (Blue), n-
2
Pr N(Red) and P(OEt)3 (Green) after 30 minutes at room
temperature.
Fig. 3. Recyclability of Pd(0)/TABAB in the reaction of
iodobenzene with triethylphosphite in water.
3
The catalytic cycle for the phosphorylation reaction involves a
series of transformations around the palladium catalyst. The
proposed mechanism is as the following. According to the UV
spectrum (Fig. 1), Pd(0) could well be generated by TBAB.
Step
the aryl halide bond and the reaction continues to perform
homogeneously in water. In step , triethylphosphite reacts with
the palladiumꢀhalide bond and then by an Arbuzov type
reaction, EtX is eliminated from adduct which is generated
1 involves an oxidative addition in which Pd inserts into
2
I
from step
II. In step
2
4
followed by the formation of ArꢀPdꢀphosphonate
, the Pd(0) catalyst is regenerated by the reductive
elimination of the palladium
(II) compound and the
corresponding aryl phosphonate is formed. (Scheme 2)
PdCl2
Fig. 2.UV spectra of PdCl2 in neat water with TBAB at
different time intervals at room temperature.
TBAB
O
4
Pd (0)
1
ArꢀX
The reduction of Pd(II) to Pd(0) in neat water at room
temperature by TBAB is shown in Fig. 2. The isobestic point at
OR
OR
ArꢀP
3
58 nm shows the pretense of both Pd(II) species and bromine
molecule in the solution.
O
II
This interesting property of TBAB to reduce Pd(II) to Pd(0) is
in similar to the reducing properties of tetralakylammonium
ArꢀPd ꢀX
II
OR
OR
ArꢀPd ꢀP
2
2a
o
22b
carboxylates at 60 C and tetrabutylammonium boronate in
II
ꢀ
ꢀ
which instead of Br , RCO2 and boronate anions have been
responsible for electron transfer to Pd(II).
R
O
X
3
II
P(OR)3
ArꢀPd ꢀP OR
2
The recyclability of this system was also examined in the
reaction of iodobenzene. For this purpose, after completion of
the reaction and extraction of the product in ethyl acetate,
iodobenzene, base and triethylphosphit were added to the
RꢀX
I OR
Scheme 2
aqueous layer containing Pd(0)/TBAB and the reaction mixture Experimental Section
was workedꢀup after 1.5 h. Quantitative conversion to the
corresponding phosphonate was observed for three runs. From
1
13
H and C spectra were recorded on a Brucker Avance DPXꢀ
3
1
2
50 spectrometer and P NMR (on a Brucker UltraSheildꢀ400
4
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spectrometer) using tetramethylsilane (TMS) as internal
standard in pure deuterated solvents. The reaction monitoring
was carried out on silica gel analytical sheets or by GC analysis
using a 1m length column packed with DCꢀ200 stationary
phase. Column chromatography was carried out on a column of
silica gel. The spectral data for the products are included in the
supporting information.
4637; (i) M. Kalek and J. Stawinski, Organometallics, 2008, 27,
5876; (j) Y. Belabassi, S. Alzghari and J. L. Montchamp, J.
Organomet. Chem., 2008, 693, 3171; (k) A. Bessmertnykh, C. M.
Douaihy, S. Muniappan and R. Guilard, Synthesis, 2008, 10, 1575; (l)
L. Coudray and J. L. Montchamp, Eur. J. Org. Chem., 2008, 4101;
(m) M. Kalek, M. Jezowska and J. Stawinski, Adv. Synth. Catal.
,
2009, 351, 3207; (n) A. Bessmertnykh, C. M. Douaihy and R.
Guilard, Chem. Lett., 2009, 38, 738; (o) Y. Luo and J. Wu,
Organometallics, 2009, 28, 6823; (p) D. Hockova, M. Dracinsky and
A. Holy, Eur. J. Org. Chem., 2010, 2885.
General procedure for phosphonation of aryl halides with
trialkylphosphites using PdCl as catalyst in neat water
2
4
For copperꢀcatalyzed C–P bond formation, see: (a) T. Ogawa, N.
Usuki and N. Ono, J. Chem. Soc., Perkin Trans. 1, 1998, 2953; (b) H.
H. Rao, Y. Jin, H. Fu, Y. Y. Jiang and Y. F. Zhao, Chem.–Eur. J.,
2006, 12, 3636; (c) C. Huang, X. Tang, Y. Y. Jiang and Y. F. Zhao,
J. Org. Chem., 2006, 71, 5020; (d) B. Xiong, M. Li, Y. Liu, Y. Zhou,
A mixture of PdCl (0.004 g, 0.022 mmol, 4.4 mol %), aryl
2
halide (0.5 mmol), trialkylphosphite (2.0 mmol), nꢀPr N (1.0
3
mmol, 0.18 mL), TBAB (0.5 mmol, 0.166 g,), in water (1.5
o
mL) was heated at 100 C. After completion of the reaction
monitored by GC or TLC analysis, the reaction mixture was
cooled to room temperature. The organic compound was
extracted with ethyl acetate (3 x 10 mL) from the aqueous layer
and dried over anhydrous Na SO , filtered, and concentrated in
C. Zhao, M. Goto, S. F. Yin, L. Han, Adv. Synth. Catal., 2014, 356,
781.
5
(a) Y. L. Zhao, G. J. Wu, Y. Li, L. X. Gao and F. S. Han, Chem.–Eur.
., 2012, 18, 9622; (b) W. Chen, T. Fu, Y. Gao, G. Hu, Z. Peng, H.
J
2
4
vacuum. The crude organic mixture was then purified by silica
gel column chromatography using petroleum ether/ethyl acetate
Qiao and Y. Zhao, Org. Lett., 2013, 15, 5362.
6
7
H. Hu, Y. Wu, K. Xu and F. Yang, Eur. J. Org. Chem., 2013, 2, 319.
4
:1 as eluent to obtain the desired product (Table 1).
(a) D. Villemen, A. Elbilali, F. Simeon, P. A. Jaffres, G. Maheut, M.
Mosaddak and A. Hakiki, J. Chem. Reaserch (S), 2003, 436; (b) E.
Jablonkai, and G. Keglevich, Tetrahedron Lett., 2013, 54, 4185; (c)
G. Keglevich, A. Gruen, A. Boelcskei, A. Gruen, L. Drahos, M.
Kraszni and G. T. Balogh, Heteroatom Chem., 2012, 23, 574; (d) A.
F. Gurley, J. J. Kiddle, Phosphorus, Sulfur Silicon Relat. Elem., 2000,
Conclusions
In conclusion we have reported the first reusable ligandꢀfree
Pd(0) catalytic method for the efficient phosphonation of aryl
halides ( X = Cl, Br, I) and also styryl bromide with different
trialkylphosphites in neat water. The role of TBAB as reducing
agent in water for the generation of Pd(0) was also
demonstrated for the first time.
160, 195.
8
(a) R. Zhuang, J. Xu, Z. Cai, G. Tang, M. Fang, and Y. Zhao, Org.
Lett., 2011, 13, 2110; (b) M. Andaloussi, M. Larhed, J. Lindh, J.
Saevmarker and P. J. R. Sjoeberg, Chem.-Eur. J., 2009, 15, 13069.
Y. Gao, G. Wang, L. Chen, P. Xu, Y. Zhao, Y. Zhou and LꢀB. Han,
J. Am. Chem. Soc. 2009, 131, 7956.
9
1
Acknowledgements
0 (a) C. Zhou, Syn. Comm., 2001, 31, 3289; (b) C. Liu, Synthesis, 1993,
We are grateful to the research council of Shiraz University and
a grant from Iran National Elite Foundation for the support of
this work.
4, 373.
1
1
1 T. Miao and L. Wang, Adv. Synth. Catal., 2014, 356; 967.
2 (a) G. R. Qu, R. Xia, X. N. Yang, J. G. Li, D. C. Wang, and H. M.
Guo, J. Org. Chem. 2008, 73, 2416; (b) R. J. Barney, R. M.
Richardson, and D. F. Wiemer, J. Org. Chem., 2011, 76, 2875; (c) B.
Das, K. Damodar and N. Bhunia, J. Org. Chem. 2009, 74, 5607; (d)
G. G. Rajeshwaran, M. Nandakumar, R. Sureshbabu, and A. K.
Mohanakrishnan, Org. Lett. 2011, 13, 1270.
Notes and references
1
(a) K. Xu, F. Yang, G. Zhang and Y. Wu, Green Chem., 2013, 15,
1
055; (b) D. S. Glueck, Top. Organomet. Chem., 2010, 31, 65; (c) C.
S. Demmer, N. K. Larsen and L. Bunch, Chem. Rev., 2011, 111
,
7
981.
13 (a) G. Axelrad, S. Laosooksathit, and R. Engel, J. Org. Chem., 1981,
46, 5200; (b) N. Hall and R. J. Price, J. Chem. Soc., Perkin Trans. 1,
1979, 2634.
2
3
N. G. Ternan, J. W. McGrath, G. McMullan and J. P. Quinn, World
J. Microbiol. Biotechnol., 1998, 14, 635.
2
For palladiumꢀcatalyzed sp hybridized C–P bond formation, see: (a) 14 R. Berrino, S. Cacchi, G. Fabrizi, A. Goggiamani and P. Stabile, Org.
T. Hirao, T. Masunaga, Y. Ohshiro and T. Agawa, Tetrahedron Lett.
,
Biomol. Chem., 2010, 8, 4518.
1
980, 21, 3595; (b) T. Hirao, T. Masunaga, N. Yamada, Y. Ohshiro 15 J. Heinicke, N. Gupta, A. Surana, N. Peulecke, B. Witt, K.
and T. Agawa, Bull. Chem. Soc. Jpn., 1982, 55, 909; (c) D. Gelman,
L. Jiang and S. L. Buchwald, Org. Lett., 2003, , 2315; (d) L. J.
Steihauser, R. R. Bansal, and P. G. Yones, Tetrahedron, 2001, 57,
5
9963.
Gooβen and M. K. Dezfuli, Synlett, 2005, 445; (e) S. Thielges, P. 16 (a) M.Rafiee, S. M. Shoaei and L. Khalafi, Electrochimica Acta,
Bisseret and Eustache, Org. Lett., 2005,
7
, 681; (f ) K. Bravoꢀ
2012, 80, 56; (b) Y. M. Kargin, E. V. Nikitin, O. V. Parakin, G. V.
Romanov and A. N. Pudovik, Phosphorus, Sulfur Silicon Relat.
Altamirano, Z. H. Huang and J. L. Montchamp, Tetrahedron, 2005,
6
1
, 6315; (g) M. Kalek and J. Stawinski, Organometallics, 2007, 26
,
,
Elem., 1980,
8, 55.
5
840; (h) M. Kalek, A. Ziadi and J. Stawinski, Org. Lett., 2008, 10
17 R. A. Dhokale and S. B. Mhaske, Org. Lett., 2013, 15, 2218.
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 5

RSC Advances
Page 6 of 6
View Article Online
ARTICLE
DOI: 10.1039/C4RA07680J
Journal Name
1
8 (a) V. V. Sentemov, E. A. Krasil'nikova and I. V. Berdnik, J. Gen.
Chem. USSR (Engl. Transl.), 1989, 59; 2406; (b) C. Yuan and H.
Feng, Synthesis, 1990, , 140; (c) T. M. Balthazor, and R. C. Grabiak,
2
J. Org. Chem., 1980, 5425; (d) C. Shen, G. Yang, L. Zhang and W.
Zhang, Tetrahedron Lett., 2011, 52, 5032.
2
1
9 For sp hybridized C–P bond formation in water, see: (a) X. H.
Zhang, H. Z. Liu, X. M. Hu, G. Tang, J. Zhu and Y. F. Zhao, Org.
Lett., 2011, 13, 3478; (b) S. M. Rmmelt, M. Ranochiari and J. A.
Bokhoven, Org. Lett., 2012, 14, 2188.
2
2
0 (a) N. Iranpoor, H. Firouzabadi, and S. Motevalli, J. Mol. Cat. A:
Chemical, 2012, 355, 69; (b) N. Iranpoor, H. Firouzabadi, S.
Motevalli, M. Talebi, J. Organomet. Chem., 2012, 708, 118
1 (a) J. H. Li, W. J. Liu and Y. X. Xie, J. Org. Chem., 2005, 70, 5409;
(
b) M. Beller, H. Fischer, K. Kiihlein, C. P. Reisinger and W. A.
Herrmarm, J. Organomet. Chem., 1996, 520, 257; (c) W. J. Liu, Y.
X. Xie, Y. Liang and J. H. Li, Synthesis, 2006, , 860.
2 (a) M. T. Reetz and E. Westermann, Angew. Chem. Int. Ed., 2000,
,165; (b) H, Bonnemann, W. Brijoux, R. Brinkmann, E. T. Denjus,
Angew. Chem., 1991, 103, 1344.
5
2
39
6
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