Synthesis and characterization of tris{2-(N,N-bis(diphenylphosphino) aminoethyl} amine derivatives: Application of a palladium(II) complex as a pre-catalyst in the Heck and Suzuki cross-coupling reactions

Article abstract of DOI:10.1016/j.jorganchem.2008.09.027

The polydendate bis(phosphino)amine, tris{2-(N,N-bis(diphenylphosphino)aminoethyl}amine 1 has been prepared in a single step from the reaction of tris(2-aminoethyl)amine with six equivalents of PPh₂Cl in the presence of NEt₃ in THF.

Full text of DOI:10.1016/j.jorganchem.2008.09.027

Journal of Organometallic Chemistry 693 (2008) 3810–3814
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and characterization of tris{2-(N,N-bis(diphenylphosphino)
aminoethyl} amine derivatives: Application of a palladium(II) complex
as a pre-catalyst in the Heck and Suzuki cross-coupling reactions
*
Murat Aydemir, Akın Baysal , Bahattin Gümgüm
Department of Chemistry, University of Dicle, 21280 Diyarbakır, Turkey
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 6 August 2008
Received in revised form 11 September
The polydendate bis(phosphino)amine, tris{2-(N,N-bis(diphenylphosphino)aminoethyl}amine 1 has been
prepared in a single step from the reaction of tris(2-aminoethyl)amine with six equivalents of PPh
the presence of NEt in THF. Oxidation of 1 with aqueous H , elemental sulfur or grey selenium gave
the corresponding oxide, sulfide or selenide derivatives. [{(P(E)Ph NCH CH N] (E: 2a O, 2b S, 2c Se),
respectively. Reaction of [{(PPh NCH CH N] with 3 equiv. of PdCl (cod) or PtCl (cod) gave the corre-
sponding chelate complexes, [Pd Cl 1] or [Pt Cl 1]. The new compounds were fully characterized by
2
Cl in
3
2 2
O
2
008
2
)
2
2
2 3
}
Accepted 19 September 2008
Available online 27 September 2008
)
2 2
2
2
}
3
2
2
3
6
3
6
NMR, IR spectroscopy and elemental analysis. The catalytic activity of the Pd(II) complex was tested in
the Suzuki coupling and Heck reactions. The Pd(II) complex catalyzed the Suzuki coupling and Heck reac-
tion affording biphenyls and stilbenes, respectively, in high yields.
Keywords:
Bis(phosphino)amine
Complexes
Ó 2008 Elsevier B.V. All rights reserved.
Catalysis
Suzuki coupling
Heck reaction
1
. Introduction
alkylation [15–18], amination [19–21], Heck [22–28], Suzuki
[
29–33], and hydrogenation reactions [34–38].
There is immense interest in the development of new phospho-
During the final quarter of the 20th century, among palladium-
rus(III) ligands for various applications principally those of
homogeneous metal-catalyzed reactions [1]. It is without a doubt
that tertiary mono- and diphosphines are the most extensively
used ligands throughout inorganic and organometallic chemistry
catalyzed coupling processes, reaction of aryl halides with olefins
(the Heck reaction) and with boronic acid (the Suzuki reaction)
have been emerging as favourite methods for formation of C–C
bonds and have found widespread applications in synthetic organ-
ic chemistry and materials science [39]. The popularity stems in
part from their tolerance of many functional groups, which allows
them to be employed in the synthesis of highly complex molecules
[40].
[
2–6]. The coordination chemistry of bis(phosphino)amines,
RN(PR , has attracted considerable interest in recent years, due
to their chemical and structural proximity to the widely used
Ph PCH PPh , [bis(diphenylphosphino)methane] [7,8]. Compared
2 2
)
2
2
2
to diphosphines with the P–C–P linkage, bis(phosphine)amines
P–N–P skeletons have proved to be much more versatile ligands,
and varying the substituents on both the P- and N-centers gives
rise to changes in the P–N–P angle and conformation around the
P-centers [9,10]. Small variations in these ligands can cause signif-
icant changes in their coordination behaviour and the structural
features of the resulting complexes [11]. This feature enables the
synthesis of a wide range of four membered ring systems contain-
ing transition metals such as Cu, Mo, Ni, Pd, Pt and Ru which have
potential uses in catalysis [12–14]. There has been recently an
increasing interest in the synthesis of new and highly active tran-
sition metal based catalysts derived from aminophosphines which
can be used in different catalytic reactions including allylic
Herein, we describe the synthesis of a new bis(phosphino)-
amine ligand and the corresponding oxides and transition metal
complexes {Pd(II) and Pt(II)}. The compounds were fully character-
ized by elemental analysis, IR, C NMR, H NMR, P-{ H} NMR
spectroscopy. We also report on the catalytic activity of Pd(II) com-
plex of 1 as a pre-catalyst in the Heck and Suzuki cross-coupling
reactions.
1
3
1
31
1
2. Results and discussion
Several methods have been developed for the synthesis of
phosphinoamines and bis(phosphino)amines, and aminolysis
seems to be most commonly used [41]. The new hexadentate
phosphinoamine was prepared from the commercially available
starting material tris(2-aminoethyl)amine by the aminolysis
*
Corresponding author.
E-mail address: akinb@dicle.edu.tr (A. Baysal).
0
022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.09.027

M. Aydemir et al. / Journal of Organometallic Chemistry 693 (2008) 3810–3814
3811
method [42–45]. It has been found that the solvent has a signifi-
cant influence on the reaction rate and on the reaction product.
139.7 ppm (d, 1J(31P-13C) 13.0 Hz, i-carbons of phenyls), 132.8 ppm
2
(d,
J(31P13C) 21.0 Hz, o-carbons of phenyls), 128.5 ppm (d,
3
[
{(PPh
2
) NCH
2
2
2
CH }
3
N] was prepared by the aminolysis method
J
(31P13C) 6.0 Hz, m-carbons of phenyls) and 128.8 ppm (s, p-car-
bons of phenyls), together with two resonances at 55.3 ppm
(NCH CH NPPh ) and 50.9 ppm (NCH CH NPPh ) for methylene
using diethyl ether or toluene as a solvent. However, this synthesis
route requires 24–36 h stirring at room temperature. With THF as a
solvent for the synthesis of 1, the reaction was completed in 3 h at
room temperature. THF is also a more-appropriate solvent for this
aminolysis reaction because of the fact that all the components
formed in the reaction are soluble in the reaction media, also
2
2
2
2
2
2
carbons. The structure of 1 was further confirmed by using IR spec-
troscopy and microanalysis, and found to be in good agreement
with the theoretical values.
Oxidation of 1 with aqueous hydrogen peroxide, elemental sul-
fur or grey selenium gave the corresponding oxide 2a, sulfide 2b or
selenide 2c derivatives, respectively (Scheme 1). With the excep-
31
allowing the reaction to be monitored by P-{H} NMR spectros-
copy. In a typical reaction, 6 equiv. of PPh Cl were added slowly
to a THF solution of [{H NCH CH N] containing Et N to afford
NCH CH N] 1
2
31
2
2
2
}
3
3
tion of 2a (d 31.7 ppm) there is a negligible change in P chemical
1
the hexzadendate bis(phosphino)amine [{(PPh
2
)
2
2
2
}
3
shift upon oxidation (d 69.6 ppm for 2b, d 67.5 ppm, J(PSe) = 775 Hz
in high yield (93.5%) (Scheme 1). The 31P-{H} NMR spectrum of
the reaction solution shows a singlet resonance at 62.0 ppm for
for 2c). As expected, the oxidation reaction using aqueous hydro-
gen peroxide was very rapid for 2a and takes place at ambient con-
ditions spontaneously. In addition a small amount of hydrolysis
3
1
1, indicating that all of the six P-atoms are equivalent. The P-
{
H} NMR spectrum also displays two doublets at 16.5 ppm and
product Ph
2
P(O)H formed as evidenced by the signal at about
1
31
I
À21.3 ppm with a
of iminobiphosphine [N(CH
tion, formation of PPh PPh
J
(PP) value of 282 Hz indicating the formation
N@PPh –PPh ] structure. In addi-
and P(O)Ph PPh were observed, as
20.0 ppm in the P-{ H} NMR spectra. The structures of the oxi-
1
13
2
)
2
2
2
dized derivatives 2a–c were further confirmed by H, C NMR,
IR spectroscopy and also microanalysis, and found to be in good
agreement with the theoretical values.
The coordination chemistry of 1 with selected transition-metals
2
(Pd and Pt) was explored. Reaction of 1 with MCl (cod) (where
2
2
2
2
indicated by signals at d À14.3 ppm as singlet and d 34.4 ppm
1
and d À23.7 ppm as doublets with J(PP) 220 Hz, respectively. These
by products were easily eliminated by washing the solid residue
with copious amounts of dry diethyl ether. Solution of 1 in CDCl
prepared under anaerobic conditions, is unstable and decompose
gradually to give oxide [{(P(O)Ph NCH CH N] and bis(diphen-
ylphosphino)monoxide [P(O)Ph PPh ] derivatives. 1 is also not sta-
3
,
M = Pd, Pt; cod = 1,5-cyclooctadiene) in THF afforded the corre-
sponding metal(II) complexes 3a and 3b in high yields (90%) and
(86%), respectively (Scheme 1). In both complexes 3a and 3b, coor-
dination to the metal center takes place preferentially at the phos-
2
)
2
2
2 3
}
2
2
3
1
I
ble in the solid state and decomposes rapidly on exposure to air or
moisture.
phorus atoms. The P-{ H} NMR spectra 3a and 3b displayed
singlets at 30.7 ppm and 16.9 ppm in DMSO, respectively. The
chemical shifts of 3a and 3b are similar and within the expected
range of other reported structurally similar complexes [46–49].
1
In the H NMR spectrum of 1, both of the methylene groups ap-
3
pear as triplets at 1.80 ppm (NCH
2
CH
2
NPPh
2
,
J
(H–H) 7.6 Hz) and
3
13
31 195
3
.59 ppm (NCH
2
2 2
CH NPPh ,
J
(H–H) 8.0 Hz). In addition, in the
C
For Pt complexes 3b, the P- Pt coupling constant (3400 Hz)
1
NMR spectrum the ligand displays four aromatic resonances at
agrees with cis ligand arrangement [50]. In the H NMR spectra
NH2
N
H N
2
NH2
(i)
PPh2
N
PPh2
PPh2
N
N
N
Ph2P
Ph2P
PPh2
Cl
E
1
Ph2P
Ph2P
N
M
(ii)
(iii)
Cl
N
E
PPh2
P
Ph
Cl
M
2
E
PPh2
N
PPh
2
N
Cl
E
N
N
N
N
P
Ph2P
PPh2
E
Ph
2
P
Ph
P
2
PPh2
Cl
Ph
2
E
M
Cl
M: Pd 3a, Pt 3b
E:
O
2a, S 2b, Se 2c
Scheme 1. Synthesis of tris{2-(N,N-bis(diphenylphosphino)aminoethyl)amine} and its derivatives.(i) Ph
M = Pd or Pt), THF.
2 2 2 2
PCl, THF; (ii) H O , elemental S or grey Se, THF; (iii) [MCl [cod)]
(

3
812
M. Aydemir et al. / Journal of Organometallic Chemistry 693 (2008) 3810–3814
of 3a and 3b, the chemical shifts of the both of the CH
slightly shifted to lower field with respect to the free ligand. Char-
2
groups were
aryl bromides bearing electron-donating and electron-withdraw-
ing groups reacted with styrene, affording the coupled products
in excellent yields. As expected, electron-deficient bromides were
beneficial for the conversions (Table 2).
acteristic J(31P-13C) coupling constants of the carbons of the phenyl
13
rings were observed in the C NMR spectra, which are consistent
with the literature values [51,52]. The complexes 3a and b could
be isolated as analytically pure solid materials and fully character-
ized by IR spectroscopy and microanalysis as well, and found to be
in good agreement with the theoretical values.
5
. Conclusion
In summary, a versatile and inexpensive bis(phosphino)amine
ligand 1 and its derivatives including oxide, sulfide and selenide,
as well as transition metal complexes containing Pd(II), Pt(II) cen-
ters were synthesized. All of these new compounds were charac-
terized using NMR, IR spectroscopy and microanalysis. Complex
1 is a precursor for the different functionalization of aryl halides,
in particular aryl bromides for Suzuki and Heck reaction. The cata-
lytic behaviour of the 3a was investigated in Suzuki coupling and
Heck reactions. Because of the strength of the Pt–C bonds, Pt(II)-
bis(phosphine)amine system 3b exhibited no catalytic activity
[53], but with Pd(II) complex, depending on the type of coupling
reaction, excellent yields of the desired products were obtained.
In general, 1-based catalyst appears to be more efficient for the
Heck reactions of aryl bromides, but its activity is much lower
for the coupling of aryl chlorides (05–20%). The complex 3a dis-
played relatively higher activity with electron-withdrawing sub-
stituents than electron-donating substituents on the aryl
bromides in both reactions.
3
. The Suzuki coupling
In order to survey the reaction parameters for the catalytic Su-
t
zuki reaction, we examined Cs
DMF and dioxane as solvent. We found that the reaction performed
in dioxane, with Cs CO as the base at 70 °C for 1 h appeared to be
best. We initially tested the catalytic activity of the complex 3a for
the coupling of p-bromoacetophenone with phenylboronic acid
and the control experiments showed that the coupling reaction
did not occur in the absence of the catalyst. Under these conditions,
p-bromoacetophenone, p-bromobenzaldehyde, p-bromobenzene,
p-bromoanisole and p-bromotoluene react with phenylboronic
acid in high yields (Table 1).
2
CO
3 2
, K CO
3
and K OBu as base and
2
3
4
. The Heck coupling
Generally, Heck reaction conducted with tertiary phosphine
complexes requires high temperatures (higher than 120 °C) and
polar solvents. For the choice of base, we surveyed Cs CO , K CO
and K OBu. Finally, we found that use of 0.01 mmol (1%) 3a and
equiv. of K CO in DMF at 100 °C led to the best conversion with-
6. Experimental
2
3
2
3
t
All reactions and manipulations were performed under argon
unless otherwise stated. Ph PCl and tris(2-aminoethyl)amine were
2
2
2
3
in 1 h. We initially tested the catalytic activity 3a for the coupling
of 4-bromoacetophenone with styrene and a control experiment
indicated that the coupling reaction did not occur in the absence
of 3a. Under the determined reaction conditions, a wide range of
purchased from Fluka and used directly. Analytical grade and deu-
terated solvents were purchased from Merck. The starting materi-
als [MCl (cod)] (M = Pd, Pt; cod = 1,5-cyclooctadiene) were
2
prepared according to literature procedures [54–55]. Solvents were
Table 1
The Suzuki coupling reactions of aryl bromides with phenylboronic acid
0.01 mmol (1 %) Pd
B(OH)2
Br
R
R
Dioxane, 70 oC, 1.0 h
Cs CO (2 equiv.)
2
3
Entry
R
Conversion (%)
Yield (%)
1
2
3
4
5
COCH
CHO
H
3
96.4
98.0
63.3
60.6
74.6
94.8
98.3
61.6
59.7
71.3
OCH
CH
3
3
Reaction conditions: 1.0 mmol of p-R-C
6
H
4
Br aryl bromide, 1.5 mmol of phenylboronic acid, 2.0 mmol Cs
2
CO
3
, 0.01 mmol (1%) Pd (Cat.), dioxane 3.0 (mL). Purity of compounds
was checked by NMR and yields are based on arylbromide. All reactions were monitored by GC; 70 °C. 1.0 h.
Table 2
The Heck coupling reactions of aryl bromides with styrene
0.01 mmol (% 1) Pd
+
Br
R
o
DMF, 100 C, 1.0 h
R
K CO (2 equiv.)
2
3
Entry
R
Conversion(%)
Yield(%)
1
2
3
4
5
COCH
CHO
H
3
94.6
98.7
71.3
56.3
70.8
90.6
96.3
87.7
55.3
60.4
OCH
CH
3
3
6 4 2 3
Reaction conditions: 1.0 mmol of p-R-C H Br aryl bromide, 1.5 mmol of styrene, 2.0 mmol K CO , 0.01 mmol (1%) Pd (Cat.), DMF 3.0 (mL). Purity of compounds was checked by
NMR and yields are based on arylbromide. All reactions were monitored by GC; 100 °C, 1.0 h.

M. Aydemir et al. / Journal of Organometallic Chemistry 693 (2008) 3810–3814
3813
dried using the appropriate reagents and distilled prior to use.
Infrared spectra were recorded as KBr pellet in the range 4000–
After allowing mixture to cool room temperature, the white solid
2b was collected by suction filtration and dried in vacuum (yield:
À1
1
1
4
00 cm on a Mattson 1000 ATI UNICAM FT-IR spectrometer.
H
0.19 g, 82.3%); mp.: 135–137 °C). H NMR (CDCl
3
) d (ppm): 7.79
1
3
31
1
(400.1 MHz), C NMR (100.6 MHz) and P-{ H} NMR spectra
162.0 MHz) were recorded spectra on a Bruker Avance 400 spec-
(dd, 24H, J = 7.2 and 14.2 Hz, o-protons of phenyls), 7.37 (t, 12H,
J = 6.8 Hz, p-protons of phenyls), 7.28 (br, 24H, m-protons of
(
3
trometer, with d referenced to external TMS and 85% H
3
PO4,
phenyls), 3.13 (t, 6H,
J
H–H = 7.0 Hz, NCH
2
CH
2
NPPh
2
), 1.86 (t, 6H,
) d (ppm):
3
13
1
respectively. GC analyses were performed on a HP 6890N Gas
Chromatograph equipped with capillary column (%5 biphenyl,
J
H–H = 7.2 Hz, NCH
2
CH
2
2
NPPh ). C-{ H} NMR (CDCl
3
1
138.9 (d,
J31P-13C = 16.2 Hz, i-carbons of phenyls), 132.2 (d,
J31P-13C = 11.0 Hz, o-carbons of phenyls), 131.5 (s, p-carbons of
2
%
95 dimethylsiloxane) (30 m  0.32 mm  0.25
l
m). Elemental
3
analysis was carried out on a Fisons EA 1108 CHNS-O instrument;
melting points by Gallenkamp Model apparatus with open
capillaries.
phenyls), 127.8 (d,
J
31P-13C = 14.3 Hz, m-carbons of phenyls), 52.9
CH NPPh ), assignment was based
(NCH CH NPPh ), 47.2 (NCH
2
2
2
2
2
2
1
1
13
31
on the H- C HETCOR spectrum. P-{ H} NMR (CDCl
3
) d (ppm):
À1
6
9.6 (s). Selected IR,
t
(cm ): 871 (P–N–P), 1438 (P–Ph), 647
6.1. Synthesis of tris{2-(N,N-bis(diphenylphosphino)amino-
(P@S). C78
H
72
N
4
6
P O
6
: Calc. C, 64.89; H, 5.03; N, 3.88. Found: C,
ethyl)amine} 1
64.55; H, 4.73; N, 3.60%.
Chlorodiphenylphosphine (2.74 g, 11.76 mmol) was added
dropwise over a period 10 min to a solution of tris(2-amino-
ethyl)amine (0.29 g, 1.96 mmol) and triethylamine (1.21 g,
6.4. Synthesis of tris{2-(N,N-bis(diphenylselenophosphino)amino-
ethyl)amine} 2c
1
1.76 mmol) in THF (50 mL) at room temperature with vigorous
2 2 2 2 3
[{(PPh ) NCH CH } N] (0.20 g, 0.16 mmol) and grey selenium
stirring. The mixture was stirred at room temperature for 3 h,
and then the white precipitate (triethylamine hydrogen chloride)
was filtered off under argon and the solvent removed in vacuum.
The remaining solid was washed with cold diethyl ether
(0.08 g, 0.96 mmol) were heated to reflux in THF (25 mL) for 2 h.
After allowing mixture to cool room temperature the dirty white
solid 2c was collected by suction filtration and dried in vacuum
1
(yield: 0.24 g, 87.0%); mp.: 189–191 °C). H NMR (CDCl
3
) d
(
3 Â 15 mL) and dried in vacuum to produce a clear, white solid
(ppm): 7.79 (dd, 24H, J = 7.1 and 13.2 Hz, o-protons of phenyls),
7.36 (d, 12H, J = 7.2 Hz, p-protons of phenyls), 7.27 (br, 24H, m-pro-
1
compound 1 (yield: 2.32 g, 93.5%); mp. 71–73 °C). H NMR (CDCl
(ppm): 7.32 (m, 24H, o-protons of phenyls), 7.29 (d, 12H,
J = 2.0 Hz, p-protons of phenyls), 7.26 (br, 24H, m-protons of
phenyls), 3.01 (t, 6H, J = 8.0 Hz, NCH CH NPPh ), 1.80 (t, 6H,
). C-{ H} NMR (CDCl ) d (ppm):
31P-13C = 13.0 Hz, i-carbons of phenyls), 132.8 (d,
31P-13C = 21.0 Hz, o-carbons of phenyls), 128.8 (s, p-carbons of
3
)
3
d
tons of phenyls), 3.42 (t, 6H,
J
H–H = 7.4 Hz, NCH
2
CH
). C-{ H} NMR (CDCl
31P-13C = 15.4 Hz, i-carbons of phenyls), 133.5
31P-13C = 5.7 Hz, o-carbons of phenyls), 131.6 (s, p-carbons of
2
NPPh
2
), 2.03
3
13
1
(t, 6H,
J
H–H = 7.0 Hz, NCH
2
CH
2
NPPh
2
3
) d
1
2
2
2
(ppm): 140.1 (d, J
3
13
1
2
J
H–H = 7.6 Hz, NCH
2
CH
2
NPPh
2
3
(t,
phenyls), 127.8 (t,
(NCH CH NPPh ), 50.0 (NCH
on the H- C HETCOR spectrum. P-{ H} NMR (CDCl
J
1
3
1
39.7 (d,
J
J
31P-13C = 6.5 Hz, m-carbons of phenyls), 53.0
CH NPPh ), assignment was based
2
J
2
2
2
2
2
2
1
3
1
13
31
phenyls), 128.5 (d,
(
on the H- C HETCOR spectrum. P-{ H} NMR (CDCl
6
C
5
J
31P-13C = 6.0 Hz, m-carbons of phenyls), 55.3
CH NPPh ), assignment was based
3
) d (ppm):
PSe: 775 Hz). Selected IR, (cm ): 869 (P–N–P), 1439
6
Se : Calc. C, 54.31; H, 4.21; N,
1
À1
NCH CH NPPh ), 50.93 (NCH
2
2
2
2
2
31
2
1
67.5 (s,
J
t
1
13
3
) d (ppm):
(cm ): 869 (P–N–P), 1439 (P–Ph).
(P–Ph), 561 (P@Se). C78
H
72
N
4
P
6
À1
2.0 (s). Selected IR,
t
3.25. Found: C, 53.89; H, 3.95; N, 3.01%.
78
H
72
N
4
6
P : Calc. C, 74.87; H, 5.80; N, 4.48. Found: C, 74.51; H,
.52; N, 4.17%.
6.5. Synthesis of tris{2-(N,N-bis(diphenylphosphino)aminoethyl)-
amine}tripalladium(II) chloride, 3a
6.2. Synthesis of tris{2-(N,N-bis(diphenyloxophosphino)aminoethyl)-
amine} 2a
2 2 2 2 2 3
[Pd(cod)Cl ] (0.17 g, 0.60 mmol) and [{(PPh ) NCH CH } N]
(
0.25 g, 0.20 mmol) were dissolved in THF (25 mL) and stirred for
Aqueous hydrogen peroxide (30%, w/w, 0.09 mL, 0.96 mmol)
was added drop wise to a suspension of [{(PPh NCH CH N]
0.20 g, 0.16 mmol) in THF and the mixture was stirred for 2 h at
room temperature. The volume was concentrated in vacuum to
ca. 1–2 mL and addition n-hexane (25 mL) gave 2a as a white solid
1 h at room temperature. The volume was concentrated to ca. 1–
2 mL under reduced pressure and addition of diethyl ether
(20 mL) gave as 3a yellow solid. The product was collected by suc-
tion filtration and dried in vacuum (yield: 0.32 g, 89.8%); mp.: 181–
2
)
2
2
2 3
}
(
1
182 °C). H NMR (DMSO) d (ppm): 7.72 (dd, 24H, J = 7.6 and
which was collected by suction filtration (yield: 0.18 g, 83.6%); mp.
16.0 Hz), 7.59 (br, 12H, p-protons of phenyls), 7.45 (br, 24H, m-pro-
1
3
1
1
2
19–121 °C). H NMR (CDCl
1.2 Hz), 7.41 (t, 12 Hz, J = 7.0 Hz, p-protons of phenyls), 7.31 (d,
3
) d (ppm): 7.73 (dd, 24H, J = 6.4 and
tons of phenyls), 3.11 (t, 6H,
J
H–H = 7.2 Hz, NCH
2
CH
). C-{ H} NMR (DMSO) d
31P–13C = 14.6 Hz, i-carbons of phenyls), 133.5
(s, o-carbons of phenyls), 128.9 (s, m-carbons of phenyls), 54.9
(NCH CH NPPh ), 46.3 (NCH CH NPPh ), assignment was based
2 2
NPPh ), 2.09
3
13
1
(t, 6H,
(ppm): 139.7 (d, J
2 2 2
JH–H = 7.4 Hz, NCH CH NPPh
3
1
4H, J = 6.8 Hz, m-protons of phenyls), 2.93 (t, 6H,
CH NPPh H–H = 7.6 Hz, NCH CH
). 1.94 (t, 6H, 3
H} NMR (CDCl ) d (ppm): 139.3 (d, 31P-13C = 12.6 Hz, i-carbons
of phenyls), 132.5 (d, 31P-13C = 17.7 Hz, o-carbons of phenyls),
31.3 (s, p-carbons of phenyls), 128.7 (d, J31P-13C = 10.8 Hz, m-car-
bons of phenyls), 53.4 (NCH CH NPPh ), 44.5 (NCH CH NPPh ),
J
H–H = 8.0 Hz,
13
NCH
2
2
2
J
2
2 2
NPPh ). C-
1
1
{
3
J
2
2
2
2
2
2
1
2
1
13
31
J
on the H- C HETCOR spectrum. P-{ H} NMR (DMSO) d (ppm):
3
À1
1
30.7 (s). Selected IR,
Pd Cl
t
(cm ): 862 (P–N–P), 1439 (P–Ph).
2
2
13
2
2
2
31
2
C
78
H
72
N
4
P
6
3
6
: Calc.: C, 52.54; H, 4.07; N, 3.14. Found: C,
1
1
assignment was based on the H- C HETCOR spectrum. P-{ H}
52.11; H, 3.69; N, 2.92%.
À1
NMR (CDCl
P), 1447 (P–Ph), 1200 (P@O). C78
.39; N, 4.16. Found: C, 69.17; H, 5.10; N, 3.93%.
3
) d (ppm): 31.7 (s). Selected IR,
t
(cm ): 912 (P–N–
H
72
N
4
6
P O
6
: Calc. C, 69.54; H,
6.6. Synthesis of tris{2-(N,N-bis(diphenylphosphino)aminoethyl)-
amine}triplatinum(II)chloride, 3b
5
6.3. Synthesis of tris{2-(N,N-bis(diphenylthiophosphino)aminoethyl)-
2 2 2 2 2 3
[Pt(cod)Cl ] (0.22 g, 0.60 mmol) and [{(PPh ) NCH CH } N]
amine} 2b
(0.20 g, 0.20 mmol) were dissolved in dry THF (25 mL) and stirred
for 1 h. The volume was concentrated to ca. 1–2 mL by evaporation
under reduced pressure and addition of diethyl ether (20 mL) affor-
ded 3b as a white solid. The product was collected by suction filtra-
[
2 2 2 2 3
{(PPh ) NCH CH } N] (0.20 g, 0.16 mmol) and elemental sulfur
(
0.04 g, 0.96 mmol) were heated to reflux in THF (25 mL) for 2 h.

3
814
M. Aydemir et al. / Journal of Organometallic Chemistry 693 (2008) 3810–3814
tion and dried in vacuum (yield: 0.35 g, 85.5%; mp.: >300 °C). 1H
NMR (DMSO) d (ppm): 7.41–7.68 (m, 60H, o,m,p-protons of phen-
yls), 3.08 (t, 6H, NCH CH NPPh ), 2.15 (br, 6H, NCH CH NPPh ).
2 2 2 2 2 2
[9] R. Keat, I.M. Muir, K.W. Muir, D.S. Ryscroft, J. Chem. Soc., Dalton Trans. (1972)
189.
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Sulfur 26 (1986) 155.
2
[
1
3
1
C-{ H} NMR (DMSO) d (ppm): 139.8 (s, i-carbons of phenyls),
32.9 (s, o-carbons of phenyls), 130.6 (s, p-carbons of phenyls),
[11] P. Bhattacharrya, J.D. Woollins, Polyhedron 14 (1995) 3367.
[
[
[
12] Z. Fei, R. Scopelliti, P.J. Dyson, J. Chem. Soc., Dalton Trans. 42 (2003) 2125.
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1
1
29.8 (s, m-carbons of phenyls), 54.2 (NCH
2 2 2
CH NPPh ), 43.5
1
13
(
NCH
2
CH NPPh ), assignment was based on the H- C HETCOR
2
2
1
3
1
1
spectrum. P-{ H} NMR (DMSO) d (ppm): 16.9 (s,
Selected IR,
J
H
PPt: 3400 Hz).
Pt Cl
[
[
À1
t
(cm ): 875 (P–N–P), 1440 (P–Ph). C78
72
N
4
P
6
3
6
:
Calc. C, 45.72; H, 3.54; N, 2.73. Found: C, 45.43; H, 3.27; N, 2.52%.
[18] T. Mino, Y. Tanaka, T. Yabusaki, D. Okumara, M. Sakamoto, T. Fujita,
Tetrahedron: Asymmetr. 14 (2003) 2503.
[
[
[
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7
. General procedure for the Suzuki coupling reaction
6
1 (2005) 9822.
Bis(phosphino)amine-palladium complex {3a, 0.01 mmol}, aryl
[
[
22] M.T. Reetz, G. Lohmer, R. Schwickardi, Angew. Chem., Int. Ed. 36 (1997) 1526.
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2 3
CO
(
2 mmol), dioxane (3 mL) were added to a small Schlenk tube in ar-
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[
[
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gon atmosphere and the mixture was heated at 70 °C for 1.0 h.
After completion of the reaction, the mixture was cooled, extracted
with ethyl acetate/hexane (1:5), filtered through a pad of silicagel
with copious washing, concentrated and purified by flash chroma-
tography on silica gel. The purity of the compounds was checked
by GC and NMR and yields are based on aryl bromide.
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[
28] D.L. Zotto, E. Zangrando, W. Baratta, A. Felluga, P. Martinuzzi, P. Rigo, Eur. J.
Inorg. Chem. (2005) 4707.
[
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[
[
[
[
[
[
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8
. General procedure for the Heck coupling reaction
Bis(phosphino)amine-palladium complex {3a, 0.01 mmol}, aryl
bromide (1.0 mmol), styrene (1.5 mmol), K
2 3
CO (2 mmol), DMF
(
2004) 2159.
(
3 mL) were added to a small Schlenk tube in argon atmosphere
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[
[
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and the mixture was heated to 100 °C for 1.0 h. After completion
of the reaction, the mixture was cooled, extracted with ethyl ace-
tate/hexane (1:5), filtered through a pad of silicagel with copious
washing, concentrated and purified by flash chromatography on
silica gel. The purity of the compounds was checked by GC and
NMR and yields are based on aryl bromide.
4
[39] A.F. Littke, G.C. Fu, Angew. Chem., Int. Ed. Eng. 41 (2002) 4176.
[
[
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1
492.
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2
[
[
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Acknowledgement
(
2004) 1243.
[45] M.S. Balakrishna, D. Suresh, P.P. George, T. Joel, J.T. Mague, Polyhedron 25
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We would like to thank Dicle University Research Fund (Project
No: DUAPK- 05-FF-27) for financial support.
(
[
[
[
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