Synthesis of functional tripodal phosphines with amino and ether groups by the hydrophosphination of trivinyl ethers with secondary phosphines

Article abstract of DOI:10.1055/s-0033-1340497

A one-pot, atom-economic, metal- and halogen-free synthesis of functional triphosphines with nitrogen and (or) oxygen atoms as additional weaker coordinating sites (new hemilabile ligands) through exhaustive addition of secondary phosphines to available trivinyl ethers of aminotriols and triols has been developed. The reaction proceeds under free-radical conditions (UV irradiation or AIBN, with 3:1 reactant molar ratio) to give chemo- and regioselectively anti-Markovnikov triadducts to all three vinyloxy groups in good to excellent yields. Georg Thieme Verlag Stuttgart New York.

Full text of DOI:10.1055/s-0033-1340497

PAPER
▌653
paper
Synthesis of Functional Tripodal Phosphines with Amino and Ether Groups by
the Hydrophosphination of Trivinyl Ethers with Secondary Phosphines
Functional Tripodal Phosphines with Amino and Ether Groups
Ludmila A. Oparina, Nina K. Gusarova, Oksana V. Vysotskaya, Alexander V. Artem’ev, Nikita A. Kolyvanov,
Boris A. Trofimov*
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 1 Favorsky Str., 664033 Irkutsk,
Russian Federation
Fax +7(395)2419346; E-mail: boris_trofimov@irioch.irk.ru
Received: 17.10.2013; Accepted after revision: 09.12.2013
yet described. One of the most straightforward and prom-
Abstract: A one-pot, atom-economic, metal- and halogen-free syn-
ising strategies through which to achieve the synthesis of
thesis of functional triphosphines with nitrogen and (or) oxygen
these ligands might be the exhaustive addition of second-
ary phosphines to trivinyl ethers of triols.
atoms as additional weaker coordinating sites (new hemilabile li-
gands) through exhaustive addition of secondary phosphines to
available trivinyl ethers of aminotriols and triols has been devel-
oped. The reaction proceeds under free-radical conditions (UV irra-
diation or AIBN, with 3:1 reactant molar ratio) to give chemo- and
regioselectively anti-Markovnikov triadducts to all three vinyloxy
groups in good to excellent yields.
Here, we report on the radical addition of available sec-
ondary phosphines 1–6, which are easily prepared from
elemental phosphorus and aryl(or hetaryl)ethenes,15 to
trivinyl ethers of aminotriols 7, 8 and triols 9–11. These
trivinyl ethers were chosen because they are efficiently
prepared by vinylation of the corresponding triols with
acetylene in superbases of the type KOH/dimethyl sulfox-
ide (DMSO).16
Key words: addition, alkenes, radical reaction, ligands, phosphor-
ylation
We have found that bis(aralkyl)phosphines 1 and 2 can be
exhaustively added to N,N,N-tris[2-(vinyloxy)eth-
yl]amine (7) in the presence of a radical initiator (AIBN,
65 °C, 60 h, 1,4-dioxane, argon, the 3:1 reactant molar ra-
tio) in an anti-Markovnikov manner to afford triphos-
phines 12а and 12b, respectively, with amino and ether
groups, in almost quantitative yields (Scheme 1). Notably,
the reaction proceeds chemo- and regioselectively, and
none of the corresponding mono-, di- or Markovnikov ad-
ducts, or cyclization or telomerization products were ob-
served (1H and 31P NMR analysis) under these conditions.
Tripodal multidentate phosphines exhibit rich and diverse
coordination chemistry and, as such, they have found an
integral place in inorganic and organometallic chemis-
try.1–3 Among these phosphines, 1,1,1-tris(diphe-
nylphosphinomethyl)ethane (triphos) is a versatile ligand
that can be used with transition metals in a variety of oxi-
dation states.2 Its complexes have been applied in the area
of catalysis, for example in hydrogenation of esters,4
alkenes5 and other substrates.6,7 Tripodal terdentate phos-
phines act as ligands in Ru-catalyzed C–O bond cleavage
in lignin8 and dehydrogenation of formic acid (as potential
hydrogen storage compound).9 In addition, these ligands
are found to be active stabilizers for noble metal nanopar-
ticles having a small core diameter (< 4 nm) and narrow
size distribution.10,11 Such nanoparticles show good to ex-
cellent catalytic activities for various synthetically impor-
tant C–C coupling reactions, namely Suzuki, Heck, and
Sonogashira, which are widely used in organic synthe-
sis.11
R
O
O
R
N
P
O
AIBN
O
N
P
R
3 R2PH
+
R
1,4-dioxane
65 °C, 60 h
R
R
1, 2
P
O
O
7
12a R = Ph(CH2)2, 96%
12b R = 4-t-BuC6H4(CH2)2, 94%
Over the last decades, research interest has increasingly
focused on polydentate ligands with phosphorus and other
donor atoms such as oxygen and nitrogen (P,O-,12 P,N-,13
and P,N,O-ligands14). In these compounds, the metal cen-
ter is bounded by phosphorus atom, and weak interactions
with the other heteroatom (N or O) ensures additional sta-
bilization of the complexes (hemilable ligands).14 Howev-
er, the synthesis of such polydentate ligands presents
some difficulties. To our knowledge, functional triphos-
phines containing amino and ether groups have not been
Scheme 1 Exhaustive free-radical addition of secondary phosphines
1 and 2 to N,N,N-tris[2-(vinyloxy)ethyl]amine (7)
Under similar conditions (AIBN, 75 °C, 72 h, benzene,
argon), bis(aralkyl)phosphines 1 and 3 react with the trivi-
nyl ether of aminotriol 8 at a 3:1 molar ratio to give anti-
Markovnikov triadducts 13а and 13b, respectively, in 92
and 86% yield (Scheme 2).
The efficacy and generality of the elaborated strategy was
confirmed by the synthesis of functional triphosphines
with ether groups by the exhaustive free-radical addition
of secondary phosphines to trivinyl ethers of triols 9–11.
Indeed, the free-radical initiation (UV irradiation or
SYNTHESIS 2014, 46, 0653–0659
Advanced online publication: 08.01.2013
0
0
3
9
-
7
8
8
1
1
4
3
7
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2
1
0
X
DOI: 10.1055/s-0033-1340497; Art ID: SS-2013-Z0684-OP
© Georg Thieme Verlag Stuttgart · New York

654
L. A. Oparina et al.
PAPER
nyl ethers of diols17 and the tetravinyl ether of
pentaerithritol.18
O
O
NH2
AIBN
3 R2PH
1, 3
+
benzene
75 °C, 72 h
The high chemo- and regioselectivity of the hydrophos-
phination found deserves special consideration. Indeed, as
noted above, neither expected cyclizations nor oligomer-
izations were discernible in this hydrophosphination.
However, in contrast to these results, it was reported that
free-radical hydrophosphorylation of divinyl ethers of di-
oles with dialkylphosphites under similar conditions
(AIBN, 67–70 °C) resulted in the formation of cyclic
products (ca. 50% yield), and macrocyclic and linear
phosphorus-containing telomeres.19 Furthermore,20 free-
radical addition of diethyl thiophosphite to diallyl ether
(AIBN, 60 °C, THF) proceeds as exclusive cyclization to
yield O,O-diethyl (4-methyltetrahydro-3-furanyl)methyl-
thiophosphonate. This occurs because initial intermediate
radical-adducts preferentially attack the neighboring dou-
ble bonds instead of abstracting a hydrogen radical from
the phosphite molecule. The astonishing full inhibition of
the side cyclization and telomerization reactions during
the hydrophosphination with secondary phosphines may
be rationalized in terms of the spin exchange between the
radical center and lone electron pair of the phosphine moi-
ety in the initial intermediate radical-adduct A (Scheme
3). Such a through-space interaction may preclude attack
of the intermediate A on the neighboring double bonds,
instead of abstracting the hydrogen atom from the P–H
bond. Since dialkylphosphites do not have the lone elec-
tron pair on the phosphorus atom, they cannot participate
in the above spin-exchange. Additionally, the P–H bond
homolization energy in dialkylphosphites is much higher
than that of phosphines (365 and 319 kJ/mol, respective-
ly).21 Therefore, in case of hydrophosphination, transfer
O
8
R
P
R
O
R
O
O
NH2
R
P
R
P
R
13a R = Ph(CH2)2, 92%
13b R = 4-t-BuOC6H4(CH2)2, 86%
Scheme 2 Synthesis of triphosphines with NH2 and ether groups
from secondary phosphines 1 and 3, and the trivinyl ether of amino-
triol 8
AIBN) proved to be effective for the full hydrophosphina-
tion of glycerol trivinyl ether 9 with a diverse range of sec-
ondary phosphines 1 and 4–6, bearing aralkyl, hetaralkyl,
and phenyl substituents, to afford anti-Markovnikov triad-
ducts 14a–d in 80–90% yield (Table 1). The reaction time
was 9 hours in the case of UV irradiation (Table 1, entries
1 and 3), and 24–53 hours when AIBN was employed
(Table 1, entries 2, 4, and 5).
Triphosphines 15a–d with ether groups have likewise
been synthesized in high yields by the reaction of trivinyl
ethers of triols (10 or 11) with bis(aralkyl)phosphines 1 or
3 in the presence of AIBN (Table 2). A preliminary appli-
cation of this strategy was reported with examples of divi-
Table 1 Exhaustive Free-Radical Addition of Secondary Phosphines 1 and 4–6 to the Trivinyl Ether of Glycerol 9a
R
O
O
P
R
P
O
O
R
UV or AIBN
O
P
O
3 R2PH
1, 4–6
+
R
R
R
14a–d
9
Entry
Phosphine
R
Initiator
Solvent
Temp (°C)
Time (h)
14
Yield (%)b
1
2
1
1
(CH2)2Ph
(CH2)2Ph
UV
1,4-dioxane
none
40с
65
9
14a
14a
90
87
AIBN
24
3
4
UV
1,4-dioxane
40с
9
14b
88
Cl
4
5
5
6
AIBN
AIBN
none
none
65
65
53
48
14c
14d
80
90
O
Ph
a Reaction conditions: phosphine (3 equiv.), 9 (1 equiv), argon, UV irradiation (200 W Hg arc lamp) or AIBN (2 wt% of total reactant mass).
b Isolated yield.
c Heating caused by UV lamp.
Synthesis 2014, 46, 653–659
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Functional Tripodal Phosphines with Amino and Ether Groups
655
Table 2 Exhaustive Free-Radical Addition of Secondary Phosphines 1 and 3 to Trivinyl Ethers 10 and 11a
R1
P
R1
P
O
R1
R1
R1
R2
O
O
R2
AIBN
R1
O
P
H
+
3
benzene
75 °C, 72 h
O
1, 3
O
10, 11
P
R1
15a–d
R1
Entry
Phosphine
R1
Trivinyl ether
R2
Adduct
Yield (%)b
1
2
1
1
(CH2)2Ph
(CH2)2Ph
10
11
Me
Et
15a
15b
88
82
3
4
3
3
10
11
Me
Et
15c
15d
92
90
O
O
a Reaction conditions: phosphine (3 equiv.), 10/11 (equiv.), AIBN (2 wt% of the total reactant mass), 75 °C, 72 h, argon.
b Isolated yield.
of the hydrogen atom from another phosphine molecule applications, particularly as ligands. Moreover, these tri-
on radical A (Scheme 3) appears to be more favorable podal phosphines of hemilabile character will likely be
than intramolecular cyclization of the latter.
used in the design of new metal complexes with diverse
and tunable catalytic activity. These compounds are also
prospective synthetic intermediates. For instance, triphos-
phine 12a easily reacts (r.t., 1 h) with iodomethane to give
salt 17 in 97% yield (Scheme 5).
R
•
P
R
R2PH
– R2P
•
P
P
R
R
O
O
R
R
O
•
A
Me
I–
Scheme 3 A through-space stabilization within radical-adduct A
R
P+
R
r.t., 1 h
O
Trialkyl- and tris(aralkyl)phosphines are known to be
readily oxidized to the corresponding phosphine oxides
on exposure to air.13c,22 Surprisingly, triphosphines 12–15
are more resistant to air oxidation. For example, after stor-
age of triphosphine 14a in an open vessel at room temper-
ature for one month, only traces of its oxide were detected
(31P NMR analysis). In contrast, triphoshines are smooth-
ly oxidized by aqueous H2O2 (r.t., 3 h, acetone) to give the
corresponding triphosphine oxides quantitatively (exem-
plified by oxidation of triphosphine 14d to triphosphine
oxide 16; Scheme 4).
12a
+
4 MeI
R
I–
R
Me
N+
I–
Me
P+
I–
R
+
P
R
Me
O
O
17 97%
Scheme 5 Exhaustive quaternization of triphosphine 12a [R =
Ph(CH2)2]
Over the last years, such phosphonium salts have been
considered as very promising alternatives to imidazolium-
based ionic liquids due to the superior thermal stability of
phosphonium analogues and their inertness in basic reac-
tion media.23
Ph
Ph
P
O
O
O
The novel tripodal phosphines 12–15 have been fully
characterized by multinuclear (1H, 13C and 31P) NMR and
IR spectroscopy; their composition was also confirmed by
elemental analysis data.
O
Ph
H2O2, acetone
r.t., 3 h
P
O
14d
Ph
Ph
P
Ph
O
16 98%
In summary, a novel group of functional triphosphines
bearing amino and (or) ether groups has been synthesized
through exhaustive chemo- and regioselective free-radical
addition of secondary phosphines to trivinyl ethers of tri-
ols, thereby demonstrating the generality and wide sub-
Scheme 4 Oxidation of trisphosphine 14d
Clearly, the stability of the synthesized triphoshines to-
wards air oxidation is advantageous for their handling and
© Georg Thieme Verlag Stuttgart · New York
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656
L. A. Oparina et al.
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1H NMR (400.13 MHz, CDCl3): δ = 1.34 (s, 54 H, 18 × Me), 1.77–
1.85 (m, 18 H, PCH2), 2.73–2.84 (m, 18 H, ArCH2, NCH2), 3.53–
3.63 (m, 12 H, OCH2), 7.14–7.35 (m, 24 H, Ar).
strate scope of this strategy for the synthesis of tripodal
phosphines with extra hemilabile sites. These triphos-
phines are prospective polydentate ligands that can be
used in the design of multipurpose metal complexes and
reactive building blocks for organic synthesis, and the pri-
mary amino group in triphosphines 13a and 13b secures
almost unlimited possibilities for the synthesis of a wide
range of novel tripodal phosphines with hemilabile sites.
2
13C NMR (100.62 MHz, CDCl3): δ = 27.6 (d, JP–C = 14.7 Hz,
1
ArСH2), 29.1 (d, JP–C = 13.8 Hz, PCH2CH2O), 31.3 (18 × Me),
1
2
31.5 (d, JP–C = 14.7 Hz, PCH2), 54.6 (NCH2), 68.8 (d, JP–C
=
20.7 Hz, CH2O), 69.4 (CH2O), 77.9 (C in t-Bu), 125.4 (C2,6 in Ar),
127.6 (C3,5 in Ar), 139.6 (d, 3JP–C = 10.8 Hz, C1 in Ar), 148.6 (C4 in
Ar).
31P NMR (161.98 MHz, CDCl3): δ = –31.7.
All reactions were carried out under an argon atmosphere. All sol-
vents were dried and purified according to standard procedures.
Secondary phosphines 1–5 were prepared from the corresponding
styrenes and 2-vinylfuran and red phosphorus as previously de-
scribed.17 Diphenylphosphine (6) was employed as purchased (Al-
drich). Trivinyl ethers 7–11 were prepared according to a published
method.18 1H, 13C, 31P NMR spectra were recorded with Bruker
DPX 400 or Bruker AV-400 spectrometers (400.13, 100.62, and
161.98 MHz, respectively) at ambient temperature for CDCl3 solu-
tions. Chemical shifts are reported in δ units (ppm) relative to
CDCl3 (1H, 13C) as internal standard or H3PO4 (31P) as external stan-
dard. FTIR spectra were recorded with a Bruker Vertex 70 spec-
trometer. Microanalyses were performed with a Flash EA 1112
Series elemental analyzer. Melting points were recorded with a Stu-
art melting-point apparatus and are uncorrected.
Anal. Сalcd for C84H126NO3P3: С, 78.16; Н, 9.84; N, 1.09; Р, 7.20.
Found: С, 78.35; Н, 9.42; N, 1.14; Р, 7.47.
1,1,1-Tris[2-(diphenethylphosphino)ethoxymethyl]methyl-
amine (13a)
Yield: 256 mg (92%); colorless oil.
IR (KBr): 752 (P–C), 3299, 3379 (N–H) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 1.74–1.78 (m, 18 H, PCH2),
2.70–2.74 (m, 12 H, PhCH2), 2.91 (s, 2 H, NH2), 3.33 (s, 6 H,
CH2O), 3.55–3.60 (m, 6 H, CH2O), 7.18–7.27 (m, 30 H, Ph).
2
13C NMR (100.62 MHz, CDCl3): δ = 27.3 (d, JP–C = 14.8 Hz,
1
1
PhСH2), 29.0 (d, JP–C = 14.0 Hz, PCH2CH2O), 32.0 (d, JP–C
=
14.6 Hz, PCH2), 55.6 (CNH2), 68.1 (d, 2JP–C = 18.8 Hz, CH2O), 72.8
(OCH2C), 125.71 (p-C in Ph), 127.8 (o-C in Ph), 128.2 (m-C in Ph),
142.5 (d, 3JP–C = 10.7 Hz, ipso-C in Ph).
Synthesis of Triphosphines 12–15; General Procedure
Method A: A solution of PH-addend 1 or 4 (0.9 mmol) and trivinyl
ether 9 (0.3 mmol) in 1,4-dioxane (0.5 mL) was irradiated (200 W
Hg arc lamp) in a quartz ampoule (the reaction time is given in Ta-
ble 1).
31P NMR (161.98 MHz, CDCl3): δ = –31.7.
Anal. Сalcd for C58H74NO3P3: С, 75.22; Н, 8.05; N, 1.51; Р, 10.03.
Found: С, 75.35; Н, 8.27; N, 1.63; Р, 9.87.
1,1,1-Tris[2-(bis[4-(tert-butoxy)phenylethyl]phosphino)ethoxy-
methyl]methylamine (13b)
Yield: 351 mg (86%); colorless oil.
IR (KBr): 756 (P–C), 3292, 3349 (N–H) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 1.33 (s, 54 H, 18 × Me), 1.73–
1.79 (m, 18 H, PCH2), 2.69–2.73 (m, 12 H, ArCH2), 3.46–3.65 (m,
14 H, CH2O, NH2), 6.89–7.09 (m, 24 H, ArH).
Method B: A solution of PH-addend 1–6 (0.9 mmol) and trivinyl
ether 7–11 (0.3 mmol) either with solvent (0.5 mL) or without sol-
vent, in the presence of AIBN (2 wt% of the total mass of reactants)
was stirred at 65–75 °C in a sealed ampoule for the given reaction
time (Table 1, Table 2, and Scheme 1).
The reaction was monitored by 31P NMR spectroscopy following
the disappearance of the peaks of the starting PH-addendes (the –82
to –69 ppm region for phosphines 1–5, and the –39 ppm region for
phosphine 7) and appearance of new peaks in the –32 to –20 ppm
region corresponding to triphosphines 12–15. The reaction mixture
was dissolved in Et2O (3 mL), and passed through a layer of Al2O3
(activity level II, 0.5 cm), and the latter was additionally washed
with n-hexane–Et2O (1:1, 3 mL). The solvents were removed under
reduced pressure to give triphosphines 12–15.
13C NMR (100.62 MHz, CDCl3): δ = 27.6 (d, JP–C = 14.7 Hz,
2
ArСH2), 28.8 (18 Me), 29.3 (d, 1JP–C = 13.4 Hz, PCH2CH2O), 31.6
(d, 1JP–C = 14.7 Hz, PCH2), 55.8 (CNH2), 69.4 (d, 2JP–C = 18.5 Hz,
CH2O), 72.9 (CH2O), 78.1 (C in t-BuO), 124.1 (C2,6 in Ar), 128.3
(C3,5 in Ar), 137.6 (d, 3JP–C = 10.4 Hz, C1 in Ar), 153.4 (C4 in Ar).
31P NMR (161.98 MHz, CDCl3): δ = –31.5.
Anal. Сalcd for C82H122NO9P3: С, 72.48; Н, 9.05; N, 1.03; Р, 6.84.
Found: С, 72.65; Н, 9.12; N, 1.17; Р, 6.77.
N,N,N-Tris[2-(diphenethylphosphino)ethoxyethyl]amine (12a)
Yield: 275 mg (96%); colorless oil.
1,2,3-Tris(2-{diphenethylphosphino}ethoxy)propane (14a)
Yield: 242 mg (90%) (method A), 234 mg (87%) (method B); col-
orless oil.
IR (KBr): 752 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 1.73–1.77 (m, 18 H, PCH2),
2.69–2.75 (m, 12 H, PhCH2), 3.45–3.62 (m, 10 H, PCH2CH2O,
CH2O), 3.75 (m, 1 H, CHO), 7.15–7.28 (m, 30 H, PhH).
IR (KBr): 752 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 1.79–1.83 (m, 18 H, PCH2),
2.75–2.83 (m, 18 H, PhCH2, NCH2), 3.52–3.64 (m, 12 H, OCH2),
7.22–7.33 (m, 30 H, Ph).
13C NMR (100.62 MHz, CDCl3): δ = 27.8 (d, JP–C = 14.6 Hz,
2
1
1
PhСH2), 29.4 (d, JP–C = 14.0 Hz, PCH2CH2O), 32.3 (d, JP–C
=
14.6 Hz, PCH2), 54.8 (NCH2), 68.9 (d, 2JP–C = 20.1 Hz, CH2O), 69.5
(CH2O), 126.0 (p-C in Ph), 128.2 (o-C in Ph), 128.5 (m-C in Ph),
142.8 (d, 3JP–C = 10.5 Hz, ipso-C in Ph).
2
13C NMR (100.62 MHz, CDCl3): δ = 27.6 (d, JP–C = 14.6 Hz,
PhСH2), 27.9 (d, 2JP–C = 14.6 Hz, PhСH2), 29.3 (d, 1JP–C = 13.8 Hz,
1
2
PCH2), 32.2 (d, JP–C = 14.6 Hz, PCH2), 68.2 (d, JP–C = 20.7 Hz,
31P NMR (161.98 MHz, CDCl3): δ = –32.3.
2
PCH2CH2O), 69.3 (d, JP–C = 20.3 Hz, PCH2CH2O), 70.9 (CH2O),
Anal. Сalcd for C60H78NO3P3: С, 75.52; Н, 8.24; N, 1.47; Р, 9.74.
Found: С, 75.58; Н, 8.33; N, 1.55; Р, 9.86.
77.9 (CHO), 125.9 (p-C in Ph), 128.1 (o-C in Ph), 128.4 (m-C in
Ph), 142.7 (d, 3JP–C = 10.4 Hz, ipso-C in Ph).
31P NMR (161.98 MHz, CDCl3): δ = –31.5 (br s).
N,N,N-Tris[2-(bis[4-(tert-butyl)phenylethyl]phosphino)ethoxy-
ethyl]amine (12b)
Anal. Сalcd for C57H71O3P3: С, 76.31; Н, 7.98; Р, 10.36. Found: C,
76.54; Н, 7.80; Р, 10.33.
Yield: 364 mg (94%); colorless oil.
IR (KBr): 771 (P–C) cm–1.
Synthesis 2014, 46, 653–659
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Functional Tripodal Phosphines with Amino and Ether Groups
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1,2,3-Tris(2-{bis[4-chlorophenethyl]phosphino}ethoxy)pro-
pane (14b)
31P NMR (161.98 MHz, CDCl3): δ = –31.5.
Anal. Сalcd for C59H75O3P3: С, 76.60; Н, 8.17; Р, 10.04. Found: С,
76.54; Н, 8.08; Р, 10.21.
Yield: 291 mg (88%) (method A); colorless oil.
IR (KBr): 651 (P–C) cm–1.
1,1,1-Tris[2-(diphenethylphosphino)ethoxymethyl]propane
1H NMR (400.13 MHz, CDCl3):
δ = 1.62–1.71 (m, 6 H,
(15b)
PCH2CH2O), 1.96–2.10 (m, 12 H, PCH2), 2.57–2.67 (m, 4 H,
CH2Ar), 2.78–2.94 (m, 8 H, CH2Ar), 3.44–3.54 (m, 5 H, CH2O,
CHO), 3.70–3.81 (m, 6 H, PCH2CH2O), 7.03–7.11 (m, 12 H, H2,6 in
Ar), 7.19–7.25 (m, 12 H, H3,5 in Ar).
Yield: 231 mg (82%); colorless oil.
IR (KBr): 752 (P–C) cm–1.
3
1H NMR (400.13 MHz, CDCl3): δ = 0.87 (t, JH–H = 7.4 Hz, 3 H,
3
13C NMR (100.62 MHz, CDCl3): δ = 27.0 (d, JP–C = 15.0 Hz,
2
Me), 1.42 (q, JH–H = 7.6 Hz, 2 H, CH2Me), 1.77–1.82 (m, 18 H,
CH2Ar), 27.3 (d, 2JP–C = 15.0 Hz, CH2Ar), 29.1 (d, 1JP–C = 14.2 Hz,
PCH2), 2.73–2.79 (m, 12 H, PhCH2), 3.30 (s, 6 H, CH2O), 3.54–
3.60 (m, 6 H, PCH2CH2O), 7.19–7.32 (m, 30 H, Ph).
1
2
PCH2CH2O), 31.5 (d, JP–C = 14.9 Hz, PCH2), 68.2 (d, JP–C
=
20.7 Hz, PCH2CH2O), 69.3 (d, 2JP–C = 20.3 Hz, PCH2CH2O), 70.9
(CH2O), 77.9 (CHO), 128.4 (C2,6 in Ar), 128.7 (C3,5 in Ar), 129.4
(C4 in Ar), 140.9 (d, 3JP–C = 10.0 Hz, C1 in Ar).
13C NMR (100.62 MHz, CDCl3): δ = 7.8 (Me), 23.1 (СH2), 27.5 (d,
1
1JP–C = 14.5 Hz, PhCH2), 29.3 (d, JP–C = 13.9 Hz, PCH2CH2O),
32.3 (d, 1JP–C = 14.5 Hz, PCH2), 43.1 (C), 69.3 (d, 2JP–C = 18.5 Hz,
CH2O), 71.4 (CH2O), 125.9 (p-C in Ph), 128.1 (o-C in Ph), 128.4
(m-C in Ph), 142.8 (d, 3JP–C = 10.8 Hz, ipso-C in Ph).
31P NMR (161.98 MHz, CDCl3): δ = –31.5 (br s).
Anal. Сalcd for C57H65Cl6O3P3: С, 62.03; Н, 5.94; Cl, 19.27; Р,
8.42. Found: С, 62.21; Н, 5.82; Cl, 19.14; Р, 8.54.
31P NMR (161.98 MHz, CDCl3): δ = –31.4.
Anal. Сalcd for C60H77O3P3: С, 76.73; Н, 8.26; Р, 9.89. Found: С,
76.69; Н, 8.30; Р, 9.47.
1,2,3-Tris(2-{bis[2-(2-furyl)ethyl]phosphino}ethoxy)propane
(14c)
Yield: 201 mg (80%) (method B); colorless oil.
1,1,1-Tris[2-bis[4-(tert-butoxy)phenethyl]phosphinoethoxy-
methyl]ethane (15c)
Yield: 375 mg (92%); colorless oil.
IR (KBr): 756 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 0.93 (s, 3 H, CH3), 1.32 (s, 54
H, 18 Me), 1.74–1.78 (m, 18 H, PCH2), 2.67–2.71 (m, 12 H,
ArCH2), 3.27 (s, 6 H, CH2O), 3.52–3.58 (m, 6 H, PCH2CH2O),
6.89–7.08 (m, 24 H, Ar).
IR (KBr): 731 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 1.70–1.78 (m, 18 H, PCH2),
2.71–2.77 (m, 12 H, CH2Fur), 3.44–3.76 (m, 11 H, CH2O, CHO),
5.98 (br s, 6 H, H3 in Fur), 6.25 (br s, 6 H, H4 in Fur), 7.27 (br s, 6 H,
H5 in Fur).
13C NMR (100.62 MHz, CDCl3): δ = 20.4 (CH2Fur), 24.6 (d, 1JP–C
=
=
1
2
13.6 Hz, PCH2), 25.4 (d, JP–C = 16.5 Hz, PCH2), 27.4 (d, JP–C
14.6 Hz, PCH2CH2O), 27.7 (d, 2JP–C = 13.2 Hz, PCH2CH2O), 68.0
(d, JP–C = 22.8 Hz, PCH2CH2O), 69.2 (d, JP–C = 19.7 Hz,
PCH2CH2O), 70.9 (CH2O), 77.9 (CHO), 104.9 (C3 in Fur), 110.1
(C4 in Fur), 140.9 (C5 in Fur), 155.9 (d, 3JP–C = 11.3 Hz, C2 in Fur).
13C NMR (100.62 MHz, CDCl3): δ = 17.6 (CH3), 27.5 (d, 1JPC
=
2
2
1
13.8 Hz, ArCH2), 28.8 (18 Me), 29.3 (d, JPC = 13.4 Hz,
PCH2CH2O), 31.6 (d, 1JPC = 14.7 Hz, PCH2), 40.8 (CMe), 69.4 (d,
2JPC = 19.0 Hz, CH2O), 73.7 (CH2O), 78.1 (C in t-BuO), 124.1 (C2,6
in Ar), 128.4 (C3,5 in Ar), 137.7 (d, 3JPC = 10.8 Hz, C1 in Ar), 153.4
(C4 in Ar).
31P NMR (161.98 MHz, CDCl3): δ = –31.9 (br s).
Anal. Сalcd for C45H59O9P3: С, 64.58; Н, 7.11; Р, 11.10. Found: С,
64.69; Н, 7.30; Р, 11.27.
31P NMR (161.98 MHz, CDCl3): δ = –31.3.
Anal. Сalcd for C83H123O9P3: С, 73.42; Н, 9.13; Р, 6.84. Found: С,
73.70; Н, 9.26; Р, 6.72.
1,2,3-Tris[2-(diphenylphosphino)ethoxy]propane (14d)
Yield: 197 mg (90%) (method B); colorless oil.
IR (KBr): 740 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 2.26–2.32 (m, 6 H, PCH2),
1,1,1-Tris[2-bis[4-(tert-butoxy)phenethyl]phosphinoethoxy-
methyl]propane (15d)
Yield: 370 mg (90%); colorless oil.
3.27–3.65 (m, 11 H, CH2O, CHO), 7.23–7.37 (m, 30 H, Ph).
IR (KBr): 756 (P–C) cm–1.
13C NMR (100.62 MHz, CDCl3): δ = 28.8 (d, JP–C = 13.0 Hz,
1
1
2
1H NMR (400.13 MHz, CDCl3): δ = 0.69 (t, 3J = 7.5 Hz, 3 H, Me),
PCH2), 29.2 (d, JP–C = 13.1 Hz, PCH2), 67.6 (d, JP–C = 25.3 Hz,
3
2
1.18 (s, 54 H, 18 × Me), 1.25 (q, JH–H = 7.5 Hz, 2 H, CH2Me),
PCH2CH2O), 68.7 (d, JP–C = 24.5 Hz, PCH2CH2O), 70.7 (CH2O),
2
1.58–1.64 (m, 18 H, PCH2), 2.53–2.59 (m, 12 H, ArCH2), 3.137 (s,
6 H, CH2O), 3.38–3.44 (m, 6 H, PCH2CH2O), 6.74–6.94 (m, 24 H,
Ar).
77.8 (CHO), 128.4 (p-C in Ph), 128.5 (d, JP–C = 13.0 Hz, o-C in
Ph), 132.7 (d, 3JP–C = 19.3 Hz, m-C in Ph), 138.4 (d, 1JP–C = 13.0 Hz,
ipso-C in Ph).
13C NMR (100.62 MHz, CDCl3): δ = 7.8 (Me), 23.0 (СH2), 27.5 (d,
31P NMR (161.98 MHz, CDCl3): δ = –20.9.
1
2JP–C = 14.2 Hz, ArСH2), 28.8 (18 Me), 29.3 (d, JP–C = 13.8 Hz,
PCH2CH2O), 31.6 (d, 1JP–C = 14.7 Hz, PCH2), 43.0 (CEt), 69.3 (d,
2JP–C = 18.5 Hz, CH2O), 71.3 (CH2O), 78.0 (C in t-BuO), 124.1 (C2,6
in Ar), 128.3 (C3,5 in Ar), 137.7 (d, 3JP–C = 11.2 Hz, C1 in Ar), 153.4
(C4 in Ar).
Anal. Сalcd for C45H47O3P3: С, 74.16; Н, 6.50; Р, 12.75. Found: С,
74.25; Н, 6.36; Р, 12.88.
1,1,1-Tris[2-(diphenethylphosphino)ethoxymethyl]ethane (15a)
Yield: 244 mg (88%); colorless oil.
IR (KBr): 753 (P–C) cm–1.
31P NMR (161.98 MHz, CDCl3): δ = –31.2.
Anal. Сalcd for C84H125O9P3: С, 73.55; Н, 9.18; Р, 6.77. Found: С,
73.63; Н, 9.30; Р, 6.84.
1H NMR (400.13 MHz, CDCl3): δ = 0.95 (s, 3 H, Me), 1.71–1.78
(m, 18 H, PCH2), 2.68–2.72 (m, 12 H, PhCH2), 3.25 (s, 6 H, CH2O),
3.52–3.56 (m, 6 H, PCH2CH2O), 7.23–7.41 (m, 30 H, Ph).
1
Oxidation of Triphosphine 14d with H2O2 (Scheme 4); Synthe-
sis of 1,2,3-Tris[2-(diphenylphosphinyl)ethoxy]propane (16)
To a solution of triphosphine 14d (146 mg, 0.2 mmol) in acetone
(5 mL), a 33% aqueous solution of H2O2 (1 mL) was added drop-
wise. The reaction mixture was stirred at 23–25 °C for 3 h, then sol-
vents were evaporated in vacuum and the residue was reprecipitated
13C NMR (100.62 MHz, CDCl3): δ = 17.6 (Me), 27.5 (d, JP–C
=
1
14.0 Hz, PhCH2), 29.2 (d, JP–C = 13.9 Hz, PCH2CH2O,), 32.2 (d,
2
1JP–C = 14.5 Hz, PCH2), 40.8 (C), 69.4 (d, JP–C = 18.9 Hz,
PCH2CH2O), 73.6 (CH2O), 125.9 (p-C in Ph), 128.0 (o-C in Ph),
128.4 (m-C in Ph), 142.8 (d, 3JP–C = 11.1 Hz, ipso-C in Ph).
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2014, 46, 653–659

658
L. A. Oparina et al.
PAPER
from chloroform to hexane and dried in vacuum to give triphos-
phine oxide 16.
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A. Organometallics 2009, 28, 3193.
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Yield: 149 mg (96%); white resin.
IR (KBr): 1173 (P=O), 751 (P–C) cm–1.
1H NMR (400.13 MHz, CDCl3): δ = 2.51–2.58 (m, 6 H, PCH2),
3.07–3.19 (m, 5 H, CH2O), 3.60–3.77 (m, 6 H, CHO), 7.41–7.76
(m, 30 H, Ph).
1
13C NMR (100.62 MHz, CDCl3): δ = 30.5 (d, JP–C = 70.7 Hz,
1
PCH2), 30.9 (d, JP–C = 70.3 Hz, PCH2), 63.5, 64.6 (PCH2CH2O),
3
70.4 (CH2O), 77.5 (CHO), 128.6 (d, JP–C = 11.6 Hz, m-C in Ph),
130.7 (d, 2JP–C = 9.5 Hz, o-C in Ph), 131.8 (p-C in Ph), 132.8 (d,
1JP–C = 100.4 Hz, ipso-C in Ph).
31P NMR (161.98 MHz, CDCl3): δ = 31.04, 31.15.
Anal. Сalcd for C45H47O6P3: С, 69.58; Н, 6.10; Р, 11.96. Found: С,
69.35; Н, 6.15; Р, 12.09.
Exhaustive Quaternization of Triphosphine 12a (Scheme 5);
Synthesis of Methyl-N,N,N-tris{2-[methyl-bis(phenyleth-
yl)phosphonio]ethoxyethyl}ammonium Tetraiodide (17)
A solution of triphosphine 12a (204 mg, 0.21 mmol) and MeI
(1 mL) in Et2O (2 mL) was stirred under an argon atmosphere at 23–
25 °C for 1 h. The solvent and excess MeI were removed in vacu-
um, the residue was ground in hexane (7 mL), and the hexane was
decanted. The white powder formed was washed with hexane
(10 mL) and dried in vacuum (1 Torr, 35–40 °C) to afford salt 17.
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Yield: 310 mg (97%); white powder; mp 68 °C.
1H NMR (400.13 MHz, CDCl3): δ = 1.95–2.28 (m, 18 H, PCH2),
2.08 (d, 1JPH = 11.7 Hz, 9 H, 3 PMe), 2.75–2.90 (m, 18 H, PhCH2,
NCH2), 3.30–3.38 (br s, 3 H, NMe), 3.91–4.04 (m, 12 H, OCH2),
7.15–7.30 (m, 30 H, Ph).
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27, 4282. (f) Deb, B.; Dutta, D. K. J. Mol. Catal. A: Chem.
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S.; Kenawy, E. R. Molecules 2010, 15, 3618. (i) Warad, I.;
Al-Far, R.; Al-Resayes, S.; Boshaala, A.; Hammouti, B. Int.
J. Phys. Sci. 2011, 6, 7183. (j) Karasik, A. A.; Sinyashin, O.
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31P NMR (161.98 MHz, CDCl3): δ = 32.46.
Anal. Сalcd for C64H90I4NO3P3: C, 50.51; H, 5.96; I, 33.35; N, 0.92;
P, 6.11. Found: C, 50.71; H, 5.95; I, 32.82; N, 1.26; P, 6.18.
Acknowledgment
This work was supported by the Russian Foundation for Basic Re-
search (grant no. 11-03-00286) and the President of the Russian Fe-
deration (program for the support of leading scientific schools,
grant NSh-1550.2012.3).
Supporting Information for this article is available online at
http://www.thieme-connect.com/ejournals/toc/synthesis.SnuIomprifgtooatrinSugpIoi
n
nfomartit
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Functional Tripodal Phosphines with Amino and Ether Groups
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Synthesis 2014, 46, 653–659