Resorcin[4]arene-derived mono- And diphosphines in suzuki cross-coupling

Article abstract of DOI:10.1002/adsc.200900767

Three resorcin[4]arene cavitands (1-3) having either one or two resorcinolic C-2 atoms substituted by a -CH₂PPh₂ podand arm were assessed in the Suzuki arylation of aryl bromides with phenylboronic acid. Using P:Pd ratios of 2:1 and operating in dioxane at 100°C with a catalyst loading of 0.001 mol% resulted in highly efficient catalytic systems. For example, TOFs up to 34570 mol(converted ArBr)-mol(Pd)^-1.h ^-1 were obtained with the proximally-disubstituted cavitand 3 when using 4-bromotoluene as substrate. The performance was shown to vary in the following order: monophosphine 1

Full text of DOI:10.1002/adsc.200900767

FULL PAPERS
DOI: 10.1002/adsc.200900767
Resorcin[4]arene-Derived Mono- and Diphosphines in Suzuki
Cross-Coupling
Hani El Moll,a David Sꢀmeril,a,* Dominique Matt,a,* and Loꢁc Toupetb
a
Laboratoire de Chimie Inorganique Molꢀculaire et Catalyse, Universitꢀ de Strasbourg, Institut de Chimie de Strasbourg,
UMR 7177 CNRS, 1, rue Blaise-Pascal, 67008 Strasbourg cedex, France
Fax : (+33)-3-9024-1749; e-mail: dsemeril@chimie.u-strasbg.fr or dmatt@chimie.u-strasbg.fr
Groupe Matiꢂre Condensꢀe et Matꢀriaux UMR 6626, Universitꢀ de Rennes 1, Campus de Beaulieu, F-35042, Rennes
b
cedex, France
Received: November 5, 2009; Published online: March 12, 2010
Supporting information for this article is available on the WWW under
http://dx.doi.org/10.1002/adsc.200900767.
Abstract: Three resorcin[4]arene cavitands (1–3) disubstituted cavitand). A comparison of the catalyt-
having either one or two resorcinolic C-2 atoms sub- ic properties of monophosphine-cavitand 1 with
À
stituted by a CH2PPh2 podand arm were assessed in those of benzyldiphenylphosphine and o-anisylme-
the Suzuki arylation of aryl bromides with phenyl- thyldiphenyl phosphine suggests that 1 functions as a
boronic acid. Using P:Pd ratios of 2:1 and operating hemilabile phosphine, the oxygen atoms close to the
in dioxane at 1008C with a catalyst loading of phosphorus atom behaving as donors able to tempo-
0.001 mol% resulted in highly efficient catalytic sys- rarily increase the electron density on the metal and/
tems. For example, TOFs up to 34570 mol(converted or favour the formation of mono-ligand Pd(0) spe-
ArBr)·mol(Pd)À1·hÀ1 were obtained with the proxi- cies.
mally-disubstituted cavitand 3 when using 4-bromo-
toluene as substrate. The performance was shown to Keywords: cavitands; hemilabile ligands; palladium;
vary in the following order: monophosphine 1<di- phosphanes; resorcinarenes; Suzuki–Miyaura cou-
phosphine 2<diphosphine 3 (where 2 is the distally pling
Introduction
suitable for complexation of transition metals, altering
neither the cavity shape nor its receptor properties.[22]
Resorcinarenes provide valuable starting compounds
for the preparation of cavitands, that is bowl-shaped
molecules having a rigid structure.[1] In addition to
their functioning as molecular receptors, cavitands
also constitute ideal platforms for arranging a set of
podand arms on a ring, thereby creating sophisticated
ligand systems allowing, e.g., several metal ions to be
maintained in close proximity. A number of investiga-
tions have recently illustrated the coordinative prop-
erties of cavitand-derived podands.[2,3] While ligands
of this class have found numerous applications in sep-
aration science and sensing technology,[4–8] catalytic
properties, surprisingly, have been little studied.[9,10]
This is in stark contrast with podands obtained from
the related calix[4]arene cavities,[11] in particular their
phosphane derivatives,[11–20] which have already led to
a rich transition metal chemistry.[2,21]
We have recently described the synthesis of the
first mono- and diphosphines built on a resorcinarene
Scheme 1. Resorcin[4]arene-derived podands used in this
cavitand (1–3, Scheme 1) and shown that these are study.
Adv. Synth. Catal. 2010, 352, 901 – 908
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
901

Hani El Moll et al.
FULL PAPERS
Table 1. Suzuki reaction catalyzed by the [PdACTHNURGTNEUNG(OAc)2]/1 sys-
As an extension of our current investigations on
cavity-shaped ligands, we now describe the catalytic
properties of resorcinarenes 1–3 in Suzuki cross-cou-
pling reactions.[23–25] The results are compared to
those for other phosphines containing a benzyl sub-
tem.[a]
Entry ArBr
Sub-
strate/ version
Pd
[%][b]
Con-
TOF
ACHUTNGERN[NUG molAHCTUNGTRNEN(UGN ArBr)·
mol(Pd)À1·hÀ1]
ACHTUNGTRENNUNGunit, notably Ph2PCH2Ph and Ph2PCH2(o-MeO-
1
2
1ꢄ104 40.6
1ꢄ105 6.4
4060
6380
C6H4). It is worth mentioning that in the three cavi-
tands assessed, the donor atoms are linked to the C-2
atoms of the resorcinol units, thus contrasting with
the vast majority of cavitand-podands, in which the
binding arms are directly connected to the oxygen
atoms.[26–35]
3[c]
4
5
6
7
1ꢄ104 80.7
1ꢄ104 100
1ꢄ105 26.7
1ꢄ104 34.4
1ꢄ105 4.4
8070
10000
26680
3440
4380
Results and Discussion
8
9
1ꢄ104 72.8
1ꢄ105 12.4
7280
12360
The phosphines used in this study (1–3) were pre-
pared according to the method reported previously.[22]
We began the Suzuki cross-coupling tests (Scheme 2)
using a catalytic system based on [PdACTHNURTGNENG(U OAc)2] and the
mono-phosphinated cavitand 1.
10
11
1ꢄ104 97.8
1ꢄ105 27.1
9780
27120
12
13
1ꢄ104 61.0
6100
20670
1ꢄ105 20.7
Catalytic testing was carried out in 1 h runs at
1008C in the presence of NaH and with 1,4-dioxane
as solvent. We noted that when operating with
Cs2CO3/DMF at 1308C, which corresponds to classical
conditions for this kind of catalysis, significantly lower
activities were observed. The best conversion, deter-
mined by using 4-bromoanisole as substrate, was ob-
served when a ratio of two phosphorus atoms per pal-
ladium was applied. This led to a conversion of 100%
vs. 80.7% when a phosphine to palladium ratio of 1
was applied (Table 1, entries 3 and 4). Performing the
runs at only 0.001 mol% of metal (ArBr/catalyst
ratio=1ꢄ105) led to TOFs of ca. 27000 mol(convert-
ed ArBr)·mol(Pd)À1·hÀ1 for 4-bromoanisole, 4-bromo-
toluene and 2-bromo-6-methoxynaphthalene (Table 1,
entries 5, 11 and 17). In comparaison, carrying out the
14
15
1ꢄ104 47.9
1ꢄ105 16.7
4790
16690
16
17
1ꢄ104 100
1ꢄ105 27.0
10000
27030
[a]
[PdACTHNUTRGNE(UGN OAc)2], 1 (2 equiv./Pd), aryl bromide (0.5 mmol),
PhB(OH)2 (0.122 g, 1.0 mmol), NaH (0.044 g, 1.0 mmol),
decane (0.05 mL), dioxane (1.5 mL), 1008C, 1 h.
Determined by GC, calibration based on decane.
[b]
[c]
[Pd
(OAc)2] (0.011 mg, 0.05 mmol),
1
(0.051 mg,
0.05 mmol, 1 equiv./Pd).
arylation of 4-bromotoluene with 2 equivalents of by ca. 50% compared to that obtained for 1 (conver-
PPh3 as ligand (substrate/Pd=10000), resulted in a sion: 45.9% against 100%). In view of the fact that
TOF of 5210 mol(converted ArBr)·mol(Pd)À1·hÀ1 (vs. the two oxygen atoms of 1, which are separated from
27120 for 1). It is worth noting that in all runs, the the phosphorus centre by four bonds, might coordi-
amount of homocoupling product was lower than 5%. nate the metal centre during catalysis, we then decid-
In order to evaluate the contribution of the cavity ed to compare this ligand with the methoxy-substitut-
scaffold on the performance of this ligand, the Suzuki
coupling of 4-bromoanisole with phenylboronic acid
was repeated with 2 equivalents of benzyldiphenyl-
phosphine (4), applying the conditions displayed in
entry 4, Table 1. In this case the conversion dropped
ed benzyldiphenylphosphine 5. This ligand was pre-
pared in 93% overall yield in a two-step sequence
(not shown): (i) phosphorylation of bromomethyl-o-
anisyl with ethyl diphenylphosphinite at 1408C; (ii)
Scheme 2. Suzuki cross-coupling reaction.
reduction of the phosphine oxide thus produced with
902
asc.wiley-vch.de
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2010, 352, 901 – 908

Resorcin[4]arene-Derived Mono- and Diphosphines in Suzuki Cross-Coupling
PhSiH3 (for a full characterization, see Experimental
Section). Surprisingly, the cross-coupling reaction of
4-bromoanisole with phenylboronic acid using 5
(same conditions as in entry 5, Table 1) led to a TOF
comparable to that observed with 1 [TOF=26400
mol(converted ArBr)·mol(Pd)À1·hÀ1]. Similar observa-
tions were made for the following substrates: 2-
bromo-6-methoxynaphthalene, 4-bromotoluene, and
1-bromonaphthalene (see Supporting Information).
These results illustrate the beneficial role of an
alkoxy substituent located at the ortho-carbon atom
of the arylmethyl fragment bearing the phosphorus
atom, and suggest that cavitand phosphine 1 behaves
as a hemilabile ligand[36] during the catalytic process.
It is worth mentioning here that some ether-phos-
phines able to form 6-membered palladacycles have
already been shown to efficiently catalyze the Suzuki
arylation. In the corresponding reports, the efficiency
Figure 1. Molecular structure of cis-[PtCl2·12] (7) (the mole-
cule possesses a C2 axis). For clarity, the molecule of hexane
located inside each cavitand is not shown. Important dis-
À
À
AHCTUNGTRENNUNG
Pt···O1 3.65, P1 Pt P2 102.9(1), Cl1 Pt Cl2 86.6(1).
was assigned to the ability of such phosphines to form tion, it is obvious from this study that there is no
P,O-chelated monophosphine intermediates.[37] Ac- steric hindrance precluding a small rotation about the
À
cording to more recent investigations on Suzuki cross- P CH2 axis so as to permit a Pt···O contact, in other
coupling reactions, the formation of a Pd(0)-mono- terms to allow the phosphine to behave as a chelating
phosphine complex appears to be a key step that pre- system.
cedes the oxidative addition step of aryl bro-
As our next investigation, we studied the catalytic
mides.[38–42] On the other hand, the transient binding properties of ligand 2, which contains two remote
of an oxygen atom is expected to increase the elec- phosphine subunits. Molecular models unambiguously
tronic density of the metal centre, thereby favouring show that diphosphine 2 is not suited for forming P,P-
the oxidation addition step, irrespective of whether chelate complexes. The propensity of 2 to form
the active species is a bis- or a mono-phosphine com- straightforward oligomeric complexes was revealed by
plex.[43] Note that the presence during the catalytic studying the reaction of [PtCl
2ACHTNUTRGNE(NUG PhCN)2] with a stoi-
process of zerovalent Pd intermediates bearing two chiometric amount of 2. This reaction gave in high
phosphine ligands cannot be excluded, since we found yield a complex of the formula [PtCl2(2)]n (8)
that the use of two equivalents of phosphine gave sig- (Scheme 3), to which we tentatively assign a cyclic,
nificantly better results than when using one. Possibly, trimeric structure on the basis of both its ESI-TOF
oxygen binding within such an intermediate would spectrum and its 31P NMR spectrum. The mass spec-
not only increase the electron density at the metal, trum shows a strong peak at m/z=4401, with the pro-
but also increase the steric encumbrance about the file expected for the corresponding [MÀCl]+ cation.
metal centre and incidentally lower the energy barrier The 31P NMR spectrum of the complex shows a
for the reductive elimination step.
The ability of 1 to bind palladium was formally num satellites. The J
only shown in the case of Pd(II). Thus, its reaction is in keeping with the platinum centres adopting a
with 0.5 equiv. of [PdCl2A(PhCN)2] in CH2Cl2 gave trans configuration.
quantitatively cis-[PdCl2·12] (6). The stereochemistry The catalytic runs carried out with 2 were again all
single, sharp peak at 13.2 ppm flanked by two plati-
AHCTUNGTRENNUNG
CTHUNGTRENNUNG
of this complex was deduced from the corresponding done in dioxane at 1008C in the presence of NaH.
31P NMR spectrum, which shows a single peak at The highest conversions were observed for a ligand/
30.6 ppm, a value which is very close that found in Pd ratio of 1:1 (Table 2, entries 2 and 3), a finding
cis-[PdCl2(Ph2PCH2C6H5)2]
(dcis =30.2 ppm;
cf. which suggests that again two phosphorus centres are
20.1 ppm for the corresponding trans complex).[44,45] coordinated to the Pd ion during catalysis. As can be
Attempts to determine the solid state structure of 6 inferred from Table 2, the general trend is that di-
failed, but single crystals suitable for such a study phosphine 2 results in higher conversions than mono-
could be obtained for the related complex cis- phosphine 1, the efficiency increase reaching ca. 70%
[PtCl2·12] (7). In the solid state (Figure 1), the latter in the case of 1-bromonaphthalene. Only with 2- and
adopts C2 symmetry. The structure reveals that 4-bromoanisole did the conversion slightly drop, but
oxygen atom O-1, which is separated by four bonds we have no rational explanation for this observation.
from the corresponding P atom, comes close to the The highest activity was for 4-bromotoluene [Table 2,
metal centre. Although the distance of O-1 to the entry 10:
platinum atom (3.65 ꢅ) rules out any bonding interac- Since the two phosphorus atoms of 2 can only bind in-
TOF=29500 molACTHNGUTERNNUG
(ArBr)·mol(Pd)À1·hÀ1].
Adv. Synth. Catal. 2010, 352, 901 – 908
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
903

Hani El Moll et al.
FULL PAPERS
Scheme 3. Synthesis of the trimeric complex 8.
Table 2. Suzuki reaction catalyzed by the [PdACTHNURGTNEUNG(OAc)2]/2 sys-
found in the catalytic intermediates derived from 1.
This could notably arise by formation of small cyclic
oligomers, in which the PMP angles would, owing to
steric congestion within the metallomacrocyclic struc-
ture, be larger than in monomeric complexes. It is
now commonly accepted that an increase of the PMP
angle in [Pd(phosphine)2XY] complexes favours the
tem.[a]
Entry ArBr
Sub-
strate/ version
Pd
[%][b]
Con-
TOF
[mol
G
ACHTUNGTRNE(NUNG ArBr)·
mol(Pd)À1·hÀ1]
1
1ꢄ104 25.5
2550
À
reductive elimination step in C C coupling reac-
tions.[46–48] Formation of such species do, of course,
not prevent from forming P,O-chelated intermediates.
The third series of tests was achieved with the prox-
imally-substituted cavitand 3. The reaction conditions
were as for 2. With the exception of 1-bromonaphtha-
lene, all substrates resulted in conversions significant-
ly higher than those obtained with 1 and 2 (Table 3).
For example, with 4-bromotoluene, the TOFs were
2[c]
3
4
5
6
1ꢄ104 72.2
1ꢄ104 91.1
1ꢄ105 25.0
1ꢄ104 45.6
1ꢄ105 13.6
7220
9110
25030
4560
13620
7
8
1ꢄ104 91.0
9100
20420
1ꢄ105 20.4
9
1ꢄ104 98.9
1ꢄ105 29.5
1ꢄ104 62.8
1ꢄ105 21.8
1ꢄ104 94.5
1ꢄ105 28.8
9890
29500
6280
21800
9450
28780
27120, 29500, and 34570 molACHTNUGRTNEUNG
(ArBr)·mol(Pd)À1·hÀ1
10
11
12
13
14
using 1, 2, and 3, respectively. It is interesting to note
that with congested aryl bromides the best results
were also obtained with diphosphine 3. Thus, the
latter gave TOFs of 8450, 15650 and 22770 mol-
AHCTUNGTRENNUNG
(converted ArBr)·mol(Pd)À1·hÀ1 (Table 3, entries 2, 6
15
16
1ꢄ104 97.7
1ꢄ105 29.4
9770
29360
and 14) with 2-bromoanisole, 2-bromotoluene and 1-
bromonaphthalene, respectively. The increased perfor-
mance of 3 vs. that of 2 possibly arises from its partial
conversion into P,P-chelate complexes in which the
ligand displays a large bite angle,[49] this latter feature
being known, as already mentioned above, to pro-
mote reductive elimination in cross-coupling reac-
tions.[46–48] Molecular mechanics calculations (SPAR-
TAN) indeed show that in hypothetical [PdX2(3)] che-
late complexes (X=halide, aryl), be they square
[a]
[PdACHTUNGTRENNUNG(OAc)2], 2 (1 equiv./Pd), aryl bromide (0.5 mmol),
PhB(OH)2 (0.122 g, 1.0 mmol), NaH (0.040 g, 1.0 mmol),
decane (0.05 mL), dioxane (1.5 mL), 1008C, 1 h.
Determined by GC, calibration based on decane.
[b]
[c]
[Pd
(OAc)2] (0.011 mg, 0.05 mmol),
2
(0.030 mg,
0.025 mmol, 0.5 equiv./Pd).
dependent metal centres, the better activities ob- planar or tetrahedral, the corresponding PMP angles
served with 2 vs. 1 probably reflect a first coordina- are significantly larger than in conventional ML2X2
tion sphere that is considerably different from the one complexes. Here the resulting strain generated within
904
asc.wiley-vch.de
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2010, 352, 901 – 908

Resorcin[4]arene-Derived Mono- and Diphosphines in Suzuki Cross-Coupling
Table 3. Suzuki reaction catalyzed by the [PdACTHNURGTNEUNG(OAc)2]/3 sys-
Conclusions
tem.[a]
In summary, the combination of [PdACTHNUTRGENUG(N OAc)2] with the
Entry ArBr
Sub-
strate/ version
Pd
[%][b]
Con-
TOF
phosphinated resorcin[4]arenes 1–3 efficiently catalyz-
es Suzuki cross-coupling reactions. The best perform-
ing of these ligands, namely the proximally substituted
cavitand 3, resulted in remarkable TOFs [up to
ACHUTNGERN[NUG molAHCTUNGTRNEN(UGN ArBr)·
mol(Pd)À1·hÀ1]
1
2
1ꢄ104 52.6
1ꢄ105 8.5
5260
8450
34570 molACTHNUTRGNEUNG
(ArBr)·mol(Pd)À1·hÀ1 when starting from 4-
bromotoluene] using catalyst loadings as low as
0.001 mol%. Overall, the reaction rates for the three
phosphines were 5–7 times higher than those ob-
served for PPh3. At least two effects may be invoked
to explain the high performances observed with these
ligands in Suzuki arylations: (i) the possibility of
forming, in the case of monophosphine 1, transient
P,O-chelate complexes involving the oxygen atoms of
the resorcinolic unit bearing the P atom(s). Oxygen
binding may assist the formation of monophosphine
palladium(0) species believed to play a key role in
substrate activation. It may further increase the elec-
tron density of the metal centre so as to facilitate oxi-
dative addition of the aryl bromide; (ii) the ability of
two 2 and 3 to generate intermediates displaying in-
creased PMP angles, the latter being induced either
by steric repulsions occurring in cyclic oligomers (pos-
sibly with ligand 2) or arising from the formation a
strained chelate complex (case of 3).
3
4
1ꢄ104 100
1ꢄ105 28.7
10000
28740
5
6
1ꢄ104 85.9
8590
15650
1ꢄ105 15.7
7
8
1ꢄ104 98.1
1ꢄ105 23.7
9810
23710
9
10
1ꢄ104 100
1ꢄ105 34.6
10000
34570
11
12
1ꢄ104 68.6
6860
24780
1ꢄ105 24.8
13
14
1ꢄ104 57.3
1ꢄ105 22.8
5730
22770
15
16
1ꢄ104 100
1ꢄ105 32.1
10000
32130
[a]
Experimental Section
[PdACHTUNGTRENNUNG(OAc)2], 3 (1 equiv./Pd), aryl bromide (0.5 mmol),
PhB(OH)2 (0.122 g, 1.0 mmol), NaH (0.040 g, 1.0 mmol),
decane (0.05 mL), dioxane (1.5 mL), 1008C, 1 h.
Determined by GC, calibration based on decane.
General Procedure
[b]
All manipulations involving phosphorus derivatives were
performed in Schlenk-type flasks under dry nitrogen. Sol-
vents were dried by conventional methods and distilled im-
mediately prior to use. CDCl3 was passed down a 5 cm thick
alumina column and stored under nitrogen over molecular
the corresponding metallomacrocycle intensifies the
steric interactions between two of the PPh rings
(those having an upward orientation) and the X sub-
stituents (Figure 2).
1
sieves (4 ꢅ). Routine H, 13C{1H} and 31P{1H} NMR spectra
were recorded with Bruker FT instruments (AC-300).
1H NMR spectra were referenced to residual protiated sol-
vents (7.26 ppm for CDCl3), 13C NMR chemical shifts are re-
ported relative to deuterated solvents (77.16 ppm for
CDCl3), and the 31P NMR data are given relative to external
H3PO4. Chemical shifts and coupling constants are reported
in ppm and in Hz, respectively. Gas chromatographic analy-
ses were performed on a Varian 3900 gas chromatograph
using a WCOT fused silica column (25 m, 0.32 mm, inside
diameter, 0.25 mm film thickness). The complex [PtCl2
AHCTUNGTRENNUNG
(PhCN)2][50] and phosphines 1–3[22] were prepared according
to the literature procedures. A high-yield synthesis of mono-
phosphine 5, starting from (2-methoxy)benzyl alcohol, is re-
ported below. The previously reported procedure gave a
yield of only 30%.[51]
(2-Methoxybenzyl) Bromide
Figure 2. SPARTAN-generated, hypothetical [Pd
complex showing the spatial proximity of upwards-oriented
PPh rings and the palladium-coordinated phenyl groups.
(C6H5)2·3]
To a solution of 2-methoxybenzyl alcohol (0.500 g, ca.
0.48 mL, 3.62 mmol) in CH2Cl2 (40 mL) was added PBr3
(0.490 g, ca. 0.17 mL, 1.81 mmol). After stirring for 1 h, the
Adv. Synth. Catal. 2010, 352, 901 – 908
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
905

Hani El Moll et al.
FULL PAPERS
reaction mixture was washed with brine (3ꢄ30 mL), and the
organic layer was separated. The latter was dried over
Na2SO4 and then evaporated under vacuum to afford the
CH of resorcinarene), 7.01 7.06 (s, 4H, arom. CH of
6
resorcin
N
1.8 Hz), 6.54 (s, 4H, arom. CH of resorcinarene), 6.45 (s,
2H, arom. CH of resorcinarene), 5.94 and 4.43 (AB spin
system, 8H, OCH2O, 2J=7.2 Hz), 5.70 and 4.52 (AB spin
product as
a colourless liquid; yield: 0.650 g (89%).
1H NMR (300 MHz, CDCl3, 258C): d=7.38–7.30 (2H, arom.
3
3
2
CH), 6.97 (dd, 1H, arom. CH, J=7.3 Hz, J=7.5 Hz), 6.90
system, 8H, OCH2O, J=7.2 Hz), 4.70 (t, 4H, CHCH2CH2,
3
(d, 1H, arom. CH, J=8.2 Hz), 4.62 (s, 2H, CH2Br), 3.98 (s,
3J=8.1 Hz), 4.47–4.39 (m, 8H, CHCH2CH2 and CH2P, over-
lapping signals), 2.25–2.02 (m, 16H, CHCH2CH2), 1.42–1.14
(m, 48H, CH2CH2CH2CH3), 0.94 (t, 12H, CH2CH3, 3J=
6.6 Hz), 0.90 (t, 12H, CH2CH3, 3J=6.9 Hz). 31P NMR
(121.5 MHz, CDCl3, 258C): d=30.6 (s, PPh2). Anal. calcd
for C130H150O16P2PdCl2 (Mr =2207.84): C 70.72, H 6.85%;
found: C 70.65, H 6.93.
3H, OCH3); 13C NMR (75 MHz, CDCl3, 258C): d=157.56
(s, arom. Cquat), 131.01 (s, arom. CH), 130.34 (s, arom. CH),
126.18 (s, arom. Cquat), 120.78 (s, arom. CH), 111.08 (s, arom.
CH), 55.65 (s, OCH3), 29.21 (s, CH2Br).
(2-Methoxybenzyl)diphenylphosphine Oxide
A
solution of (2-methoxybenzyl) bromide (0.300 g,
cis-P,P-Dichloro-bis{5-diphenylphosphinomethyl-
4(24),6(10),12(16),18(22)-tetramethylenedioxy-
2,8,14,20-tetrapentylresorcin[4]arene}platinum(II) (7)
1.49 mmol) in ethyl diphenylphosphinite (0.343 g, ca.
0.32 mL, 1.49 mmol) was stirred for 12 h at 1408C. After
cooling to room temperature, the product was precipitated
with diisopropyl ether (5 mL); yield: 0.460 g (95%).
1H NMR (300 MHz, CDCl3, 258C): d=7.73–7.66 (m, 4H,
CH of PPh2), 7.49–7.34 (7H, CH of PPh2 and benzyl), 7.14
(pseudo t, 1H, CH of benzyl), 6.86 (dd, 1H, CH of benzyl,
3J=7.5 Hz, 3J=7.3 Hz), 6.65 (d, 1H, CH of benzyl, 3J=
8.2 Hz), 3.74 (d, 2H, CH2P, 3J=14.2 Hz), 3.44 (s, 3H,
OCH3); 13C NMR (75 MHz, CDCl3, 258C): d=156.77,
132.85, 119.81 (3 arom. Cq), 131.66, 131.50, 131.17, 128.16,
To a solution of 1 (0.090 g, 0.089 mmol) in CH2Cl2 (10 mL)
was added
a
solution of [PtCl2ACTHUNGTRENNU(G PhCN)2] (0.021 g,
0.044 mmol) in CH2Cl2 (10 mL). After stirring for 12 h, the
reaction mixture was concentrated to ca. 2 mL, whereupon
n-hexane (50 mL) was added. The white precipitate was re-
covered by filtration and dried under vacuum; yield: 0.086 g
(85%). 1H NMR (300 MHz, CDCl3, 258C): d=7.52–7.43
(8H, PPh2), 7.10 (t, 4H, PPh2, 3J=7.2 Hz), 7.04 (s, 2H,
arom. CH of resorcinarene), 7.00 (s, 4H, arom. CH of resor-
cinarene), 6.93–6.88 (m, 8H, PPh2), 6.80 (s, 2H, arom. CH
of resorcinarene), 6.46 (s, 4H, arom. CH of resorcinarene),
6.45 (s, 2H, arom. CH of resorcinarene), 6.02 and 4.28 (AB
spin system, 8H, OCH2O, 2J=7.1 Hz), 5.71 and 4.38 (AB
spin system, 8H, OCH2O, 2J=7.0 Hz), 4.69 (t, 4H,
CHCH2CH2, 3J=8.0 Hz), 4.55–4.50 (m, 4H, CHCH2CH2),
4.26–4.22 (m, 4H, CH2P), 2.22–2.10 (m, 12H, CHCH2CH2),
2.05–1.94 (m, 4H, CHCH2CH2), 1.44–1.27 (m, 36H,
CH2CH2CH2CH3), 1.23–1.13 (m, 12H, CH2CH2CH2CH3),
128.13, 120.56, 110.16 (7 arom. CH), 54.84 (s, OCH3), 31.08
1
(d, CH2P, JP, C =67.9 Hz). The J
N
are not given. 31P NMR (121.5 MHz, CDCl3): d=30 (s,
CH2P).
(2-Methoxybenzyl)diphenylphosphine (5)
A
suspension of (2-methoxybenzyl) diphenylphosphine
oxide (0.200 g, 0.62 mmol) in PhSiH3 (0.134 g, ca. 0.15 cm3,
1.24 mmol) was stirred for 8 h at 1108C. The reaction mix-
ture was cooled to room temperature and PhSiH3 in excess
was removed under vacuum. The residue was washed with
diisopropyl ether (2ꢄ10 mL) to afford the product as a pure
white solid; yield: 0.186 g (98%). 1H NMR (300 MHz,
CDCl3, 258C): 7.76–7.69 (m, 1H, CH of benzyl), 7.47–7.40
(m, 4H, PPh2), 7.34–7.31 (m, 6H, PPh2), 7.17–7.11 (m, 1H,
CH of benzyl), 6.91–6.66 (m, 2H, CH of benzyl), 3.72 (s,
3H, OCH3), 3.46 (s, 2H, CH2P); 13C NMR (75 MHz, CDCl3,
258C): d=157.22, 138.91, 131.23 (3 arom. Cq), 133.03,
130.58, 128.32, 128.25, 128.18, 120.16, 110.34 (7 arom. CH),
55.29 (s, OCH3), 29.52 (d, CH2P, 1JP, C =15.5 Hz). The J-
3
0.94 (t, 12H, CH2CH3, J=6.8 Hz), 0.90 (t, 12H, CH2CH3,
3J=6.7 Hz); 13C NMR (75 MHz, CDCl3, 258C): d=154.87–
137.40 (arom. Cquat), 134.24 (s br, arom. CH of PPh2), 130.18
(s, arom. CH of PPh2), 127.51–127.27 (arom. CH of PPh2),
120.54, 120.40, 118.18, 116.62, 116.34 (5 s, arom. CH of resor-
cinarene), 99.53 (s, OCH2O), 99.01 (s, OCH2O), 36.62 (s,
CHCH2), 36.30 (s, CHCH2), 32.16 (s, CH2CH2CH3), 31.98 (s,
CH2CH2CH3), 29.85 (s, CHCH2), 29.79 (s, CHCH2), 27.93 (s,
CHCH2CH2), 27.49 (s, CHCH2CH2), 22.86 (s, CH2CH3),
22.66 (s, CH2CH3), 14.15 (s, CH2CH3), 14.08 (s, CH2CH3).
The PCH2 signal, which is usually weak, was not detected.
31P NMR (121.5 MHz, CDCl3, 258C): d=9.6 (s with Pt satel-
ACHTUNGTRENNUNG(P,Carom)
coupling constants are not given. 31P NMR
(121.5 MHz, CDCl3): d=À11.8 (s, CH2P).
lites,
PPh2,
JPPt =3810 Hz);
anal.
calcd.
for
C130H150O16P2PtCl2·CH2Cl2 (Mr =2296.50 + 84.93): C 66.07,
H 6.43%; found: C 66.19, H 6.37. MS (ESI-TOF): m/z=
2258.95 [MÀCl]+, expected isotope profiles.
cis-P,P-Dichloro-bis{5-diphenylphosphinomethyl-
4(24),6(10),12(16),18(22)-tetramethylenedioxy-
2,8,14,20-tetrapentylresorcin[4]arene}palladium(II)
(6)
Reaction of 2 with [PtCl2ACTHNUTRGNEN(UG PhCN)2]
To a solution of 1 (0.080 g, 0.079 mmol) in CH2Cl2 (5 mL)
was added
a
solution of [PdCl
(PhCN)2] (0.015 g,
To a solution of 2 (0.095 g, 0.078 mmol) in CH2Cl2 (10 mL)
was slowly added a solution of [PtCl2A(PhCN)2] (0.037 g,
0.039 mmol) in CH2Cl2 (5 mL). After stirring for 0.5 h, the
reaction mixture was concentrated to ca. 1 mL, whereupon
n-hexane (20 mL) was added. The yellow precipitate was re-
covered by filtration and dried under vacuum; yield: 0.081 g
(95%). 1H NMR (300 MHz, CDCl3, 258C): d=7.83–7.77
(4H, PPh2), 7.68–7.42 (m, 16H, PPh2), 7.06 (s, 2H, arom.
CHTUNGTRENNUNG
0.078 mmol) in CH2Cl2 (10 mL). After stirring for 48 h, the
reaction mixture was concentrated to ca. 2 mL, whereupon
n-hexane (50 mL) was added. The yellow precipitate (8) was
recovered by filtration and dried under vacuum; yield:
1
0.100 g (86%). H NMR (300 MHz, CDCl3, 258C): d=7.87–
906
asc.wiley-vch.de
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2010, 352, 901 – 908

Resorcin[4]arene-Derived Mono- and Diphosphines in Suzuki Cross-Coupling
7.72 (m, 24H, PPh2), 7.30 (m, 36H, PPh2), 6.93 (s br, 6H, References
arom. CH of resorcinarene), 6.74 (s br, 6H, arom. CH of re-
sorcinarene), 6.35 (s br, 6H, arom. CH of resorcinarene),
5.85 and 4.21 (br AB spin system, 24H, OCH2O), 4.62–4.45
(m, 12H, CHCH2), 3.97 (br d with Pt satellites, 12H, CH2P,
[1] D. Cram, J. M. Cram, Container Molecules and their
Guests, Monographs in Supramolecular Chemistry, Vol.
4, (Ed.: J. F. Stoddart), Royal Society of Chemistry,
Cambridge, 1994.
2J(PH)=13 Hz, 3J
ACTHNUTRGNE(NUG PtH)=42 Hz), 2.22–2.09 (m, 12H,
CHCH2), 2.02–1.90 (m, 12H, CHCH2), 1.46–1.31 (m, 48H,
CH2CH2CH2CH3), 1.29–1.17 (m, 24H, CH2CH2CH2CH3),
1.00–0.90 (m, 36H, CH2CH3); 31P NMR (121.5 MHz, CDCl3,
258C): d=13.2 (s with Pt satellites, PPh2, JPPt =2581 Hz);
anal. calcd. for C234H258O24P6Pt3Cl6 (Mr =4438.33): C 63.32,
H 5.86%; found: C 63.21, H 5.73; MS (ESI-TOF): m/z=
4401.48 [(PtCl2·2)3ÀCl]+, expected isotope profile.
[2] C. Wieser, C. B. Dieleman, D. Matt, Coord. Chem. Rev.
1997, 165, 93–161.
[3] R. J. Puddephatt, Can. J. Chem. 2006, 84, 1505–1514.
[4] H. Boerrigter, W. Verboom, D. N. Reinhoudt, J. Org.
Chem. 1997, 62, 7148–7155.
[5] H. Boerrigter, T. Tomasberger, W. Verboom, D. N.
Reinhoudt, Eur. J. Org. Chem. 1999, 665–674.
[6] M. Suman, M. Freddi, C. Massera, F. Ugozzoli, E. Dal-
canale, J. Am. Chem. Soc. 2003, 125, 12068–12069.
[7] E. Malinowska, L. Gꢆrski, D. Wojciechowska, M. M.
Reinoso-Garcıꢇ, W. Verboom, D. N. Reinhoudt, New J.
Chem. 2003, 27, 1440–1445.
Crystallography
Single crystals of 7·2 C6H14 suitable for diffraction study
were obtained by slow diffusion of hexane into a dichloro-
methane solution of the complex. Mr =2468.77, monoclinic,
space group C2/c, a=43.811(5), b=14.546(1), c=
29.621(3) ꢅ, b=131.24(1)8, V=14194(2) ꢅ3, Z=4, Dx =
1.155 mg.mÀ3, l(MoK<inf>a</inf>)=0.71073 ꢅ, m=
[8] C. D. Tran, I. Mejac, J. Rebek Jr, R. J. Hooley, Anal.
Chem. 2009, 81, 1244–1254.
[9] C. Gibson, J. Rebeck, Org. Lett. 2002, 4, 1887–1890.
[10] H. El Moll, D. Sꢀmeril, D. Matt, M.-T. Youinou, L.
Toupet, Org. Biomol. Chem. 2009, 7, 495–501.
[11] C. Wieser-Jeunesse, D. Matt, A. De Cian, Angew.
Chem. 1998, 110, 3056; Angew. Chem. Int. Ed. 1998, 37,
2861–2864.
[12] C. Floriani, F. Corazza, W. Lesueur, A. Chiesi-Villa, C.
Guastini, Angew. Chem. 1989, 101, 1430–1431; Angew.
Chem. Int. Ed. Engl. 1989, 28, 1376–1377.
[13] R. Paciello, L. Siggel, M. Rçper, Angew. Chem. 1999,
111, 2045–2048; Angew. Chem. Int. Ed. 1999, 38, 1920–
1923.
11.06 cmÀ1, F
ACHTUNGTRENNUNG(000)=5200, T=150(2) K. Data were collected
on a Oxford Diffraction Xcalibur Saphir 3 diffractometer
(graphite MoKa radiation, l=0.71073 ꢅ). The structure was
solved with SIR-97,[52] which revealed the non-hydrogen
atoms of the molecule. After anisotropic refinement, many
hydrogen atoms were found with a Fourier difference analy-
sis. The whole structure was refined with SHELX-97[53] and
full-matrix least-square techniques (use of F2; x, y, z, bij for
P, C and O atoms, x, y, z in riding mode for H atoms; 754
variables and 9498 observations with I>2.0 s(I); calc w=1/
2
2
ACHTUNGTRENNUNG
[s2(F0 )+(0.0886P)2] where P=(Fo +2Fc2)/3. R1=0.047,
[14] F. J. Parlevliet, C. Kiener, J. Fraanje, K. Goubitz, M.
Lutz, A. L. Spek, P. C. J. Kamer, P. W. N. M. van Leeu-
wen, J. Chem. Soc. Dalton Trans. 2000, 1113–1122.
[15] C. J. Cobley, D. D. Ellis, A. G. Orpen, P. G. Pringle, J.
Chem. Soc. Dalton Trans. 2000, 1109–1112.
[16] C. Kunze, D. Selent, I. Neda, R. Schmutzler, A. Span-
nenberg, A. Bçrner, Heteroat. Chem. 2001, 12, 577–
585.
[17] M. Vꢀzina, J. Gagnon, K. Villeneuve, M. Drouin, P. D.
Harvey, Organometallics 2001, 20, 273–281.
[18] D. Sꢀmeril, C. Jeunesse, D. Matt, L. Toupet, Angew.
Chem. 2006, 118, 5946; Angew. Chem. Int. Ed. 2006, 45,
5810–5814.
wR2=0.153, Sw =1.062, D1<2.7eꢅÀ3. The A level alerts ob-
served in the checkcif are mainly due to a disordered pentyl
group (C38···C42). The observed voids are classical in this
family of compounds. CCDC 722727 contains the supple-
mentary crystallographic data for this compound. These
data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
General Procedure for Suzuki Cross-Coupling
Reactions
A solution of [PdACHTUNGTRENNUNG(OAc)2] in dioxane (0.5 mL) was mixed
[19] A. Sarkar, M. Nethaji, S. S. Krishnamurthy, J. Organo-
with a solution of phosphine in dioxane (0.5 mL) in a
Schlenk tube. NaH (60% in mineral oil, 0.044 g, 1.00 mmol),
PhB(OH)2 (0.122 g, 1.0 mmol), aryl bromide (0.5 mmol),
and dioxane (0.5 mL) were then added successively. The re-
action mixture was heated at 1008C for 1 hour. After cool-
ing, decane (0.05 mL) was added as internal reference. A
sample of 0.5 mL was taken and filtered over Celite for GC
analysis.
met. Chem. 2008, 693, 2097–2110.
[20] S. Sameni, M. Lejeune, C. Jeunesse, D. Matt, R.
Welter, Dalton Trans. 2009, 7912–7923.
[21] D. M. Homden, C. Redshaw, Chem. Rev. 2008, 108,
5086–5130.
[22] H. El Moll, D. Sꢀmeril, D. Matt, L. Toupet, Eur. J. Org.
Chem. 2010, 1158–1168.
[23] N. Miyaura, A. Suzuki, Chem. Rev. 1995, 95, 2457–
2483.
[24] F. Bellina, A. Carpita, R. Rossi, Synthesis 2004, 2419–
2440.
[25] J.-C. Hierso, A. Fihri, R. Amardeil, P. Meunier, H.
Doucet, M. Santelli, B. Donnadieu, Organometallics
2003, 22, 4490–4499.
Acknowledgements
The authors thank the French Agence Nationale de la Re-
cherche for financial support (ANR project MATCALCAT).
Johnson Matthey is gratefully acknowledged for a generous
gift of palladium.
[26] W. Xu, J. P. Rourke, J. J. Vittal, R. J. Puddephatt, J.
Chem. Soc. Chem. Commun. 1993, 145–147.
Adv. Synth. Catal. 2010, 352, 901 – 908
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
907

Hani El Moll et al.
FULL PAPERS
[27] W. Xu, J. P. Rourke, J. J. Vittal, R. J. Puddephatt, Inorg.
Chem. 1995, 34, 323–329.
[28] J.-P. Dutasta, B. Bibal, P. Delangle, I. Gosse, J.-C. Mu-
latier, Phosphorus Sulfur Silicon 1999, 144–146, 337–
341.
[41] C. Barnard, Platinum Met. Rev. 2008, 52, 38–45.
[42] D. J. M. Snelders, G. van Koten, R. J. M. Klein Geb-
bink, J. Am. Chem. Soc. 2009, 131, 11407–11416.
[43] A. Bader, E. Lindner, Coord. Chem. Rev. 1991, 108,
27–110.
[29] P. Jacopozzi, E. Dalcanale, S. Spera, L. A. J. Chrisstof-
fels, D. N. Reinhoudt, T. Lippmann, G. Mann, J. Chem.
Soc. Perkin Trans. 2 1998, 671–677.
[44] H.-P. Abicht, K. Issleib, J. Organomet. Chem. 1980,
185, 265–275.
[45] T. Bartik, T. Himmler, J. Organomet. Chem. 1985, 293,
343–351.
[46] J. E. Marcone, K. G. Moloy, J. Am. Chem. Soc. 1998,
120, 8527–8528.
[47] M.-N. Birkholz, Z. Freixa, P. W. N. M. van Leeuwen,
Chem. Soc. Rev. 2009, 38, 1099–1118.
[30] R. V. Merkulov, V. I. Maslennikova, E. E. Nifant’ev,
Russ. J. Gen. Chem. 2000, 70, 1929–1930.
[31] I. L. Nikolaeva, A. R. Burilov, M. A. Pudovik, W. D.
Habicher, A. I. Konovalov, Russ. Chem. Bull. Int. Ed.
2001, 50, 748–750.
[32] B. Bibal, J.-P. Declercq, J.-P. Dutasta, B. Tinant, A.-G.
[48] L. Monnereau, D. Sꢀmeril, D. Matt, L. Toupet, A. J.
Mota, Adv. Synth. Catal. 2009, 351, 1383–1389.
[49] As revealed by combined MS and 31P NMR studies, the
Valade, Tetrahedron 2003, 59, 5849–5854.
[33] V. I. Maslennikova, O. S. Serkova, M. Gruner, S.
Goutal, I. Bauer, W. D. Habicher, K. A. Lyssenko,
M. Y. Antipin, E. E. Nifantyev, Eur. J. Org. Chem.
2004, 4884–4893.
[34] D. J. Eisler, R. J. Puddephatt, Can. J. Chem. 2004, 82,
185–194.
[35] S. Torella, E. Dalcanale, F. Longobardi, A. Visconti, M.
Suman, R. Ranieri, (to Barilla, G. and Fratelli. R
S.p.A.), Eur. Pat. Appl. EP 1873161A1, 2008.
[36] J. C. Jeffrey, T. B. Rauchfuss, Inorg. Chem. 1979, 18,
2658–2666.
[37] X. Bei, H. W. Turner, W. H. Weinberg, A. S. Guram,
J. L. Petersen, J. Org. Chem. 1999, 64, 6797–6803.
[38] F. Barrios-Landeros, J. F. Hartwig, J. Am. Chem. Soc.
2005, 127, 6944–6945.
reaction of 3 with [RhACTHUNGTERN(NUNG acac)(CO)2] resulted in a mix-
ture of complexes, among which the chelate complex
[RhACTHNUTRGNEU(GN acac)·3] was unambiguously detected by mass
spectroscopy (MS: m/z=1437.51 [M+Na+], expected
isotope profile). Attempts to isolate a chelate complex
of formula [PdX2·3] failed.
[50] F. R. Hartley, The Chemistry of Platinum and Palladi-
um, Wiley, New York 1973.
[51] K. Kellner, S. Rothe, E.-M. Steyer, A. Tzschach, Phos-
phorus and Sulfur 1980, 8, 269–274.
[52] A. Altomare, M. C. Burla, M. Camalli, G. Cascarano,
C. Giacovazzo, A. Guagliardi, A. G. G. Moliterni, G.
Polidori, R. Spagna, J. Appl. Crystallogr. 1998, 31, 74–
77.
[53] G. M. Sheldrick, SHELXL-97, Programm for the Re-
finement of Crystal Stuctures, University of Gçttingen,
Germany, 1997.
[39] Q. Dai, W. Gao, D. Liu, L. M. Kapes, X. Zhang, J. Org.
Chem. 2006, 71, 3928–3934.
[40] H. Ohta, M. Tokunaga, Y. Obora, T. Iwai, T. Iwasawa,
T. Fujihara, Y. Tsuji, Org. Lett. 2007, 9, 89–92.
908
asc.wiley-vch.de
ꢃ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2010, 352, 901 – 908