Macrocyclic core phosphorus dendrimers covered on the surface by N,P ligands

Article abstract of DOI:10.1002/ejoc.201001464

A new family of dendrimers up to the third generation is synthesized starting from a 15-membered triolefinic azamacrocycle. γ-Iminophosphane groups are anchored on the surface of the second and third generations, and their corresponding Pd^II co

Full text of DOI:10.1002/ejoc.201001464

FULL PAPER
DOI: 10.1002/ejoc.201001464
Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P
Ligands
Elena Badetti,[a] Gregory Franc,[b,c] Jean-Pierre Majoral,[b,c] Anne-Marie Caminade,*[b,c]
Rosa María Sebastián,*[a] and Marcial Moreno-Mañas[a]
Dedicated to Prof. Dr. Pelayo Camps on the occasion of his 65th birthday
Keywords: Dendrimers / N,P ligands / Macrocycles / Palladium / Platinum / Nanoparticles
A new family of dendrimers up to the third generation is syn-
thesized starting from a 15-membered triolefinic azamacro-
cycle. γ-Iminophosphane groups are anchored on the surface
of the second and third generations, and their corresponding
PdII complexes are prepared. To investigate the effect of
shielding upon the coordinating ability of the macrocyclic
core, the coordination with Pd0 and Pt0 atoms is studied. Dur-
ing this process, two new materials containing Pd0 or Pt0
nanoparticles stabilized by these dendrimers are charac-
terized by high-resolution transmission electron microscopy,
IR spectroscopy, and elemental analysis.
combining both metal-coordinating abilities at the core and
on the surface at the same time has been described, to the
best of our knowledge.
Introduction
Several synthetic methodologies have been described to
prepare dendrimers, a class of monodisperse organic mate-
rials containing functionalities in the core, in the dendritic
backbone, or on the surface.[1] The most important feature
of dendrimer chemistry is the design of the structure and
the possibility to insert selected chemical units in predeter-
mined sites of the dendritic structure. The combination of
dendrimers and other macromolecular topologies as build-
ing blocks is an attractive and promising approach in
the development of molecular recognition,[2] artificial
light-harvesting antennae,[3] imaging contrast agents,[4]
and new catalytic systems.[5] Phthalocyanines,[6] por-
phyrins,[2a,2b,2d,3b,3c,7] crown ethers,[8] and cyclam[3a,9]
among others[10] have been more frequently used as macro-
cyclic dendritic cores. However, relatively few examples of
this type of dendrimer have been reported as well-defined
metal-coordinating cores,[9a–9e,11] the exception being made
for those based on porphyrins[2a,2b,2d,3c,7] and phthalocyan-
ines.[6c] More common is the presence of metal ligands on
the surfaces of dendrimers.[12] Nevertheless, no dendrimer
The well-established divergent synthesis of phosphorus-
containing dendrimers allows a wide choice of core and ter-
minal groups.[12d,13] Only two examples of macrocyclic
cores have been reported so far;[6c,6d,14] however, a large
number of functional groups have been anchored onto the
surface, some of them being metal ligands (P,P; P,N; P,P; or
N,N ligands).[15] 15-Membered azamacrocycles containing
three endocyclic olefins (1, Figure 1) have also been incor-
porated onto the surface of phosphorus dendrimers. These
macromolecules coordinate Pd0 atoms through the olefins
of the macrocycles and stabilize Pd0 nanoparticles; both
systems are active as catalysts in Mizoroki–Heck reac-
tions.[5a]
[a] Department of Chemistry, Universitat Autònoma de Barcelona,
Cerdanyola del Vallès, 08193 Barcelona, Spain
Fax: +34-93-5811265
Figure 1. Structure of 15-membered macrocycle containing three
endocyclic olefins.
E-mail: rosamaria.sebastian@uab.es
[b] CNRS, LCC (Laboratoire de Chimie de Coordination),
205, route de Narbonne, 31077 Toulouse, France
E-mail: caminade@lcc-toulouse.fr
In this paper, we present the synthesis and characteriza-
tion of phosphorus dendrimers containing a triolefinic 15-
membered macrocycle as a core and iminophosphane li-
gands on the surface up to the third generation. The effect
[c] Université de Toulouse, UPS, INPT, LCC,
31077 Toulouse, France
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201001464.
1256
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2011, 1256–1265

Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P Ligands
of the steric isolation of the macrocyclic core on its metal
coordinating ability will be studied. The presence of met-
allic ligands in both the core and the surface of these new
macromolecules leads to the possibility to create new spe-
cies able to complex different metals, in different oxidation
states with potential applications in catalysis.
Results and Discussion
The first step of the synthesis of the dendrimers having
a macrocycle as core is a Staudinger reaction between 15-
membered macrocycle 2,[16] containing three phosphane
groups as substituents, and the azide N3P(S)(OC6H4-p-
CHO)2 (3).[17] The reaction was complete in 3 h at room
temperature under an inert atmosphere to prevent the oxi-
Scheme 1. Synthesis of first-generation dendrimer 4-GM1Ј.
The condensation reaction between the aldehyde groups
dation of the phosphane groups. Under these conditions, of 4-GM1Ј and phosphorhydrazide 5 occurs overnight at
dendrimer 4-GM1Ј was isolated in 68% yield after workup room temperature. The second generation of the dendrimer,
(Scheme 1). Due to the small size of this dendrimer, it can 4-GM2, can be isolated in good yield after workup (84%,
be purified by column chromatography; however, the other Scheme 2). The condensation reaction induces the total dis-
bigger macromolecules reported in this work are purified appearance of the signals corresponding to the aldehydes in
1
by washing as usual in this type of chemistry. The evolution the H and 13C NMR spectra, as well as in the IR spectra.
of the reaction was followed by 31P NMR spectroscopic Furthermore, this reaction induces the appearance of a new
monitoring of the crude solution; the disappearance of the signal in the 31P NMR spectrum at δ = 66.5 ppm, which
signal corresponding to the phosphane groups of 2 (δ = corresponds to the P(S)Cl2 end groups; internal phosphorus
–3.8 ppm) and the appearance of two doublets (2JP,P
32.4 Hz) at δ = 13.9 (P=N) and 50.3 (P=S) ppm, indicate
the end of the reaction.
=
signals are slightly modified (δ = 16.5 and 54.9 ppm).
The six chlorine atoms of the three P(S)Cl2 functions of
the surface of dendrimer 4-GM2 can be easily modified by
Scheme 2. Synthesis of second- and third-generation dendrimers 4-GM2, 4-GM2Ј, and 4-GM3
.
Eur. J. Org. Chem. 2011, 1256–1265
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1257

A.-M. Caminade, R. M. Sebastián et al.
FULL PAPER
Scheme 3. Synthesis of dendrimers containing iminophosphane ligands on the surface (8-GM2 and 8-GM3).
nucleophilic substitution with phenols in basic media. Their coordination ability of 15-membered triolefinic macrocycles
reaction with 4-hydroxybenzaldehyde (6, 6 equiv.) in the of type 1 (Figure 1) was studied previously by some of us.[19]
presence of Cs2CO3 for 12 h at room temperature gives den- They are excellent coordination agents for Pd0 and Pt0,
drimer 4-GM2Ј (66%), after centrifugation of the salts. Nu- forming stable complexes through the three endocyclic ole-
cleophilic substitution induces a slight deshielding of the fins, but not for PdII atoms. In order to verify that the 15-
signal corresponding to the phosphorus that undergo the membered macrocycle retains its complexing ability when
reaction, from δ = 66.5 ppm for 4-GM2 to δ = 64.0 ppm for used as core of a dendrimer, we decided to try to react den-
4-GM2Ј in the 31P NMR spectra. Aldehyde functions on the drimer 4-GM1Ј with Pd(dba)2 (1.7 equiv.) as a source of Pd0
surface are again obtained with this substitution. Conden- (dba = dibenzylideneacetone). We choose a small genera-
sation reaction of 4-GM2Ј with phosphorhydrazide 5 affords tion to be able to detect easily the complexation at the core.
third-generation dendrimer 4-GM3 in good yield after The mixture was stirred under reflux overnight. Then, the
workup (91%) and containing 24 reactive chlorine atoms residue was chromatographed on silica gel, and complex 9-
(Scheme 2). Repetition of the substitution reaction with 6
G
M1Ј was isolated in 69% yield (Scheme 4). The 31P NMR
followed by condensation with 5 affords dendrimers of spectrum of the complex reveals the appearance of two
higher generations. However, at this point, we decided to doublets, of relative intensity 2:1, for each expected phos-
functionalize dendrimers 4-GM2 and 4-GM3 with another phorus signal [17.2 and 17.4 ppm for PPh2 and 53.4 and
phenol containing an N,P ligand in its structure.
53.5 ppm for P(S), J ≈ 32 Hz]. It is known that the presence
Phosphorus and nitrogen donor ligands are among the of a palladium atom in macrocycles of type 1 breaks the
most attractive and useful ligands in catalysis thanks to the symmetry of the compound, and the complexation of palla-
presence of both soft and hard donor atoms, which allows dium by one olefin is different with respect to the other
their complexation properties to be tailored.[18] Phosphorus two.[19] Usually, this effect is observed by 1H and 13C NMR
dendrimers containing this type of ligand on the surface spectroscopic analysis of the olefinic and methylenic groups
were previously prepared and used as easily recoverable cat- of the cycle. In complex 9-GM1Ј, this asymmetry is also ob-
alysts in Stille coupling reactions.[15c] Following the same served for the phosphorus atoms at the 8th and 10th bonds
methodology, the reaction of 4-GM2 or 4-GM3 with phenol of the olefinic groups, illustrating the high sensitivity of 31
P
7[15c] in the presence of cesium carbonate leads to the for- NMR spectroscopy to subtle modifications in the environ-
mation of dendrimers of the second (8-GM2, 94%) and third ments of phosphorus atoms, as some of us have previously
generations (8-GM3, 67%), containing 12 and 24 γ-imino- reported.[13b,20]
phosphane groups on the surface, respectively (Scheme 3).
These new macromolecules have the potential ability to co-
ordinate to transition metals in both positions (surface and
core).
Due to the presence of two types of coordinating sites in
dendrimers 8-GM2 and 8-GM3, their complexation ability
might be difficult to examine; thus, in a first attempt, it
appeared desirable to test independently the properties of
both types of complexing sites. We have already shown that
Scheme 4. Preparation of complex 9-GM1Ј.
γ-iminophosphane groups linked to the surface of dendri-
mers complex PdIICl2 cleanly;[15c] thus, only the complexing
This experiment reassured us of the complexation ability
ability of the macrocyclic core has to be tested. The metal of the core, and we thought that this complex could be used
1258
www.eurjoc.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2011, 1256–1265

Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P Ligands
to continue the growth of the dendrimer to obtain a new ric amounts of PdCl2(COD) for 3 h. Resulting complexed
series with a complexed core. For this purpose, 9-GM1Ј was dendrimers 10-GM2 and 10-GM3 were obtained in good
treated with phosphorhydrazide 5. The reaction went to yields after workup (76 and 86%, respectively; Scheme 5).
completion (total disappearance of the aldehyde functions); It is important to highlight that the products were prepared
however, a substantial part of the palladium atom was de- in anhydrous THF; however, after being isolated as solids
complexed, and the mixture of compounds obtained could and dried, their solubility changes and they are only soluble
neither be isolated nor characterized. This experiment indi- in DMF, which is the solvent used for NMR spectroscopy.
cates that the complexation of the macrocyclic core is rela- Linking palladium(II) atoms to PPh2 end groups produces
tively fragile, contrarily to the complexation of the terminal an important shielding of the signal of the phosphorus in
phosphanyl groups.[15c] Thus, in the case of dendrimers pos- the 31P NMR spectra, from δ ≈ –15 ppm in the starting
sessing complexing sites both at the core and on the surface, materials to δ ≈ 28.5 ppm in the metallic complexes. The
the complexation reactions must be carried out first with 1H and 31P NMR spectra of 10-GM3 showed large bands,
the phosphane terminal groups and PdII and then with the probably due to the steric hindrance present on the surface.
macrocyclic core and Pd0 (or Pt0).
Such enlargement might be due also to interaction of PdII
Dendrimers containing γ-iminophosphane end groups in atoms with other parts of the dendrimers. To verify this
solution in dichloromethane were treated with stoichiomet- assumption, we prepared two model molecules possessing
Scheme 5. Synthesis of palladium(II) complexes 10-GM2 and 10-GM3
.
Eur. J. Org. Chem. 2011, 1256–1265
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1259

A.-M. Caminade, R. M. Sebastián et al.
FULL PAPER
the same heteroatom linkages as the dendrimers, Ph3P = troduced into the reaction). Due to the high insolubility of
N-P(S)(OPh)2 (11)[21] and PhCH=NN(Me)P(S)(OPh)2 (12; the obtained solid, the elimination of Pd black formed dur-
Figure 2). When treated with PdCl2(COD) under the same ing the reaction was not possible.
experimental conditions as those used for dendrimers 8, no
1
interaction is observed in the H and 31P NMR spectra,
showing that PdII atoms are only complexed by the imino-
phosphane ligands of the surface and not by the other he-
teroatoms present in the dendrimer branches. Moreover, as
tested by our group, the macrocyclic core can coordinate
Pd0 atoms through the three endocyclic olefins but not PdII
atoms.[19]
Figure 2. Model molecules prepared containing the same func-
tional groups as dendrimers 8.
We have shown with 9-GM1Ј that the macrocyclic core is
a good coordinating site for Pd0. If the accessibility of Pd0
atoms to the macrocyclic core of the highest generations
dendrimers 10-GM2 and 10-GM3 remains possible, the prep-
aration of dendrimers containing both Pd0 and PdII atoms
in the core and on the surface at the same time can be
carried out for the first time. With this aim, dendrimer 10-
GM2 was treated with a stoichiometric amount of Pd(dba)2
in DMF at 60 °C. Partial complexation of the macrocyclic
1
core (50%) was observed by H NMR spectroscopy after
the reaction was left overnight. Part of the olefinic protons
are deshielded, following the behavior of simple macro-
cycles previously studied by some of us.[19] For the next 9 d,
a large excess of the palladium(0) source (9 equiv.) was
added to fully complex the core. However, a black insoluble
Figure 3. Characterization of nanoparticles stabilized by dendrimer
solid was formed, containing an organic part as shown by
10-GM2 and/or its palladium(0) complex. (a and b) HRTEM pic-
ture and core size distribution histogram of nanoparticles of Pd0,
IR spectroscopy. This material was analyzed by high-resolu-
tion transmission electron microscopy (HRTEM), and the respectively; (c) electron diffraction patterns corresponding to Pd0
fcc of Pd0 nanoparticles; (d and e) HRTEM picture and core size
presence of palladium(0) nanoparticles with diameters of
distribution histogram of nanoparticles of Pt0, respectively;
5.8Ϯ0.7 nm was detected (Figure 3). Electron diffraction of
a sample of the nanoparticles showed the characteristic
(f) EDX spectra of Pt0 nanoparticles.
pattern of face-centered cubic (fcc) palladium(0); experi-
The reaction of phosphorus dendrimers containing 15-
mental values are indicated in Figure 3. The insolubility of membered macrocycles 1 with a Pt0 source has not been
this new nanoparticulated material in conventional organic previously tested, but similar free macrocycles were pre-
solvents precluded its characterization by NMR spec- viously shown to be able to complex Pt0.[19] Thus, den-
troscopy, so the total complexation of the core could not drimer 10-GM2 was treated with a slight excess amount of
be confirmed. The stabilization of Pd0 nanoparticles by Pt(PPh3)4 (1.5 equiv.) at 130 °C in DMF for 9 d. After that
phosphorus dendrimers containing 15-membered macro- time, the solvent was evaporated, and the resulting insoluble
cycles on the surface was observed and deeply studied in material was analyzed. Also in this case, using a smaller
previous work.[5a] The use of stoichiometric amounts of a amount of metal source, nanoparticles were observed by
palladium(0) source favored the formation of the corre- HRTEM (Figure 3); they are so small (1.3Ϯ0.2 nm of dia-
sponding Pd0 macrocyclic complexes on the surface of the meter) that the electron diffraction experiment cannot be
dendrimers; however, when an excess amount of Pd0 was perform to confirm the structure of the Pt0 in the nanopar-
used, the nanoparticles were formed as observed also in this ticles. However, the presence of Pt0 was confirmed by en-
work. The elemental analysis of the nanoparticulated mate- ergy dispersive X-ray analysis (EDX). NMR experiments
rial obtained here reveals that 29.4% of the mass is Pd could also not be carried out due to the high insolubility of
(43% yield calculated with respect to the amount of Pd in- this material, so the complexation of the core cannot be
1260
www.eurjoc.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2011, 1256–1265

Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P Ligands
confirmed. The yield of the obtained material is 64% with is important to highlight that the formation of nanopar-
respect to the amount of Pt0 introduced into the reaction.
ticles does not require any reducing process, as is usual in
The size of the metal nanoparticles obtained seems to the preparation of nanoparticles stabilized by dendrimers.
be sensible to the quantity of the metal source used in the These new nanoparticulated materials were characterized
procedure, as was observed in our previous work on related by HRTEM, IR spectroscopy, and elemental analysis. The
dendrimers.[5a] No change in the nanoparticle size is ex- very small size of the obtained nanoparticles makes them
pected with higher dendrimer generations, as was observed interesting as potentially easily recoverable heterogeneous
in related studies.[5a] Due to the size of the dendrimer used catalysts. Moreover, the ligands on the surface of the nano-
as stabilizer (a second-generation one) and its likely flat particles’ stabilizing agent could play an important role
shape, we could assume that nanoparticles should not be during the catalytic cycle of the catalyzed reaction, stabiliz-
included in the dendrimer structures; they should be consid- ing PdII or PtII atoms coming from the oxidation of the
ered as dendrimer-stabilized metal nanoparticles.[22] γ-Imi- metallic atoms of the nanoparticles. Mechanistic studies
nophosphane–PdII complexes anchored on the surface of should be developed.
10-GM2 were stable under the reaction conditions used for
the preparation of metal nanoparticles; their characteristic
signal in the 31P NMR spectrum around 28.5 ppm was ob-
served during the process and also in a blank experiment
without the presence of a metal(0) source, so the direct par-
Experimental Section
General Remarks: Melting points were determined with a Kofler
apparatus. IR spectra were recorded by attenuated total reflectance
ticipation of the phosphane groups on the surface of den-
mode (ATR) with a Bruker Tensor 27 spectrometer. NMR spectra
drimers in the stabilization of nanoparticles should not be
were recorded with a Bruker ARX200, DPX250, DPX360, or
considered.
AV500 instrument. 1H NMR and 13C{1H} NMR chemical shifts
are reported relative to tetramethylsilane. 31P{1H} NMR are re-
1
ported relative to H3PO4 85% in water. The attribution of H and
13C NMR spectra were done by using DEPT, nOe, COSY, HMQC,
HMBC, and TOCSY experiments when necessary. The numbering
used for the assignment of the NMR signals is shown in Figure 4.
Elemental analyses for C, H, N, P, Pd, and Pt are the average of
two determinations. TEM analyses were performed at the “Servei
de Microscòpia” of the Universitat Autònoma de Barcelona, with
a Hitachi H-7000 model at 100 kV. Insoluble nanoparticulated ma-
terials were sonicated in THF for 2 min, and one drop of the finely
divided suspension in THF was placed on a specially produced
structure less carbon support film having a thickness of 4–6 nm
and dried before observation. The yields of the nanoparticles were
determined as (metal incorporated in nanoparticles/metal intro-
duced)ϫ100. All preparations of dendrimers were performed un-
der an inert atmosphere. Complexes and nanoparticles were pre-
pared with Schlenk-type glassware. Anhydrous solvents were used
thoroughly. Compounds 2,[16] 3,[17] 5,[13b] 7,[15c] and 11[21] were syn-
thesized according to published procedures.
Conclusions
A new family of phosphorus dendrimers containing a 15-
membered triolefinic macrocycle as a core has been de-
scribed up to the third generation. Nucleophilic substitu-
tion of the chlorine atoms of the P(S)Cl2 end groups with
the appropriate phenol has allowed two dendrimers of the
second and third generations containing 12 and 24 γ-imino-
phosphane groups on the surface, respectively, to be ob-
tained. These compounds are new macromolecules that
possess metal coordinating sites in the core and on the sur-
face at the same time. On a small dendrimer (first genera-
tion), the complexation ability of the core towards Pd0 has
been demonstrated. Then, the coordinating ability of the
surface ligands was proved by preparation of the corre-
sponding PdII complexes. When the complexed dendrimer
of the second generation was treated with a Pd0 or Pt0
source, not only partial coordination of the core occurred,
but the appearance of metal nanoparticles was also ob-
served. The formation of the complex at the core was more
difficult than with the first generation, probably due to ste-
Preparation of 4-GM1Ј: Compound 2 (0.43 g, 0.39 mmol) dissolved
in CH2Cl2 (2 mL) was added by cannula to a previously prepared
solution of 3 (0.40 g, 1.15 mmol) in CH2Cl2 (1 mL) at 0 °C over
10 min. The mixture was stirred for 3 h at room temperature. The
formation of N2 gas was observed. Then, 2 mL of the solvent was
ric hindrance induced by the branches of the dendrimer. It evaporated and pentane (10 mL) was added to precipitate the
Figure 4. Numbering used for NMR assignment.
Eur. J. Org. Chem. 2011, 1256–1265
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1261

A.-M. Caminade, R. M. Sebastián et al.
FULL PAPER
formed dendrimer. The product was purified by column
chromatography (silica gel; CHCl3/CH3CN, 97:3). Compound 4- (d, JC,P = 12.2 Hz, C-5), 127.5 (dd, JC,P = 108.9 Hz, JC,P
13.7 Hz, C-16), 50.6 (C-2), 122.0 (d, 3JH,P = 4.5 Hz, C-12,18), 126.9
2
1
3
=
3
GM1Ј was obtained (0.58 g, 68%) as a white solid. M.p. 113–116 °C.
3.8 Hz, C-7), 128.1 (C-13), 129.0 (d, JC,P = 13.3 Hz, C-9), 129.5
(C-14), 130.8 (C-1), 131.5 (C-19), 132.7 (d, JC,P = 10.5 Hz, C-8),
2
IR (ATR): ν = 3056, 1696, 1595, 1499, 1205, 1153, 1113, 886,
˜
1
3
3
692 cm–1. H NMR (500 MHz, CDCl3, 25 °C): δ = 3.73 (d, JH,H 133.2 (C-20), 133.7 (C-10), 133.9 (d, JC,P = 11.5 Hz, C-4), 134.2
3
1
3
= 5.0 Hz, 12 H, 2-H), 5.60 (t, JH,H = 5.0 Hz, 6 H, 1-H), 7.32 (dd, (d, JC,P = 85.0 Hz, C-6), 140.1 (d, JC,P = 13.7 Hz, C-15), 143.1
3JH,H = 10.0 Hz, JH,P = 5.0 Hz, 12 H, 12-H), 7.49 (dt, JH,H
=
(C-3), 153.1 (d, JC,P = 9.2 Hz, C-17), 155.2 (d, JC,P = 7.0 Hz, C-
4
3
2
2
4
10.0 Hz, JH,P = 5.0 Hz, 12 H, 9-H), 7.61–7.68 (m, 18 H, 8-H, 10-
11), 190.8 (C-21) ppm. 31P{1H} NMR (81 MHz, CDCl3, 25 °C): δ
H), 7.80 (d, 3JH,H = 10.0 Hz, 12 H, 13-H), 7.83 (d, 3JH,H = 15.0 Hz, = 16.5 (d, JP,P = 31.0 Hz, Pa-Ph2), 55.0 (d, JP,P = 31.0 Hz, Pb=S),
6 H, 4-H), 7.87 (dd, 3JH,H = 10.0 Hz, 3JH,P = 5 Hz, 6 H, 5-H), 9.94 64.0 (Pc=S) ppm. C198H168N18O36P12S12 (4132.1): calcd. C 57.55,
(s, 6 H, 15-H) ppm. 13C{1H} NMR (125.8 MHz, CDCl3, 25 °C): δ H 4.10, N 6.10; found C 57.78, H 4.33, N 6.15.
2
2
1
2
= 50.7 (C-2), 122.0 (d, JC,P = 5.0 Hz, C-12), 127.0 (d, JC,P
12.6 Hz, C-5), 127.2 (dd, JC,P = 108.2 Hz, JC,P = 3.8 Hz, C-7),
=
Preparation of 4-GM3: Dendrimer 4-GM2Ј (0.12 g, 0.03 mmol) was
dissolved in CHCl3 at room temperature and then cooled to 0 °C.
A solution of 5 (1.7 mL, 0.38 mmol) in CHCl3 was added, and the
mixture was stirred for 45 min. The solvent was evaporated, and
the solid was washed three times with a mixture of THF/pentane
(1:10). Compound 4-GM3 was obtained as a white solid (0.16 g,
1
3
3
129.1 (d, JC,P = 13.8 Hz, C-9), 129.6 (C-1), 131.3 (C-13), 132.7 (d,
2JC,P = 11.3 Hz, C-8), 132.8 (C-14), 133.4 (C-10), 133.6 (d, JC,P
=
1
3
105.6 Hz, C-6), 133.8 (d, JC,P = 11.3 Hz, C-4), 143.4 (C-3), 156.7
(d, JC,P = 10.1 Hz, C-11), 191.0 (C-15) ppm. 31P{1H} NMR
2
2
(202.5 MHz, CDCl3, 25 °C): δ = 13.9 (d, JP,P = 32.4 Hz, Pa-Ph2),
91%). M.p. 180 °C (decomp.). IR (ATR): ν = 2866, 1601, 1502,
˜
50.3 (d, JP,P = 32.4 Hz, Pb=S) ppm. 31P{1H} NMR (81 MHz,
2
1190, 911, 836, 778, 689 cm–1. 1H NMR (200 MHz, CDCl3, 25 °C):
δ = 3.30 (d, 3JH,P = 14.0 Hz, 18 H, 16-H), 3.43 (d, 3JH,P = 14.0 Hz,
36 H, 22-H), 3.64 (s, 12 H, 2-H), 5.48 (s, 6 H, 1-H), 7.10–7.90 (m,
132 H, H aromatic and CH=N) ppm. 13C{1H} NMR (62.5 MHz,
2
2
CDCl3): δ = 13.9 (d, JP,P = 32.4 Hz, Pa-Ph2), 50.3 (d, JP,P
=
32.4 Hz, Pb=S) ppm. C108H90N6O18P6S6 (2138.2): calcd. C 60.67,
H 4.24, N 3.93; found C 60.82, H 4.35, N 4.02.
2
2
Preparation of 4-GM2: Dendrimer 4-GM1Ј (0.35 g, 0.16 mmol) was CDCl3, 25 °C): δ = 31.9 (d, JC,P = 13.3 Hz, C-22), 33.1 (d, JC,P
3
dissolved in CHCl3 (1 mL). After cooling the solution to 0 °C, a
solution of H2NNMeP(S)Cl2 (5; 4.7 mL, 1.09 mmol) in CHCl3 was
added. The mixture was stirred overnight at room temperature, and
then the solvent was evaporated. THF (0.3 mL) was added to dis-
solve the solid, and the product was precipitated by adding pentane
(3 mL). The solid was filtered by cannula and washed twice more
with a mixture THF/pentane (0.3:3 mL). After drying, compound
4-GM2 was obtained (0.43 g, 84%) as a white solid. M.p. 165 °C
= 13.3 Hz, C-16), 50.7 (C-2), 121.9 (d, JH,P = 3.6 Hz, C-12,C-18),
2
1
3
126.9 (d, JC,P = 13.1 Hz, C-5), 127.4 (dd, JC,P = 107.9 Hz, JC,P
3
= 3.8 Hz, C-7), 128.1 (C-13), 128.8 (C-19), 129.0 (d, JC,P
=
13.5 Hz, C-9), 129.5 (C-14), 131.0 (C-1), 131.5 (C-20), 132.7 (d,
3
2JC,P = 11.2 Hz, C-8), 133.2 (C-10), 133.9 (d, JC,P = 11.2 Hz, C-
2
3
4), 134.2 (d, JC,P = 105.6 Hz, C-6), 139.5 (d, JC,P = 13.7 Hz, C-
15), 140.8 (d, 3JC,P = 18.4 Hz, C-21), 143.1 (C-3), 151.9 (d, JC,P
=
2
7.4 Hz, C-17), 153.0 (d, 2JC,P = 8.8 Hz, C-11) ppm. 31P{1H} NMR
(decomp.). IR (ATR): ν = 1600, 1503, 1437, 1199, 1160, 886, 777, (81 MHz, CDCl3, 25 °C): δ = 16.4 (d, 2JP,P = 30.0 Hz, Pa-Ph2), 55.0
˜
1
3
2
687 cm–1. H NMR (200 MHz, CDCl3, 25 °C): δ = 3.46 (d, JH,P (d, JP,P
= 30.0 Hz, Pb=S), 65.6 (Pc=S), 66.4 (Pd=S) ppm.
= 14.1 Hz, 18 H, 16-H), 3.68 (s, 12 H, 2-H), 5.50 (s, 6 H, 1-H), C210H204Cl24N42O24P24S24 (6063.9): calcd. C 41.59, H 3.39, N 9.70;
3
7.19 (d, JH,H = 8.3 Hz, 12 H, 12-H), 7.45–7.51 (m, 12 H, 9-H), found C 41.72, H 3.45, N 9.78.
3
7.52–7.69 (m, 24 H, 8-H, 10-H, 15-H), 7.62 (d, JH,H = 8.3 Hz,
Preparation of 8-GM2: A mixture of dendrimer 4-GM2 (0.10 g,
12 H, 13-H), 7.70–7.80 (m, 12 H, 4-H, 5-H) ppm. 13C{1H} NMR
0.03 mmol), 7 (0.17 g, 0.45 mmol), and Cs2CO3 (0.28 g, 0.86 mmol)
in THF (10 mL) was stirred at room temperature overnight. The
salts were filtered after centrifugation, and then part of the solvent
(2.0 mL) was evaporated and pentane (5 mL) was added. The mix-
ture was stirred, and the solid was filtered by cannula. The solid
was washed twice with a mixture of THF/pentane (1:10). Com-
pound 8-GM2 was obtained as a yellow solid (0.22 g, 94%). M.p.
(62.5 MHz, CDCl3, 25 °C): δ = 31.9 (d, 2JC,P = 12.3 Hz, C-16), 50.6
(C-2), 122.0 (d, JC,P = 5.5 Hz, C-12), 126.9 (d, 3JC,P = 12.4 Hz, C-
3
1
3
5), 127.4 (dd, JC,P = 102.3 Hz, JC,P = 3.8 Hz, C-7), 128.5 (C-13),
3
129.0 (d, JC,P = 13.6 Hz, C-9), 129.5 (C-14), 130.5 (C-1), 132.7 (d,
2JC,P = 10.8 Hz, C-8), 133.2 (C-10), 133.8 (d, JC,P = 105.6 Hz, C-
1
2
3
6), 133.9 (d, JC,P = 11.3 Hz, C-4), 141.2 (d, JC,P = 18.3 Hz, C-
4
2
15), 143.2 (d, JC,P = 3.6 Hz, C-3), 153.4 (d, JC,P = 8.3 Hz, C-11)
Ͼ300 °C. IR (ATR): ν = 3051, 2866, 1619, 1492, 1181, 911,
˜
ppm. 31P{1H} NMR (81 MHz, CDCl3, 25 °C): δ = 16.5 (d, JP,P
=
2
1
3
694 cm–1. H NMR (500 MHz, CDCl3, 25 °C): δ = 3.22 (d, JH,P
2
31.0 Hz, Pa-Ph2), 54.9 (d, JP,P = 31.0 Hz, Pb=S), 66.5 [Pc=S(Cl)2]
ppm. C114H108Cl12N18O12P12S12 (3104.1): calcd. C 44.11, H 3.51,
N 8.12; found C 44.32, H 3.58, N 8.25.
= 10 Hz, 18 H, 16-H), 3.72 (s, 12 H, 2-H), 5.58 (s, 6 H, 1-H), 6.91
3
(d, JH,H = 10 Hz, 24 H, 19-H), 6.92–7.10 (m, 12 H, 26-H), 7.19
3
(d, JH,H = 10 Hz, 24 H, 18-H), 7.24–7.30 (m, 12 H, 12-H), 7.30–
Preparation of 4-GM2Ј: A mixture of dendrimer 4-GM2 (0.20 g, 7.40 (m, 132 H, 24-H, 29-H, 30-H, 31-H), 7.40–7.50 (m, 24 H, 9-
0.06 mmol), 6 (0.10 g, 0.81 mmol), and Cs2CO3 (0.53 g, 1.60 mmol)
in THF (2 mL) was stirred at room temperature overnight. Then,
the salts were filtered after centrifugation. The solvent (2 mL) was
evaporated, and then pentane (5 mL) was added. The mixture was
stirred for 15 min. The solid was filtered by cannula and washed
twice with a mixture of THF/pentane (1:10). Compound 4-GM2Ј
H,25-H), 7.50–7.60 (m, 6 H, 10-H), 7.61–7.76 (m, 30 H, 8-H, 13-
H, 15-H), 7.82–7.92 (m, 12 H, 4-H, 5-H), 8.22 (ap d, 3JH,H = 10 Hz,
12 H, 23-H), 9.08 (m, 12 H, 21-H) ppm. 13C{1H} NMR
2
(125.8 MHz, CDCl3, 25 °C): δ = 33.2 (d, JC,P = 12.6 Hz, C-16),
2
50.7 (C-2), 122.1 (C-12,C-18,C-19), 127.0 (d, JC,P = 13.2 Hz, C-
1
3
5), 127.6 (dd, JC,P = 108.4, JC,P = 3.8 Hz, C-7), 128.0 (C-13),
2
3
was obtained as white solid (0.18 g. 66%). M.p. 128 °C. IR (ATR):
128.4 (d, JC,P = 3.7 Hz, C-26), 128.8 (d, JC,P = 7.5 Hz, C-30),
129.0 (C-9,24,31), 129.6 (C-1), 131.0 (C-25), 131.3 (C-14), 132.8 (d,
2JC,P = 10.0 Hz, C-8), 133.2 (C-10), 133.7 (C-23), 133.8–134.2 (C-
1
ν = 2729, 1698, 1595, 1499, 1200, 1152, 903, 780 cm–1. H NMR
˜
3
(200 MHz, CDCl3, 25 °C): δ = 3.38 (d, JH,P = 11.0 Hz, 18 H, 16-
H), 3.66 (s, 12 H, 2-H), 5.50 (s, 6 H, 1-H), 7.20 (d, 3JH,H = 7.8 Hz,
4,6), 134.1 (d, 2JC,P = 20.0 Hz, C-29), 136.5 (d, JC,P = 10.3 Hz, C-
1
3
2
1
12 H, 12-H), 7.36 (d, JH,H = 7.8 Hz, 24 H, 18-H), 7.40–7.80 (m, 28), 138.7 (d, JC,P = 20.0 Hz, C-22), 139.1 (d, JC,P = 16.0 Hz, C-
48 H, H-aromatics, 15-H), 7.57 (d, JH,H = 7.8 Hz, 12 H, 13-H),
3
3
4
27), 139.3 (d, JC,P = 12.6 Hz, C-15), 143.2 (d, JC,P = 2.5 Hz, C-
3
2
2
7.85 (d, JH,H = 7.8 Hz, 24 H, 19-H), 9.92 (s, 12 H, 21-H) ppm.
3), 148.77 (d, JC,P = 7.2 Hz, C-17), 148.8 (C-20), 153.0 (d, JC,P =
13C{1H} NMR (62.5 MHz, CDCl3, 25 °C): δ = 32.9 (d, JC,P
=
10.0 Hz, C-11), 158.8 (d, JC,P = 20.0 Hz, C-21) ppm. 31P{1H}
2
2
1262
www.eurjoc.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2011, 1256–1265

Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P Ligands
1
NMR (101.3 MHz, CDCl3, 25 °C): δ = –15.3 (Pd-Ph2), 10.5 (d, 2JP,P ν = 3054, 1605, 1493, 1435, 1159, 1100, 908, 690 cm–1. H NMR
˜
2
= 30.4 Hz, Pa-Ph2), 49.3 (d, JP,P = 30.4 Hz, Pb=S), 61.0 (Pc=S) (250 MHz, [D7]DMF, 25 °C): δ = 3.50 (br. s, 18 H, 16-H), 3.80 (br.
ppm. C414H336N30O24P24S12 (7243.4): calcd. C 68.65, H 4.68, N s, 12 H, 2-H), 5.57 (m, 6 H, 1-H), 7.10–8.15 (m, 276 H, H aromatics
5.80; found C 69.73, H 4.75, N 5.88.
and 15-H), 8.31 (m, 12 H, 23-H), 8.75 (m, 12 H, 21-H) ppm.
2
13C{1H} NMR (62.5 MHz, [D7]DMF, 25 °C): δ = 33.3 (d, JC,P
=
Preparation of 8-GM3: A mixture of dendrimer 4-GM3 (0.05 g,
8.6ϫ10–3 mmol), 7 (0.09 g, 0.24 mmol), and Cs2CO3 (0.14 g,
0.41 mmol) in THF (2.5 mL) was stirred overnight at room tem-
perature. Then the salts were filtered after centrifugation, and part
of the solvent was evaporated (2.0 mL). Pentane (5 mL) was added,
and the solid formed was filtered by cannula and washed twice with
a mixture of THF/pentane (1:10). Compound 8-GM3 was isolated
11.4 Hz, C-16), 50.8 (C-2), 121.5 (C-19), 121.5 (C-18), 122.2 (C-
2
12), 122.4 (m, C-27), 125.6 (C-13), 126.2 (br. d, JC,P = 60 Hz, C-
3
28), 127.8 (d, JC,P = 12.9 Hz, C-4), 128.2 (1JP,P = 132.0 Hz, C-7),
128.7 (C-9), 129.6 (C-23), 129.8 (C-24,30), 130.0 (C-1), 132.0 (C-
14), 133.0 (C-31), 133.1 (C-8), 133.8 (C-10), 133.8 (C-25), 134.1 (C-
2
26), 134.7 (d, JC,P = 12.0 Hz, C-29), 135.3 (C-5,C-6), 137.5 (d,
2JC,P = 15.9 Hz, C-22), 138.4 (m, C-15), 143.9 (C-3), 150.07 (C-20),
as a yellow solid (0.08 g, 67%). M.p. Ͼ300 °C. IR (ATR): ν = 3050,
˜
2
2
150.1 (d, JC,P = 6.9 Hz, C-17), 153.5 (d, JC,P = 8.9 Hz, C-11),
1602, 1493, 1433, 1181, 907, 834, 781, 694 cm–1. 1H NMR
3
168.4 (d, JC,P = 8.0 Hz, C-21) ppm. 31P{1H} NMR (101.3 MHz,
(250 MHz, CDCl3, 25 °C): δ = 3.33 (m, 54 H, 16-H, 22-H), 3.63
2
[D7]DMF, 25 °C): δ = 10.7 (d, JP,P = 30.4 Hz, Pa-Ph2), 28.6 (Pd-
Ph2), 49.3 (d, JP,P
3
(br. s, 12 H, 2-H), 5.54 (br. s, 6 H, 1-H), 6.86 (d, JH,H = 8.5 Hz,
2
= 30.4 Hz, Pb=S), 60.3 (Pc=S) ppm.
3
48 H, 24-H), 7.14 (d, JH,H = 8.5 Hz, 48 H, 25-H), 6.90–7.90 (m,
C414H336Cl24N30O24P24Pd12S12 (9371.5): calcd. C 53.06, H 3.61, N
444 H, H-aromatics, 15-H, 21-H), 8.10–8.30 (m, 24 H, 29-H), 9.03
4.48; found C 53.33, H 3.85, N 4.53.
4
(d, JH,P = 5.0 Hz, 24 H, 27-H) ppm. 13C{1H} NMR (62.5 MHz,
2
2
CDCl3, 25 °C): δ = 33.4 (d, JC,P = 12.4 Hz, C-16), 33.5 (d, JC,P Preparation of 10-GM3: A mixture of dendrimer 8-GM3 (0.03 g,
= 15.3 Hz, C-22), 51.2 (C-2), 122.3 (C-12,C-18), 122.4 (C-24,25),
1.8ϫ10–3 mmol) and PdCl2(COD) (0.01 g, 4.8ϫ10–2 mmol) in de-
1
127.3 (C-5), 127.8 (d, JC,P = 85.8 Hz, C-7), 128.5 (C-13,C-19), gassed CH2Cl2 (6 mL) was stirred at room temperature for 3 h. The
128.7 (C-32), 129.1 (d, 3JC,P = 6.9 Hz, C-36), 129.2 (C-9), 129.3 (C-
solvent was evaporated, and the solid was washed three times with
30), 129.4 (C-37), 130.0 (C-1), 131.3 (C-31), 131.5 (C-14), 132.7 (C-
20), 133.1 (d, JC,P = 10.6 Hz, C-8), 133.5 (C-10), 134.0 (C-4,C-
a mixture of THF/pentane (1:10). Compound 10-GM3 was isolated
2
as a yellow solid (0.03 g, 86%). M.p. Ͼ300 °C. IR (ATR): ν = 3054,
˜
2
1
6,C-29), 134.5 (d, JC,P = 20.0 Hz, C-35), 136.9 (d, JC,P = 9.6 Hz,
1605, 1493, 1435, 1198, 1159, 1100, 910, 690 cm–1. 1H NMR
2
C-34), 139.1 (C-15,C-21), 139.2 (d, JC,P = 20.8 Hz, C-28), 139.5 (360 MHz, [D7]DMF, 25 °C): δ = 3.48 (m, 54 H, 16-H, 22-H), 3.77
(d, 1JC,P = 16.0 Hz, C-33), 143.5 (C-3), 149.1 (d, 2JC,P = 5.1 Hz, C- (br. s, 12 H, 2-H), 5.56 (br. s, 6 H, 1-H), 7.10–8.10 (m, 540 H, H
23), 149.2 (C-26), 151.8 (d, 2JC,P = 8.3 Hz, C-17), 153.2 (d, JC,P
=
aromatics, 15-H, 21-H), 8.30 (m, 24 H, 29-H), 8.74 (s, 24 H, 27-H)
ppm. 13C{1H} NMR (90.6 MHz, [D7]DMF, 25 °C): δ = 32.5–33.5
(m, C-16, C-22), 50.5 (C-2), 121.2 (C-25), 121.5–122.7 (m, C-12,C-
2
11.4 Hz, C-11), 159.2 (d, JC,P = 21.8 Hz, C-27) ppm. 31P{1H}
3
NMR (101.3 MHz, CDCl3, 25 °C): δ = –15.2 (Pe-Ph2), 10.5 (d, 2JP,P
2
1
= 31.8 Hz, Pa-Ph2), 49.4 (d, JP,P = 31.8 Hz, Pb=S), 60.4 (Pc=S),
18,C-24,C-33), 125.3 (C-13,C-19), 125.8 (d, JC,P = 58 Hz, C-34),
60.8 (Pd=S) ppm. C810H660N66O48P48S24 (14342.6): calcd. C 67.83,
H 6.64, N 6.45; found C 67.94, H 6.75, N 6.62.
127.8 (C-4), 128.2 (d, 1JC,P = 132.0 Hz, C-7), 128.6 (C-9), 129.1 (C-
29), 129.4 (C-30), 129.5 (C-36), 129.6 (C-1), 131.6 (C-14,C-20),
132.8 (C-37), 133.1 (C-8), 133.6 (C-10), 133.8 (C-31), 133.9 (C-32),
Preparation of 9-GM1Ј: A mixture of dendrimer 4-GM1Ј (0.11 g,
5.10ϫ10–2 mmol) and Pd(dba)2 (0.05 g, 9.14ϫ10–2 mmol) in THF
(5 mL) was stirred under reflux overnight. The solvent was evapo-
rated, and the residue was purified by chromatography (silica gel;
ether/pentane of increasing polarity). Compound 9-GM1Ј was ob-
2
135.1 (d, JC,P = 10.0 Hz, C-35), 135.0–135.2 (m, C-5,C-6), 137.2
2
(d, JC,P = 13.6 Hz, C-28), 138.2 (C-15,C-21), 143.6 (C-3), 149.8
2
(d, JC,P = 6.3 Hz, C-23), 149.9 (C-26), 151.2–152.0 (m, C-11,C-
17), 168.1 (m, C-27) ppm. 31P{1H} NMR (145.8 MHz, [D7]DMF,
2
25 °C): δ = 10.4 (d, JP,P = 32.8 Hz, Pa-Ph2), 28.4 (Pe-Ph2), 49.2 (d,
tained as a brown solid (0.08 g, 69%). M.p. Ͼ300 °C. IR (ATR): ν
˜
2JP,P
=
32.8 Hz, Pb=S), 60.1 (Pc=S), 60.2 (Pd=S) ppm.
= 2962, 1697, 1595, 1500, 1205, 1013, 794 cm–1. 1H NMR
(200 MHz, CDCl3, 25 °C): δ = 1.70–1.94 (m, 4 H, 2-H), 2.65–2.82
(m, 2 H, 1-H), 2.90–3.15 (m, 2 H, 2-H), 3.48–3.60 (m, 2 H, 1-H),
3.61–3.97 (m, 2 H, 1-H), 4.40–4.75 (m, 6 H, 2-H), 7.10–8.10 (m, 66
C810H660Cl48N66O48P48Pd24S24 (18598.7): calcd. C 52.31, H 3.58,
N 4.97; found C 53.45, H 3.88, N 5.11.
Preparation of 12: A mixture of PhCH=NN(Me)P(S)Cl2 (0.20 g,
H, H aromatic), 9.89 (s, 4 H, 15-H), 9.91 (s, 2 H, 15-H) ppm. 0.75 mmol),[23] PhOH (0.15 g, 1.64 mmol), and Cs2CO3 (1.02 g,
13C{1H} NMR (50.3 MHz, CDCl3, 25 °C): δ = 45.2 (C-2), 47.7 (C- 3.13 mmol) in THF (2 mL) was stirred at room temperature over-
3
2), 48.8 (C-2), 77.3 (C-1), 78.1 (C-1), 78.3 (C-1), 121.9 (d, JC,P
=
=
night. The salts were filtered after centrifugation, and the solvent
was evaporated. A mixture of ether/pentane (1:10) was added, and
the insoluble solid was eliminated by filtration. The filtrate was
evaporated, and compound 12 was recrystallized from pentane
2
1
5.0 Hz, C-12), 126.9 (d, JC,P = 12.9 Hz, C-5), 127.0 (dd, JC,P
3
3
109.9 Hz, JC,P = 3.8 Hz, C-7), 129.1 (d, JC,P = 13.2 Hz, C-9),
131.2 (C-13), 132.5 (d, JC,P = 11.0 Hz, C-8), 132.8 (C-14), 133.1
2
1
3
(d, JC,P = 105.6 Hz, C-6), 133.4 (C-10), 133.8 (d, JC,P = 11.4 Hz,
(0.16 g, 56%). M.p. 59–61 °C. IR (ATR): ν = 3060, 2944, 1588,
˜
C-4), 143.0 (C-3), 143.4 (C-3), 156.5 (d, 2JC,P = 8.3 Hz, C-11), 191.0 1486, 1241, 1184, 1157, 917 cm–1. 1H NMR (250 MHz, CDCl3,
(C-15) ppm. 31P{1H} NMR (81 MHz, CDCl3, 25 °C): δ = 17.2 (d, 25 °C): δ = 3.40 (d, JH,P = 10.8 Hz, 3 H, 6-H), 7.10–7.85 (m, 16
3
2JP,P = 32.4 Hz, Pa-Ph2), 17.4 (d, JP,P = 32.8 Hz, Pa-Ph2), 53.4 (d,
H, H aromatics and 5-H) ppm. 13C{1H} NMR (62.5 MHz, CDCl3,
2
2JP,P = 32.4 Hz, Pb=S), 53.5 (d, JP,P = 32.8 Hz, Pb=S) ppm.
25 °C): δ = 33.5 (d, JC,P = 13.1 Hz, C-6), 122.0 (d, 3JC,P = 4.9 Hz,
2
2
C108H90N6O18P6PdS6 (2244.6): calcd. C 57.79, H 4.04, N 3.74; C-8), 125.8 (d, 5JC,P = 1.8 Hz, C-10), 127.5 (C-2), 129.2 (C-3), 128.8
4
3
found C 57.85, H 4.19, N 3.83.
(C-1), 129.9 (d, JC,P = 1.6 Hz, C-9), 135.4 (C-4), 140.1 (d, JC,P =
14.1 Hz, C-5), 151.3 (d, JC,P = 7.1 Hz, C-7) ppm. 31P{1H} NMR
(101.3 MHz, CDCl3, 25 °C): δ = 60.4 ppm. C20H19N2O2PS (382.4):
calcd. C 62.65, H 4.99, N 7.31; found C 62.58, H 5.06, N 7.43.
2
Preparation of 10-GM2: A mixture of dendrimer 8-GM2 (0.05 g,
0.70ϫ10–2 mmol) and PdCl2(COD) (0.03 g, 8.28ϫ10–2 mmol) in
degassed CH2Cl2 (3 mL) was stirred for 3 h at room temperature.
The solvent was evaporated, and the solid was washed three times
with a mixture of THF/pentane (1:10). Compound 10-GM2 was
obtained as a yellow solid (0.05 g, 76%). M.p. Ͼ300 °C. IR (ATR):
Palladium Nanoparticles Formed from 10-GM2: A mixture of den-
drimer 10-GM2 (0.05 g, 5.20ϫ10–3 mmol) and Pd(dba)2 (0.003 g.
5.20ϫ10–3 mmol) in DMF (3 mL) was stirred at 60 °C for 24 h.
Eur. J. Org. Chem. 2011, 1256–1265
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1263

A.-M. Caminade, R. M. Sebastián et al.
FULL PAPER
After that time, H NMR spectroscopy showed that only 50% of
the core of the starting dendrimer was coordinated to Pd0. An ex-
cess amount of Pd(dba)2 (9 equiv., 0.027 g, 0.05 mmol) was added
in portions over 9 d. The formation of a black solid was observed.
The solvent was evaporated, and the residue was washed, first with
CHCl3 and then twice with pentane to eliminate dba. A black
nanoparticulated material was isolated [0.018 g, 43% vs. palla-
1
Chem. 2007, 12, 406–420; b) J. Rudovský, M. Botta, P. Herm-
ann, K. I. Hardcastle, I. Lukesˇ, S. Aime, Bioconjugate Chem.
2006, 17, 975–987; c) C. Wu, M. W. Brechbiel, R. Kozak, O. A.
Gansow, Bioorg. Med. Chem. Lett. 1994, 4, 449–454; d) T. R.
Krishna, M. Parent, M. H. V. Werts, L. Moreaux, S. Gmouh,
S. Charpak, A.-M. Caminade, J.-P. Majoral, M. Blanchard-De-
sce, Angew. Chem. 2006, 118, 4761–4764; Angew. Chem. Int.
Ed. 2006, 45, 4645–4648.
a) E. Badetti, A.-M. Caminade, J.-P. Majoral, M. Moreno-
Mañas, R. M. Sebastián, Langmuir 2008, 24, 2090–2101; b) P.
Gamez, P. De Hoog, M. Lutz, A. L. Spek, J. Reedijk, Inorg.
Chim. Acta 2003, 351, 319–325; c) G. Rodríguez, M. Lutz,
A. L. Spek, G. van Koten, Chem. Eur. J. 2002, 8, 45–57; for
reviews related to metallodendrimers and catalysis, see, for in-
stance: d) A.-M. Caminade, P. Servin, R. Laurent, J.-P. Majo-
ral, Chem. Soc. Rev. 2008, 37, 56–67; e) R. Andrés, E. de Jesús,
J. C. Flores, New J. Chem. 2007, 31, 1161–1191; f) B. Helms,
J. M. J. Fréchet, Adv. Synth. Catal. 2006, 348, 1125–1148; g) R.
van Heerbeek, P. C. J. Kamer, P. W. N. M. van Leeuwen,
J. N. H. Reek, Chem. Rev. 2002, 102, 3717–3756.
dium(0) used]. M.p. Ͼ300 °C. IR (ATR): ν = 3057, 1664, 1500,
˜
[5]
1436, 1187, 1181, 1160, 1100 cm–1. Elemental analysis found: P 3.3,
Pd 29.4. HRTEM: 5.8Ϯ0.7 nm (THF, average calculated for 85
particles). ED (200 KV): d(fcc Pd) = 2.29, 1.93 Å.
Platinum Nanoparticles Formed from 10-GM2: A mixture of den-
drimer 10-GM2 (0.04 g, 4.26ϫ10–3 mmol) and Pt(PPh3)4 (0.008 g,
6.39ϫ10–3) in DMF (0.5 mL) was stirred for 9 d at 130 °C. Then
the solvent was evaporated, and the solid was washed three times
with CH2Cl2. A black nanoparticulated material was isolated
(0.025 g, 64% vs. platinum). M.p. Ͼ300 °C. IR (ATR): ν = 2788,
˜
1610, 1469, 1022 cm–1. Elemental analysis found: P 4.59, Pd, 15.1,
Pt 3.19. HRTEM: 1.3Ϯ0.2 nm (THF, average calculated for 84
particles).
[6]
a) M. Brewis, M. Helliwell, N. B. Mckeown, Tetrahedron 2003,
59, 3863–3872 and references cited therein; b) K. P.
Ng Dennos, C. R. Chim. 2003, 6, 903–910 and references cited
therein; c) J. Leclaire, R. Dagiral, A. Pla-Quintana, A.-M. Ca-
minade, J.-P. Majoral, Eur. J. Inorg. Chem. 2007, 2890–2896
and references cited therein; d) J. Leclaire, Y. Coppel, A.-M.
Caminade, J.-P. Majoral, J. Am. Chem. Soc. 2004, 126, 2304–
2305.
Supporting Information (see footnote on the first page of this arti-
cle): NMR and IR spectra of 4-GM1Ј, 4-GM2, 4-GM2Ј, 4-GM3, 8-
GM2, 8-GM3, 9-GM1Ј, 10-GM2, 10-GM3, and 12. IR spectra of Pd
and Pt nanoparticles prepared from 10-GM2, and XPS spectrum of
Pd nanoparticles prepared from 10-GM2
.
[7]
[8]
[9]
a) E. M. Harth, S. Hecht, B. Helms, E. E. Malmström, J. M. J.
Fréchet, C. J. Hawker, J. Am. Chem. Soc. 2005, 124, 3926–3938;
b) R. Sadamoto, N. Tomioka, T. Aida, J. Am. Chem. Soc. 1996,
118, 3978–3979.
Acknowledgments
This work was financially supported by the Ministry of Science and
Innovation of Spain (formally Ministry of Science and Technology)
(Projects 2002BQU-04002, CTQ-2005-04968/BQU, CTQ2008-
05409-C02-01/BQU, HF2004-0212, Consolider INGENIO 2010:
CSD2007-00006) and the Generalitat de Catalunya (Projects
2001SGR00181, 2005SGR003305, 2009SGR1441). The Ministry of
Education and Science of Spain is also gratefully acknowledged for
predoctoral scholarships to E.B. We also thank the Centre
National de la Recherche Scientifique (CNRS) for financial sup-
port and the European Community (Fond Social Européen) for a
grant to G.F.
a) D. Alivertis, V. Theodorou, G. Paraskevopoulos, K. Skob-
ridis, Tetrahedron Lett. 2007, 48, 4091–4095; b) Y. Pan, M. Lu,
Z. Peng, J. S. Meliger, Org. Biomol. Chem. 2003, 1, 4465–4470;
c) I. Gitsov, P. T. Ivanova, Chem. Commun. 2000, 269–270.
a) G. Bergamini, P. Ceroni, M. Maestri, S.-K. Lee, J. van Heyst,
F. Vögtle, Inorg. Chim. Acta 2007, 360, 1043–1051; b) B.
Branchi, P. Ceroni, G. Bergamini, V. Balzani, M. Maestri, J.
van Heyst, S.-K. Lee, F. Luppertz, F. Vögtle, Chem. Eur. J.
2006, 12, 8926–8934; c) T. Gu, J. K. Whitesell, M. A. Fox, J.
Phys. Chem. B 2006, 110, 25149–25152; d) G. Bergamini, P.
Ceroni, V. Balzani, L. Cornelissen, J. van Heyst, S.-K. Lee, F.
Vögtle, J. Mater. Chem. 2005, 15, 2959–2964; e) C. Saudan, V.
Balzani, M. Gorka, S.-K. Lee, J. van Heyst, M. Maestri, P.
Ceroni, V. Vicinelli, F. Vögtle, Chem. Eur. J. 2004, 10, 899–905;
f) C. Saudan, V. Balzani, P. Ceroni, M. Gorka, M. Maestri, V.
Vicinelli, F. Vögtle, Tetrahedron 2003, 59, 3845–3852; g) P. An-
toni, M. Malkoch, G. Vamvounis, D. Nyström, A. Nyström,
M. Lindgren, A. Hult, J. Mater. Chem. 2008, 18, 2545–2554.
a) N. Christinat, R. Scopelliti, K. Severin, J. Org. Chem. 2007,
72, 2192–2200; b) J. Ipaktschi, R. Hosseinzadeh, P. Schlaf, An-
gew. Chem. 1999, 111, 1765; Angew. Chem. Int. Ed. 1999, 38,
1658–1660; c) Y. Yamakawa, M. Ueda, R. Nagahata, K. Take-
uchi, M. Asai, J. Chem. Soc. Perkin Trans. 1 1998, 4135–4139.
a) A. Jarzebin´ska, M. Pietraszkiewcz, R. Bilewicz, Mater. Sci.
Eng. C 2001, 18, 61–64.
[1] For reviews, see: a) G. R. Newkome, C. N. Moorefield, F.
Vögtle, Dendrimers and Dendrons: Concepts, Syntheses, Appli-
cations, Wiley-VCH, Weinheim, 2001; b) J. M. J. Fréchet, D. A.
Tomalia, Dendrimers and Other Dendritic Polymers, Wiley,
Chichester, 2001; c) C. A. Shalley, F. Vögtle, Dendrimers V:
Functional and Hyperbranched Building, Springer, Berlin, 2003;
d) G. R. Newkome, C. D. Shreiner, Polymer 2008, 49, 1–173; e)
D. Astruc, E. Boisselier, C. Ornelas, Chem. Rev. 2010, 110,
1857–1959; f) G. R. Newkome, C. Shreiner, Chem. Rev. 2010,
110, 6338–6442.
[2] a) N. Nishiyama, W.-D. Jang, K. Kataoka, New J. Chem. 2007,
31, 1074–1082; b) J. P. Collman, L. Fu, A. Zingg, F. Diederich,
Chem. Commun. 1997, 193–194; c) D. K. Smith, F. Diederich,
Chem. Commun. 1998, 2501–2502; d) G. M. Dykes, D. K.
Smith, Tetrahedron 2003, 59, 3999–4009; e) S. Shinoda, J. In-
clusion Phenom. Macrocyclic Chem. 2007, 59, 1–9.
[3] a) C. Giansante, P. Ceroni, V. Balzani, F. Vögtle, Angew. Chem.
2008, 120, 5502; Angew. Chem. Int. Ed. 2008, 47, 5422–5425;
b) H. Imahori, J. Phys. Chem. B 2004, 108, 6130–6143; c) Y.-
J. Mo, D.-L. Jiang, M. Uyemura, T. Aida, T. Kitagawa, J. Am.
Chem. Soc. 2005, 127, 10020–10027; d) S. Serroni, S. Cam-
pagna, F. Puntoriero, F. Loiseau, V. Ricevuto, R. Passalacqua,
M. Galletta, C. R. Chim. 2003, 6, 883–893.
[10]
[11]
[12]
a) S.-H. Hwang, C. D. Shreiner, C. N. Moorefield, G. R. Newk-
ome, New J. Chem. 2007, 31, 1192–1217; b) Y. Tsuji, T. Fujih-
ara, Inorg. Chem. 2007, 46, 1895–1902; c) P. A. Chase,
R. J. M. K. Gebbink, G. van Koten, J. Organomet. Chem. 2004,
689, 4016–4054; d) A.-M. Caminade, V. Maraval, R. Laurent,
C.-O. Turrin, P. Sutra, J. Leclaire, L. Griffe, P. Marchand, C.
Baudoin-Dehoux, C. Rebout, J.-P. Majoral, C. R. Chim. 2003,
6, 791–801; e) J. N. H. Reek, D. de Groot, G. E. Oosterom,
P. C. J. Kamer, P. W. N. M. van Leeuwen, C. R. Chim. 2003, 6,
1061–1077.
[13]
a) J.-P. Majoral, A.-M. Caminade, Chem. Rev. 1999, 99, 845–
880; b) N. Launay, A.-M. Caminade, R. Lahana, J.-P. Majoral,
Angew. Chem. 1994, 106, 1682; Angew. Chem. Int. Ed. Engl.
[4] a) Z. Jászberényi, L. Moriggi, P. Schmidt, C. Wiedensteiner, R.
Kneuer, A. E. Merbach, L. Helm, E. Tóth, J. Biol. Inorg.
1264
www.eurjoc.org
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2011, 1256–1265

Macrocyclic Core Phosphorus Dendrimers Covered on the Surface by N,P Ligands
1994, 33, 1589–1592; c) V. Maraval, A.-M. Caminade, J.-P. Ma-
joral, J.-C. Blais, Angew. Chem. 2003, 115, 1866; Angew. Chem.
Int. Ed. 2003, 42, 1822–1826; d) A.-M. Caminade, V. Maraval,
R. Laurent, J.-P. Majoral, Curr. Org. Chem. 2002, 6, 739–774;
e) L. Griffe, M. Poupot, P. Marchand, A. Maraval, C.-O. Tur-
rin, O. Rolland, P. Métivier, G. Bacquet, J.-J. Fournié, A.-M.
Caminade, R. Poupot, J.-P. Majoral, Angew. Chem. 2007, 119,
2575; Angew. Chem. Int. Ed. 2007, 46, 2523–2526; f) A.-M.
Caminade, J.-P. Majoral, Acc. Chem. Res. 2004, 37, 341–348;
g) A.-M. Caminade, C.-O. Turrin, R. Laurent, A. Maraval, J.-
P. Majoral, Curr. Org. Chem. 2006, 10, 2333–2355.
Gissibl, C. Padié, M. Hager, F. Jaroschick, R. Rasappan, E.
Cuevas-Yanez, C.-O. Turrin, A.-M. Caminade, J.-P. Majoral,
O. Reiser, Org. Lett. 2007, 9, 2895–2898; g) P. Servin, R. Laur-
ent, A. Romerosa, M. Peruzzini, J.-P. Majoral, A.-M. Camin-
ade, Organometallics 2008, 27, 2066–2073.
M. Moreno-Mañas, J. Spengler, Tetrahedron 2002, 58, 7769–
7774.
J. Mitjaville, A.-M. Caminade, R. Mathieu, J.-P. Majoral, J.
Am. Chem. Soc. 1994, 116, 5007–5008.
I. D. Kostas, Curr. Org. Synth. 2008, 5, 227–249.
For reviews, see: a) M. Moreno-Mañas, R. Pleixats, A. Rog-
lans, R. M. Sebastián, A. Vallribera, ARKIVOC 2004, 4, 109–
129, available from http://www.arkat-usa.org; b) M. Moreno-
Mañas, R. Pleixats, R. M. Sebastián, A. Vallribera, A. Roglans,
J. Organomet. Chem. 2004, 689, 3669–3684.
[16]
[17]
[18]
[19]
[14] a) J. Leclaire, R. Dagiral, S. Fery-Forgues, Y. Coppel, B. Don-
nadieu, A.-M. Caminade, J.-P. Majoral, J. Am. Chem. Soc.
2005, 127, 15762–15770; b) C.-O. Turrin, A. Maraval, G. Ma-
gro, V. Maraval, A.-M. Caminade, J.-P. Majoral, Eur. J. Inorg.
Chem. 2006, 2556–2560; c) J. Mitjaville, A.-M. Caminade, J.-C.
Daran, B. Donnadieu, J.-P. Majoral, J. Am. Chem. Soc. 1995,
117, 1712–1721.
[20] D. Prévôté, A.-M. Caminade, J.-P. Majoral, J. Org. Chem.
1997, 62, 4834.
[15] a) A.-M. Caminade, J.-P. Majoral, Coord. Chem. Rev. 2005,
249, 1917–1926; b) V. Maraval, R. Laurent, A.-M. Caminade,
J.-P. Majoral, Organometallics 2000, 19, 4025–4029; c) M. Kop-
rowsky, R. M. Sebastián, V. Maraval, M. Zablocka, V. Cadi-
erno, B. Donnadieu, A. Igau, A.-M. Caminade, J.-P. Majoral,
Organometallics 2002, 21, 4680–4687; d) R. Laurent, A.-M.
Caminade, J.-P. Majoral, Tetrahedron Lett. 2005, 46, 6503–
6506; e) A. Ouali, R. Laurent, A.-M. Caminade, J.-P. Majoral,
M. Taillefer, J. Am. Chem. Soc. 2006, 128, 15990–15991; f) A.
[21] R. Appel, H. Einig, Chem. Ber. 1975, 108, 914–918.
[22] a) K. Esumi, Top. Curr. Chem. 2003, 227, 31–52; b) K. Esumi,
A. Suzuki, A. Llamaría, K. Torigoe, Langmuir 2000, 16, 2604–
2608; c) K. Esumi, R. Isono, T. Yoshimura, Langmuir 2004,
20, 237–243.
[23] D. Prévôté, B. Donnadieu, M. Moreno-Mañas, A.-M. Camin-
ade, J.-P. Majoral, Eur. J. Org. Chem. 1999, 7, 1701–1708.
Received: October 28, 2010
Published Online: January 20, 2011
Eur. J. Org. Chem. 2011, 1256–1265
© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1265