Phosphorus dendrimers and dendrons functionalized with the cage ligand tris(1,2-dimethylhydrazino)diphosphane

Article abstract of DOI:10.1002/hc.20611

The synthesis of a new phosphorus dendrimer peripherally functionalized with the cage ligand tris(1,2-dimethylhydrazino) diphosphane is described. In addition, dendrons (dendritic wedges) containing the same cage ligand at the focal point are also reporte

Full text of DOI:10.1002/hc.20611

Heteroatom Chemistry
Volume 21, Number 5, 2010
Phosphorus Dendrimers and Dendrons
Functionalized with the Cage Ligand
Tris(1,2-dimethylhydrazino)diphosphane
Lara-Isabel Rodr´ıguez,1 Maria Zablocka,2 Anne-Marie Caminade,3,4
Miquel Seco,1 Oriol Rossell,1 and Jean Pierre Majoral3,4
1Departament de Qu´ımica Inorga`nica, Universitat de Barcelona, 08028 Barcelona, Spain
2Centre of Molecular and Macromolecular Studies, The Polish Academy of Sciences,
90363 Lodz, Poland
3CNRS, LCC (Laboratoire de Chimie de Coordination), F-31077 Toulouse, France
4Universite´ de Toulouse, UPS, INP, LCC, F-31077 Toulouse, France
Received 3 March 2010; revised 14 April 2010
(THDP) 4 [4] (Fig. 1), are well known for their unique
ABSTRACT: The synthesis of a new phosphorus den-
properties specially in catalysis allowing a number
drimer peripherally functionalized with the cage ligand
of reactions to take place in mild conditions and in
tris(1,2-dimethylhydrazino) diphosphane is described.
high yields. Our interest in the use of dendrimers
In addition, dendrons (dendritic wedges) containing
as ligands in catalysis already exemplified in several
the same cage ligand at the focal point are also reported
reports [5,6] leads us to investigate the possibility to
along with their corresponding ruthenium derivatives,
graft some of these phosphorus cage compounds on
which are thought to be potential catalysts in aqueous
the surface of dendrimers with the hope to observe a
ꢀ
C
media. 2010 Wiley Periodicals, Inc. Heteroatom Chem
positive dendritic effect, i.e. an enhancement in the
catalytic activity when moving from the monomer to
dendrimers decorated with several monomer units.
21:290–297, 2010; Published online in Wiley InterScience
(www.interscience.wiley.com). DOI 10.1002/hc.20611
Indeed some examples of such a dendritic effect have
been reported in the literature [7].
Recently, some of us [4a] described the prepa-
ration of several monomeric ruthenium, rhodium,
INTRODUCTION
Phosphorus “cage” compounds, as for example
the proazaphosphatrane 1 [1], the triaza- or the
trihydrazino- phosphoadamantanes 2 [2], or 3 [3], as
well as the tris(1,2 dimethylhydrazino) diphosphane
and iridium complexes containing the cage ligand
THDP 4 (Scheme 1) and their catalytic behav-
ior in the atom-transfer radical addition of bro-
motrichloromethane to olefins (the Karasch reac-
tion) in aqueous media.
The excellent catalytic results observed in such
a process incited us to explore the possibility of syn-
thesizing new species having the ligand 4 grafted on
the surface of phosphorus dendritic systems to ob-
tain multimetallic dendritic complexes
We report here the different synthetic strategies
investigated for this purpose, as well as the synthe-
sis of several new monomers incorporating 4 and
Correspondence to: Anne-Marie Caminade; e-mail: caminade@
lcc-toulouse.fr. Oriol Rossell; e-mail: oriol.rossell@qi.ub.es.
Jean Pierre Majoral; e-mail: majoral@lcc-toulouse.fr.
Contract grant sponsor: L.E.A. (Laboratoire Europe´en Associe´
LTPMM).
Contract grant sponsor: Generalitat de Catalunya.
Contract grant sponsor: CNRS.
c
ꢀ
2010 Wiley Periodicals, Inc.
290

Phosphorus Dendrimers and Dendrons Functionalized with the Cage Ligand Tris(1,2-dimethylhydrazino)diphosphane 291
FIGURE 1 Examples of phosphorus cage compounds.
the preparation of dendron (dendritic wedge) and
dendrimer ruthenium complexes.
RESULTS AND DISCUSSION
Dendrimers Containing THDP Cage Units
on the Surface
As can be seen in Scheme 1, the dinuclear THDP-
based complexes recently reported [4] are the result
of the simultaneous functionalization of both phos-
phorus atoms of the cage. However, the formation of
the dendritic systems containing the THDP units on
the periphery requires the functionalization of only
one phosphorus atom while the other should remain
available for coordination to the appropriate metal
fragment. Our strategy to link the THDP cage to the
dendrimer takes into account the report by Verkade
and co-workers, which proved that the Staudinger
reaction between 4 and different azides is possible
[8]. In addition, it is interesting to note that the
Staudinger reaction between an azide and a phos-
phorus PR3 compound produces as a by-product just
a N2 molecule.
SCHEME 2 Synthesis of dendrimers ended by phosphorus
cage ligands.
In this paper, the chosen azide was
N3(CH2)3NH2, since it possesses a NH2 group
that can be used to anchor the fragment to a termi-
nated P(S)Cl2 dendrimer. The reaction between 4
and N3(CH2)3NH2 was performed in toluene at dif-
ferent temperatures and molecular ratio to optimize
the formation of the monosubstituted compound
5. Even when the reaction was carried out at room
temperature and an excess of 4 was used, a mixture
of the disubstituted 6 and the desired monosubsti-
tuted 5 products was obtained (Scheme 2). The best
reaction conditions found were 50◦C and a 4/azide
ratio of 1:1.3. The monosubstituted compound 5
was isolated and purified by successive precipitation
of the disubstituted product 6 at −30◦C in n-heptane.
The product 5 was obtained as a colorless oil with
53% of yield. The 31P NMR spectrum of 5 showed
two doublets at 95.1 ppm (free phosphorus atom)
and 2.8 ppm (P N atom) with a coupling constant
3
of JPP = 74.6 Hz. The methylene group located at
the middle of the chain appeared as a quintuplet
of doublets because of its coupling with the four
protons of the methylene groups attached to it
SCHEME
1
Synthesis of dinuclear THDP-based
complexes.
Heteroatom Chemistry DOI 10.1002/hc

292 Rodriguez et al.
(3 JHH = 6.9 Hz) and with the P N phosphorus atom
(4 JHP = 1.5 Hz).
the expected deshielding effect (from 95.3 for 8 to
114.5 ppm for 9). The metallodendrimer was isolated
as a red solid in high yield (93%), and its characteri-
zation was completed with 1H and 13C NMR spectra.
The new compound is air-stable and soluble in com-
mon polar organic solvents such as CHCl3, CH2Cl2,
and acetone.
A two-dimensional 1H 13C HMQC experiment
permitted to assign unequivocally the 13C NMR spec-
trum of 5 and to correlate each carbon signal of the
chain with its corresponding proton atoms. In ad-
dition, the 13C NMR spectra with individual irradia-
tion of the two phosphorus atoms were performed to
assign unambiguously the two doublets correspond-
ing to the two different methyl groups of the cage
that appeared at 37.8 (2 JCP = 10.8 Hz) and 36.2 ppm
(2 JCP = 2.2 Hz). Thus, the irradiation of the phospho-
rus nuclei P N produced the disappearance of the
coupling of the carbon signal at 36.2 ppm, indicating
that this was the corresponding signal for the closest
methyl groups. Both chemical ionization and elec-
trospray ionization mass spectra showed the molec-
ular peak of the compound, confirming the identity
of the product.
Dendrons Containing a THDP Unit
at the Focal Point
As discussed earlier, a number of metallodendrimers
have been reported to show “dendritic effects,”
which can be relevant in catalysis. This effect can
be particularly strong in metallodendrons, in which
the catalytic site is at the focal point. In such kind
of species, due to the steric hindrance, the access to
the metal center can be restricted in increasing the
dendron generation. Thus, in many cases, the reac-
tivity and selectivity of metallodendrons depend on
their particular generation [11]. With this in mind,
we envisaged the construction of metallodendrons
in which the metal/THDP unit is localized at the fo-
cal point. Furthermore, we wanted to functionalize
the dendron with amino groups at the periphery. It
is well known that the incorporation of hydrophilic
groups into different dendritic structures is a good
strategy for enhancing water solubility in the system.
Protonated amines, carboxylate, sulfonate, phospho-
nic, or bisphosphonic groups are examples of the
surface functionalities used for this purpose [12].
Several strategies were investigated to prepare
diversely functionalized metallodendrons. The reac-
tion of 4 with the azide 10 [13] yielded 11 after 2 days
of reaction (Scheme 3). In spite of the fact that the re-
action taking place through both phosphorus atoms
of 4 was always observed whatever the experimental
conditions used, the dendron 11 was isolated in 66%
yield. Complexation of 11 with the ruthenium dimer
[RuCl(μ-Cl)(η6-p-cymene)]2 resulted in the forma-
tion of the desired complex 12 in 90% yield as a
red solid. Unfortunately, 12 was not a suitable com-
plex for the growing of the dendron since addition of
the monomethylhydrazono-dichloro-thiophosphine
on the terminal aldehyde groups (a classical reac-
tion for the preparation of phosphorus dendrons and
dendrimers [9]) provokes the degradation of 12 and
not the formation of the metallodendron 13 as it was
expected.
Functionalization of the phosphorus dendrimer
7 (generation 1) [9] with the aminoderivative 5 pro-
ceeds nicely, in the presence of cesium carbonate
as base to give the dendrimer 8 in 91% yield. As a
result of the complete substitution of both chlorine
atoms of the P(S)Cl2 branches, the 31P NMR sig-
nal of this group appeared downfield as a unique
signal (it shifted from 62.4 to 66.8 ppm). The phos-
phorus atoms of the cage resonated at 95.3 ppm (ex-
ternal P atom) and at 2.1 ppm (P N), coupled to
3
each other and with a coupling constant of JPP
=
74.6 Hz, whereas the equivalent phosphorus atoms
of the core appeared as a broad singlet at 8.5 ppm.
1H and 13C NMR spectra were collected to com-
plete the characterization of this compound. As in
the case of 5, 13C NMR spectra with selective irra-
diation of phosphorus nuclei and two-dimensional
1H-13C HMQC spectrum were essential to complete
the assignment of the signals. Unfortunately, nei-
ther MALDI nor ES mass spectra confirmed the
identity of the compound, due to its high degree of
fragmentation, well known for phosphorhydrazone-
containing dendrimers [10].
The functionalization of the external phospho-
rus atoms of the dendrimer 8 was attempted by us-
ing two different metal complexes, [RuCl(μ-Cl)(η6-
p-cymene)]2 and [Ir(μ-Cl)(η4-cod)]2. When trying to
complex the dendrimer with the dimer [Ir(μ-Cl)(η4-
cod)]2, a dark brown solid was observed. No char-
acterization of this product was obtained due to
the high degree of insolubility of the solid in all
the organic solvents tested. However, the ruthenium
metallodendrimer 9 could be obtained as shown in
Scheme 2. The process was monitored by 31P NMR
spectroscopy, which evidenced the complete coordi-
nation of all the external phosphorus atoms, showing
To overcome these difficulties, another way of
preparation of dendrons was defined. It consists first
on the reaction of 4 with the azide 14, which was
prepared in 83% yield from the azide 10, and the
monomethylhydrazono-dichloro-thiophosphine us-
ing a slight modification of the previously reported
Heteroatom Chemistry DOI 10.1002/hc

Phosphorus Dendrimers and Dendrons Functionalized with the Cage Ligand Tris(1,2-dimethylhydrazino)diphosphane 293
SCHEME 4 Synthesis of multifunctional dendrons.
SCHEME 3 Synthesis of a small dendron complex.
corroborating again the substitution of the chlorine
atoms.
synthesis [14]. To avoid the formation of the P N
bond at both sides of compound 4, a slight excess of
the diphosphane was added (4/14 ratio 1.2:1). After
14 h of reaction at room temperature, the 31P NMR
spectrum showed the disappearance of the signal
due to the N3P(S) group (δ = 57.9 ppm) of the start-
ing compound 14 on behalf of a doublet at 44.0 ppm
(2 JPP = 66.9 Hz) characteristic for the P S unit of a
P N–P S linkage and of a doublet of doublets for
Compound 16 was purified by washing the prod-
1
uct with pentane at −30◦C. The H NMR spectrum
showed no evidence of amine in excess, confirming
the purity of the compound, which was obtained as
yellow oil in 82% yield. Characterization of the den-
dron included two-dimensional HSQC 1H 13C spectra
to assign unambiguously all the proton and carbon
signals. ES mass spectroscopy showed the molecular
peak [M]+ of 16.
3
2
the P N unit (δ = 1.5 ppm, JPP = 86.7 Hz, JPP
=
66.9 Hz), as it was also coupled with the external
phosphorus atom, now acting as the focal point of
the resulting dendron 15. Alternatively, compound
15 was also obtained from the reaction of dendron
11 with H2NNMeP(S)Cl2 (Scheme 4).
As in the case of 8 and 11, dendron 16 was func-
tionalized with the ruthenium fragment RuCl2(η6-p-
cymene). The reaction was carried out in a molar
ratio 16/[RuCl(μ-Cl)(η6-p-cymene)]2 2:1 to guaran-
tee complete coordination and, at the same time, to
avoid the presence of ruthenium dimer in excess.
However, 31P NMR spectrum of the reaction mix-
ture revealed that the complexation of 16 was not
The second step of the construction of a dendron
bearing a free phosphino group at the focal point
was the substitution of the terminal chlorine atom
of 15 with N,Nꢁ-diethylethylenediamine. The reac-
tion was performed in CH2Cl2 and in the presence of
cesium carbonate leading to the dendron 16 stable
for months under inert atmosphere (Scheme 4).
The 31P NMR spectrum of the reaction mixture
showed, after 14 h, no signal for the initial P(S)Cl2
group (δ = 63.2 ppm) and the appearance in its place
of a singlet at 68.0 ppm. The other 31P shift values
remained almost unchanged. In the 13C NMR spec-
trum, one methylene carbon appeared coupled with
1
complete. The H NMR spectrum showed the sig-
nals corresponding to the p-cymene ligand of the
organometallic fragment coordinated to the den-
dron, as well as a new set of signals in the same
region, which did not correspond either to 17 or to
free dimer. Probably, this was due to the existence
of a competition in the complexation of the ruthe-
nium fragment between the amine groups of the den-
dron and the phosphorus atom located at the focal
point. Therefore, these signals could be attributed to
a partial coordination of the organometallic unit to
2
the phosphorus atom (53.5 ppm, d, JCP = 7.9 Hz)
Heteroatom Chemistry DOI 10.1002/hc

294 Rodriguez et al.
the amine groups of compound 16. Monitoring by
31P NMR was necessary to complete the functional-
ization at the focal point of 16 by successive addi-
tion of the ruthenium dimer. Finally, the 31P NMR
spectrum of the reaction mixture showed no signals
corresponding to 16 but the expected deshielding
of the external phosphorus atom from 99.1 ppm (d,
3 JPP = 87.4 Hz) to 118.8 ppm (d, 3 JPP = 99.0 Hz). The
1H NMR spectrum revealed that approximately 20%
of the total amount of the organometallic fragment
present in the sample was presumably coordinated
to the amine groups.
CONCLUSION
FIGURE 2 Numbering used for NMR assignment.
We have described the methodology for prepar-
ing phosphorous dendrimers bearing on the sur-
face the cage like THDP ligand. The metallation
of the species occurs by the coordination of the
RuCl2(η6-p-cymene) fragment to the free phospho-
rous atom of the cage. On the other hand, we have
also reported the synthetic procedure for phospho-
rous ruthenadendrons bearing a Ru/THDP unit lo-
calized at the focal point. Both types of species are
thought to be potential precursors for catalysts in
the Karasch reaction in both organic and aqueous
media. These studies are currently in progress.
0.382 g, 3.804 mmol) was added. After stirring the
resulting solution at 50◦C for 24 h, the solvent was
removed in vacuo. 5 was obtained as a colorless oil
after purification by successive precipitation of the
disubstituted 6 product at −30◦C in heptane. Yield:
1
0.478 g (53%). 31P{ H} NMR (121.5 MHz, CDCl3,
3
298 K, δ, ppm): 95.1 (d, JPP = 74.6 Hz, P), 2.8 (d,
1
3 JPP = 74.6 Hz, P N). H NMR (300.1 MHz, CDCl3,
3
1
298 K, δ, ppm): 3.30 (t, JHH = 6.9 Hz, 2H, CH2),
3
3
3
3.26 (t, JHH = 6.9 Hz, 2H, CH2), 1.65 (qd, JHH
=
4
2
6.9 Hz, JHP = 1.5 Hz, 2H, CH2), 1.44 (s, 2H, NH2).
13C{ H} NMR (75.4 MHz, CDCl3, 298 K, δ, ppm):
1
EXPERIMENTAL SECTION
General Data
41.2 (s, 1CH2), 40.6 (s, 3CH2), 38.8 (d, 3 JCP = 15.1 Hz,
2CH2), 37.8 (d, 2 JCP = 10.8 Hz, 2CH3), 36.2 (d, 2 JCP
=
1
All manipulations were performed under purified ni-
trogen using standard Schlenk techniques. All sol-
vents were distilled from appropriate drying agents.
2.2 Hz, CH3). MS (CI, NH3), m/z: 309.2 (309.3 cal-
culated) [M + H]+. MS (EI, NH3), m/z: 308.3 (308.3
calculated) [M]+.
1
1
1H, 13C{ H}, 31P{ H}, and two-dimensional NMR
spectra were recorded on a Bruker 300 (DPX300),
200 (AC200) MHz, and Varian Mercury 400 spec-
trometers. Chemical shifts are reported in ppm rel-
ative to external standards (TMS for 1H and 13C
and 85% H3PO4 for 31P), and coupling constants are
given in hertz. The numbering used for NMR assign-
ment is shown in Fig. 2. MS ESI(+) spectra were
recorded using a LC/MSD-TOF (Agilent technolo-
gies) spectrometer. Mass spectrometry was recorded
on a Thermo Fisher DS QII or Neromag R10-10.
Compounds 4 [8b–d], 10 [13], and 14 [14] were pre-
pared as previously described. Other reagents were
used as received from commercial suppliers.
Synthesis of 8. To a mixture of 7 (0.104 g
0.057 mmol) and Cs2CO3 (0.666 g, 2.052 mmol) in
THF (20 mL), a solution of 5 (0.210 g, 0.684 mmol)
in THF (5 mL) was added dropwise at 0◦C. The mix-
ture was allowed to reach room temperature; and
after 3 days of stirring, completion was achieved.
Cs2CO3 was filtered through celite and the solution
was concentrated to 5 mL. The product was pre-
cipitated as a white solid by addition of pentane.
1
Yield: 0.262 g (91%). 31P{ H} NMR (121.5 MHz,
3
CD2Cl2, 298 K, δ, ppm): 95.3 (d, JPP = 74.6 Hz,
3
P), 66.8 (s, P(S)), 8.5 (s (br), [N3P3]), 2.1 (d, JPP
=
74.6 Hz, P N). 1H NMR (300.1 MHz, CD2Cl2, 298 K,
δ, ppm): 7.70–7.30 (m, 18H, oꢁ-C6H4 + CH N), 7.30–
6.80 (m, 12H, o-C6H4), 4.52 (s (br), 12H, NH), 3.40–
Syntheses
3.25 (m, 24H, 1CH2), 3.25–3.10 (m, 42H, 3CH2
+
1
2
Synthesis of 5. To a solution of 4 (0.382 g,
3.804 mmol) in 10 mL of toluene, 8.595 g of a
solution in toluene of N3-(CH2)3-NH2 (4.44% w/w,
P(S)NCH3), 2.90–2.65 (m, 216H, CH3 + CH3), 1.66
(s, 24H, CH2). 13C{ H} NMR (75.4 MHz, CD2Cl2,
298 K, δ, ppm): 150.4 (s (br), i-C6H4), 135.0 (s (br),
2 1
Heteroatom Chemistry DOI 10.1002/hc

Phosphorus Dendrimers and Dendrons Functionalized with the Cage Ligand Tris(1,2-dimethylhydrazino)diphosphane 295
CH N), 133.4 (s(br), iꢁ-C6H4), 127.4 (s, oꢁ-C6H4),
121.1 (s, o-C6H4), 42.0 (s, CH2), 41.3 (s, CH2), 37.7
2
1
2CH3), 36.7 (d, JCP = 4.1 Hz, CH3). Anal. Calcd for
C20H28N7O4P3S (555.5): C, 43.25; H, 5.08; N, 17.65.
Found: C, 43.32; H, 5.11; N, 17.58.
1
3
2
2
(d, JCP = 2.1 Hz, 2CH3), 36.0 (d, JCP = 2.8 Hz,
1CH3), 34.9 (dd, 3 JCP = 16.5 Hz, 3 JCP = 7.8 Hz, 2CH2),
2
32.0 (d, JCP = 12 Hz, P(S)NCH3). Anal. Calcd for
Synthesis of 12. The procedure was analogous
to that used for product 6. Starting with 0.200 g
(0.360 mmol) of 11 and 0.110 g (0.180 mmol) of the
ruthenium dimer, 12 was obtained as a red solid.
C156H348N111O6P33S6 (5089.7): C, 36.81; H, 6.89; N,
30.55. Found: C, 36.98; H, 6.94; N, 30.39.
Yield: 0.279 g (90%). 31P{ H} NMR (121.5 MHz,
1
Synthesis of 9. To a solution of 8 (0.090 g,
3
0.018 mmol) in CH2Cl2 (10 mL), 0.065
g
CDCl3, 298 K, δ, ppm): 118.7 (d, JPP = 98.8 Hz, P-
(0.108 mmol) of [RuCl(μ-Cl)(η6-p-cymene)]2 was
added. After 30 min, the solvent was removed in
vacuo and the crude product was washed three
times with pentane. The desired product was ob-
2
3
Ru), 43.7 (d, JPP = 67.1 Hz, P(S)), 1.5 (dd, JPP
=
98.8 Hz, 2 JPP = 67.1 Hz, P N). 1H NMR (250.1 MHz,
CDCl3, 298 K, δ, ppm): 10.0 (s, 2H, CHO), 7.91
(d, JHH = 8.2 Hz, 4H, oꢁ-C6H4), 7.44 (dd, JHH
=
3
3
1
tained as a red solid. Yield: 0.144 g (93%). 31P{ H}
4
8.2 Hz, JHP = 1.3 Hz, 4H, o-C6H4), 5.77–5.26 (m,
4H, C6H4 p-cymene), 3.03 (m, 1H, CH(CH3)2), 2.77 (d,
NMR (121.5 MHz, CD2Cl2, 298 K, δ, ppm): 114.5
(s (br), P-Ru), 67.1 (s, P(S)), 8.5 (s (br), [N3P3]),
1.5 (s (br), P N). 1H NMR (300.1 MHz, CD2Cl2,
298 K, δ ppm): 7.70–7.30 (m, 18H, oꢁ-C6H4 + CH N),
7.30–6.80 (m, 12H, o-C6H4), 5.65 (s (br), 24H, C6H4
cymene), 5.28 (s (br), 24H, C6H4 cymene), 4.44 (s
(br), 12H, NH), 3.45–3.25 (m, 24H, 1CH2), 3.25–
3 JHP = 9.7 Hz, 18H, CH3 + CH3), 2.26 (s, 3H, CH -
1
2
3
C6H4), 1.39 (d, 3 JHH = 6.7 Hz, 6H, CH(CH )2). 13C{ H}
1
3
NMR (62.9 MHz, CD2Cl2, 298 K, δ, ppm): 190.8
(s, CHO), 157.0 (s, i-C6H4), 133.3 (s, iꢁ-C6H4), 131.2
(s, oꢁ-C6H4), 122.0 (d, JCP = 5.7 Hz, o-C6H4), 114.4
3
(s, C-CH(CH3)2), 100.6 (s, C-CH3), 91.5 (m, C6H4
3.05 (m, 42H, 3CH2 + P(S)NCH3), 3.06–2.80 (m,
p-cymene), 88.3 (m, C6H4 p-cymene), 38.3 (d, 2 JCP
=
2
228H, 1CH3 + CH3 + CH(CH3)2), 2.20 (s, 36H, CH -
2
2
1
6.9 Hz, CH3), 35.9 (d, JCP = 6.3 Hz, CH3), 30.7
(s, CH(CH3)2), 22.0 (s (br), CH(CH3)2), 17.6 (s, CH3-
C6H4). Anal. Calcd for C30H42Cl2N7O4P3RuS (861.7):
C, 41.82; H, 4.91; N, 11.38. Found: C, 41.91; H, 4.95;
N, 11.30.
3
2
3
C6H4), 1.73 (s (br), 24H, CH2), 1.36 (d, 72H, JHH
=
6.9 Hz, CH(CH )2). 13C{ H} NMR (75.4 MHz, CD2Cl2,
1
3
298 K, δ, ppm): 150.3 (s (br), i-C6H4), 135.0 (s (br),
CH N), 133.0 (s (br), iꢁ-C6H4), 127.7 (s, oꢁ-C6H4),
121.0 (s, o-C6H4), 113.6 (s, C-CH(CH3)2), 100.3 (s,
C-CH3), 91.5 (s (br), C6H4 cymene), 87.9 (s, C6H4
Synthesis of 15. This product was prepared us-
cymene), 41.7 (s, 1CH2), 40.9 (s, 3CH2), 38.3 (d, 2 JCP
=
ing two different procedures. In both cases, the re-
2
1
2
1
15.1 Hz, CH3), 36.1 (s, CH3), 34.8 (s (br), CH2),
32.0 (s (br), P(S)NCH3), 30.6 (s, CH(CH3)2), 22.0
(s (br), CH(CH3)2), 17.5 (s, CH3-C6H4). Anal. Calcd
for C276H516Cl24N111O6P33Ru12S6 (8764.1): C, 37.83; H,
5.93; N, 17.74. Found: C, 37.95; H, 5.99; N, 17.58.
action were quantitative and followed by 31P{ H}
NMR. (a) 0.175 g (0.262 mmol) of compound 14 was
dissolved in 5 mL of CH2Cl2 and added to a solu-
tion of 4 (0.075 g, 0.314 mmol) in 10 mL of CH2Cl2
at 0◦C. The resulting solution was stirred overnight.
(b) 3.3 mL of a solution of H2NNMeP(S)Cl2 2.0 M in
CHCl3 (0.660 mmol) were added dropwise to a solu-
tion of 11 (0.183 g, 0.329 mmol) in CH2Cl2 (10 mL)
in the presence of molecular sieves. The mixture was
Synthesis of 11. To a solution of 4 (0.392 g,
0.166 mmol) in CH2Cl2 and at 0◦C, a solution of
10 (0.577 g, 0.166 mmol) in 15 mL of CH2Cl2 was
added dropwise. The temperature and stirring were
maintained for 2 days. The desired product was ob-
tained as a colorless oil after purification by suc-
cessive precipitation of the by-products with di-
stirred for 2 days at room temperature. 31P{ H} NMR
1
(121.5 MHz, CH2Cl2/C6D6, 298 K, δ, ppm): 99.1 (d,
3 JPP = 86.7 Hz, P), 63.2 (s, P(S)Cl2), 44.0 (d, JPP
=
2
66.9 Hz, P(S)), 1.5 (dd, 3 JPP = 86.7 Hz, 2 JPP = 66.9 Hz,
1
1
ethylether at 0◦C. Yield: 0.607 g (66%). 31P{ H} NMR
P N). H NMR (250.1 MHz, CDCl3, 298 K, δ, ppm):
3
3
(121.5 MHz, CD2Cl2, 298 K, δ, ppm): 99.3 (d, JPP
=
7.59 (d, JHH = 8.0 Hz, 4H, oꢁ-C6H4), 7.48 (s, 2H,
2
87.6 Hz, P), 42.5 (d, JPP = 67.1 Hz, P(S)), 1.8 (dd,
CH N), 7.25 (d, 3 JHH = 8.0 Hz, 4H, o-C6H4), 3.19 (d,
3 JHP = 10.3 Hz, 6H, P(S)NCH3), 2.85–2.70 (m, 18H,
3 JPP = 87.6 Hz, JPP = 67.1 Hz, P N). 1H NMR
2
2
(200.1 MHz, CD2Cl2, 298 K, δ, ppm): 9.96 (s, 2H,
CHO), 7.87 (d, 3 JHH = 8.3 Hz, 4H, oꢁ-C6H4), 7.40 (dd,
3 JHH = 8.3 Hz, 4 JHP = 1.5 Hz, 4H, o-C6H4), 2.85–2.76
1CH3 + CH3). Anal. Calcd for C22H34Cl4N11O2P5S3
(877.5): C, 30.11; H, 3.91; N, 17.56. Found: C, 30.20;
H, 3.96; N, 17.45.
(m, 18H, CH3 + CH3). 13C{ H} NMR (50.3 MHz,
CD2Cl2, 298 K, δ, ppm): 191.6 (s, CHO), 157.3 (s,
i-C6H4), 133.8 (s, iꢁ-C6H4), 131.9 (s, oꢁ-C6H4), 122.7
1
2
1
Synthesis of 16. To a mixture of 15 (0.229 g,
0.262 mmol) and Cs2CO3 (1.022 g, 3.138 mmol)
in CH2Cl2 (15 mL) and at 0◦C, a solution of
3
2
(d, JCP = 5.4 Hz, o-C6H4), 38.3 (d, JCP = 10.1 Hz,
Heteroatom Chemistry DOI 10.1002/hc

296 Rodriguez et al.
Verkade, J. G. J Org Chem 2009, 74, 5683–5686;
(c) Wadhwa, K.; Verkade, J. G. J Org Chem 2009,
74, 4368–4371.
diethylethylenediamine (0.148 mL, 1.048 mmol,
15 mL of CH2Cl2) was added dropwise. The mix-
ture was stirred overnight and, afterwards, Cs2CO3
was filtered through celite and the solvent was re-
moved in vacuo. The crude product was washed
three times with pentane at −30◦C. The desired prod-
uct was obtained as a pale yellow oil. Yield: 0.256 g
(82%). 31P NMR (121.5 MHz, CDCl3, 298 K, δ, ppm):
[2] (a) Phillips, A. D.; Gonsalvi, L.; Romerosa, A.; Vizza,
F.; Peruzzini, M. Coord Chem Rev 2004, 248, 955–
993; (b) Bravo, J.; Bolano, S.; Gonsalvi, L.; Peruzzini,
M. Coord Chem Rev 2010, 254, 555–607.
´
[3] (a) D´ıaz-Alvarez, A.; Crochet, P.; Zablocka, M.;
Duhayon, C.; Cadierno, V.; Gimeno, J.; Majoral, J. P.
Adv Synth Catal 2006, 348, 1671–1679; (b) Lacour,
M. A.; Zablocka, M.; Duhayon, C.; Majoral, J. P.;
Taillefer, M. Adv Synth Catal 2008, 350, 2677–2682;
(c) Zablocka, M.; Duhayon, C. Tetrahedron Lett 2006,
47, 2687–2690.
3
99.1 (d, JPP = 87.4 Hz, P), 68.0 (s, P2(S)), 44.1
2
3
(d, JPP = 66.8 Hz, P1(S)), 1.3 (dd, JPP = 87.4 Hz,
2 JPP = 66.8 Hz, P N). H NMR (400.1 MHz, CDCl3,
1
298 K, δ, ppm): 7.57 (d, 3 JHH = 8.1 Hz, 4H, oꢁ-C6H4),
´
[4] D´ıaz-Alvarez, A. E.; Crochet, P.; Zablocka, M.;
3
7.47 (s, 2H, CH N), 7.23 (d, JHH = 8.1 Hz, 4H, o-
Duhayon, C.; Cadierno, V.; Majoral, J. P. Eur J Inorg
Chem 2008, 786–794.
3
C6H4), 4.07 (s (br), 4H, NH), 3.16 (d, JHP = 9.3 Hz,
6H, P(S)NCH3), 3.14–2.90 (m, 8H, NCH CH2NEt2),
2
[5] (a) Servin, P.; Laurent, R.; Gonsalvi, L.; Tristany,
M.; Peruzzini, M.; Majoral, J. P.; Caminade, A. M.
Dalton Trans 2009, 4432–4434; (b) Gissibl, A.;
Padie´, C.; Hager, M.; Jaroschick, F.; Rasappan, R.;
Cuevas-Yanez, E.; Turrin, C. O.; Caminade, A. M.;
Majoral, J. P.; Reiser, O. Org Lett 2007, 9, 2895–
2898; (c) Routaboul, L.; Vincendeau, S.; Turrin, C. O.;
Caminade, A. M.; Majoral, J. P.; Daran, J. C.;
Manoury, E. J. Organomet Chem 2007, 692, 1064–
1073; (d) Ouali, A.; Laurent, R.; Taillefer, M.;
2.85–2.70 (m, 18H, 1CH3 + CH3), 2.70–2.54 (m, 24H,
2
3
NCH2CH N(CH CH3)2), 1.00 (t, JHH = 6.9 Hz, 24H,
2
2
N(CH2CH )2). 13C{ H} NMR (100.6 MHz, CDCl3,
1
3
2
298 K, δ, ppm): 152.2 (d, JCP = 9.4 Hz, i-C6H4),
136.1 (d, JCP = 12.4 Hz, CH N), 132.4 (s, iꢁ-C6H4),
3
127.5 (s, oꢁ-C6H4), 121.8 (d, JCP = 4.9 Hz, o-C6H4),
3
2
53.5 (d, JCP = 7.9 Hz, NCH2CH2NEt2), 46.9 (s,
N(CH2CH3)2), 38.8 (s, NCH2CH2NEt2), 38.0 (d, 2 JCP
=
Caminade, A. M.; Majoral, J. P.
J Am Chem
10.2 Hz, 2CH3), 36.3 (d, 2 JCP = 4.2 Hz, 1CH3), 31.0 (d,
2 JCP = 11.0 Hz, P(S)NCH3), 11.7 (s, N(CH2CH3)2).
EM (ESI(+)), m/z: 1197.3 (1197.1 calculated) [M]+.
Soc 2006, 128, 15990–15911; (e) Koprowski, M.;
Sebastian, R. M.; Maraval, V.; Zablocka, M.;
Cadierno-Menendez, V.; Donnadieu, B.; Igau, A.;
Caminade, A. M.; Majoral, J. P. Organometallics
2002, 21, 4680–4687.
[6] (a) Benito, M.; Rossell, O.; Seco, M.; Muller, G.;
Ordinas, J. I.; Font-Bardia, M.; Solans, X. Eur J
Inorg Chem 2002, 2477–2487; (b) Angurell, I.; Muller,
G.; Rocamora, M.; Rossell, O.; Seco, M. Dalton
Trans 2003, 1194–1200; (c) Angurell, I.; Muller, G.;
Rocamora, M.; Rossell, O.; Seco, M. Dalton Trans
2004, 2450–2457; (d) Rodrı´guez, L. I.; Rossell, O.;
Seco, M.; Grabulosa, A.; Muller, G.; Rocamora, M.
Organometallics 2006, 25, 1368–1376; (e) Rodr´ıguez,
L. I.; Rossell, O.; Seco, M.; Muller, G. J Organomet
Chem 2007, 692, 851–858; (f) Rodrı´guez, L. I.;
Rossell, O.; Seco, M.; Muller, G. J Organomet Chem
2009, 694, 1938–1942.
[7] For reviews of dendrimer catalysis, see the selected
examples: (a) Mery, D.; Astruc, D. Coord Chem Rev
2006, 250, 1965–1979; (b) Andre´s, R.; de Jesu´s, E.;
Flores, J. C. New J Chem 2007, 31, 1161–1191;
(c) Caminade, A. M.; Servin, P.; Laurent, R.; Majoral,
J. P. Chem Soc Rev 2008, 37, 56–67; (d) Reek, J. N. H.;
Are´valo, S.; van Heerbeek, R.; Kamer, P. C. J.; van
Leeuwen, P. W. N. M. Adv Catal 2006, 49, 71–79; (e)
Berger, A.; Gebbink, R. J. M. K.; van Koten, G. Top
Organomet Chem 2006, 201–210.
Synthesis of 17. To a solution of 16 (0.130 g,
0.109 mmol) in CH2Cl2 (15 mL), [RuCl(μ-Cl)(η6-p-
cymene)]2 was added until total disappearance of
1
the signal at δ = 99.1 ppm in the 31P{ H} NMR was
observed. The solution was concentrated to 5 mL,
and 15 mL of pentane was added to precipitate the
desired product that was washed three times with
pentane (3 × 15 mL) and obtained as a dark red
1
solid. 31P{ H} NMR (121.5 MHz, CDCl3, 298 K, δ,
ppm): 118.8 (d, 3 JPP = 99.0 Hz, P-Ru), 68.0 (s, P2(S)),
44.1 (d, 2 JPP = 63.7 Hz, P1(S)), 0.7 (dd, 3 JPP = 99.0 Hz,
1
2 JPP = 63.7 Hz, P N). H NMR (300.1 MHz, CDCl3,
3
298 K, δ, ppm): 7.62 (d, JHH = 8.4 Hz, 4H, oꢁ-
3
C6H4), 7.50 (s, 2H, CH N), 7.27 (d, JHH = 8.4 Hz,
4H, o-C6H4), 5.69–5.64 (m, 2H, C6H4 cymene), 5.34–
5.24 (m, 2H, C6H4 cymene), 4.20 (s (br), 4H, NH),
3
3.20 (d, JHP = 9.3 Hz, 6H, P(S)NCH3), 3.40 (m,
1
2
1H, CH(CH3)2), 3.18–2.50 (m, 50H, CH3 + CH3 +
NCH CH N(CH CH3)2), 2.24 (s, 3H, CH -C6H4), 1.37
2
2
2
3
3
(d, JHH = 5.1 Hz, 6H, CH(CH )2), 1.07 (s(br), 24H,
[8] (a) Kroshefsky, R. D.; Verkade, J. G. Inorg Chem
1975, 14, 3090–3095; for the synthesis of 4 see:
(b) Payne, D. S.; No¨th, H.; Henniger, G. Chem Com-
mun 1965, 327–329; (c) Goetze, R.; No¨th, H.; Payne,
D. S. Chem Ber 1972, 105, 2637–2644; (d) No¨th, H.;
Ullmann, R. Chem Ber 1974, 107, 1019–1025.
[9] Launay, N.; Caminade, A. M.; Majoral, J. P. J
Organomet Chem 1997, 529, 51–58.
3
N(CH2CH )2). 17 was not stable enough to allow us
3
to register 13C NMR data.
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Heteroatom Chemistry DOI 10.1002/hc

Phosphorus Dendrimers and Dendrons Functionalized with the Cage Ligand Tris(1,2-dimethylhydrazino)diphosphane 297
[11] Selected examples: (a) Ribourdouille, Y.; Engel, G. D.;
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[12] Some examples of water-soluble dendrimers:
(a) Kska, S. W.; Seyferth, D. J Am Chem Soc 1998,
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Heteroatom Chemistry DOI 10.1002/hc